Bug 1485066 - Part 1: Remove JSAutoByteString. r=Waldo

dom/base/ChromeUtils.cpp

@@ -6,7 +6,7 @@
 
 #include "ChromeUtils.h"
 
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/SavedFrameAPI.h"
 #include "jsfriendapi.h"
 #include "WrapperFactory.h"
@@ -467,11 +467,11 @@ namespace module_getter {
 
     JS::Rooted<JSString*> moduleURI(
       aCx, js::GetFunctionNativeReserved(callee, SLOT_URI).toString());
-    JSAutoByteString bytes;
+    JS::UniqueChars bytes = JS_EncodeStringToUTF8(aCx, moduleURI);
-    if (!bytes.encodeUtf8(aCx, moduleURI)) {
+    if (!bytes) {
       return false;
     }
-    nsDependentCString uri(bytes.ptr());
+    nsDependentCString uri(bytes.get());
 
     RefPtr<mozJSComponentLoader> moduleloader = mozJSComponentLoader::Get();
     MOZ_ASSERT(moduleloader);

dom/base/nsJSUtils.h

@@ -19,7 +19,6 @@
 #include "GeckoProfiler.h"
 #include "jsapi.h"
 #include "jsfriendapi.h"
-#include "js/AutoByteString.h"
 #include "js/Conversions.h"
 #include "js/StableStringChars.h"
 #include "nsString.h"

dom/bindings/BindingUtils.h

@@ -8,7 +8,7 @@
 #define mozilla_dom_BindingUtils_h__
 
 #include "jsfriendapi.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/Wrapper.h"
 #include "js/Conversions.h"
 #include "mozilla/ArrayUtils.h"
@@ -1313,12 +1313,12 @@ inline bool
 EnumValueNotFound<true>(JSContext* cx, JS::HandleString str, const char* type,
                         const char* sourceDescription)
 {
-  JSAutoByteString deflated;
+  JS::UniqueChars deflated = JS_EncodeStringToUTF8(cx, str);
-  if (!deflated.encodeUtf8(cx, str)) {
+  if (!deflated) {
     return false;
   }
   return ThrowErrorMessage(cx, MSG_INVALID_ENUM_VALUE, sourceDescription,
-                           deflated.ptr(), type);
+                           deflated.get(), type);
 }
 
 template<typename CharT>

dom/bindings/CallbackInterface.cpp

@@ -6,6 +6,7 @@
 
 #include "mozilla/dom/CallbackInterface.h"
 #include "jsapi.h"
+#include "js/CharacterEncoding.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "nsPrintfCString.h"
 
@@ -21,10 +22,9 @@ CallbackInterface::GetCallableProperty(JSContext* cx, JS::Handle<jsid> aPropId,
   }
   if (!aCallable.isObject() ||
       !JS::IsCallable(&aCallable.toObject())) {
-    char* propName =
+    JS::UniqueChars propName =
       JS_EncodeString(cx, JS_FORGET_STRING_FLATNESS(JSID_TO_FLAT_STRING(aPropId)));
-    nsPrintfCString description("Property '%s'", propName);
+    nsPrintfCString description("Property '%s'", propName.get());
-    JS_free(cx, propName);
     ThrowErrorMessage(cx, MSG_NOT_CALLABLE, description.get());
     return false;
   }

ipc/testshell/XPCShellEnvironment.cpp

@@ -16,7 +16,7 @@
 #include "base/basictypes.h"
 
 #include "jsapi.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/CompilationAndEvaluation.h"
 #include "js/SourceBufferHolder.h"
 
@@ -83,10 +83,10 @@ Print(JSContext *cx, unsigned argc, JS::Value *vp)
         JSString *str = JS::ToString(cx, args[i]);
         if (!str)
             return false;
-        JSAutoByteString bytes(cx, str);
+        JS::UniqueChars bytes = JS_EncodeString(cx, str);
         if (!bytes)
             return false;
-        fprintf(stdout, "%s%s", i ? " " : "", bytes.ptr());
+        fprintf(stdout, "%s%s", i ? " " : "", bytes.get());
         fflush(stdout);
     }
     fputc('\n', stdout);
@@ -119,11 +119,11 @@ Dump(JSContext *cx, unsigned argc, JS::Value *vp)
     JSString *str = JS::ToString(cx, args[0]);
     if (!str)
         return false;
-    JSAutoByteString bytes(cx, str);
+    JS::UniqueChars bytes = JS_EncodeString(cx, str);
     if (!bytes)
       return false;
 
-    fputs(bytes.ptr(), stdout);
+    fputs(bytes.get(), stdout);
     fflush(stdout);
     return true;
 }
@@ -147,20 +147,20 @@ Load(JSContext *cx,
         JS::Rooted<JSString*> str(cx, JS::ToString(cx, args[i]));
         if (!str)
             return false;
-        JSAutoByteString filename(cx, str);
+        JS::UniqueChars filename = JS_EncodeString(cx, str);
         if (!filename)
             return false;
-        FILE *file = fopen(filename.ptr(), "r");
+        FILE *file = fopen(filename.get(), "r");
         if (!file) {
-            filename.clear();
+            filename = JS_EncodeStringToUTF8(cx, str);
-            if (!filename.encodeUtf8(cx, str))
+            if (!filename)
                 return false;
-            JS_ReportErrorUTF8(cx, "cannot open file '%s' for reading", filename.ptr());
+            JS_ReportErrorUTF8(cx, "cannot open file '%s' for reading", filename.get());
             return false;
         }
         JS::CompileOptions options(cx);
         options.setUTF8(true)
-               .setFileAndLine(filename.ptr(), 1);
+               .setFileAndLine(filename.get(), 1);
         JS::Rooted<JSScript*> script(cx);
         bool ok = JS::Compile(cx, options, file, &script);
         fclose(file);
@@ -346,13 +346,13 @@ XPCShellEnvironment::ProcessFile(JSContext *cx,
                 /* Suppress warnings from JS::ToString(). */
                 older = JS::SetWarningReporter(cx, nullptr);
                 str = JS::ToString(cx, result);
-                JSAutoByteString bytes;
+                JS::UniqueChars bytes;
                 if (str)
-                    bytes.encodeLatin1(cx, str);
+                    bytes = JS_EncodeString(cx, str);
                 JS::SetWarningReporter(cx, older);
 
                 if (!!bytes)
-                    fprintf(stdout, "%s\n", bytes.ptr());
+                    fprintf(stdout, "%s\n", bytes.get());
                 else
                     ok = false;
             }

js/public/AutoByteString.h

@@ -1,140 +0,0 @@
-/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-/*
- * DEPRECATED functions and classes for heap-allocating copies of a JSString's
- * data.
- */
-
-#ifndef js_AutoByteString_h
-#define js_AutoByteString_h
-
-#include "mozilla/Assertions.h" // MOZ_ASSERT
-#include "mozilla/Attributes.h" // MOZ_RAII, MOZ_GUARD*
-
-#include <string.h> // strlen
-
-#include "jstypes.h" // JS_PUBLIC_API
-
-#include "js/MemoryFunctions.h" // JS_free
-#include "js/RootingAPI.h" // JS::Handle
-#include "js/TypeDecls.h" // JSContext, JSString
-#include "js/Utility.h" // js_free, JS::UniqueChars
-
-/**
- * DEPRECATED
- *
- * Allocate memory sufficient to contain the characters of |str| truncated to
- * Latin-1 and a trailing null terminator, fill the memory with the characters
- * interpreted in that manner plus the null terminator, and return a pointer to
- * the memory.  The memory must be freed using JS_free to avoid leaking.
- *
- * This function *loses information* when it copies the characters of |str| if
- * |str| contains code units greater than 0xFF.  Additionally, users that
- * depend on null-termination will misinterpret the copied characters if |str|
- * contains any nulls.  Avoid using this function if possible, because it will
- * eventually be removed.
- */
-extern JS_PUBLIC_API(char*)
-JS_EncodeString(JSContext* cx, JSString* str);
-
-/**
- * DEPRECATED
- *
- * Same behavior as JS_EncodeString(), but encode into a UTF-8 string.
- *
- * This function *loses information* when it copies the characters of |str| if
- * |str| contains invalid UTF-16: U+FFFD REPLACEMENT CHARACTER will be copied
- * instead.
- *
- * The returned string is also subject to misinterpretation if |str| contains
- * any nulls (which are faithfully transcribed into the returned string, but
- * which will implicitly truncate the string if it's passed to functions that
- * expect null-terminated strings).
- *
- * Avoid using this function if possible, because we'll remove it once we can
- * devise a better API for the task.
- */
-extern JS_PUBLIC_API(char*)
-JS_EncodeStringToUTF8(JSContext* cx, JS::Handle<JSString*> str);
-
-/**
- * DEPRECATED
- *
- * A lightweight RAII helper class around the various JS_Encode* functions
- * above, subject to the same pitfalls noted above.  Avoid using this class if
- * possible, because as with the functions above, it too needs to be replaced
- * with a better, safer API.
- */
-class MOZ_RAII JSAutoByteString final
-{
-  private:
-    char* mBytes;
-    MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
-
-  private:
-    JSAutoByteString(const JSAutoByteString& another) = delete;
-    void operator=(const JSAutoByteString& another) = delete;
-
-  public:
-    JSAutoByteString(JSContext* cx, JSString* str
-                     MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
-      : mBytes(JS_EncodeString(cx, str))
-    {
-        MOZ_ASSERT(cx);
-        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
-    }
-
-    explicit JSAutoByteString(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM)
-      : mBytes(nullptr)
-    {
-        MOZ_GUARD_OBJECT_NOTIFIER_INIT;
-    }
-
-    ~JSAutoByteString() {
-        JS_free(nullptr, mBytes);
-    }
-
-    /* Take ownership of the given byte array. */
-    void initBytes(JS::UniqueChars&& bytes) {
-        MOZ_ASSERT(!mBytes);
-        mBytes = bytes.release();
-    }
-
-    char* encodeLatin1(JSContext* cx, JSString* str) {
-        MOZ_ASSERT(!mBytes);
-        MOZ_ASSERT(cx);
-        mBytes = JS_EncodeString(cx, str);
-        return mBytes;
-    }
-
-    char* encodeUtf8(JSContext* cx, JS::Handle<JSString*> str) {
-        MOZ_ASSERT(!mBytes);
-        MOZ_ASSERT(cx);
-        mBytes = JS_EncodeStringToUTF8(cx, str);
-        return mBytes;
-    }
-
-    void clear() {
-        js_free(mBytes);
-        mBytes = nullptr;
-    }
-
-    char* ptr() const {
-        return mBytes;
-    }
-
-    bool operator!() const {
-        return !mBytes;
-    }
-
-    size_t length() const {
-        if (!mBytes)
-            return 0;
-        return strlen(mBytes);
-    }
-};
-
-#endif /* js_AutoByteString_h */

js/public/CharacterEncoding.h

@@ -331,4 +331,41 @@ StringIsASCII(const char* s);
 inline void JS_free(JS::Latin1CharsZ& ptr) { js_free((void*)ptr.get()); }
 inline void JS_free(JS::UTF8CharsZ& ptr) { js_free((void*)ptr.get()); }
 
+/**
+ * DEPRECATED
+ *
+ * Allocate memory sufficient to contain the characters of |str| truncated to
+ * Latin-1 and a trailing null terminator, fill the memory with the characters
+ * interpreted in that manner plus the null terminator, and return a pointer to
+ * the memory.
+ *
+ * This function *loses information* when it copies the characters of |str| if
+ * |str| contains code units greater than 0xFF.  Additionally, users that
+ * depend on null-termination will misinterpret the copied characters if |str|
+ * contains any nulls.  Avoid using this function if possible, because it will
+ * eventually be removed.
+ */
+extern JS_PUBLIC_API(JS::UniqueChars)
+JS_EncodeString(JSContext* cx, JSString* str);
+
+/**
+ * DEPRECATED
+ *
+ * Same behavior as JS_EncodeString(), but encode into a UTF-8 string.
+ *
+ * This function *loses information* when it copies the characters of |str| if
+ * |str| contains invalid UTF-16: U+FFFD REPLACEMENT CHARACTER will be copied
+ * instead.
+ *
+ * The returned string is also subject to misinterpretation if |str| contains
+ * any nulls (which are faithfully transcribed into the returned string, but
+ * which will implicitly truncate the string if it's passed to functions that
+ * expect null-terminated strings).
+ *
+ * Avoid using this function if possible, because we'll remove it once we can
+ * devise a better API for the task.
+ */
+extern JS_PUBLIC_API(JS::UniqueChars)
+JS_EncodeStringToUTF8(JSContext* cx, JS::Handle<JSString*> str);
+
 #endif /* js_CharacterEncoding_h */

js/rust/build.rs

@@ -319,7 +319,6 @@ const WHITELIST_FUNCTIONS: &'static [&'static str] = &[
     "JS_DestroyContext",
     "JS::DisableIncrementalGC",
     "js::Dump.*",
-    "JS_EncodeStringToUTF8",
     "JS::EnterRealm",
     "JS_EnumerateStandardClasses",
     "JS_ErrorFromException",

js/rust/src/glue.rs

@@ -340,6 +340,10 @@ extern "C" {
                                              dest: *mut JSStructuredCloneData)
                                              -> bool;
 
+    pub fn JSEncodeStringToUTF8(cx: *mut JSContext,
+                                string: JS::HandleString)
+                                -> *mut ::libc::c_char;
+
     pub fn IsDebugBuild() -> bool;
 }
 

js/rust/src/jsglue.cpp

@@ -15,6 +15,7 @@
 #include "jsapi.h"
 #include "jsfriendapi.h"
 #include "js/Proxy.h"
+#include "js/CharacterEncoding.h"
 #include "js/Class.h"
 #include "js/MemoryMetrics.h"
 #include "js/Principals.h"
@@ -920,4 +921,10 @@ WriteBytesToJSStructuredCloneData(const uint8_t* src, size_t len, JSStructuredCl
     return dest->AppendBytes(reinterpret_cast<const char*>(src), len);
 }
 
+char*
+JSEncodeStringToUTF8(JSContext* cx, JS::HandleString string)
+{
+    return JS_EncodeStringToUTF8(cx, string).release();
+}
+
 } // extern "C"

js/rust/tests/callback.rs

@@ -7,11 +7,11 @@ extern crate js;
 extern crate libc;
 
 use js::ar::AutoRealm;
+use js::glue::JSEncodeStringToUTF8;
 use js::jsapi::root::JS::CallArgs;
 use js::jsapi::root::JS::RealmOptions;
 use js::jsapi::root::JSContext;
 use js::jsapi::root::JS_DefineFunction;
-use js::jsapi::root::JS_EncodeStringToUTF8;
 use js::jsapi::root::JS_NewGlobalObject;
 use js::jsapi::root::JS_ReportErrorASCII;
 use js::jsapi::root::JS::OnNewGlobalHookOption;
@@ -55,7 +55,7 @@ unsafe extern "C" fn puts(context: *mut JSContext, argc: u32, vp: *mut Value) ->
     let arg = args.get(0);
     let js = js::rust::ToString(context, arg);
     rooted!(in(context) let message_root = js);
-    let message = JS_EncodeStringToUTF8(context, message_root.handle());
+    let message = JSEncodeStringToUTF8(context, message_root.handle());
     let message = CStr::from_ptr(message);
     println!("{}", str::from_utf8(message.to_bytes()).unwrap());
 

js/src/builtin/Profilers.cpp

@@ -28,6 +28,7 @@
 # define getpid _getpid
 #endif
 
+#include "js/CharacterEncoding.h"
 #include "js/Utility.h"
 #include "util/Text.h"
 #include "vm/Probes.h"
@@ -203,7 +204,7 @@ RequiredStringArg(JSContext* cx, const CallArgs& args, size_t argi, const char*
         return nullptr;
     }
 
-    return UniqueChars(JS_EncodeString(cx, args[argi].toString()));
+    return JS_EncodeString(cx, args[argi].toString());
 }
 
 static bool

js/src/builtin/ReflectParse.cpp

@@ -3394,7 +3394,7 @@ reflect_parse(JSContext* cx, uint32_t argc, Value* vp)
                 if (!str)
                     return false;
 
-                filename.reset(JS_EncodeString(cx, str));
+                filename = JS_EncodeString(cx, str);
                 if (!filename)
                     return false;
             }

js/src/builtin/TestingFunctions.cpp

@@ -41,7 +41,7 @@
 #include "jit/BaselineJIT.h"
 #include "jit/InlinableNatives.h"
 #include "jit/JitRealm.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/CompilationAndEvaluation.h"
 #include "js/CompileOptions.h"
 #include "js/Debug.h"
@@ -1414,13 +1414,13 @@ CallFunctionWithAsyncStack(JSContext* cx, unsigned argc, Value* vp)
     RootedObject function(cx, &args[0].toObject());
     RootedObject stack(cx, &args[1].toObject());
     RootedString asyncCause(cx, args[2].toString());
-    JSAutoByteString utf8Cause;
+    UniqueChars utf8Cause = JS_EncodeStringToUTF8(cx, asyncCause);
-    if (!utf8Cause.encodeUtf8(cx, asyncCause)) {
+    if (!utf8Cause) {
         MOZ_ASSERT(cx->isExceptionPending());
         return false;
     }
 
-    JS::AutoSetAsyncStackForNewCalls sas(cx, stack, utf8Cause.ptr(),
+    JS::AutoSetAsyncStackForNewCalls sas(cx, stack, utf8Cause.get(),
                                          JS::AutoSetAsyncStackForNewCalls::AsyncCallKind::EXPLICIT);
     return Call(cx, UndefinedHandleValue, function,
                 JS::HandleValueArray::empty(), args.rval());
@@ -2194,16 +2194,16 @@ DumpHeap(JSContext* cx, unsigned argc, Value* vp)
         if (v.isString()) {
             if (!fuzzingSafe) {
                 RootedString str(cx, v.toString());
-                JSAutoByteString fileNameBytes;
+                UniqueChars fileNameBytes = JS_EncodeString(cx, str);
-                if (!fileNameBytes.encodeLatin1(cx, str))
+                if (!fileNameBytes)
                     return false;
-                const char* fileName = fileNameBytes.ptr();
+                const char* fileName = fileNameBytes.get();
                 dumpFile = fopen(fileName, "w");
                 if (!dumpFile) {
-                    fileNameBytes.clear();
+                    fileNameBytes = JS_EncodeStringToUTF8(cx, str);
-                    if (!fileNameBytes.encodeUtf8(cx, str))
+                    if (!fileNameBytes)
                         return false;
-                    JS_ReportErrorUTF8(cx, "can't open %s", fileNameBytes.ptr());
+                    JS_ReportErrorUTF8(cx, "can't open %s", fileNameBytes.get());
                     return false;
                 }
             }
@@ -2746,23 +2746,25 @@ class CloneBufferObject : public NativeObject {
     setCloneBuffer_impl(JSContext* cx, const CallArgs& args) {
         Rooted<CloneBufferObject*> obj(cx, &args.thisv().toObject().as<CloneBufferObject>());
 
-        uint8_t* data = nullptr;
+        const char* data = nullptr;
-        UniquePtr<uint8_t[], JS::FreePolicy> dataOwner;
+        UniqueChars dataOwner;
         uint32_t nbytes;
 
         if (args.get(0).isObject() && args[0].toObject().is<ArrayBufferObject>()) {
             ArrayBufferObject* buffer = &args[0].toObject().as<ArrayBufferObject>();
             bool isSharedMemory;
-            js::GetArrayBufferLengthAndData(buffer, &nbytes, &isSharedMemory, &data);
+            uint8_t* dataBytes = nullptr;
+            js::GetArrayBufferLengthAndData(buffer, &nbytes, &isSharedMemory, &dataBytes);
             MOZ_ASSERT(!isSharedMemory);
+            data = reinterpret_cast<char*>(dataBytes);
         } else {
             JSString* str = JS::ToString(cx, args.get(0));
             if (!str)
                 return false;
-            data = reinterpret_cast<uint8_t*>(JS_EncodeString(cx, str));
+            dataOwner = JS_EncodeString(cx, str);
-            if (!data)
+            if (!dataOwner)
                 return false;
-            dataOwner.reset(data);
+            data = dataOwner.get();
             nbytes = JS_GetStringLength(str);
         }
 
@@ -2777,7 +2779,7 @@ class CloneBufferObject : public NativeObject {
             return false;
         }
 
-        MOZ_ALWAYS_TRUE(buf->AppendBytes((const char*)data, nbytes));
+        MOZ_ALWAYS_TRUE(buf->AppendBytes(data, nbytes));
         obj->discard();
         obj->setData(buf.release(), true);
 
@@ -2914,17 +2916,17 @@ ParseCloneScope(JSContext* cx, HandleString str)
 {
     mozilla::Maybe<JS::StructuredCloneScope> scope;
 
-    JSAutoByteString scopeStr(cx, str);
+    UniqueChars scopeStr = JS_EncodeString(cx, str);
     if (!scopeStr)
         return scope;
 
-    if (strcmp(scopeStr.ptr(), "SameProcessSameThread") == 0)
+    if (strcmp(scopeStr.get(), "SameProcessSameThread") == 0)
         scope.emplace(JS::StructuredCloneScope::SameProcessSameThread);
-    else if (strcmp(scopeStr.ptr(), "SameProcessDifferentThread") == 0)
+    else if (strcmp(scopeStr.get(), "SameProcessDifferentThread") == 0)
         scope.emplace(JS::StructuredCloneScope::SameProcessDifferentThread);
-    else if (strcmp(scopeStr.ptr(), "DifferentProcess") == 0)
+    else if (strcmp(scopeStr.get(), "DifferentProcess") == 0)
         scope.emplace(JS::StructuredCloneScope::DifferentProcess);
-    else if (strcmp(scopeStr.ptr(), "DifferentProcessForIndexedDB") == 0)
+    else if (strcmp(scopeStr.get(), "DifferentProcessForIndexedDB") == 0)
         scope.emplace(JS::StructuredCloneScope::DifferentProcessForIndexedDB);
 
     return scope;
@@ -2951,13 +2953,13 @@ Serialize(JSContext* cx, unsigned argc, Value* vp)
             JSString* str = JS::ToString(cx, v);
             if (!str)
                 return false;
-            JSAutoByteString poli(cx, str);
+            UniqueChars poli = JS_EncodeString(cx, str);
             if (!poli)
                 return false;
 
-            if (strcmp(poli.ptr(), "allow") == 0) {
+            if (strcmp(poli.get(), "allow") == 0) {
                 // default
-            } else if (strcmp(poli.ptr(), "deny") == 0) {
+            } else if (strcmp(poli.get(), "deny") == 0) {
                 policy.denySharedArrayBuffer();
             } else {
                 JS_ReportErrorASCII(cx, "Invalid policy value for 'SharedArrayBuffer'");
@@ -4121,12 +4123,12 @@ SetGCCallback(JSContext* cx, unsigned argc, Value* vp)
     JSString* str = JS::ToString(cx, v);
     if (!str)
         return false;
-    JSAutoByteString action(cx, str);
+    UniqueChars action = JS_EncodeString(cx, str);
     if (!action)
         return false;
 
     int32_t phases = 0;
-    if ((strcmp(action.ptr(), "minorGC") == 0) || (strcmp(action.ptr(), "majorGC") == 0)) {
+    if ((strcmp(action.get(), "minorGC") == 0) || (strcmp(action.get(), "majorGC") == 0)) {
         if (!JS_GetProperty(cx, opts, "phases", &v))
             return false;
         if (v.isUndefined()) {
@@ -4135,15 +4137,15 @@ SetGCCallback(JSContext* cx, unsigned argc, Value* vp)
             JSString* str = JS::ToString(cx, v);
             if (!str)
                 return false;
-            JSAutoByteString phasesStr(cx, str);
+            UniqueChars phasesStr = JS_EncodeString(cx, str);
             if (!phasesStr)
                 return false;
 
-            if (strcmp(phasesStr.ptr(), "begin") == 0)
+            if (strcmp(phasesStr.get(), "begin") == 0)
                 phases = (1 << JSGC_BEGIN);
-            else if (strcmp(phasesStr.ptr(), "end") == 0)
+            else if (strcmp(phasesStr.get(), "end") == 0)
                 phases = (1 << JSGC_END);
-            else if (strcmp(phasesStr.ptr(), "both") == 0)
+            else if (strcmp(phasesStr.get(), "both") == 0)
                 phases = (1 << JSGC_BEGIN) | (1 << JSGC_END);
             else {
                 JS_ReportErrorASCII(cx, "Invalid callback phase");
@@ -4164,7 +4166,7 @@ SetGCCallback(JSContext* cx, unsigned argc, Value* vp)
         gcCallback::prevMinorGC = nullptr;
     }
 
-    if (strcmp(action.ptr(), "minorGC") == 0) {
+    if (strcmp(action.get(), "minorGC") == 0) {
         auto info = js_new<gcCallback::MinorGC>();
         if (!info) {
             ReportOutOfMemory(cx);
@@ -4174,7 +4176,7 @@ SetGCCallback(JSContext* cx, unsigned argc, Value* vp)
         info->phases = phases;
         info->active = true;
         JS_SetGCCallback(cx, gcCallback::minorGC, info);
-    } else if (strcmp(action.ptr(), "majorGC") == 0) {
+    } else if (strcmp(action.get(), "majorGC") == 0) {
         if (!JS_GetProperty(cx, opts, "depth", &v))
             return false;
         int32_t depth = 1;
@@ -4734,11 +4736,11 @@ SetTimeZone(JSContext* cx, unsigned argc, Value* vp)
     };
 
     if (args[0].isString() && !args[0].toString()->empty()) {
-        JSAutoByteString timeZone;
+        UniqueChars timeZone = JS_EncodeString(cx, args[0].toString());
-        if (!timeZone.encodeLatin1(cx, args[0].toString()))
+        if (!timeZone)
             return false;
 
-        if (!setTimeZone(timeZone.ptr())) {
+        if (!setTimeZone(timeZone.get())) {
             JS_ReportErrorASCII(cx, "Failed to set 'TZ' environment variable");
             return false;
         }
@@ -4824,11 +4826,11 @@ SetDefaultLocale(JSContext* cx, unsigned argc, Value* vp)
             return false;
         }
 
-        JSAutoByteString locale;
+        UniqueChars locale = JS_EncodeString(cx, str);
-        if (!locale.encodeLatin1(cx, str))
+        if (!locale)
             return false;
 
-        if (!JS_SetDefaultLocale(cx->runtime(), locale.ptr())) {
+        if (!JS_SetDefaultLocale(cx->runtime(), locale.get())) {
             ReportOutOfMemory(cx);
             return false;
         }

js/src/builtin/TypedObject.cpp

@@ -12,6 +12,7 @@
 #include "jsutil.h"
 
 #include "gc/Marking.h"
+#include "js/CharacterEncoding.h"
 #include "js/Vector.h"
 #include "util/StringBuffer.h"
 #include "vm/GlobalObject.h"
@@ -1598,7 +1599,7 @@ ReportTypedObjTypeError(JSContext* cx,
 {
     // Serialize type string of obj
     RootedAtom typeReprAtom(cx, &obj->typeDescr().stringRepr());
-    UniqueChars typeReprStr(JS_EncodeStringToUTF8(cx, typeReprAtom));
+    UniqueChars typeReprStr = JS_EncodeStringToUTF8(cx, typeReprAtom);
     if (!typeReprStr)
         return false;
 
@@ -1705,7 +1706,7 @@ ReportPropertyError(JSContext* cx,
     if (!str)
         return false;
 
-    UniqueChars propName(JS_EncodeStringToUTF8(cx, str));
+    UniqueChars propName = JS_EncodeStringToUTF8(cx, str);
     if (!propName)
         return false;
 

js/src/builtin/intl/Collator.cpp

@@ -17,7 +17,7 @@
 #include "builtin/intl/ScopedICUObject.h"
 #include "builtin/intl/SharedIntlData.h"
 #include "gc/FreeOp.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/StableStringChars.h"
 #include "js/TypeDecls.h"
 #include "vm/GlobalObject.h"
@@ -200,11 +200,11 @@ js::intl_availableCollations(JSContext* cx, unsigned argc, Value* vp)
     MOZ_ASSERT(args.length() == 1);
     MOZ_ASSERT(args[0].isString());
 
-    JSAutoByteString locale(cx, args[0].toString());
+    UniqueChars locale = JS_EncodeString(cx, args[0].toString());
     if (!locale)
         return false;
     UErrorCode status = U_ZERO_ERROR;
-    UEnumeration* values = ucol_getKeywordValuesForLocale("co", locale.ptr(), false, &status);
+    UEnumeration* values = ucol_getKeywordValuesForLocale("co", locale.get(), false, &status);
     if (U_FAILURE(status)) {
         ReportInternalError(cx);
         return false;
@@ -277,7 +277,7 @@ NewUCollator(JSContext* cx, Handle<CollatorObject*> collator)
 
     if (!GetProperty(cx, internals, internals, cx->names().locale, &value))
         return nullptr;
-    JSAutoByteString locale(cx, value.toString());
+    UniqueChars locale = JS_EncodeString(cx, value.toString());
     if (!locale)
         return nullptr;
 
@@ -300,7 +300,7 @@ NewUCollator(JSContext* cx, Handle<CollatorObject*> collator)
         if (StringEqualsAscii(usage, "search")) {
             // ICU expects search as a Unicode locale extension on locale.
             // Unicode locale extensions must occur before private use extensions.
-            const char* oldLocale = locale.ptr();
+            const char* oldLocale = locale.get();
             const char* p;
             size_t index;
             size_t localeLen = strlen(oldLocale);
@@ -323,8 +323,7 @@ NewUCollator(JSContext* cx, Handle<CollatorObject*> collator)
             memcpy(newLocale, oldLocale, index);
             memcpy(newLocale + index, insert, insertLen);
             memcpy(newLocale + index + insertLen, oldLocale + index, localeLen - index + 1); // '\0'
-            locale.clear();
+            locale = JS::UniqueChars(newLocale);
-            locale.initBytes(JS::UniqueChars(newLocale));
         } else {
             MOZ_ASSERT(StringEqualsAscii(usage, "sort"));
         }
@@ -386,7 +385,7 @@ NewUCollator(JSContext* cx, Handle<CollatorObject*> collator)
     }
 
     UErrorCode status = U_ZERO_ERROR;
-    UCollator* coll = ucol_open(IcuLocale(locale.ptr()), &status);
+    UCollator* coll = ucol_open(IcuLocale(locale.get()), &status);
     if (U_FAILURE(status)) {
         ReportInternalError(cx);
         return nullptr;

js/src/builtin/intl/DateTimeFormat.cpp

@@ -19,7 +19,7 @@
 #include "builtin/intl/SharedIntlData.h"
 #include "builtin/intl/TimeZoneDataGenerated.h"
 #include "gc/FreeOp.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/StableStringChars.h"
 #include "vm/DateTime.h"
 #include "vm/GlobalObject.h"
@@ -236,10 +236,10 @@ js::intl_DateTimeFormat_availableLocales(JSContext* cx, unsigned argc, Value* vp
 }
 
 static bool
-DefaultCalendar(JSContext* cx, const JSAutoByteString& locale, MutableHandleValue rval)
+DefaultCalendar(JSContext* cx, const UniqueChars& locale, MutableHandleValue rval)
 {
     UErrorCode status = U_ZERO_ERROR;
-    UCalendar* cal = ucal_open(nullptr, 0, locale.ptr(), UCAL_DEFAULT, &status);
+    UCalendar* cal = ucal_open(nullptr, 0, locale.get(), UCAL_DEFAULT, &status);
 
     // This correctly handles nullptr |cal| when opening failed.
     ScopedICUObject<UCalendar, ucal_close> closeCalendar(cal);
@@ -283,7 +283,7 @@ js::intl_availableCalendars(JSContext* cx, unsigned argc, Value* vp)
     MOZ_ASSERT(args.length() == 1);
     MOZ_ASSERT(args[0].isString());
 
-    JSAutoByteString locale(cx, args[0].toString());
+    UniqueChars locale = JS_EncodeString(cx, args[0].toString());
     if (!locale)
         return false;
 
@@ -302,7 +302,7 @@ js::intl_availableCalendars(JSContext* cx, unsigned argc, Value* vp)
 
     // Now get the calendars that "would make a difference", i.e., not the default.
     UErrorCode status = U_ZERO_ERROR;
-    UEnumeration* values = ucal_getKeywordValuesForLocale("ca", locale.ptr(), false, &status);
+    UEnumeration* values = ucal_getKeywordValuesForLocale("ca", locale.get(), false, &status);
     if (U_FAILURE(status)) {
         intl::ReportInternalError(cx);
         return false;
@@ -360,7 +360,7 @@ js::intl_defaultCalendar(JSContext* cx, unsigned argc, Value* vp)
     MOZ_ASSERT(args.length() == 1);
     MOZ_ASSERT(args[0].isString());
 
-    JSAutoByteString locale(cx, args[0].toString());
+    UniqueChars locale = JS_EncodeString(cx, args[0].toString());
     if (!locale)
         return false;
 
@@ -527,7 +527,7 @@ js::intl_patternForSkeleton(JSContext* cx, unsigned argc, Value* vp)
     MOZ_ASSERT(args[0].isString());
     MOZ_ASSERT(args[1].isString());
 
-    JSAutoByteString locale(cx, args[0].toString());
+    UniqueChars locale = JS_EncodeString(cx, args[0].toString());
     if (!locale)
         return false;
 
@@ -538,7 +538,7 @@ js::intl_patternForSkeleton(JSContext* cx, unsigned argc, Value* vp)
     mozilla::Range<const char16_t> skelChars = skeleton.twoByteRange();
 
     UErrorCode status = U_ZERO_ERROR;
-    UDateTimePatternGenerator* gen = udatpg_open(IcuLocale(locale.ptr()), &status);
+    UDateTimePatternGenerator* gen = udatpg_open(IcuLocale(locale.get()), &status);
     if (U_FAILURE(status)) {
         intl::ReportInternalError(cx);
         return false;
@@ -564,7 +564,7 @@ js::intl_patternForStyle(JSContext* cx, unsigned argc, Value* vp)
     MOZ_ASSERT(args.length() == 4);
     MOZ_ASSERT(args[0].isString());
 
-    JSAutoByteString locale(cx, args[0].toString());
+    UniqueChars locale = JS_EncodeString(cx, args[0].toString());
     if (!locale)
         return false;
 
@@ -612,7 +612,7 @@ js::intl_patternForStyle(JSContext* cx, unsigned argc, Value* vp)
     mozilla::Range<const char16_t> timeZoneChars = timeZone.twoByteRange();
 
     UErrorCode status = U_ZERO_ERROR;
-    UDateFormat* df = udat_open(timeStyle, dateStyle, IcuLocale(locale.ptr()),
+    UDateFormat* df = udat_open(timeStyle, dateStyle, IcuLocale(locale.get()),
                                 timeZoneChars.begin().get(), timeZoneChars.length(),
                                 nullptr, -1, &status);
     if (U_FAILURE(status)) {
@@ -645,7 +645,7 @@ NewUDateFormat(JSContext* cx, Handle<DateTimeFormatObject*> dateTimeFormat)
 
     if (!GetProperty(cx, internals, internals, cx->names().locale, &value))
         return nullptr;
-    JSAutoByteString locale(cx, value.toString());
+    UniqueChars locale = JS_EncodeString(cx, value.toString());
     if (!locale)
         return nullptr;
 
@@ -673,7 +673,7 @@ NewUDateFormat(JSContext* cx, Handle<DateTimeFormatObject*> dateTimeFormat)
 
     UErrorCode status = U_ZERO_ERROR;
     UDateFormat* df =
-        udat_open(UDAT_PATTERN, UDAT_PATTERN, IcuLocale(locale.ptr()),
+        udat_open(UDAT_PATTERN, UDAT_PATTERN, IcuLocale(locale.get()),
                   timeZoneChars.begin().get(), timeZoneChars.length(),
                   patternChars.begin().get(), patternChars.length(), &status);
     if (U_FAILURE(status)) {

js/src/builtin/intl/IntlObject.cpp

@@ -21,7 +21,7 @@
 #include "builtin/intl/NumberFormat.h"
 #include "builtin/intl/PluralRules.h"
 #include "builtin/intl/ScopedICUObject.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/Class.h"
 #include "js/StableStringChars.h"
 #include "vm/GlobalObject.h"
@@ -50,14 +50,14 @@ js::intl_GetCalendarInfo(JSContext* cx, unsigned argc, Value* vp)
     CallArgs args = CallArgsFromVp(argc, vp);
     MOZ_ASSERT(args.length() == 1);
 
-    JSAutoByteString locale(cx, args[0].toString());
+    UniqueChars locale = JS_EncodeString(cx, args[0].toString());
     if (!locale)
         return false;
 
     UErrorCode status = U_ZERO_ERROR;
     const UChar* uTimeZone = nullptr;
     int32_t uTimeZoneLength = 0;
-    UCalendar* cal = ucal_open(uTimeZone, uTimeZoneLength, locale.ptr(), UCAL_DEFAULT, &status);
+    UCalendar* cal = ucal_open(uTimeZone, uTimeZoneLength, locale.get(), UCAL_DEFAULT, &status);
     if (U_FAILURE(status)) {
         intl::ReportInternalError(cx);
         return false;
@@ -371,8 +371,8 @@ js::intl_ComputeDisplayNames(JSContext* cx, unsigned argc, Value* vp)
 
     // 1. Assert: locale is a string.
     RootedString str(cx, args[0].toString());
-    JSAutoByteString locale;
+    UniqueChars locale = JS_EncodeStringToUTF8(cx, str);
-    if (!locale.encodeUtf8(cx, str))
+    if (!locale)
         return false;
 
     // 2. Assert: style is a string.
@@ -405,7 +405,7 @@ js::intl_ComputeDisplayNames(JSContext* cx, unsigned argc, Value* vp)
     UErrorCode status = U_ZERO_ERROR;
 
     UDateFormat* fmt =
-        udat_open(UDAT_DEFAULT, UDAT_DEFAULT, IcuLocale(locale.ptr()),
+        udat_open(UDAT_DEFAULT, UDAT_DEFAULT, IcuLocale(locale.get()),
         nullptr, 0, nullptr, 0, &status);
     if (U_FAILURE(status)) {
         intl::ReportInternalError(cx);
@@ -415,7 +415,7 @@ js::intl_ComputeDisplayNames(JSContext* cx, unsigned argc, Value* vp)
 
     // UDateTimePatternGenerator will be needed for translations of date and
     // time fields like "month", "week", "day" etc.
-    UDateTimePatternGenerator* dtpg = udatpg_open(IcuLocale(locale.ptr()), &status);
+    UDateTimePatternGenerator* dtpg = udatpg_open(IcuLocale(locale.get()), &status);
     if (U_FAILURE(status)) {
         intl::ReportInternalError(cx);
         return false;
@@ -461,7 +461,7 @@ js::intl_GetLocaleInfo(JSContext* cx, unsigned argc, Value* vp)
     CallArgs args = CallArgsFromVp(argc, vp);
     MOZ_ASSERT(args.length() == 1);
 
-    JSAutoByteString locale(cx, args[0].toString());
+    UniqueChars locale = JS_EncodeString(cx, args[0].toString());
     if (!locale)
         return false;
 
@@ -472,7 +472,7 @@ js::intl_GetLocaleInfo(JSContext* cx, unsigned argc, Value* vp)
     if (!DefineDataProperty(cx, info, cx->names().locale, args[0]))
         return false;
 
-    bool rtl = uloc_isRightToLeft(IcuLocale(locale.ptr()));
+    bool rtl = uloc_isRightToLeft(IcuLocale(locale.get()));
 
     RootedValue dir(cx, StringValue(rtl ? cx->names().rtl : cx->names().ltr));
 

js/src/builtin/intl/NumberFormat.cpp

@@ -20,6 +20,7 @@
 #include "builtin/intl/ScopedICUObject.h"
 #include "ds/Sort.h"
 #include "gc/FreeOp.h"
+#include "js/CharacterEncoding.h"
 #include "js/RootingAPI.h"
 #include "js/StableStringChars.h"
 #include "js/TypeDecls.h"
@@ -213,12 +214,12 @@ js::intl_numberingSystem(JSContext* cx, unsigned argc, Value* vp)
     MOZ_ASSERT(args.length() == 1);
     MOZ_ASSERT(args[0].isString());
 
-    JSAutoByteString locale(cx, args[0].toString());
+    UniqueChars locale = JS_EncodeString(cx, args[0].toString());
     if (!locale)
         return false;
 
     UErrorCode status = U_ZERO_ERROR;
-    UNumberingSystem* numbers = unumsys_open(IcuLocale(locale.ptr()), &status);
+    UNumberingSystem* numbers = unumsys_open(IcuLocale(locale.get()), &status);
     if (U_FAILURE(status)) {
         intl::ReportInternalError(cx);
         return false;
@@ -255,7 +256,7 @@ NewUNumberFormat(JSContext* cx, Handle<NumberFormatObject*> numberFormat)
 
     if (!GetProperty(cx, internals, internals, cx->names().locale, &value))
         return nullptr;
-    JSAutoByteString locale(cx, value.toString());
+    UniqueChars locale = JS_EncodeString(cx, value.toString());
     if (!locale)
         return nullptr;
 
@@ -347,7 +348,7 @@ NewUNumberFormat(JSContext* cx, Handle<NumberFormatObject*> numberFormat)
     uUseGrouping = value.toBoolean();
 
     UErrorCode status = U_ZERO_ERROR;
-    UNumberFormat* nf = unum_open(uStyle, nullptr, 0, IcuLocale(locale.ptr()), nullptr, &status);
+    UNumberFormat* nf = unum_open(uStyle, nullptr, 0, IcuLocale(locale.get()), nullptr, &status);
     if (U_FAILURE(status)) {
         intl::ReportInternalError(cx);
         return nullptr;

js/src/builtin/intl/PluralRules.cpp

@@ -15,7 +15,7 @@
 #include "builtin/intl/ICUStubs.h"
 #include "builtin/intl/ScopedICUObject.h"
 #include "gc/FreeOp.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "vm/GlobalObject.h"
 #include "vm/JSContext.h"
 #include "vm/StringType.h"
@@ -196,7 +196,7 @@ NewUNumberFormatForPluralRules(JSContext* cx, Handle<PluralRulesObject*> pluralR
 
     if (!GetProperty(cx, internals, internals, cx->names().locale, &value))
         return nullptr;
-    JSAutoByteString locale(cx, value.toString());
+    UniqueChars locale = JS_EncodeString(cx, value.toString());
     if (!locale)
         return nullptr;
 
@@ -234,7 +234,7 @@ NewUNumberFormatForPluralRules(JSContext* cx, Handle<PluralRulesObject*> pluralR
 
     UErrorCode status = U_ZERO_ERROR;
     UNumberFormat* nf =
-        unum_open(UNUM_DECIMAL, nullptr, 0, IcuLocale(locale.ptr()), nullptr, &status);
+        unum_open(UNUM_DECIMAL, nullptr, 0, IcuLocale(locale.get()), nullptr, &status);
     if (U_FAILURE(status)) {
         intl::ReportInternalError(cx);
         return nullptr;
@@ -269,7 +269,7 @@ NewUPluralRules(JSContext* cx, Handle<PluralRulesObject*> pluralRules)
 
     if (!GetProperty(cx, internals, internals, cx->names().locale, &value))
         return nullptr;
-    JSAutoByteString locale(cx, value.toString());
+    UniqueChars locale = JS_EncodeString(cx, value.toString());
     if (!locale)
         return nullptr;
 
@@ -291,7 +291,7 @@ NewUPluralRules(JSContext* cx, Handle<PluralRulesObject*> pluralRules)
     }
 
     UErrorCode status = U_ZERO_ERROR;
-    UPluralRules* pr = uplrules_openForType(IcuLocale(locale.ptr()), category, &status);
+    UPluralRules* pr = uplrules_openForType(IcuLocale(locale.get()), category, &status);
     if (U_FAILURE(status)) {
         intl::ReportInternalError(cx);
         return nullptr;

js/src/builtin/intl/RelativeTimeFormat.cpp

@@ -15,7 +15,7 @@
 #include "builtin/intl/ICUStubs.h"
 #include "builtin/intl/ScopedICUObject.h"
 #include "gc/FreeOp.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "vm/GlobalObject.h"
 #include "vm/JSContext.h"
 
@@ -224,7 +224,7 @@ NewURelativeDateTimeFormatter(JSContext* cx, Handle<RelativeTimeFormatObject*> r
 
     if (!GetProperty(cx, internals, internals, cx->names().locale, &value))
         return nullptr;
-    JSAutoByteString locale(cx, value.toString());
+    UniqueChars locale = JS_EncodeString(cx, value.toString());
     if (!locale)
         return nullptr;
 
@@ -249,7 +249,7 @@ NewURelativeDateTimeFormatter(JSContext* cx, Handle<RelativeTimeFormatObject*> r
 
     UErrorCode status = U_ZERO_ERROR;
     URelativeDateTimeFormatter* rtf =
-        ureldatefmt_open(IcuLocale(locale.ptr()), nullptr, relDateTimeStyle,
+        ureldatefmt_open(IcuLocale(locale.get()), nullptr, relDateTimeStyle,
                          UDISPCTX_CAPITALIZATION_FOR_STANDALONE, &status);
     if (U_FAILURE(status)) {
         intl::ReportInternalError(cx);

js/src/ctypes/CTypes.cpp

@@ -39,9 +39,10 @@
 #include "gc/FreeOp.h"
 #include "gc/Policy.h"
 #include "jit/AtomicOperations.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/StableStringChars.h"
 #include "js/UniquePtr.h"
+#include "js/Utility.h"
 #include "js/Vector.h"
 #include "util/Windows.h"
 #include "vm/JSContext.h"
@@ -982,20 +983,22 @@ GetErrorMessage(void* userRef, const unsigned errorNumber)
 }
 
 static const char*
-EncodeLatin1(JSContext* cx, AutoString& str, JSAutoByteString& bytes)
+EncodeLatin1(JSContext* cx, AutoString& str, JS::UniqueChars& bytes)
 {
-  return bytes.encodeLatin1(cx, NewUCString(cx, str.finish()));
+  bytes = JS_EncodeString(cx, NewUCString(cx, str.finish()));
+  return bytes.get();
 }
 
 static const char*
-CTypesToSourceForError(JSContext* cx, HandleValue val, JSAutoByteString& bytes)
+CTypesToSourceForError(JSContext* cx, HandleValue val, JS::UniqueChars& bytes)
 {
   if (val.isObject()) {
       RootedObject obj(cx, &val.toObject());
       if (CType::IsCType(obj) || CData::IsCDataMaybeUnwrap(&obj)) {
           RootedValue v(cx, ObjectValue(*obj));
           RootedString str(cx, JS_ValueToSource(cx, v));
-          return bytes.encodeLatin1(cx, str);
+          bytes = JS_EncodeString(cx, str);
+          return bytes.get();
       }
   }
   return ValueToSourceForError(cx, val, bytes);
@@ -1179,7 +1182,7 @@ ConvError(JSContext* cx, const char* expectedStr, HandleValue actual,
           HandleObject funObj = nullptr, unsigned argIndex = 0,
           HandleObject arrObj = nullptr, unsigned arrIndex = 0)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actual, valBytes);
   if (!valStr)
     return false;
@@ -1195,7 +1198,7 @@ ConvError(JSContext* cx, const char* expectedStr, HandleValue actual,
       SprintfLiteral(indexStr, "%u", arrIndex);
 
       AutoString arrSource;
-      JSAutoByteString arrBytes;
+      JS::UniqueChars arrBytes;
       BuildTypeSource(cx, arrObj, true, arrSource);
       if (!arrSource)
           return false;
@@ -1211,13 +1214,13 @@ ConvError(JSContext* cx, const char* expectedStr, HandleValue actual,
     case TYPE_struct: {
       JSFlatString* name = GetFieldName(arrObj, arrIndex);
       MOZ_ASSERT(name);
-      JSAutoByteString nameBytes;
+      JS::UniqueChars nameBytes = JS_EncodeString(cx, name);
-      const char* nameStr = nameBytes.encodeLatin1(cx, name);
+      const char* nameStr = nameBytes.get();
       if (!nameStr)
         return false;
 
       AutoString structSource;
-      JSAutoByteString structBytes;
+      JS::UniqueChars structBytes;
       BuildTypeSource(cx, arrObj, true, structSource);
       if (!structSource)
           return false;
@@ -1225,7 +1228,7 @@ ConvError(JSContext* cx, const char* expectedStr, HandleValue actual,
       if (!structStr)
         return false;
 
-      JSAutoByteString posBytes;
+      JS::UniqueChars posBytes;
       const char* posStr;
       if (funObj) {
         AutoString posSource;
@@ -1258,7 +1261,7 @@ ConvError(JSContext* cx, const char* expectedStr, HandleValue actual,
     SprintfLiteral(indexStr, "%u", argIndex + 1);
 
     AutoString funSource;
-    JSAutoByteString funBytes;
+    JS::UniqueChars funBytes;
     BuildFunctionTypeSource(cx, funObj, funSource);
     if (!funSource)
         return false;
@@ -1275,7 +1278,7 @@ ConvError(JSContext* cx, const char* expectedStr, HandleValue actual,
     MOZ_ASSERT(funObj);
 
     AutoString funSource;
-    JSAutoByteString funBytes;
+    JS::UniqueChars funBytes;
     BuildFunctionTypeSource(cx, funObj, funSource);
     if (!funSource)
         return false;
@@ -1291,7 +1294,7 @@ ConvError(JSContext* cx, const char* expectedStr, HandleValue actual,
     MOZ_ASSERT(funObj);
 
     AutoString funSource;
-    JSAutoByteString funBytes;
+    JS::UniqueChars funBytes;
     BuildFunctionTypeSource(cx, funObj, funSource);
     if (!funSource)
         return false;
@@ -1324,7 +1327,7 @@ ConvError(JSContext* cx, HandleObject expectedType, HandleValue actual,
   MOZ_ASSERT(CType::IsCType(expectedType));
 
   AutoString expectedSource;
-  JSAutoByteString expectedBytes;
+  JS::UniqueChars expectedBytes;
   BuildTypeSource(cx, expectedType, true, expectedSource);
   if (!expectedSource)
       return false;
@@ -1340,7 +1343,7 @@ static bool
 ArgumentConvError(JSContext* cx, HandleValue actual, const char* funStr,
                   unsigned argIndex)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actual, valBytes);
   if (!valStr)
     return false;
@@ -1369,7 +1372,7 @@ ArrayLengthMismatch(JSContext* cx, unsigned expectedLength, HandleObject arrObj,
 {
   MOZ_ASSERT(arrObj && CType::IsCType(arrObj));
 
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actual, valBytes);
   if (!valStr)
     return false;
@@ -1380,7 +1383,7 @@ ArrayLengthMismatch(JSContext* cx, unsigned expectedLength, HandleObject arrObj,
   SprintfLiteral(actualLengthStr, "%u", actualLength);
 
   AutoString arrSource;
-  JSAutoByteString arrBytes;
+  JS::UniqueChars arrBytes;
   BuildTypeSource(cx, arrObj, true, arrSource);
   if (!arrSource)
       return false;
@@ -1401,7 +1404,7 @@ ArrayLengthOverflow(JSContext* cx, unsigned expectedLength, HandleObject arrObj,
 {
   MOZ_ASSERT(arrObj && CType::IsCType(arrObj));
 
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actual, valBytes);
   if (!valStr)
     return false;
@@ -1412,7 +1415,7 @@ ArrayLengthOverflow(JSContext* cx, unsigned expectedLength, HandleObject arrObj,
   SprintfLiteral(actualLengthStr, "%u", actualLength);
 
   AutoString arrSource;
-  JSAutoByteString arrBytes;
+  JS::UniqueChars arrBytes;
   BuildTypeSource(cx, arrObj, true, arrSource);
   if (!arrSource)
       return false;
@@ -1454,8 +1457,8 @@ CannotConstructError(JSContext* cx, const char* type)
 static bool
 DuplicateFieldError(JSContext* cx, Handle<JSFlatString*> name)
 {
-  JSAutoByteString nameBytes;
+  JS::UniqueChars nameBytes = JS_EncodeString(cx, name);
-  const char* nameStr = nameBytes.encodeLatin1(cx, name);
+  const char* nameStr = nameBytes.get();
   if (!nameStr)
     return false;
 
@@ -1476,7 +1479,7 @@ static bool
 EmptyFinalizerError(JSContext* cx, ConversionType convType,
                     HandleObject funObj = nullptr, unsigned argIndex = 0)
 {
-  JSAutoByteString posBytes;
+  JS::UniqueChars posBytes;
   const char* posStr;
   if (funObj) {
     AutoString posSource;
@@ -1504,13 +1507,13 @@ FieldCountMismatch(JSContext* cx,
 {
   MOZ_ASSERT(structObj && CType::IsCType(structObj));
 
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actual, valBytes);
   if (!valStr)
     return false;
 
   AutoString structSource;
-  JSAutoByteString structBytes;
+  JS::UniqueChars structBytes;
   BuildTypeSource(cx, structObj, true, structSource);
   if (!structSource)
       return false;
@@ -1523,7 +1526,7 @@ FieldCountMismatch(JSContext* cx,
   char actualCountStr[16];
   SprintfLiteral(actualCountStr, "%u", actualCount);
 
-  JSAutoByteString posBytes;
+  JS::UniqueChars posBytes;
   const char* posStr;
   if (funObj) {
     AutoString posSource;
@@ -1547,7 +1550,7 @@ FieldCountMismatch(JSContext* cx,
 static bool
 FieldDescriptorCountError(JSContext* cx, HandleValue typeVal, size_t length)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, typeVal, valBytes);
   if (!valStr)
     return false;
@@ -1563,7 +1566,7 @@ FieldDescriptorCountError(JSContext* cx, HandleValue typeVal, size_t length)
 static bool
 FieldDescriptorNameError(JSContext* cx, HandleId id)
 {
-  JSAutoByteString idBytes;
+  JS::UniqueChars idBytes;
   RootedValue idVal(cx, IdToValue(id));
   const char* propStr = CTypesToSourceForError(cx, idVal, idBytes);
   if (!propStr)
@@ -1578,14 +1581,14 @@ static bool
 FieldDescriptorSizeError(JSContext* cx, HandleObject typeObj, HandleId id)
 {
   RootedValue typeVal(cx, ObjectValue(*typeObj));
-  JSAutoByteString typeBytes;
+  JS::UniqueChars typeBytes;
   const char* typeStr = CTypesToSourceForError(cx, typeVal, typeBytes);
   if (!typeStr)
     return false;
 
   RootedString idStr(cx, IdToString(cx, id));
-  JSAutoByteString idBytes;
+  JS::UniqueChars idBytes = JS_EncodeString(cx, idStr);
-  const char* propStr = idBytes.encodeLatin1(cx, idStr);
+  const char* propStr = idBytes.get();
   if (!propStr)
     return false;
 
@@ -1597,7 +1600,7 @@ FieldDescriptorSizeError(JSContext* cx, HandleObject typeObj, HandleId id)
 static bool
 FieldDescriptorNameTypeError(JSContext* cx, HandleValue typeVal)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, typeVal, valBytes);
   if (!valStr)
     return false;
@@ -1610,14 +1613,14 @@ FieldDescriptorNameTypeError(JSContext* cx, HandleValue typeVal)
 static bool
 FieldDescriptorTypeError(JSContext* cx, HandleValue poroVal, HandleId id)
 {
-  JSAutoByteString typeBytes;
+  JS::UniqueChars typeBytes;
   const char* typeStr = CTypesToSourceForError(cx, poroVal, typeBytes);
   if (!typeStr)
     return false;
 
   RootedString idStr(cx, IdToString(cx, id));
-  JSAutoByteString idBytes;
+  JS::UniqueChars idBytes = JS_EncodeString(cx, idStr);
-  const char* propStr = idBytes.encodeLatin1(cx, idStr);
+  const char* propStr = idBytes.get();
   if (!propStr)
     return false;
 
@@ -1629,15 +1632,15 @@ FieldDescriptorTypeError(JSContext* cx, HandleValue poroVal, HandleId id)
 static bool
 FieldMissingError(JSContext* cx, JSObject* typeObj, JSFlatString* name_)
 {
-  JSAutoByteString typeBytes;
+  JS::UniqueChars typeBytes;
   RootedString name(cx, name_);
   RootedValue typeVal(cx, ObjectValue(*typeObj));
   const char* typeStr = CTypesToSourceForError(cx, typeVal, typeBytes);
   if (!typeStr)
     return false;
 
-  JSAutoByteString nameBytes;
+  JS::UniqueChars nameBytes = JS_EncodeString(cx, name);
-  const char* nameStr = nameBytes.encodeLatin1(cx, name);
+  const char* nameStr = nameBytes.get();
   if (!nameStr)
     return false;
 
@@ -1651,13 +1654,13 @@ FinalizerSizeError(JSContext* cx, HandleObject funObj, HandleValue actual)
 {
   MOZ_ASSERT(CType::IsCType(funObj));
 
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actual, valBytes);
   if (!valStr)
     return false;
 
   AutoString funSource;
-  JSAutoByteString funBytes;
+  JS::UniqueChars funBytes;
   BuildFunctionTypeSource(cx, funObj, funSource);
   if (!funSource)
       return false;
@@ -1677,7 +1680,7 @@ FunctionArgumentLengthMismatch(JSContext* cx,
                                bool isVariadic)
 {
   AutoString funSource;
-  JSAutoByteString funBytes;
+  JS::UniqueChars funBytes;
   Value slot = JS_GetReservedSlot(funObj, SLOT_REFERENT);
   if (!slot.isUndefined() && Library::IsLibrary(&slot.toObject())) {
     BuildFunctionTypeSource(cx, funObj, funSource);
@@ -1708,7 +1711,7 @@ static bool
 FunctionArgumentTypeError(JSContext* cx,
                           uint32_t index, HandleValue typeVal, const char* reason)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, typeVal, valBytes);
   if (!valStr)
     return false;
@@ -1725,7 +1728,7 @@ FunctionArgumentTypeError(JSContext* cx,
 static bool
 FunctionReturnTypeError(JSContext* cx, HandleValue type, const char* reason)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, type, valBytes);
   if (!valStr)
     return false;
@@ -1738,7 +1741,7 @@ FunctionReturnTypeError(JSContext* cx, HandleValue type, const char* reason)
 static bool
 IncompatibleCallee(JSContext* cx, const char* funName, HandleObject actualObj)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   RootedValue val(cx, ObjectValue(*actualObj));
   const char* valStr = CTypesToSourceForError(cx, val, valBytes);
   if (!valStr)
@@ -1762,7 +1765,7 @@ IncompatibleThisProto(JSContext* cx, const char* funName,
 static bool
 IncompatibleThisProto(JSContext* cx, const char* funName, HandleValue actualVal)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actualVal, valBytes);
   if (!valStr)
     return false;
@@ -1786,7 +1789,7 @@ static bool
 IncompatibleThisType(JSContext* cx, const char* funName, const char* actualType,
                      HandleValue actualVal)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actualVal, valBytes);
   if (!valStr)
     return false;
@@ -1800,7 +1803,7 @@ IncompatibleThisType(JSContext* cx, const char* funName, const char* actualType,
 static bool
 InvalidIndexError(JSContext* cx, HandleValue val)
 {
-  JSAutoByteString idBytes;
+  JS::UniqueChars idBytes;
   const char* indexStr = CTypesToSourceForError(cx, val, idBytes);
   if (!indexStr)
     return false;
@@ -1837,7 +1840,7 @@ NonPrimitiveError(JSContext* cx, HandleObject typeObj)
   MOZ_ASSERT(CType::IsCType(typeObj));
 
   AutoString typeSource;
-  JSAutoByteString typeBytes;
+  JS::UniqueChars typeBytes;
   BuildTypeSource(cx, typeObj, true, typeSource);
   if (!typeSource)
       return false;
@@ -1853,7 +1856,7 @@ NonPrimitiveError(JSContext* cx, HandleObject typeObj)
 static bool
 NonStringBaseError(JSContext* cx, HandleValue thisVal)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, thisVal, valBytes);
   if (!valStr)
     return false;
@@ -1866,7 +1869,7 @@ NonStringBaseError(JSContext* cx, HandleValue thisVal)
 static bool
 NullPointerError(JSContext* cx, const char* action, HandleObject obj)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   RootedValue val(cx, ObjectValue(*obj));
   const char* valStr = CTypesToSourceForError(cx, val, valBytes);
   if (!valStr)
@@ -1882,18 +1885,18 @@ PropNameNonStringError(JSContext* cx, HandleId id, HandleValue actual,
                        ConversionType convType,
                        HandleObject funObj = nullptr, unsigned argIndex = 0)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actual, valBytes);
   if (!valStr)
     return false;
 
-  JSAutoByteString idBytes;
+  JS::UniqueChars idBytes;
   RootedValue idVal(cx, IdToValue(id));
   const char* propStr = CTypesToSourceForError(cx, idVal, idBytes);
   if (!propStr)
     return false;
 
-  JSAutoByteString posBytes;
+  JS::UniqueChars posBytes;
   const char* posStr;
   if (funObj) {
     AutoString posSource;
@@ -1923,7 +1926,7 @@ SizeOverflow(JSContext* cx, const char* name, const char* limit)
 static bool
 TypeError(JSContext* cx, const char* expected, HandleValue actual)
 {
-  JSAutoByteString bytes;
+  JS::UniqueChars bytes;
   const char* src = CTypesToSourceForError(cx, actual, bytes);
   if (!src)
     return false;
@@ -1936,7 +1939,7 @@ TypeError(JSContext* cx, const char* expected, HandleValue actual)
 static bool
 TypeOverflow(JSContext* cx, const char* expected, HandleValue actual)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actual, valBytes);
   if (!valStr)
     return false;
@@ -1950,7 +1953,7 @@ static bool
 UndefinedSizeCastError(JSContext* cx, HandleObject targetTypeObj)
 {
   AutoString targetTypeSource;
-  JSAutoByteString targetTypeBytes;
+  JS::UniqueChars targetTypeBytes;
   BuildTypeSource(cx, targetTypeObj, true, targetTypeSource);
   if (!targetTypeSource)
       return false;
@@ -1969,7 +1972,7 @@ SizeMismatchCastError(JSContext* cx,
                       size_t sourceSize, size_t targetSize)
 {
   AutoString sourceTypeSource;
-  JSAutoByteString sourceTypeBytes;
+  JS::UniqueChars sourceTypeBytes;
   BuildTypeSource(cx, sourceTypeObj, true, sourceTypeSource);
   if (!sourceTypeSource)
       return false;
@@ -1978,7 +1981,7 @@ SizeMismatchCastError(JSContext* cx,
     return false;
 
   AutoString targetTypeSource;
-  JSAutoByteString targetTypeBytes;
+  JS::UniqueChars targetTypeBytes;
   BuildTypeSource(cx, targetTypeObj, true, targetTypeSource);
   if (!targetTypeSource)
       return false;
@@ -2001,7 +2004,7 @@ SizeMismatchCastError(JSContext* cx,
 static bool
 UndefinedSizePointerError(JSContext* cx, const char* action, HandleObject obj)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   RootedValue val(cx, ObjectValue(*obj));
   const char* valStr = CTypesToSourceForError(cx, val, valBytes);
   if (!valStr)
@@ -2015,7 +2018,7 @@ UndefinedSizePointerError(JSContext* cx, const char* action, HandleObject obj)
 static bool
 VariadicArgumentTypeError(JSContext* cx, uint32_t index, HandleValue actual)
 {
-  JSAutoByteString valBytes;
+  JS::UniqueChars valBytes;
   const char* valStr = CTypesToSourceForError(cx, actual, valBytes);
   if (!valStr)
     return false;

js/src/ctypes/Library.cpp

@@ -10,7 +10,7 @@
 #include "prlink.h"
 
 #include "ctypes/CTypes.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/StableStringChars.h"
 
 using JS::AutoStableStringChars;
@@ -169,13 +169,13 @@ Library::Create(JSContext* cx, HandleValue path, const JSCTypesCallbacks* callba
 #undef MAX_ERROR_LEN
 
     if (JS::StringIsASCII(error)) {
-      JSAutoByteString pathCharsUTF8;
+      JS::UniqueChars pathCharsUTF8 = JS_EncodeStringToUTF8(cx, pathStr);
-      if (pathCharsUTF8.encodeUtf8(cx, pathStr))
+      if (pathCharsUTF8)
-        JS_ReportErrorUTF8(cx, "couldn't open library %s: %s", pathCharsUTF8.ptr(), error);
+        JS_ReportErrorUTF8(cx, "couldn't open library %s: %s", pathCharsUTF8.get(), error);
     } else {
-      JSAutoByteString pathCharsLatin1;
+      JS::UniqueChars pathCharsLatin1 = JS_EncodeString(cx, pathStr);
-      if (pathCharsLatin1.encodeLatin1(cx, pathStr))
+      if (pathCharsLatin1)
-        JS_ReportErrorLatin1(cx, "couldn't open library %s: %s", pathCharsLatin1.ptr(), error);
+        JS_ReportErrorLatin1(cx, "couldn't open library %s: %s", pathCharsLatin1.get(), error);
     }
     return nullptr;
   }

js/src/frontend/EmitterScope.cpp

@@ -8,7 +8,6 @@
 
 #include "frontend/BytecodeEmitter.h"
 #include "frontend/TDZCheckCache.h"
-#include "js/AutoByteString.h"
 
 #include "vm/GlobalObject.h"
 
@@ -400,13 +399,13 @@ EmitterScope::dump(BytecodeEmitter* bce)
     for (NameLocationMap::Range r = nameCache_->all(); !r.empty(); r.popFront()) {
         const NameLocation& l = r.front().value();
 
-        JSAutoByteString bytes;
+        UniqueChars bytes;
         if (!AtomToPrintableString(bce->cx, r.front().key(), &bytes))
             return;
         if (l.kind() != NameLocation::Kind::Dynamic)
-            fprintf(stdout, "  %s %s ", BindingKindString(l.bindingKind()), bytes.ptr());
+            fprintf(stdout, "  %s %s ", BindingKindString(l.bindingKind()), bytes.get());
         else
-            fprintf(stdout, "  %s ", bytes.ptr());
+            fprintf(stdout, "  %s ", bytes.get());
 
         switch (l.kind()) {
           case NameLocation::Kind::Dynamic:

js/src/frontend/Parser.cpp

@@ -37,7 +37,6 @@
 #include "frontend/FoldConstants.h"
 #include "frontend/TokenStream.h"
 #include "irregexp/RegExpParser.h"
-#include "js/AutoByteString.h"
 #include "vm/BytecodeUtil.h"
 #include "vm/JSAtom.h"
 #include "vm/JSContext.h"
@@ -171,13 +170,13 @@ ParseContext::Scope::dump(ParseContext* pc)
 
     fprintf(stdout, "\n  decls:\n");
     for (DeclaredNameMap::Range r = declared_->all(); !r.empty(); r.popFront()) {
-        JSAutoByteString bytes;
+        UniqueChars bytes;
         if (!AtomToPrintableString(cx, r.front().key(), &bytes))
             return;
         DeclaredNameInfo& info = r.front().value().wrapped;
         fprintf(stdout, "    %s %s%s\n",
                 DeclarationKindString(info.kind()),
-                bytes.ptr(),
+                bytes.get(),
                 info.closedOver() ? " (closed over)" : "");
     }
 
@@ -1227,12 +1226,12 @@ GeneralParser<ParseHandler, CharT>::reportRedeclaration(HandlePropertyName name,
                                                         DeclarationKind prevKind,
                                                         TokenPos pos, uint32_t prevPos)
 {
-    JSAutoByteString bytes;
+    UniqueChars bytes;
     if (!AtomToPrintableString(context, name, &bytes))
         return;
 
     if (prevPos == DeclaredNameInfo::npos) {
-        errorAt(pos.begin, JSMSG_REDECLARED_VAR, DeclarationKindString(prevKind), bytes.ptr());
+        errorAt(pos.begin, JSMSG_REDECLARED_VAR, DeclarationKindString(prevKind), bytes.get());
         return;
     }
 
@@ -1261,7 +1260,7 @@ GeneralParser<ParseHandler, CharT>::reportRedeclaration(HandlePropertyName name,
     }
 
     errorWithNotesAt(std::move(notes), pos.begin, JSMSG_REDECLARED_VAR,
-                     DeclarationKindString(prevKind), bytes.ptr());
+                     DeclarationKindString(prevKind), bytes.get());
 }
 
 // notePositionalFormalParameter is called for both the arguments of a regular
@@ -1291,10 +1290,10 @@ GeneralParser<ParseHandler, CharT>::notePositionalFormalParameter(Node fn, Handl
         // In such cases, report will queue up the potential error and return
         // 'true'.
         if (pc->sc()->needStrictChecks()) {
-            JSAutoByteString bytes;
+            UniqueChars bytes;
             if (!AtomToPrintableString(context, name, &bytes))
                 return false;
-            if (!strictModeError(JSMSG_DUPLICATE_FORMAL, bytes.ptr()))
+            if (!strictModeError(JSMSG_DUPLICATE_FORMAL, bytes.get()))
                 return false;
         }
 
@@ -2426,11 +2425,11 @@ Parser<FullParseHandler, CharT>::moduleBody(ModuleSharedContext* modulesc)
 
         DeclaredNamePtr p = modulepc.varScope().lookupDeclaredName(name);
         if (!p) {
-            JSAutoByteString str;
+            UniqueChars str;
             if (!AtomToPrintableString(context, name, &str))
                 return null();
 
-            errorAt(TokenStream::NoOffset, JSMSG_MISSING_EXPORT, str.ptr());
+            errorAt(TokenStream::NoOffset, JSMSG_MISSING_EXPORT, str.get());
             return null();
         }
 
@@ -5464,11 +5463,11 @@ Parser<FullParseHandler, CharT>::checkExportedName(JSAtom* exportName)
     if (!pc->sc()->asModuleContext()->builder.hasExportedName(exportName))
         return true;
 
-    JSAutoByteString str;
+    UniqueChars str;
     if (!AtomToPrintableString(context, exportName, &str))
         return false;
 
-    error(JSMSG_DUPLICATE_EXPORT_NAME, str.ptr());
+    error(JSMSG_DUPLICATE_EXPORT_NAME, str.get());
     return false;
 }
 

js/src/jsapi-tests/tests.h

@@ -17,7 +17,7 @@
 
 #include "gc/GC.h"
 #include "js/AllocPolicy.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/Vector.h"
 #include "vm/JSContext.h"
 
@@ -105,9 +105,8 @@ class JSAPITest
     JSAPITestString jsvalToSource(JS::HandleValue v) {
         JSString* str = JS_ValueToSource(cx, v);
         if (str) {
-            JSAutoByteString bytes(cx, str);
+            if (JS::UniqueChars bytes = JS_EncodeString(cx, str))
-            if (!!bytes)
+                return JSAPITestString(bytes.get());
-                return JSAPITestString(bytes.ptr());
         }
         JS_ClearPendingException(cx);
         return JSAPITestString("<<error converting value to string>>");
@@ -233,9 +232,8 @@ class JSAPITest
             JS_ClearPendingException(cx);
             JSString* s = JS::ToString(cx, v);
             if (s) {
-                JSAutoByteString bytes(cx, s);
+                if (JS::UniqueChars bytes = JS_EncodeString(cx, s))
-                if (!!bytes)
+                    message += bytes.get();
-                    message += bytes.ptr();
             }
         }
 
@@ -273,11 +271,10 @@ class JSAPITest
             JSString* str = JS::ToString(cx, args[i]);
             if (!str)
                 return false;
-            char* bytes = JS_EncodeString(cx, str);
+            JS::UniqueChars bytes = JS_EncodeString(cx, str);
             if (!bytes)
                 return false;
-            printf("%s%s", i ? " " : "", bytes);
+            printf("%s%s", i ? " " : "", bytes.get());
-            JS_free(cx, bytes);
         }
 
         putchar('\n');

js/src/jsapi.cpp

@@ -55,7 +55,6 @@
 #include "gc/WeakMap.h"
 #include "jit/JitCommon.h"
 #include "jit/JitSpewer.h"
-#include "js/AutoByteString.h"
 #include "js/CharacterEncoding.h"
 #include "js/CompilationAndEvaluation.h"
 #include "js/CompileOptions.h"
@@ -181,8 +180,8 @@ JS::ObjectOpResult::reportStrictErrorOrWarning(JSContext* cx, HandleObject obj,
         if (!str)
             return false;
 
-        JSAutoByteString propName;
+        UniqueChars propName = JS_EncodeStringToUTF8(cx, str);
-        if (!propName.encodeUtf8(cx, str))
+        if (!propName)
             return false;
 
         if (code_ == JSMSG_SET_NON_OBJECT_RECEIVER) {
@@ -193,16 +192,16 @@ JS::ObjectOpResult::reportStrictErrorOrWarning(JSContext* cx, HandleObject obj,
                     return false;
             }
             return ReportValueErrorFlags(cx, flags, code_, JSDVG_IGNORE_STACK, val,
-                                         nullptr, propName.ptr(), nullptr);
+                                         nullptr, propName.get(), nullptr);
         }
 
         if (ErrorTakesObjectArgument(code_)) {
             return JS_ReportErrorFlagsAndNumberUTF8(cx, flags, GetErrorMessage, nullptr, code_,
-                                                    obj->getClass()->name, propName.ptr());
+                                                    obj->getClass()->name, propName.get());
         }
 
         return JS_ReportErrorFlagsAndNumberUTF8(cx, flags, GetErrorMessage, nullptr, code_,
-                                                propName.ptr());
+                                                propName.get());
     }
     return JS_ReportErrorFlagsAndNumberASCII(cx, flags, GetErrorMessage, nullptr, code_);
 }
@@ -1649,7 +1648,7 @@ JS::GetFirstArgumentAsTypeHint(JSContext* cx, CallArgs args, JSType *result)
         return true;
     }
 
-    JSAutoByteString bytes;
+    UniqueChars bytes;
     const char* source = ValueToSourceForError(cx, args.get(0), bytes);
     if (!source) {
         ReportOutOfMemory(cx);
@@ -5066,9 +5065,8 @@ JS::DumpPromiseAllocationSite(JSContext* cx, JS::HandleObject promise)
 {
     RootedObject stack(cx, promise->as<PromiseObject>().allocationSite());
     JSPrincipals* principals = cx->realm()->principals();
-    UniqueChars stackStr(
+    UniqueChars stackStr = BuildUTF8StackString(cx, principals, stack);
-        reinterpret_cast<char*>(BuildUTF8StackString(cx, principals, stack).get()));
+    if (stackStr)
-    if (stackStr.get())
         fputs(stackStr.get(), stderr);
 }
 
@@ -5077,9 +5075,8 @@ JS::DumpPromiseResolutionSite(JSContext* cx, JS::HandleObject promise)
 {
     RootedObject stack(cx, promise->as<PromiseObject>().resolutionSite());
     JSPrincipals* principals = cx->realm()->principals();
-    UniqueChars stackStr(
+    UniqueChars stackStr = BuildUTF8StackString(cx, principals, stack);
-        reinterpret_cast<char*>(BuildUTF8StackString(cx, principals, stack).get()));
+    if (stackStr)
-    if (stackStr.get())
         fputs(stackStr.get(), stderr);
 }
 #endif
@@ -6055,22 +6052,22 @@ JS_DecodeBytes(JSContext* cx, const char* src, size_t srclen, char16_t* dst, siz
     return true;
 }
 
-JS_PUBLIC_API(char*)
+JS_PUBLIC_API(JS::UniqueChars)
 JS_EncodeString(JSContext* cx, JSString* str)
 {
     AssertHeapIsIdle();
     CHECK_THREAD(cx);
 
-    return js::EncodeLatin1(cx, str).release();
+    return js::EncodeLatin1(cx, str);
 }
 
-JS_PUBLIC_API(char*)
+JS_PUBLIC_API(JS::UniqueChars)
 JS_EncodeStringToUTF8(JSContext* cx, HandleString str)
 {
     AssertHeapIsIdle();
     CHECK_THREAD(cx);
 
-    return StringToNewUTF8CharsZ(cx, *str).release();
+    return StringToNewUTF8CharsZ(cx, *str);
 }
 
 JS_PUBLIC_API(size_t)

js/src/jsexn.cpp

@@ -23,7 +23,6 @@
 
 #include "gc/FreeOp.h"
 #include "gc/Marking.h"
-#include "js/AutoByteString.h"
 #include "js/CharacterEncoding.h"
 #include "js/UniquePtr.h"
 #include "js/Wrapper.h"
@@ -884,7 +883,7 @@ ErrorReport::init(JSContext* cx, HandleValue exn,
         if (JS_GetProperty(cx, exnObject, filename_str, &val)) {
             RootedString tmp(cx, ToString<CanGC>(cx, val));
             if (tmp)
-                filename.encodeUtf8(cx, tmp);
+                filename = JS_EncodeStringToUTF8(cx, tmp);
             else
                 cx->clearPendingException();
         } else {
@@ -909,7 +908,7 @@ ErrorReport::init(JSContext* cx, HandleValue exn,
 
         reportp = &ownedReport;
         new (reportp) JSErrorReport();
-        ownedReport.filename = filename.ptr();
+        ownedReport.filename = filename.get();
         ownedReport.lineno = lineno;
         ownedReport.exnType = JSEXN_INTERNALERR;
         ownedReport.column = column;
@@ -935,8 +934,10 @@ ErrorReport::init(JSContext* cx, HandleValue exn,
     }
 
     const char* utf8Message = nullptr;
-    if (str)
+    if (str) {
-        utf8Message = toStringResultBytesStorage.encodeUtf8(cx, str);
+        toStringResultBytesStorage = JS_EncodeStringToUTF8(cx, str);
+        utf8Message = toStringResultBytesStorage.get();
+    }
     if (!utf8Message)
         utf8Message = "unknown (can't convert to string)";
 
@@ -1054,7 +1055,7 @@ JS::CreateError(JSContext* cx, JSExnType type, HandleObject stack, HandleString
 }
 
 const char*
-js::ValueToSourceForError(JSContext* cx, HandleValue val, JSAutoByteString& bytes)
+js::ValueToSourceForError(JSContext* cx, HandleValue val, UniqueChars& bytes)
 {
     if (val.isUndefined())
         return "undefined";
@@ -1093,14 +1094,16 @@ js::ValueToSourceForError(JSContext* cx, HandleValue val, JSAutoByteString& byte
             return "<<error converting value to string>>";
     } else {
         MOZ_ASSERT(val.isBoolean() || val.isSymbol());
-        return bytes.encodeLatin1(cx, str);
+        bytes = JS_EncodeString(cx, str);
+        return bytes.get();
     }
     if (!sb.append(str))
         return "<<error converting value to string>>";
     str = sb.finishString();
     if (!str)
         return "<<error converting value to string>>";
-    return bytes.encodeLatin1(cx, str);
+    bytes = JS_EncodeString(cx, str);
+    return bytes.get();
 }
 
 bool

js/src/jsexn.h

@@ -17,8 +17,6 @@
 #include "js/UniquePtr.h"
 #include "vm/JSContext.h"
 
-class JSAutoByteString;
-
 namespace js {
 class ErrorObject;
 
@@ -134,7 +132,7 @@ class AutoAssertNoPendingException
 };
 
 extern const char*
-ValueToSourceForError(JSContext* cx, HandleValue val, JSAutoByteString& bytes);
+ValueToSourceForError(JSContext* cx, HandleValue val, JS::UniqueChars& bytes);
 
 bool
 GetInternalError(JSContext* cx, unsigned errorNumber, MutableHandleValue error);

js/src/jsfriendapi.cpp

@@ -20,7 +20,7 @@
 #include "gc/GCInternals.h"
 #include "gc/PublicIterators.h"
 #include "gc/WeakMap.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/Printf.h"
 #include "js/Proxy.h"
 #include "js/Wrapper.h"
@@ -808,7 +808,7 @@ js::DumpScript(JSContext* cx, JSScript* scriptArg)
 #endif
 
 static const char*
-FormatValue(JSContext* cx, const Value& vArg, JSAutoByteString& bytes)
+FormatValue(JSContext* cx, const Value& vArg, UniqueChars& bytes)
 {
     RootedValue v(cx, vArg);
 
@@ -832,7 +832,8 @@ FormatValue(JSContext* cx, const Value& vArg, JSAutoByteString& bytes)
 
     if (!str)
         return nullptr;
-    const char* buf = bytes.encodeLatin1(cx, str);
+    bytes = JS_EncodeString(cx, str);
+    const char* buf = bytes.get();
     if (!buf)
         return nullptr;
     const char* found = strstr(buf, "function ");
@@ -892,8 +893,8 @@ FormatFrame(JSContext* cx, const FrameIter& iter, JS::UniqueChars&& inBuf, int n
     // print the frame number and function name
     JS::UniqueChars buf(std::move(inBuf));
     if (funname) {
-        JSAutoByteString funbytes;
+        UniqueChars funbytes = JS_EncodeString(cx, funname);
-        char* str = funbytes.encodeLatin1(cx, funname);
+        char* str = funbytes.get();
         if (!str)
             return nullptr;
         buf = sprintf_append(cx, std::move(buf), "%d %s(", num, str);
@@ -925,7 +926,7 @@ FormatFrame(JSContext* cx, const FrameIter& iter, JS::UniqueChars&& inBuf, int n
                 arg = MagicValue(JS_OPTIMIZED_OUT);
             }
 
-            JSAutoByteString valueBytes;
+            UniqueChars valueBytes;
             const char* value = FormatValue(cx, arg, valueBytes);
             if (!value) {
                 if (cx->isThrowingOutOfMemory())
@@ -933,13 +934,14 @@ FormatFrame(JSContext* cx, const FrameIter& iter, JS::UniqueChars&& inBuf, int n
                 cx->clearPendingException();
             }
 
-            JSAutoByteString nameBytes;
+            UniqueChars nameBytes;
             const char* name = nullptr;
 
             if (i < iter.numFormalArgs()) {
                 MOZ_ASSERT(fi.argumentSlot() == i);
                 if (!fi.isDestructured()) {
-                    name = nameBytes.encodeLatin1(cx, fi.name());
+                    nameBytes = JS_EncodeString(cx, fi.name());
+                    name = nameBytes.get();
                     if (!name)
                         return nullptr;
                 } else {
@@ -985,7 +987,7 @@ FormatFrame(JSContext* cx, const FrameIter& iter, JS::UniqueChars&& inBuf, int n
     // print the value of 'this'
     if (showLocals) {
         if (!thisVal.isUndefined()) {
-            JSAutoByteString thisValBytes;
+            UniqueChars thisValBytes;
             RootedString thisValStr(cx, ToString<CanGC>(cx, thisVal));
             if (!thisValStr) {
                 if (cx->isThrowingOutOfMemory())
@@ -993,7 +995,8 @@ FormatFrame(JSContext* cx, const FrameIter& iter, JS::UniqueChars&& inBuf, int n
                 cx->clearPendingException();
             }
             if (thisValStr) {
-                const char* str = thisValBytes.encodeLatin1(cx, thisValStr);
+                thisValBytes = JS_EncodeString(cx, thisValStr);
+                const char* str = thisValBytes.get();
                 if (!str)
                     return nullptr;
                 buf = sprintf_append(cx, std::move(buf), "    this = %s\n", str);
@@ -1032,7 +1035,7 @@ FormatFrame(JSContext* cx, const FrameIter& iter, JS::UniqueChars&& inBuf, int n
                 continue;
             }
 
-            JSAutoByteString nameBytes;
+            UniqueChars nameBytes;
             const char* name = FormatValue(cx, key, nameBytes);
             if (!name) {
                 if (cx->isThrowingOutOfMemory())
@@ -1040,7 +1043,7 @@ FormatFrame(JSContext* cx, const FrameIter& iter, JS::UniqueChars&& inBuf, int n
                 cx->clearPendingException();
             }
 
-            JSAutoByteString valueBytes;
+            UniqueChars valueBytes;
             const char* value = FormatValue(cx, v, valueBytes);
             if (!value) {
                 if (cx->isThrowingOutOfMemory())

js/src/jsfriendapi.h

@@ -15,7 +15,6 @@
 
 #include "jspubtd.h"
 
-#include "js/AutoByteString.h"
 #include "js/CallArgs.h"
 #include "js/CallNonGenericMethod.h"
 #include "js/CharacterEncoding.h"
@@ -1464,13 +1463,13 @@ struct MOZ_STACK_CLASS JS_FRIEND_API(ErrorReport)
     JS::RootedObject exnObject;
 
     // And for our filename.
-    JSAutoByteString filename;
+    JS::UniqueChars filename;
 
     // We may have a result of error.toString().
     // FIXME: We should not call error.toString(), since it could have side
     //        effect (see bug 633623).
     JS::ConstUTF8CharsZ toStringResult_;
-    JSAutoByteString toStringResultBytesStorage;
+    JS::UniqueChars toStringResultBytesStorage;
 };
 
 /* Implemented in vm/StructuredClone.cpp. */

js/src/jsnum.cpp

@@ -27,6 +27,7 @@
 
 #include "builtin/String.h"
 #include "double-conversion/double-conversion.h"
+#include "js/CharacterEncoding.h"
 #include "js/Conversions.h"
 #if !EXPOSE_INTL_API
 #include "js/LocaleSensitive.h"
@@ -796,10 +797,10 @@ num_toLocaleString_impl(JSContext* cx, const CallArgs& args)
      * Create the string, move back to bytes to make string twiddling
      * a bit easier and so we can insert platform charset seperators.
      */
-    JSAutoByteString numBytes(cx, str);
+    UniqueChars numBytes = JS_EncodeString(cx, str);
     if (!numBytes)
         return false;
-    const char* num = numBytes.ptr();
+    const char* num = numBytes.get();
     if (!num)
         return false;
 

js/src/moz.build

@@ -124,7 +124,6 @@ EXPORTS += [
 
 EXPORTS.js += [
     '../public/AllocPolicy.h',
-    '../public/AutoByteString.h',
     '../public/CallArgs.h',
     '../public/CallNonGenericMethod.h',
     '../public/CharacterEncoding.h',

js/src/proxy/ScriptedProxyHandler.cpp

@@ -8,7 +8,7 @@
 
 #include "jsapi.h"
 
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "vm/Interpreter.h" // For InstanceOfOperator
 
 #include "vm/JSObject-inl.h"
@@ -179,11 +179,11 @@ GetProxyTrap(JSContext* cx, HandleObject handler, HandlePropertyName name, Mutab
 
     // Step 4.
     if (!IsCallable(func)) {
-        JSAutoByteString bytes(cx, name);
+        UniqueChars bytes = JS_EncodeString(cx, name);
         if (!bytes)
             return false;
 
-        JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_BAD_TRAP, bytes.ptr());
+        JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_BAD_TRAP, bytes.get());
         return false;
     }
 

js/src/shell/OSObject.cpp

@@ -25,7 +25,7 @@
 
 #include "builtin/String.h"
 #include "gc/FreeOp.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/Conversions.h"
 #include "js/Wrapper.h"
 #include "shell/jsshell.h"
@@ -58,9 +58,9 @@ const char PathSeparator = '/';
 #endif
 
 static bool
-IsAbsolutePath(const JSAutoByteString& filename)
+IsAbsolutePath(const UniqueChars& filename)
 {
-    const char* pathname = filename.ptr();
+    const char* pathname = filename.get();
 
     if (pathname[0] == PathSeparator)
         return true;
@@ -106,7 +106,7 @@ ResolvePath(JSContext* cx, HandleString filenameStr, PathResolutionMode resolveM
 #endif
     }
 
-    JSAutoByteString filename(cx, filenameStr);
+    UniqueChars filename = JS_EncodeString(cx, filenameStr);
     if (!filename)
         return nullptr;
 
@@ -148,7 +148,7 @@ ResolvePath(JSContext* cx, HandleString filenameStr, PathResolutionMode resolveM
 
     size_t len = strlen(buffer);
     buffer[len] = '/';
-    strncpy(buffer + len + 1, filename.ptr(), sizeof(buffer) - (len+1));
+    strncpy(buffer + len + 1, filename.get(), sizeof(buffer) - (len+1));
     if (buffer[PATH_MAX] != '\0')
         return nullptr;
 
@@ -158,34 +158,34 @@ ResolvePath(JSContext* cx, HandleString filenameStr, PathResolutionMode resolveM
 JSObject*
 FileAsTypedArray(JSContext* cx, JS::HandleString pathnameStr)
 {
-    JSAutoByteString pathname(cx, pathnameStr);
+    UniqueChars pathname = JS_EncodeString(cx, pathnameStr);
     if (!pathname)
         return nullptr;
 
-    FILE* file = fopen(pathname.ptr(), "rb");
+    FILE* file = fopen(pathname.get(), "rb");
     if (!file) {
         /*
          * Use Latin1 variant here because the encoding of the return value of
          * strerror function can be non-UTF-8.
          */
-        JS_ReportErrorLatin1(cx, "can't open %s: %s", pathname.ptr(), strerror(errno));
+        JS_ReportErrorLatin1(cx, "can't open %s: %s", pathname.get(), strerror(errno));
         return nullptr;
     }
     AutoCloseFile autoClose(file);
 
     RootedObject obj(cx);
     if (fseek(file, 0, SEEK_END) != 0) {
-        pathname.clear();
+        pathname = JS_EncodeStringToUTF8(cx, pathnameStr);
-        if (!pathname.encodeUtf8(cx, pathnameStr))
+        if (!pathname)
             return nullptr;
-        JS_ReportErrorUTF8(cx, "can't seek end of %s", pathname.ptr());
+        JS_ReportErrorUTF8(cx, "can't seek end of %s", pathname.get());
     } else {
         size_t len = ftell(file);
         if (fseek(file, 0, SEEK_SET) != 0) {
-            pathname.clear();
+            pathname = JS_EncodeStringToUTF8(cx, pathnameStr);
-            if (!pathname.encodeUtf8(cx, pathnameStr))
+            if (!pathname)
                 return nullptr;
-            JS_ReportErrorUTF8(cx, "can't seek start of %s", pathname.ptr());
+            JS_ReportErrorUTF8(cx, "can't seek start of %s", pathname.get());
         } else {
             obj = JS_NewUint8Array(cx, len);
             if (!obj)
@@ -201,10 +201,10 @@ FileAsTypedArray(JSContext* cx, JS::HandleString pathnameStr)
                 // temporary buffer, read into that, and use a
                 // race-safe primitive to copy memory into the
                 // buffer.)
-                pathname.clear();
+                pathname = JS_EncodeStringToUTF8(cx, pathnameStr);
-                if (!pathname.encodeUtf8(cx, pathnameStr))
+                if (!pathname)
                     return nullptr;
-                JS_ReportErrorUTF8(cx, "can't read %s: shared memory buffer", pathname.ptr());
+                JS_ReportErrorUTF8(cx, "can't read %s: shared memory buffer", pathname.get());
                 return nullptr;
             }
             char* buf = static_cast<char*>(ta.viewDataUnshared());
@@ -215,12 +215,12 @@ FileAsTypedArray(JSContext* cx, JS::HandleString pathnameStr)
                      * Use Latin1 variant here because the encoding of the return
                      * value of strerror function can be non-UTF-8.
                      */
-                    JS_ReportErrorLatin1(cx, "can't read %s: %s", pathname.ptr(), strerror(errno));
+                    JS_ReportErrorLatin1(cx, "can't read %s: %s", pathname.get(), strerror(errno));
                 } else {
-                    pathname.clear();
+                    pathname = JS_EncodeStringToUTF8(cx, pathnameStr);
-                    if (!pathname.encodeUtf8(cx, pathnameStr))
+                    if (!pathname)
                         return nullptr;
-                    JS_ReportErrorUTF8(cx, "can't read %s: short read", pathname.ptr());
+                    JS_ReportErrorUTF8(cx, "can't read %s: short read", pathname.get());
                 }
                 obj = nullptr;
             }
@@ -319,17 +319,17 @@ osfile_writeTypedArrayToFile(JSContext* cx, unsigned argc, Value* vp)
     if (!str)
         return false;
 
-    JSAutoByteString filename(cx, str);
+    UniqueChars filename = JS_EncodeString(cx, str);
     if (!filename)
         return false;
 
-    FILE* file = fopen(filename.ptr(), "wb");
+    FILE* file = fopen(filename.get(), "wb");
     if (!file) {
         /*
          * Use Latin1 variant here because the encoding of the return value of
          * strerror function can be non-UTF-8.
          */
-        JS_ReportErrorLatin1(cx, "can't open %s: %s", filename.ptr(), strerror(errno));
+        JS_ReportErrorLatin1(cx, "can't open %s: %s", filename.get(), strerror(errno));
         return false;
     }
     AutoCloseFile autoClose(file);
@@ -340,20 +340,20 @@ osfile_writeTypedArrayToFile(JSContext* cx, unsigned argc, Value* vp)
         // Must opt in to use shared memory.  For now, don't.
         //
         // See further comments in FileAsTypedArray, above.
-        filename.clear();
+        filename = JS_EncodeStringToUTF8(cx, str);
-        if (!filename.encodeUtf8(cx, str))
+        if (!filename)
             return false;
-        JS_ReportErrorUTF8(cx, "can't write %s: shared memory buffer", filename.ptr());
+        JS_ReportErrorUTF8(cx, "can't write %s: shared memory buffer", filename.get());
         return false;
     }
     void* buf = obj->viewDataUnshared();
     if (fwrite(buf, obj->bytesPerElement(), obj->length(), file) != obj->length() ||
         !autoClose.release())
     {
-        filename.clear();
+        filename = JS_EncodeStringToUTF8(cx, str);
-        if (!filename.encodeUtf8(cx, str))
+        if (!filename)
             return false;
-        JS_ReportErrorUTF8(cx, "can't write %s", filename.ptr());
+        JS_ReportErrorUTF8(cx, "can't write %s", filename.get());
         return false;
     }
 
@@ -472,16 +472,16 @@ redirect(JSContext* cx, HandleString relFilename, RCFile** globalFile)
     RootedString filename(cx, ResolvePath(cx, relFilename, RootRelative));
     if (!filename)
         return nullptr;
-    JSAutoByteString filenameABS(cx, filename);
+    UniqueChars filenameABS = JS_EncodeString(cx, filename);
     if (!filenameABS)
         return nullptr;
-    RCFile* file = RCFile::create(cx, filenameABS.ptr(), "wb");
+    RCFile* file = RCFile::create(cx, filenameABS.get(), "wb");
     if (!file) {
         /*
          * Use Latin1 variant here because the encoding of the return value of
          * strerror function can be non-UTF-8.
          */
-        JS_ReportErrorLatin1(cx, "cannot redirect to %s: %s", filenameABS.ptr(), strerror(errno));
+        JS_ReportErrorLatin1(cx, "cannot redirect to %s: %s", filenameABS.get(), strerror(errno));
         return nullptr;
     }
 
@@ -636,7 +636,7 @@ ospath_isAbsolute(JSContext* cx, unsigned argc, Value* vp)
         return false;
     }
 
-    JSAutoByteString path(cx, args[0].toString());
+    UniqueChars path = JS_EncodeString(cx, args[0].toString());
     if (!path)
         return false;
 
@@ -665,7 +665,7 @@ ospath_join(JSContext* cx, unsigned argc, Value* vp)
             return false;
         }
 
-        JSAutoByteString path(cx, args[i].toString());
+        UniqueChars path = JS_EncodeString(cx, args[i].toString());
         if (!path)
             return false;
 
@@ -711,11 +711,11 @@ os_getenv(JSContext* cx, unsigned argc, Value* vp)
     RootedString key(cx, ToString(cx, args[0]));
     if (!key)
         return false;
-    JSAutoByteString keyBytes;
+    UniqueChars keyBytes = JS_EncodeStringToUTF8(cx, key);
-    if (!keyBytes.encodeUtf8(cx, key))
+    if (!keyBytes)
         return false;
 
-    if (const char* valueBytes = getenv(keyBytes.ptr())) {
+    if (const char* valueBytes = getenv(keyBytes.get())) {
         RootedString value(cx, JS_NewStringCopyZ(cx, valueBytes));
         if (!value)
             return false;
@@ -795,11 +795,11 @@ os_system(JSContext* cx, unsigned argc, Value* vp)
     if (!str)
         return false;
 
-    JSAutoByteString command(cx, str);
+    UniqueChars command = JS_EncodeString(cx, str);
     if (!command)
         return false;
 
-    int result = system(command.ptr());
+    int result = system(command.get());
     if (result == -1) {
         ReportSysError(cx, "system call failed");
         return false;
@@ -824,7 +824,7 @@ os_spawn(JSContext* cx, unsigned argc, Value* vp)
     if (!str)
         return false;
 
-    JSAutoByteString command(cx, str);
+    UniqueChars command = JS_EncodeString(cx, str);
     if (!command)
         return false;
 
@@ -842,7 +842,7 @@ os_spawn(JSContext* cx, unsigned argc, Value* vp)
     // We are in the child
 
     const char* cmd[] = {"sh", "-c", nullptr, nullptr};
-    cmd[2] = command.ptr();
+    cmd[2] = command.get();
 
     execvp("sh", (char * const*)cmd);
     exit(1);

js/src/shell/js.cpp

@@ -77,7 +77,7 @@
 #include "jit/JitcodeMap.h"
 #include "jit/JitRealm.h"
 #include "jit/shared/CodeGenerator-shared.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/CompilationAndEvaluation.h"
 #include "js/CompileOptions.h"
 #include "js/Debug.h"
@@ -1053,7 +1053,6 @@ BoundToAsyncStack(JSContext* cx, unsigned argc, Value* vp)
     RootedObject options(cx, &GetFunctionNativeReserved(&args.callee(), 1).toObject());
 
     RootedSavedFrame stack(cx, nullptr);
-    JSAutoByteString cause;
     bool isExplicit;
 
     RootedValue v(cx);
@@ -1069,7 +1068,13 @@ BoundToAsyncStack(JSContext* cx, unsigned argc, Value* vp)
     if (!JS_GetProperty(cx, options, "cause", &v))
         return false;
     RootedString causeString(cx, ToString(cx, v));
-    if (!causeString || !cause.encodeUtf8(cx, causeString)) {
+    if (!causeString) {
+        MOZ_ASSERT(cx->isExceptionPending());
+        return false;
+    }
+
+    UniqueChars cause = JS_EncodeStringToUTF8(cx, causeString);
+    if (!cause) {
         MOZ_ASSERT(cx->isExceptionPending());
         return false;
     }
@@ -1082,7 +1087,7 @@ BoundToAsyncStack(JSContext* cx, unsigned argc, Value* vp)
                  ? JS::AutoSetAsyncStackForNewCalls::AsyncCallKind::EXPLICIT
                  : JS::AutoSetAsyncStackForNewCalls::AsyncCallKind::IMPLICIT);
 
-    JS::AutoSetAsyncStackForNewCalls asasfnckthxbye(cx, stack, cause.ptr(), kind);
+    JS::AutoSetAsyncStackForNewCalls asasfnckthxbye(cx, stack, cause.get(), kind);
     return Call(cx, UndefinedHandleValue, function,
                 JS::HandleValueArray::empty(), args.rval());
 }
@@ -1176,11 +1181,10 @@ EvalAndPrint(JSContext* cx, const char* bytes, size_t length,
         if (!str)
             return false;
 
-        char* utf8chars = JS_EncodeStringToUTF8(cx, str);
+        UniqueChars utf8chars = JS_EncodeStringToUTF8(cx, str);
         if (!utf8chars)
             return false;
-        fprintf(gOutFile->fp, "%s\n", utf8chars);
+        fprintf(gOutFile->fp, "%s\n", utf8chars.get());
-        JS_free(cx, utf8chars);
     }
     return true;
 }
@@ -1360,7 +1364,7 @@ CreateMappedArrayBuffer(JSContext* cx, unsigned argc, Value* vp)
     JSString* filenameStr = ResolvePath(cx, rawFilenameStr, ScriptRelative);
     if (!filenameStr)
         return false;
-    JSAutoByteString filename(cx, filenameStr);
+    UniqueChars filename = JS_EncodeString(cx, filenameStr);
     if (!filename)
         return false;
 
@@ -1382,9 +1386,9 @@ CreateMappedArrayBuffer(JSContext* cx, unsigned argc, Value* vp)
         }
     }
 
-    FILE* file = fopen(filename.ptr(), "rb");
+    FILE* file = fopen(filename.get(), "rb");
     if (!file) {
-        ReportCantOpenErrorUnknownEncoding(cx, filename.ptr());
+        ReportCantOpenErrorUnknownEncoding(cx, filename.get());
         return false;
     }
     AutoCloseFile autoClose(file);
@@ -1470,13 +1474,13 @@ Options(JSContext* cx, unsigned argc, Value* vp)
             return false;
         args[i].setString(str);
 
-        JSAutoByteString opt;
+        UniqueChars opt = JS_EncodeStringToUTF8(cx, str);
-        if (!opt.encodeUtf8(cx, str))
+        if (!opt)
             return false;
 
-        if (strcmp(opt.ptr(), "strict") == 0) {
+        if (strcmp(opt.get(), "strict") == 0) {
             JS::ContextOptionsRef(cx).toggleExtraWarnings();
-        } else if (strcmp(opt.ptr(), "werror") == 0) {
+        } else if (strcmp(opt.get(), "werror") == 0) {
             // Disallow toggling werror when there are off-thread jobs, to avoid
             // confusing CompileError::throwError.
             ShellContext* sc = GetShellContext(cx);
@@ -1485,16 +1489,16 @@ Options(JSContext* cx, unsigned argc, Value* vp)
                 return false;
             }
             JS::ContextOptionsRef(cx).toggleWerror();
-        } else if (strcmp(opt.ptr(), "throw_on_asmjs_validation_failure") == 0) {
+        } else if (strcmp(opt.get(), "throw_on_asmjs_validation_failure") == 0) {
             JS::ContextOptionsRef(cx).toggleThrowOnAsmJSValidationFailure();
-        } else if (strcmp(opt.ptr(), "strict_mode") == 0) {
+        } else if (strcmp(opt.get(), "strict_mode") == 0) {
             JS::ContextOptionsRef(cx).toggleStrictMode();
         } else {
             JS_ReportErrorUTF8(cx,
                                "unknown option name '%s'."
                                " The valid names are strict,"
                                " werror, and strict_mode.",
-                               opt.ptr());
+                               opt.get());
             return false;
         }
     }
@@ -1547,7 +1551,7 @@ LoadScript(JSContext* cx, unsigned argc, Value* vp, bool scriptRelative)
             JS_ReportErrorASCII(cx, "unable to resolve path");
             return false;
         }
-        JSAutoByteString filename(cx, str);
+        UniqueChars filename = JS_EncodeString(cx, str);
         if (!filename)
             return false;
         errno = 0;
@@ -1558,8 +1562,8 @@ LoadScript(JSContext* cx, unsigned argc, Value* vp, bool scriptRelative)
             .setNoScriptRval(true);
         RootedScript script(cx);
         RootedValue unused(cx);
-        if ((compileOnly && !Compile(cx, opts, filename.ptr(), &script)) ||
+        if ((compileOnly && !Compile(cx, opts, filename.get(), &script)) ||
-            !Evaluate(cx, opts, filename.ptr(), &unused))
+            !Evaluate(cx, opts, filename.get(), &unused))
         {
             return false;
         }
@@ -1586,7 +1590,7 @@ LoadScriptRelativeToScript(JSContext* cx, unsigned argc, Value* vp)
 // bytes.
 static bool
 ParseCompileOptions(JSContext* cx, CompileOptions& options, HandleObject opts,
-                    JSAutoByteString& fileNameBytes)
+                    UniqueChars& fileNameBytes)
 {
     RootedValue v(cx);
     RootedString s(cx);
@@ -1609,7 +1613,8 @@ ParseCompileOptions(JSContext* cx, CompileOptions& options, HandleObject opts,
         s = ToString(cx, v);
         if (!s)
             return false;
-        char* fileName = fileNameBytes.encodeLatin1(cx, s);
+        fileNameBytes = JS_EncodeString(cx, s);
+        char* fileName = fileNameBytes.get();
         if (!fileName)
             return false;
         options.setFile(fileName);
@@ -1818,7 +1823,7 @@ Evaluate(JSContext* cx, unsigned argc, Value* vp)
     }
 
     CompileOptions options(cx);
-    JSAutoByteString fileNameBytes;
+    UniqueChars fileNameBytes;
     RootedString displayURL(cx);
     RootedString sourceMapURL(cx);
     RootedObject global(cx, nullptr);
@@ -2092,34 +2097,34 @@ Evaluate(JSContext* cx, unsigned argc, Value* vp)
 JSString*
 js::shell::FileAsString(JSContext* cx, JS::HandleString pathnameStr)
 {
-    JSAutoByteString pathname(cx, pathnameStr);
+    UniqueChars pathname = JS_EncodeString(cx, pathnameStr);
     if (!pathname)
         return nullptr;
 
     FILE* file;
 
-    file = fopen(pathname.ptr(), "rb");
+    file = fopen(pathname.get(), "rb");
     if (!file) {
-        ReportCantOpenErrorUnknownEncoding(cx, pathname.ptr());
+        ReportCantOpenErrorUnknownEncoding(cx, pathname.get());
         return nullptr;
     }
 
     AutoCloseFile autoClose(file);
 
     if (fseek(file, 0, SEEK_END) != 0) {
-        pathname.clear();
+        pathname = JS_EncodeStringToUTF8(cx, pathnameStr);
-        if (!pathname.encodeUtf8(cx, pathnameStr))
+        if (!pathname)
             return nullptr;
-        JS_ReportErrorUTF8(cx, "can't seek end of %s", pathname.ptr());
+        JS_ReportErrorUTF8(cx, "can't seek end of %s", pathname.get());
         return nullptr;
     }
 
     size_t len = ftell(file);
     if (fseek(file, 0, SEEK_SET) != 0) {
-        pathname.clear();
+        pathname = JS_EncodeStringToUTF8(cx, pathnameStr);
-        if (!pathname.encodeUtf8(cx, pathnameStr))
+        if (!pathname)
             return nullptr;
-        JS_ReportErrorUTF8(cx, "can't seek start of %s", pathname.ptr());
+        JS_ReportErrorUTF8(cx, "can't seek start of %s", pathname.get());
         return nullptr;
     }
 
@@ -2130,12 +2135,12 @@ js::shell::FileAsString(JSContext* cx, JS::HandleString pathnameStr)
     size_t cc = fread(buf.get(), 1, len, file);
     if (cc != len) {
         if (ptrdiff_t(cc) < 0) {
-            ReportCantOpenErrorUnknownEncoding(cx, pathname.ptr());
+            ReportCantOpenErrorUnknownEncoding(cx, pathname.get());
         } else {
-            pathname.clear();
+            pathname = JS_EncodeStringToUTF8(cx, pathnameStr);
-            if (!pathname.encodeUtf8(cx, pathnameStr))
+            if (!pathname)
                 return nullptr;
-            JS_ReportErrorUTF8(cx, "can't read %s: short read", pathname.ptr());
+            JS_ReportErrorUTF8(cx, "can't read %s: short read", pathname.get());
         }
         return nullptr;
     }
@@ -2144,10 +2149,10 @@ js::shell::FileAsString(JSContext* cx, JS::HandleString pathnameStr)
         JS::LossyUTF8CharsToNewTwoByteCharsZ(cx, JS::UTF8Chars(buf.get(), len), &len).get()
     );
     if (!ucbuf) {
-        pathname.clear();
+        pathname = JS_EncodeStringToUTF8(cx, pathnameStr);
-        if (!pathname.encodeUtf8(cx, pathnameStr))
+        if (!pathname)
             return nullptr;
-        JS_ReportErrorUTF8(cx, "Invalid UTF-8 in file '%s'", pathname.ptr());
+        JS_ReportErrorUTF8(cx, "Invalid UTF-8 in file '%s'", pathname.get());
         return nullptr;
     }
 
@@ -2188,13 +2193,13 @@ Run(JSContext* cx, unsigned argc, Value* vp)
     int64_t startClock = PRMJ_Now();
     {
         /* FIXME: This should use UTF-8 (bug 987069). */
-        JSAutoByteString filename(cx, str);
+        UniqueChars filename = JS_EncodeString(cx, str);
         if (!filename)
             return false;
 
         JS::CompileOptions options(cx);
         options.setIntroductionType("js shell run")
-               .setFileAndLine(filename.ptr(), 1)
+               .setFileAndLine(filename.get(), 1)
                .setIsRunOnce(true)
                .setNoScriptRval(true);
         if (!JS_CompileUCScript(cx, srcBuf, options, &script))
@@ -2340,7 +2345,7 @@ ReadLineBuf(JSContext* cx, unsigned argc, Value* vp)
         RootedString str(cx, JS::ToString(cx, args[0]));
         if (!str)
             return false;
-        sc->readLineBuf = UniqueChars(JS_EncodeStringToUTF8(cx, str));
+        sc->readLineBuf = JS_EncodeStringToUTF8(cx, str);
         if (!sc->readLineBuf)
             return false;
 
@@ -2366,11 +2371,10 @@ PutStr(JSContext* cx, unsigned argc, Value* vp)
         RootedString str(cx, JS::ToString(cx, args[0]));
         if (!str)
             return false;
-        char* bytes = JS_EncodeStringToUTF8(cx, str);
+        UniqueChars bytes = JS_EncodeStringToUTF8(cx, str);
         if (!bytes)
             return false;
-        fputs(bytes, gOutFile->fp);
+        fputs(bytes.get(), gOutFile->fp);
-        JS_free(cx, bytes);
         fflush(gOutFile->fp);
     }
 
@@ -2399,11 +2403,10 @@ PrintInternal(JSContext* cx, const CallArgs& args, RCFile* file)
         RootedString str(cx, JS::ToString(cx, args[i]));
         if (!str)
             return false;
-        char* bytes = JS_EncodeStringToUTF8(cx, str);
+        UniqueChars bytes = JS_EncodeStringToUTF8(cx, str);
         if (!bytes)
             return false;
-        fprintf(file->fp, "%s%s", i ? " " : "", bytes);
+        fprintf(file->fp, "%s%s", i ? " " : "", bytes.get());
-        JS_free(cx, bytes);
     }
 
     fputc('\n', file->fp);
@@ -2507,13 +2510,14 @@ StopTimingMutator(JSContext* cx, unsigned argc, Value* vp)
 }
 
 static const char*
-ToSource(JSContext* cx, MutableHandleValue vp, JSAutoByteString* bytes)
+ToSource(JSContext* cx, MutableHandleValue vp, UniqueChars* bytes)
 {
     JSString* str = JS_ValueToSource(cx, vp);
     if (str) {
         vp.setString(str);
-        if (bytes->encodeLatin1(cx, str))
+        *bytes = JS_EncodeString(cx, str);
-            return bytes->ptr();
+        if (*bytes)
+            return bytes->get();
     }
     JS_ClearPendingException(cx);
     return "<<error converting value to string>>";
@@ -2538,19 +2542,19 @@ AssertEq(JSContext* cx, unsigned argc, Value* vp)
     if (!JS_SameValue(cx, args[0], args[1], &same))
         return false;
     if (!same) {
-        JSAutoByteString bytes0, bytes1;
+        UniqueChars bytes0, bytes1;
         const char* actual = ToSource(cx, args[0], &bytes0);
         const char* expected = ToSource(cx, args[1], &bytes1);
         if (args.length() == 2) {
             JS_ReportErrorNumberLatin1(cx, my_GetErrorMessage, nullptr, JSSMSG_ASSERT_EQ_FAILED,
                                        actual, expected);
         } else {
-            JSAutoByteString bytes2(cx, args[2].toString());
+            UniqueChars bytes2 = JS_EncodeString(cx, args[2].toString());
             if (!bytes2)
                 return false;
             JS_ReportErrorNumberLatin1(cx, my_GetErrorMessage, nullptr,
                                        JSSMSG_ASSERT_EQ_FAILED_MSG,
-                                       actual, expected, bytes2.ptr());
+                                       actual, expected, bytes2.get());
         }
         return false;
     }
@@ -3148,7 +3152,7 @@ DisassFile(JSContext* cx, unsigned argc, Value* vp)
     JSString* str = JS::ToString(cx, HandleValue::fromMarkedLocation(&p.argv[0]));
     if (!str)
         return false;
-    JSAutoByteString filename(cx, str);
+    UniqueChars filename = JS_EncodeString(cx, str);
     if (!filename)
         return false;
     RootedScript script(cx);
@@ -3157,11 +3161,11 @@ DisassFile(JSContext* cx, unsigned argc, Value* vp)
         CompileOptions options(cx);
         options.setIntroductionType("js shell disFile")
                .setUTF8(true)
-               .setFileAndLine(filename.ptr(), 1)
+               .setFileAndLine(filename.get(), 1)
                .setIsRunOnce(true)
                .setNoScriptRval(true);
 
-        if (!JS::Compile(cx, options, filename.ptr(), &script))
+        if (!JS::Compile(cx, options, filename.get(), &script))
             return false;
     }
 
@@ -3368,7 +3372,7 @@ Crash(JSContext* cx, unsigned argc, Value* vp)
     RootedString message(cx, JS::ToString(cx, args[0]));
     if (!message)
         return false;
-    char* utf8chars = JS_EncodeStringToUTF8(cx, message);
+    UniqueChars utf8chars = JS_EncodeStringToUTF8(cx, message);
     if (!utf8chars)
         return false;
     if (args.get(1).isObject()) {
@@ -3380,9 +3384,9 @@ Crash(JSContext* cx, unsigned argc, Value* vp)
             js::NoteIntentionalCrash();
     }
 #ifndef DEBUG
-    MOZ_ReportCrash(utf8chars, __FILE__, __LINE__);
+    MOZ_ReportCrash(utf8chars.get(), __FILE__, __LINE__);
 #endif
-    MOZ_CRASH_UNSAFE_OOL(utf8chars);
+    MOZ_CRASH_UNSAFE_OOL(utf8chars.get());
 }
 
 static bool
@@ -4373,7 +4377,7 @@ ParseModule(JSContext* cx, unsigned argc, Value* vp)
         }
 
         RootedString str(cx, args[1].toString());
-        filename.reset(JS_EncodeString(cx, str));
+        filename = JS_EncodeString(cx, str);
         if (!filename)
             return false;
 
@@ -4756,7 +4760,7 @@ BinParse(JSContext* cx, unsigned argc, Value* vp)
             } else if (StringEqualsAscii(linearFormat, "simple")) {
                 useMultipart = false;
             } else {
-                JSAutoByteString printable;
+                UniqueChars printable;
                 JS_ReportErrorUTF8(cx,
                                    "Unknown value for option `format`, expected 'multipart' or "
                                    "'simple', got %s",
@@ -4983,7 +4987,7 @@ OffThreadCompileScript(JSContext* cx, unsigned argc, Value* vp)
         return false;
     }
 
-    JSAutoByteString fileNameBytes;
+    UniqueChars fileNameBytes;
     CompileOptions options(cx);
     options.setIntroductionType("js shell offThreadCompileScript")
            .setFileAndLine("<string>", 1);
@@ -5088,7 +5092,7 @@ OffThreadCompileModule(JSContext* cx, unsigned argc, Value* vp)
         return false;
     }
 
-    JSAutoByteString fileNameBytes;
+    UniqueChars fileNameBytes;
     CompileOptions options(cx);
     options.setIntroductionType("js shell offThreadCompileModule")
            .setFileAndLine("<string>", 1);
@@ -5192,7 +5196,7 @@ OffThreadDecodeScript(JSContext* cx, unsigned argc, Value* vp)
     }
     RootedObject cacheEntry(cx, &args[0].toObject());
 
-    JSAutoByteString fileNameBytes;
+    UniqueChars fileNameBytes;
     CompileOptions options(cx);
     options.setIntroductionType("js shell offThreadDecodeScript")
            .setFileAndLine("<string>", 1);
@@ -5421,7 +5425,7 @@ NestedShell(JSContext* cx, unsigned argc, Value* vp)
         if (!str)
             return false;
 
-        UniqueChars arg(JS_EncodeString(cx, str));
+        UniqueChars arg = JS_EncodeString(cx, str);
         if (!arg || !argv.append(std::move(arg)))
             return false;
 
@@ -6961,7 +6965,7 @@ class ShellAutoEntryMonitor : JS::dbg::AutoEntryMonitor {
 
         RootedString displayId(cx, JS_GetFunctionDisplayId(function));
         if (displayId) {
-            UniqueChars displayIdStr(JS_EncodeStringToUTF8(cx, displayId));
+            UniqueChars displayIdStr = JS_EncodeStringToUTF8(cx, displayId);
             if (!displayIdStr) {
                 // We report OOM in buildResult.
                 cx->recoverFromOutOfMemory();
@@ -7159,11 +7163,11 @@ SetARMHwCapFlags(JSContext* cx, unsigned argc, Value* vp)
         return false;
 
 #if defined(JS_CODEGEN_ARM)
-    JSAutoByteString flagsList(cx, flagsListString);
+    UniqueChars flagsList = JS_EncodeString(cx, flagsListString);
     if (!flagsList)
         return false;
 
-    jit::ParseARMHwCapFlags(flagsList.ptr());
+    jit::ParseARMHwCapFlags(flagsList.get());
 #endif
 
     args.rval().setUndefined();
@@ -8197,7 +8201,7 @@ PrintStackTrace(JSContext* cx, HandleValue exn)
     if (!BuildStackString(cx, principals, stackObj, &stackStr, 2))
         return false;
 
-    UniqueChars stack(JS_EncodeStringToUTF8(cx, stackStr));
+    UniqueChars stack = JS_EncodeStringToUTF8(cx, stackStr);
     if (!stack)
         return false;
 
@@ -9056,7 +9060,7 @@ ProcessArgs(JSContext* cx, OptionParser* op)
         if (!absolutePath)
             return false;
 
-        sc->moduleLoadPath = UniqueChars(JS_EncodeString(cx, absolutePath));
+        sc->moduleLoadPath = JS_EncodeString(cx, absolutePath);
     } else {
         sc->moduleLoadPath = js::shell::GetCWD();
     }

js/src/vm/BytecodeUtil.cpp

@@ -32,7 +32,6 @@
 #include "frontend/SourceNotes.h"
 #include "gc/FreeOp.h"
 #include "gc/GCInternals.h"
-#include "js/AutoByteString.h"
 #include "js/CharacterEncoding.h"
 #include "js/Printf.h"
 #include "util/StringBuffer.h"
@@ -1132,7 +1131,7 @@ js::DumpScript(JSContext* cx, JSScript* scriptArg, FILE* fp)
 }
 
 static bool
-ToDisassemblySource(JSContext* cx, HandleValue v, JSAutoByteString* bytes)
+ToDisassemblySource(JSContext* cx, HandleValue v, UniqueChars* bytes)
 {
     if (v.isString()) {
         Sprinter sprinter(cx);
@@ -1146,7 +1145,7 @@ ToDisassemblySource(JSContext* cx, HandleValue v, JSAutoByteString* bytes)
             ReportOutOfMemory(cx);
             return false;
         }
-        bytes->initBytes(std::move(copy));
+        *bytes = std::move(copy);
         return true;
     }
 
@@ -1156,7 +1155,7 @@ ToDisassemblySource(JSContext* cx, HandleValue v, JSAutoByteString* bytes)
             ReportOutOfMemory(cx);
             return false;
         }
-        bytes->initBytes(std::move(source));
+        *bytes = std::move(source);
         return true;
     }
 
@@ -1168,14 +1167,16 @@ ToDisassemblySource(JSContext* cx, HandleValue v, JSAutoByteString* bytes)
             JSString* str = JS_DecompileFunction(cx, fun);
             if (!str)
                 return false;
-            return bytes->encodeLatin1(cx, str);
+            *bytes = JS_EncodeString(cx, str);
+            return !!*bytes;
         }
 
         if (obj.is<RegExpObject>()) {
             JSString* source = obj.as<RegExpObject>().toString(cx);
             if (!source)
                 return false;
-            return bytes->encodeLatin1(cx, source);
+            *bytes = JS_EncodeString(cx, source);
+            return !!*bytes;
         }
     }
 
@@ -1183,7 +1184,7 @@ ToDisassemblySource(JSContext* cx, HandleValue v, JSAutoByteString* bytes)
 }
 
 static bool
-ToDisassemblySource(JSContext* cx, HandleScope scope, JSAutoByteString* bytes)
+ToDisassemblySource(JSContext* cx, HandleScope scope, UniqueChars* bytes)
 {
     UniqueChars source = JS_smprintf("%s {", ScopeKindString(scope->kind()));
     if (!source) {
@@ -1192,11 +1193,11 @@ ToDisassemblySource(JSContext* cx, HandleScope scope, JSAutoByteString* bytes)
     }
 
     for (Rooted<BindingIter> bi(cx, BindingIter(scope)); bi; bi++) {
-        JSAutoByteString nameBytes;
+        UniqueChars nameBytes;
         if (!AtomToPrintableString(cx, bi.name(), &nameBytes))
             return false;
 
-        source = JS_sprintf_append(std::move(source), "%s: ", nameBytes.ptr());
+        source = JS_sprintf_append(std::move(source), "%s: ", nameBytes.get());
         if (!source) {
             ReportOutOfMemory(cx);
             return false;
@@ -1249,7 +1250,7 @@ ToDisassemblySource(JSContext* cx, HandleScope scope, JSAutoByteString* bytes)
         return false;
     }
 
-    bytes->initBytes(std::move(source));
+    *bytes = std::move(source);
     return true;
 }
 
@@ -1421,10 +1422,10 @@ Disassemble1(JSContext* cx, HandleScript script, jsbytecode* pc,
 
       case JOF_SCOPE: {
         RootedScope scope(cx, script->getScope(GET_UINT32_INDEX(pc)));
-        JSAutoByteString bytes;
+        UniqueChars bytes;
         if (!ToDisassemblySource(cx, scope, &bytes))
             return 0;
-        if (!sp->jsprintf(" %s", bytes.ptr()))
+        if (!sp->jsprintf(" %s", bytes.get()))
             return 0;
         break;
       }
@@ -1432,31 +1433,31 @@ Disassemble1(JSContext* cx, HandleScript script, jsbytecode* pc,
       case JOF_ENVCOORD: {
         RootedValue v(cx,
             StringValue(EnvironmentCoordinateName(cx->caches().envCoordinateNameCache, script, pc)));
-        JSAutoByteString bytes;
+        UniqueChars bytes;
         if (!ToDisassemblySource(cx, v, &bytes))
             return 0;
         EnvironmentCoordinate ec(pc);
-        if (!sp->jsprintf(" %s (hops = %u, slot = %u)", bytes.ptr(), ec.hops(), ec.slot()))
+        if (!sp->jsprintf(" %s (hops = %u, slot = %u)", bytes.get(), ec.hops(), ec.slot()))
             return 0;
         break;
       }
 
       case JOF_ATOM: {
         RootedValue v(cx, StringValue(script->getAtom(GET_UINT32_INDEX(pc))));
-        JSAutoByteString bytes;
+        UniqueChars bytes;
         if (!ToDisassemblySource(cx, v, &bytes))
             return 0;
-        if (!sp->jsprintf(" %s", bytes.ptr()))
+        if (!sp->jsprintf(" %s", bytes.get()))
             return 0;
         break;
       }
 
       case JOF_DOUBLE: {
         RootedValue v(cx, script->getConst(GET_UINT32_INDEX(pc)));
-        JSAutoByteString bytes;
+        UniqueChars bytes;
         if (!ToDisassemblySource(cx, v, &bytes))
             return 0;
-        if (!sp->jsprintf(" %s", bytes.ptr()))
+        if (!sp->jsprintf(" %s", bytes.get()))
             return 0;
         break;
       }
@@ -1471,11 +1472,11 @@ Disassemble1(JSContext* cx, HandleScript script, jsbytecode* pc,
 
         JSObject* obj = script->getObject(GET_UINT32_INDEX(pc));
         {
-            JSAutoByteString bytes;
+            UniqueChars bytes;
             RootedValue v(cx, ObjectValue(*obj));
             if (!ToDisassemblySource(cx, v, &bytes))
                 return 0;
-            if (!sp->jsprintf(" %s", bytes.ptr()))
+            if (!sp->jsprintf(" %s", bytes.get()))
                 return 0;
         }
         break;
@@ -1483,11 +1484,11 @@ Disassemble1(JSContext* cx, HandleScript script, jsbytecode* pc,
 
       case JOF_REGEXP: {
         js::RegExpObject* obj = script->getRegExp(pc);
-        JSAutoByteString bytes;
+        UniqueChars bytes;
         RootedValue v(cx, ObjectValue(*obj));
         if (!ToDisassemblySource(cx, v, &bytes))
             return 0;
-        if (!sp->jsprintf(" %s", bytes.ptr()))
+        if (!sp->jsprintf(" %s", bytes.get()))
             return 0;
         break;
       }
@@ -2317,7 +2318,7 @@ js::DecompileValueGenerator(JSContext* cx, int spindex, HandleValue v,
             return nullptr;
     }
 
-    return UniqueChars(JS_EncodeString(cx, fallback));
+    return JS_EncodeString(cx, fallback);
 }
 
 static bool
@@ -2407,7 +2408,7 @@ js::DecompileArgument(JSContext* cx, int formalIndex, HandleValue v)
     if (!fallback)
         return nullptr;
 
-    return UniqueChars(JS_EncodeString(cx, fallback));
+    return JS_EncodeString(cx, fallback);
 }
 
 extern bool

js/src/vm/Debugger.cpp

@@ -25,7 +25,7 @@
 #include "gc/PublicIterators.h"
 #include "jit/BaselineDebugModeOSR.h"
 #include "jit/BaselineJIT.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/Date.h"
 #include "js/SourceBufferHolder.h"
 #include "js/StableStringChars.h"
@@ -486,10 +486,10 @@ ParseEvalOptions(JSContext* cx, HandleValue value, EvalOptions& options)
         RootedString url_str(cx, ToString<CanGC>(cx, v));
         if (!url_str)
             return false;
-        JSAutoByteString url_bytes(cx, url_str);
+        UniqueChars url_bytes = JS_EncodeString(cx, url_str);
         if (!url_bytes)
             return false;
-        if (!options.setFilename(cx, url_bytes.ptr()))
+        if (!options.setFilename(cx, url_bytes.get()))
             return false;
     }
 
@@ -4481,7 +4481,7 @@ class MOZ_STACK_CLASS Debugger::ScriptQuery
     RootedValue url;
 
     /* url as a C string. */
-    JSAutoByteString urlCString;
+    UniqueChars urlCString;
 
     /* If this is a string, matching scripts' sources have displayURLs equal to
      * it. */
@@ -4567,7 +4567,8 @@ class MOZ_STACK_CLASS Debugger::ScriptQuery
         // Compute urlCString and displayURLChars, if a url or displayURL was
         // given respectively.
         if (url.isString()) {
-            if (!urlCString.encodeLatin1(cx, url.toString()))
+            urlCString = JS_EncodeString(cx, url.toString());
+            if (!urlCString)
                 return false;
         }
 
@@ -4608,14 +4609,14 @@ class MOZ_STACK_CLASS Debugger::ScriptQuery
 
     template <typename T>
     MOZ_MUST_USE bool commonFilter(T script, const JS::AutoRequireNoGC& nogc) {
-        if (urlCString.ptr()) {
+        if (urlCString) {
             bool gotFilename = false;
-            if (script->filename() && strcmp(script->filename(), urlCString.ptr()) == 0)
+            if (script->filename() && strcmp(script->filename(), urlCString.get()) == 0)
                 gotFilename = true;
 
             bool gotSourceURL = false;
             if (!gotFilename && script->scriptSource()->introducerFilename() &&
-                strcmp(script->scriptSource()->introducerFilename(), urlCString.ptr()) == 0)
+                strcmp(script->scriptSource()->introducerFilename(), urlCString.get()) == 0)
             {
                 gotSourceURL = true;
             }
@@ -4920,7 +4921,7 @@ class MOZ_STACK_CLASS Debugger::ObjectQuery
 
         if (!className.isUndefined()) {
             const char* objClassName = obj->getClass()->name;
-            if (strcmp(objClassName, classNameCString.ptr()) != 0)
+            if (strcmp(objClassName, classNameCString.get()) != 0)
                 return true;
         }
 
@@ -4941,7 +4942,7 @@ class MOZ_STACK_CLASS Debugger::ObjectQuery
     RootedValue className;
 
     /* The className member, as a C string. */
-    JSAutoByteString classNameCString;
+    UniqueChars classNameCString;
 
     /*
      * Given that either omittedQuery or parseQuery has been called, prepare the
@@ -4949,7 +4950,8 @@ class MOZ_STACK_CLASS Debugger::ObjectQuery
      */
     bool prepareQuery() {
         if (className.isString()) {
-            if (!classNameCString.encodeLatin1(cx, className.toString()))
+            classNameCString = JS_EncodeString(cx, className.toString());
+            if (!classNameCString)
                 return false;
         }
 

js/src/vm/EnvironmentObject.cpp

@@ -8,7 +8,6 @@
 
 #include "builtin/ModuleObject.h"
 #include "gc/Policy.h"
-#include "js/AutoByteString.h"
 #include "vm/ArgumentsObject.h"
 #include "vm/AsyncFunction.h"
 #include "vm/GlobalObject.h"
@@ -1415,10 +1414,10 @@ namespace {
 static void
 ReportOptimizedOut(JSContext* cx, HandleId id)
 {
-    JSAutoByteString printable;
+    UniqueChars printable;
     if (ValueToPrintableLatin1(cx, IdToValue(id), &printable)) {
         JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_DEBUG_OPTIMIZED_OUT,
-                                   printable.ptr());
+                                   printable.get());
     }
 }
 
@@ -3359,11 +3358,11 @@ js::CheckVarNameConflict(JSContext* cx, Handle<LexicalEnvironmentObject*> lexica
 static void
 ReportCannotDeclareGlobalBinding(JSContext* cx, HandlePropertyName name, const char* reason)
 {
-    JSAutoByteString printable;
+    UniqueChars printable;
     if (AtomToPrintableString(cx, name, &printable)) {
         JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr,
                                    JSMSG_CANT_DECLARE_GLOBAL_BINDING,
-                                   printable.ptr(), reason);
+                                   printable.get(), reason);
     }
 }
 

js/src/vm/ErrorObject.cpp

@@ -13,7 +13,6 @@
 
 #include "jsexn.h"
 
-#include "js/AutoByteString.h"
 #include "js/CallArgs.h"
 #include "js/CharacterEncoding.h"
 #include "vm/GlobalObject.h"
@@ -146,10 +145,10 @@ js::ErrorObject::getOrCreateErrorReport(JSContext* cx)
     report.exnType = type_;
 
     // Filename.
-    JSAutoByteString filenameStr;
+    UniqueChars filenameStr = JS_EncodeString(cx, fileName(cx));
-    if (!filenameStr.encodeLatin1(cx, fileName(cx)))
+    if (!filenameStr)
         return nullptr;
-    report.filename = filenameStr.ptr();
+    report.filename = filenameStr.get();
 
     // Coordinates.
     report.lineno = lineNumber();

js/src/vm/Interpreter.cpp

@@ -31,7 +31,7 @@
 #include "jit/Ion.h"
 #include "jit/IonAnalysis.h"
 #include "jit/Jit.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "util/StringBuffer.h"
 #include "vm/AsyncFunction.h"
 #include "vm/AsyncIteration.h"
@@ -1861,7 +1861,7 @@ js::ReportInNotObjectError(JSContext* cx, HandleValue lref, int lindex,
             if (!str)
                 return nullptr;
         }
-        return UniqueChars(JS_EncodeString(cx, str));
+        return JS_EncodeString(cx, str);
     };
 
     if (lref.isString() && rref.isString()) {
@@ -5339,9 +5339,9 @@ js::ReportRuntimeLexicalError(JSContext* cx, unsigned errorNumber, HandleId id)
 {
     MOZ_ASSERT(errorNumber == JSMSG_UNINITIALIZED_LEXICAL ||
                errorNumber == JSMSG_BAD_CONST_ASSIGN);
-    JSAutoByteString printable;
+    UniqueChars printable;
     if (ValueToPrintableLatin1(cx, IdToValue(id), &printable))
-        JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, errorNumber, printable.ptr());
+        JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, errorNumber, printable.get());
 }
 
 void
@@ -5382,10 +5382,10 @@ js::ReportRuntimeLexicalError(JSContext* cx, unsigned errorNumber,
 void
 js::ReportRuntimeRedeclaration(JSContext* cx, HandlePropertyName name, const char* redeclKind)
 {
-    JSAutoByteString printable;
+    UniqueChars printable;
     if (AtomToPrintableString(cx, name, &printable)) {
         JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_REDECLARED_VAR,
-                                   redeclKind, printable.ptr());
+                                   redeclKind, printable.get());
     }
 }
 
@@ -5461,11 +5461,11 @@ js::ThrowUninitializedThis(JSContext* cx, AbstractFramePtr frame)
 
     if (fun->isDerivedClassConstructor()) {
         const char* name = "anonymous";
-        JSAutoByteString str;
+        UniqueChars str;
         if (fun->explicitName()) {
             if (!AtomToPrintableString(cx, fun->explicitName(), &str))
                 return false;
-            name = str.ptr();
+            name = str.get();
         }
 
         JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_UNINITIALIZED_THIS, name);

js/src/vm/JSAtom.cpp

@@ -21,7 +21,7 @@
 
 #include "builtin/String.h"
 #include "gc/Marking.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "util/Text.h"
 #include "vm/JSContext.h"
 #include "vm/SymbolType.h"
@@ -117,13 +117,13 @@ js::AtomStateEntry::asPtr(JSContext* cx) const
 }
 
 const char*
-js::AtomToPrintableString(JSContext* cx, JSAtom* atom, JSAutoByteString* bytes)
+js::AtomToPrintableString(JSContext* cx, JSAtom* atom, UniqueChars* bytes)
 {
     JSString* str = QuoteString(cx, atom, 0);
     if (!str)
         return nullptr;
-    bytes->initBytes(EncodeLatin1(cx, str));
+    *bytes = EncodeLatin1(cx, str);
-    return bytes->ptr();
+    return bytes->get();
 }
 
 #define DEFINE_PROTO_STRING(name,init,clasp) const char js_##name##_str[] = #name;

js/src/vm/JSAtom.h

@@ -11,10 +11,9 @@
 
 #include "gc/Rooting.h"
 #include "js/TypeDecls.h"
+#include "js/Utility.h"
 #include "vm/CommonPropertyNames.h"
 
-class JSAutoByteString;
-
 namespace js {
 
 /*
@@ -22,7 +21,7 @@ namespace js {
  * The lifetime of the result matches the lifetime of bytes.
  */
 extern const char*
-AtomToPrintableString(JSContext* cx, JSAtom* atom, JSAutoByteString* bytes);
+AtomToPrintableString(JSContext* cx, JSAtom* atom, UniqueChars* bytes);
 
 class PropertyName;
 

js/src/vm/JSContext.cpp

@@ -37,7 +37,6 @@
 #include "gc/Marking.h"
 #include "jit/Ion.h"
 #include "jit/PcScriptCache.h"
-#include "js/AutoByteString.h"
 #include "js/CharacterEncoding.h"
 #include "js/Printf.h"
 #ifdef JS_SIMULATOR_ARM64
@@ -442,10 +441,10 @@ js::ReportUsageErrorASCII(JSContext* cx, HandleObject callee, const char* msg)
         JS_ReportErrorASCII(cx, "%s", msg);
     } else {
         RootedString usageStr(cx, usage.toString());
-        JSAutoByteString str;
+        UniqueChars str = JS_EncodeStringToUTF8(cx, usageStr);
-        if (!str.encodeUtf8(cx, usageStr))
+        if (!str)
             return;
-        JS_ReportErrorUTF8(cx, "%s. Usage: %s", msg, str.ptr());
+        JS_ReportErrorUTF8(cx, "%s. Usage: %s", msg, str.get());
     }
 }
 
@@ -893,10 +892,10 @@ js::ReportErrorNumberUCArray(JSContext* cx, unsigned flags, JSErrorCallback call
 void
 js::ReportIsNotDefined(JSContext* cx, HandleId id)
 {
-    JSAutoByteString printable;
+    UniqueChars printable;
     if (!ValueToPrintableUTF8(cx, IdToValue(id), &printable))
         return;
-    JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr, JSMSG_NOT_DEFINED, printable.ptr());
+    JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr, JSMSG_NOT_DEFINED, printable.get());
 }
 
 void
@@ -934,15 +933,15 @@ js::ReportIsNullOrUndefinedForPropertyAccess(JSContext* cx, HandleValue v, bool
     }
 }
 
-char*
+static UniqueChars
-EncodeIdAsLatin1(JSContext* cx, HandleId id, JSAutoByteString& bytes)
+EncodeIdAsLatin1(JSContext* cx, HandleId id)
 {
     RootedValue idVal(cx, IdToValue(id));
-    RootedString idStr(cx, ValueToSource(cx, idVal));
+    JSString* idStr = ValueToSource(cx, idVal);
     if (!idStr)
         return nullptr;
 
-    return bytes.encodeLatin1(cx, idStr);
+    return EncodeLatin1(cx, idStr);
 }
 
 void
@@ -951,13 +950,13 @@ js::ReportIsNullOrUndefinedForPropertyAccess(JSContext* cx, HandleValue v, Handl
 {
     MOZ_ASSERT(v.isNullOrUndefined());
 
-    JSAutoByteString keyBytes;
+    UniqueChars keyBytes = EncodeIdAsLatin1(cx, key);
-    if (!EncodeIdAsLatin1(cx, key, keyBytes))
+    if (!keyBytes)
         return;
 
     if (!reportScanStack) {
         JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_PROPERTY_FAIL,
-                                   keyBytes.ptr(),
+                                   keyBytes.get(),
                                    v.isUndefined() ? js_undefined_str : js_null_str);
         return;
     }
@@ -968,14 +967,14 @@ js::ReportIsNullOrUndefinedForPropertyAccess(JSContext* cx, HandleValue v, Handl
 
     if (strcmp(bytes.get(), js_undefined_str) == 0 || strcmp(bytes.get(), js_null_str) == 0) {
         JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_PROPERTY_FAIL,
-                                   keyBytes.ptr(), bytes.get());
+                                   keyBytes.get(), bytes.get());
     } else if (v.isUndefined()) {
         JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_PROPERTY_FAIL_EXPR,
-                                   bytes.get(), js_undefined_str, keyBytes.ptr());
+                                   bytes.get(), js_undefined_str, keyBytes.get());
     } else {
         MOZ_ASSERT(v.isNull());
         JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_PROPERTY_FAIL_EXPR,
-                                   bytes.get(), js_null_str, keyBytes.ptr());
+                                   bytes.get(), js_null_str, keyBytes.get());
     }
 }
 

js/src/vm/JSFunction-inl.h

@@ -11,19 +11,20 @@
 
 #include "gc/Allocator.h"
 #include "gc/GCTrace.h"
+#include "js/CharacterEncoding.h"
 #include "vm/EnvironmentObject.h"
 
 #include "vm/JSObject-inl.h"
 
-class JSAutoByteString;
-
 namespace js {
 
 inline const char*
-GetFunctionNameBytes(JSContext* cx, JSFunction* fun, JSAutoByteString* bytes)
+GetFunctionNameBytes(JSContext* cx, JSFunction* fun, UniqueChars* bytes)
 {
-    if (JSAtom* name = fun->explicitName())
+    if (JSAtom* name = fun->explicitName()) {
-        return bytes->encodeLatin1(cx, name);
+        *bytes = JS_EncodeString(cx, name);
+        return bytes->get();
+    }
     return js_anonymous_str;
 }
 

js/src/vm/JSFunction.cpp

@@ -31,7 +31,6 @@
 #include "gc/Policy.h"
 #include "jit/InlinableNatives.h"
 #include "jit/Ion.h"
-#include "js/AutoByteString.h"
 #include "js/CallNonGenericMethod.h"
 #include "js/CompileOptions.h"
 #include "js/Proxy.h"
@@ -2499,7 +2498,7 @@ js::ReportIncompatibleMethod(JSContext* cx, const CallArgs& args, const Class* c
 #endif
 
     if (JSFunction* fun = ReportIfNotFunction(cx, args.calleev())) {
-        JSAutoByteString funNameBytes;
+        UniqueChars funNameBytes;
         if (const char* funName = GetFunctionNameBytes(cx, fun, &funNameBytes)) {
             JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_INCOMPATIBLE_PROTO,
                                        clasp->name, funName, InformalValueTypeName(thisv));
@@ -2511,7 +2510,7 @@ void
 js::ReportIncompatible(JSContext* cx, const CallArgs& args)
 {
     if (JSFunction* fun = ReportIfNotFunction(cx, args.calleev())) {
-        JSAutoByteString funNameBytes;
+        UniqueChars funNameBytes;
         if (const char* funName = GetFunctionNameBytes(cx, fun, &funNameBytes)) {
             JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_INCOMPATIBLE_METHOD,
                                        funName, "method", InformalValueTypeName(args.thisv()));

js/src/vm/JSObject.cpp

@@ -35,7 +35,7 @@
 #include "frontend/BytecodeCompiler.h"
 #include "gc/Policy.h"
 #include "jit/BaselineJIT.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/MemoryMetrics.h"
 #include "js/Proxy.h"
 #include "js/UbiNode.h"
@@ -95,7 +95,7 @@ js::ReportNotObjectArg(JSContext* cx, const char* nth, const char* fun, HandleVa
 {
     MOZ_ASSERT(!v.isObject());
 
-    JSAutoByteString bytes;
+    UniqueChars bytes;
     if (const char* chars = ValueToSourceForError(cx, v, bytes)) {
         JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_NOT_NONNULL_OBJECT_ARG,
                                    nth, fun, chars);
@@ -107,7 +107,7 @@ js::ReportNotObjectWithName(JSContext* cx, const char* name, HandleValue v)
 {
     MOZ_ASSERT(!v.isObject());
 
-    JSAutoByteString bytes;
+    UniqueChars bytes;
     if (const char* chars = ValueToSourceForError(cx, v, bytes)) {
         JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_NOT_NONNULL_OBJECT_NAME,
                                    name, chars);
@@ -261,15 +261,15 @@ js::Throw(JSContext* cx, jsid id, unsigned errorNumber, const char* details)
     JSString* idstr = ValueToSource(cx, idVal);
     if (!idstr)
        return false;
-    JSAutoByteString bytes(cx, idstr);
+    UniqueChars bytes = JS_EncodeString(cx, idstr);
     if (!bytes)
         return false;
 
     if (details) {
-        JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, errorNumber, bytes.ptr(),
+        JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, errorNumber, bytes.get(),
                                    details);
     } else {
-        JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, errorNumber, bytes.ptr());
+        JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, errorNumber, bytes.get());
     }
 
     return false;

js/src/vm/NativeObject.cpp

@@ -12,7 +12,7 @@
 #include "mozilla/DebugOnly.h"
 
 #include "gc/Marking.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/Value.h"
 #include "vm/Debugger.h"
 #include "vm/TypedArrayObject.h"
@@ -2475,11 +2475,11 @@ MaybeReportUndeclaredVarAssignment(JSContext* cx, HandleString propname)
             return true;
     }
 
-    JSAutoByteString bytes;
+    UniqueChars bytes = JS_EncodeStringToUTF8(cx, propname);
-    if (!bytes.encodeUtf8(cx, propname))
+    if (!bytes)
         return false;
     return JS_ReportErrorFlagsAndNumberUTF8(cx, flags, GetErrorMessage, nullptr,
-                                            JSMSG_UNDECLARED_VAR, bytes.ptr());
+                                            JSMSG_UNDECLARED_VAR, bytes.get());
 }
 
 /*

js/src/vm/Probes.cpp

@@ -6,7 +6,7 @@
 
 #include "vm/Probes-inl.h"
 
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "vm/JSContext.h"
 
 #ifdef INCLUDE_MOZILLA_DTRACE
@@ -34,13 +34,14 @@ ScriptFilename(const JSScript* script)
 }
 
 static const char*
-FunctionName(JSContext* cx, JSFunction* fun, JSAutoByteString* bytes)
+FunctionName(JSContext* cx, JSFunction* fun, UniqueChars* bytes)
 {
     if (!fun)
         return probes::nullName;
     if (!fun->displayAtom())
         return probes::anonymousName;
-    return bytes->encodeLatin1(cx, fun->displayAtom()) ? bytes->ptr() : probes::nullName;
+    *bytes = JS_EncodeString(cx, fun->displayAtom());
+    return *bytes ? bytes->get() : probes::nullName;
 }
 
 /*
@@ -53,7 +54,7 @@ FunctionName(JSContext* cx, JSFunction* fun, JSAutoByteString* bytes)
 void
 probes::DTraceEnterJSFun(JSContext* cx, JSFunction* fun, JSScript* script)
 {
-    JSAutoByteString funNameBytes;
+    UniqueChars funNameBytes;
     JAVASCRIPT_FUNCTION_ENTRY(ScriptFilename(script), probes::nullName,
                               FunctionName(cx, fun, &funNameBytes));
 }
@@ -61,7 +62,7 @@ probes::DTraceEnterJSFun(JSContext* cx, JSFunction* fun, JSScript* script)
 void
 probes::DTraceExitJSFun(JSContext* cx, JSFunction* fun, JSScript* script)
 {
-    JSAutoByteString funNameBytes;
+    UniqueChars funNameBytes;
     JAVASCRIPT_FUNCTION_RETURN(ScriptFilename(script), probes::nullName,
                                FunctionName(cx, fun, &funNameBytes));
 }

js/src/vm/SavedStacks.cpp

@@ -1820,15 +1820,14 @@ const SavedStacks::MetadataBuilder SavedStacks::metadataBuilder;
 /* static */ ReconstructedSavedFramePrincipals ReconstructedSavedFramePrincipals::IsSystem;
 /* static */ ReconstructedSavedFramePrincipals ReconstructedSavedFramePrincipals::IsNotSystem;
 
-UTF8CharsZ
+UniqueChars
 BuildUTF8StackString(JSContext* cx, JSPrincipals* principals, HandleObject stack)
 {
     RootedString stackStr(cx);
     if (!JS::BuildStackString(cx, principals, stack, &stackStr))
-        return UTF8CharsZ();
+        return nullptr;
 
-    char* chars = JS_EncodeStringToUTF8(cx, stackStr);
+    return JS_EncodeStringToUTF8(cx, stackStr);
-    return UTF8CharsZ(chars, strlen(chars));
 }
 
 uint32_t

js/src/vm/SavedStacks.h

@@ -320,7 +320,7 @@ struct MutableWrappedPtrOperations<SavedStacks::LocationValue, Wrapper>
     }
 };
 
-UTF8CharsZ
+JS::UniqueChars
 BuildUTF8StackString(JSContext* cx, JSPrincipals* principals, HandleObject stack);
 
 uint32_t

js/src/vm/Scope.cpp

@@ -14,7 +14,6 @@
 #include "builtin/ModuleObject.h"
 #include "gc/Allocator.h"
 #include "gc/FreeOp.h"
-#include "js/AutoByteString.h"
 #include "util/StringBuffer.h"
 #include "vm/EnvironmentObject.h"
 #include "vm/JSScript.h"
@@ -1520,10 +1519,10 @@ js::DumpBindings(JSContext* cx, Scope* scopeArg)
 {
     RootedScope scope(cx, scopeArg);
     for (Rooted<BindingIter> bi(cx, BindingIter(scope)); bi; bi++) {
-        JSAutoByteString bytes;
+        UniqueChars bytes;
         if (!AtomToPrintableString(cx, bi.name(), &bytes))
             return;
-        fprintf(stderr, "%s %s ", BindingKindString(bi.kind()), bytes.ptr());
+        fprintf(stderr, "%s %s ", BindingKindString(bi.kind()), bytes.get());
         switch (bi.location().kind()) {
           case BindingLocation::Kind::Global:
             if (bi.isTopLevelFunction())

js/src/vm/SelfHosting.cpp

@@ -38,7 +38,6 @@
 #include "gc/Policy.h"
 #include "jit/AtomicOperations.h"
 #include "jit/InlinableNatives.h"
-#include "js/AutoByteString.h"
 #include "js/CharacterEncoding.h"
 #include "js/CompilationAndEvaluation.h"
 #include "js/Date.h"
@@ -293,28 +292,28 @@ ThrowErrorWithType(JSContext* cx, JSExnType type, const CallArgs& args)
     MOZ_ASSERT(efs->exnType == type, "error-throwing intrinsic and error number are inconsistent");
 #endif
 
-    JSAutoByteString errorArgs[3];
+    UniqueChars errorArgs[3];
     for (unsigned i = 1; i < 4 && i < args.length(); i++) {
         RootedValue val(cx, args[i]);
         if (val.isInt32()) {
             JSString* str = ToString<CanGC>(cx, val);
             if (!str)
                 return;
-            errorArgs[i - 1].encodeLatin1(cx, str);
+            errorArgs[i - 1] = JS_EncodeString(cx, str);
         } else if (val.isString()) {
-            errorArgs[i - 1].encodeLatin1(cx, val.toString());
+            errorArgs[i - 1] = JS_EncodeString(cx, val.toString());
         } else {
             UniqueChars bytes = DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, val, nullptr);
             if (!bytes)
                 return;
-            errorArgs[i - 1].initBytes(std::move(bytes));
+            errorArgs[i - 1] = std::move(bytes);
         }
         if (!errorArgs[i - 1])
             return;
     }
 
     JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, errorNumber,
-                               errorArgs[0].ptr(), errorArgs[1].ptr(), errorArgs[2].ptr());
+                               errorArgs[0].get(), errorArgs[1].get(), errorArgs[2].get());
 }
 
 static bool
@@ -1869,7 +1868,7 @@ js::ReportIncompatibleSelfHostedMethod(JSContext* cx, const CallArgs& args)
     while (!iter.done()) {
         MOZ_ASSERT(iter.callee(cx)->isSelfHostedOrIntrinsic() &&
                    !iter.callee(cx)->isBoundFunction());
-        JSAutoByteString funNameBytes;
+        UniqueChars funNameBytes;
         const char* funName = GetFunctionNameBytes(cx, iter.callee(cx), &funNameBytes);
         if (!funName)
             return false;

js/src/vm/StringType.cpp

@@ -20,7 +20,7 @@
 #include "gc/GCInternals.h"
 #include "gc/Marking.h"
 #include "gc/Nursery.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/StableStringChars.h"
 #include "js/UbiNode.h"
 #include "util/StringBuffer.h"
@@ -2063,7 +2063,7 @@ js::EncodeLatin1(JSContext* cx, JSString* str)
 }
 
 const char*
-js::ValueToPrintableLatin1(JSContext* cx, const Value& vArg, JSAutoByteString* bytes,
+js::ValueToPrintableLatin1(JSContext* cx, const Value& vArg, UniqueChars* bytes,
                            bool asSource)
 {
     RootedValue v(cx, vArg);
@@ -2077,11 +2077,12 @@ js::ValueToPrintableLatin1(JSContext* cx, const Value& vArg, JSAutoByteString* b
     str = QuoteString(cx, str, 0);
     if (!str)
         return nullptr;
-    return bytes->encodeLatin1(cx, str);
+    *bytes = JS_EncodeString(cx, str);
+    return bytes->get();
 }
 
 const char*
-js::ValueToPrintableUTF8(JSContext* cx, const Value& vArg, JSAutoByteString* bytes, bool asSource)
+js::ValueToPrintableUTF8(JSContext* cx, const Value& vArg, UniqueChars* bytes, bool asSource)
 {
     RootedValue v(cx, vArg);
     JSString* str;
@@ -2091,7 +2092,8 @@ js::ValueToPrintableUTF8(JSContext* cx, const Value& vArg, JSAutoByteString* byt
         str = ToString<CanGC>(cx, v);
     if (!str)
         return nullptr;
-    return bytes->encodeUtf8(cx, RootedString(cx, str));
+    *bytes = JS_EncodeStringToUTF8(cx, RootedString(cx, str));
+    return bytes->get();
 }
 
 template <AllowGC allowGC>

js/src/vm/StringType.h

@@ -26,7 +26,6 @@
 #include "util/Text.h"
 #include "vm/Printer.h"
 
-class JSAutoByteString;
 class JSDependentString;
 class JSExtensibleString;
 class JSExternalString;
@@ -1687,14 +1686,14 @@ EncodeLatin1(JSContext* cx, JSString* str);
  * string.
  */
 extern const char*
-ValueToPrintableLatin1(JSContext* cx, const Value&, JSAutoByteString* bytes,
+ValueToPrintableLatin1(JSContext* cx, const Value&, UniqueChars* bytes,
                        bool asSource = false);
 
 /*
  * Convert a value to a printable C string encoded in UTF-8.
  */
 extern const char*
-ValueToPrintableUTF8(JSContext* cx, const Value&, JSAutoByteString* bytes, bool asSource = false);
+ValueToPrintableUTF8(JSContext* cx, const Value&, UniqueChars* bytes, bool asSource = false);
 
 /*
  * Convert a non-string value to a string, returning null after reporting an

js/src/vm/UbiNodeCensus.cpp

@@ -6,7 +6,7 @@
 
 #include "js/UbiNodeCensus.h"
 
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/StableStringChars.h"
 #include "util/Text.h"
 #include "vm/JSContext.h"
@@ -1265,12 +1265,12 @@ ParseBreakdown(JSContext* cx, HandleValue breakdownValue)
     if (!bySource)
         return nullptr;
 
-    JSAutoByteString byBytes(cx, bySource);
+    UniqueChars byBytes = JS_EncodeString(cx, bySource);
     if (!byBytes)
         return nullptr;
 
     JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_DEBUG_CENSUS_BREAKDOWN,
-                               byBytes.ptr());
+                               byBytes.get());
     return nullptr;
 }
 

js/src/wasm/AsmJS.cpp

@@ -32,7 +32,6 @@
 #include "builtin/String.h"
 #include "frontend/Parser.h"
 #include "gc/Policy.h"
-#include "js/AutoByteString.h"
 #include "js/MemoryMetrics.h"
 #include "js/Printf.h"
 #include "js/SourceBufferHolder.h"
@@ -2015,9 +2014,9 @@ class MOZ_STACK_CLASS JS_HAZ_ROOTED ModuleValidator
     bool failNameOffset(uint32_t offset, const char* fmt, PropertyName* name) {
         // This function is invoked without the caller properly rooting its locals.
         gc::AutoSuppressGC suppress(cx_);
-        JSAutoByteString bytes;
+        UniqueChars bytes;
         if (AtomToPrintableString(cx_, name, &bytes))
-            failfOffset(offset, fmt, bytes.ptr());
+            failfOffset(offset, fmt, bytes.get());
         return false;
     }
 

js/xpconnect/loader/mozJSComponentLoader.cpp

@@ -17,7 +17,7 @@
 #endif
 
 #include "jsapi.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/CompilationAndEvaluation.h"
 #include "js/Printf.h"
 #include "nsCOMPtr.h"
@@ -106,12 +106,12 @@ Dump(JSContext* cx, unsigned argc, Value* vp)
     if (!str)
         return false;
 
-    JSAutoByteString utf8str;
+    JS::UniqueChars utf8str = JS_EncodeStringToUTF8(cx, str);
-    if (!utf8str.encodeUtf8(cx, str))
+    if (!utf8str)
         return false;
 
 #ifdef ANDROID
-    __android_log_print(ANDROID_LOG_INFO, "Gecko", "%s", utf8str.ptr());
+    __android_log_print(ANDROID_LOG_INFO, "Gecko", "%s", utf8str.get());
 #endif
 #ifdef XP_WIN
     if (IsDebuggerPresent()) {
@@ -121,7 +121,7 @@ Dump(JSContext* cx, unsigned argc, Value* vp)
         OutputDebugStringW(wstr.get());
     }
 #endif
-    fputs(utf8str.ptr(), stdout);
+    fputs(utf8str.get(), stdout);
     fflush(stdout);
     return true;
 }
@@ -1241,12 +1241,12 @@ mozJSComponentLoader::ExtractExports(JSContext* aCx, ComponentLoaderInfo& aInfo,
         symbolHolder = ResolveModuleObjectPropertyById(cx, aMod->obj, symbolId);
         if (!symbolHolder ||
             !JS_GetPropertyById(cx, symbolHolder, symbolId, &value)) {
-            JSAutoByteString bytes;
             RootedString symbolStr(cx, JSID_TO_STRING(symbolId));
-            if (!bytes.encodeUtf8(cx, symbolStr))
+            JS::UniqueChars bytes = JS_EncodeStringToUTF8(cx, symbolStr);
+            if (!bytes)
                 return NS_ERROR_FAILURE;
             return ReportOnCallerUTF8(cxhelper, ERROR_GETTING_SYMBOL,
-                                      aInfo, bytes.ptr());
+                                      aInfo, bytes.get());
         }
 
         if (value.isUndefined()) {
@@ -1254,20 +1254,20 @@ mozJSComponentLoader::ExtractExports(JSContext* aCx, ComponentLoaderInfo& aInfo,
         }
 
         if (!JS_SetPropertyById(cx, aExports, symbolId, value)) {
-            JSAutoByteString bytes;
             RootedString symbolStr(cx, JSID_TO_STRING(symbolId));
-            if (!bytes.encodeUtf8(cx, symbolStr))
+            JS::UniqueChars bytes = JS_EncodeStringToUTF8(cx, symbolStr);
+            if (!bytes)
                 return NS_ERROR_FAILURE;
             return ReportOnCallerUTF8(cxhelper, ERROR_GETTING_SYMBOL,
-                                      aInfo, bytes.ptr());
+                                      aInfo, bytes.get());
         }
 #ifdef DEBUG
         if (i == 0) {
             logBuffer.AssignLiteral("Installing symbols [ ");
         }
-        JSAutoByteString bytes(cx, JSID_TO_STRING(symbolId));
+        JS::UniqueChars bytes = JS_EncodeString(cx, JSID_TO_STRING(symbolId));
         if (!!bytes)
-            logBuffer.Append(bytes.ptr());
+            logBuffer.Append(bytes.get());
         logBuffer.Append(' ');
         if (i == symbolCount - 1) {
             nsCString location;

js/xpconnect/src/Sandbox.cpp

@@ -10,7 +10,7 @@
 
 #include "AccessCheck.h"
 #include "jsfriendapi.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/CompilationAndEvaluation.h"
 #include "js/Proxy.h"
 #include "js/SourceBufferHolder.h"
@@ -140,8 +140,8 @@ SandboxDump(JSContext* cx, unsigned argc, Value* vp)
     if (!str)
         return false;
 
-    JSAutoByteString utf8str;
+    JS::UniqueChars utf8str = JS_EncodeStringToUTF8(cx, str);
-    char* cstr = utf8str.encodeUtf8(cx, str);
+    char* cstr = utf8str.get();
     if (!cstr)
         return false;
 
@@ -855,69 +855,69 @@ xpc::GlobalProperties::Parse(JSContext* cx, JS::HandleObject obj)
             return false;
         }
         RootedString nameStr(cx, nameValue.toString());
-        JSAutoByteString name;
+        JS::UniqueChars name = JS_EncodeStringToUTF8(cx, nameStr);
-        if (!name.encodeUtf8(cx, nameStr))
+        if (!name)
             return false;
-        if (!strcmp(name.ptr(), "Blob")) {
+        if (!strcmp(name.get(), "Blob")) {
             Blob = true;
-        } else if (!strcmp(name.ptr(), "ChromeUtils")) {
+        } else if (!strcmp(name.get(), "ChromeUtils")) {
             ChromeUtils = true;
-        } else if (!strcmp(name.ptr(), "CSS")) {
+        } else if (!strcmp(name.get(), "CSS")) {
             CSS = true;
-        } else if (!strcmp(name.ptr(), "CSSRule")) {
+        } else if (!strcmp(name.get(), "CSSRule")) {
             CSSRule = true;
-        } else if (!strcmp(name.ptr(), "Directory")) {
+        } else if (!strcmp(name.get(), "Directory")) {
             Directory = true;
-        } else if (!strcmp(name.ptr(), "DOMParser")) {
+        } else if (!strcmp(name.get(), "DOMParser")) {
             DOMParser = true;
-        } else if (!strcmp(name.ptr(), "Element")) {
+        } else if (!strcmp(name.get(), "Element")) {
             Element = true;
-        } else if (!strcmp(name.ptr(), "Event")) {
+        } else if (!strcmp(name.get(), "Event")) {
             Event = true;
-        } else if (!strcmp(name.ptr(), "File")) {
+        } else if (!strcmp(name.get(), "File")) {
             File = true;
-        } else if (!strcmp(name.ptr(), "FileReader")) {
+        } else if (!strcmp(name.get(), "FileReader")) {
             FileReader = true;
-        } else if (!strcmp(name.ptr(), "FormData")) {
+        } else if (!strcmp(name.get(), "FormData")) {
             FormData = true;
-        } else if (!strcmp(name.ptr(), "InspectorUtils")) {
+        } else if (!strcmp(name.get(), "InspectorUtils")) {
             InspectorUtils = true;
-        } else if (!strcmp(name.ptr(), "MessageChannel")) {
+        } else if (!strcmp(name.get(), "MessageChannel")) {
             MessageChannel = true;
-        } else if (!strcmp(name.ptr(), "Node")) {
+        } else if (!strcmp(name.get(), "Node")) {
             Node = true;
-        } else if (!strcmp(name.ptr(), "NodeFilter")) {
+        } else if (!strcmp(name.get(), "NodeFilter")) {
             NodeFilter = true;
-        } else if (!strcmp(name.ptr(), "TextDecoder")) {
+        } else if (!strcmp(name.get(), "TextDecoder")) {
             TextDecoder = true;
-        } else if (!strcmp(name.ptr(), "TextEncoder")) {
+        } else if (!strcmp(name.get(), "TextEncoder")) {
             TextEncoder = true;
-        } else if (!strcmp(name.ptr(), "URL")) {
+        } else if (!strcmp(name.get(), "URL")) {
             URL = true;
-        } else if (!strcmp(name.ptr(), "URLSearchParams")) {
+        } else if (!strcmp(name.get(), "URLSearchParams")) {
             URLSearchParams = true;
-        } else if (!strcmp(name.ptr(), "XMLHttpRequest")) {
+        } else if (!strcmp(name.get(), "XMLHttpRequest")) {
             XMLHttpRequest = true;
-        } else if (!strcmp(name.ptr(), "XMLSerializer")) {
+        } else if (!strcmp(name.get(), "XMLSerializer")) {
             XMLSerializer = true;
-        } else if (!strcmp(name.ptr(), "atob")) {
+        } else if (!strcmp(name.get(), "atob")) {
             atob = true;
-        } else if (!strcmp(name.ptr(), "btoa")) {
+        } else if (!strcmp(name.get(), "btoa")) {
             btoa = true;
-        } else if (!strcmp(name.ptr(), "caches")) {
+        } else if (!strcmp(name.get(), "caches")) {
             caches = true;
-        } else if (!strcmp(name.ptr(), "crypto")) {
+        } else if (!strcmp(name.get(), "crypto")) {
             crypto = true;
-        } else if (!strcmp(name.ptr(), "fetch")) {
+        } else if (!strcmp(name.get(), "fetch")) {
             fetch = true;
-        } else if (!strcmp(name.ptr(), "indexedDB")) {
+        } else if (!strcmp(name.get(), "indexedDB")) {
             indexedDB = true;
 #ifdef MOZ_WEBRTC
-        } else if (!strcmp(name.ptr(), "rtcIdentityProvider")) {
+        } else if (!strcmp(name.get(), "rtcIdentityProvider")) {
             rtcIdentityProvider = true;
 #endif
         } else {
-            JS_ReportErrorUTF8(cx, "Unknown property name: %s", name.ptr());
+            JS_ReportErrorUTF8(cx, "Unknown property name: %s", name.get());
             return false;
         }
     }
@@ -1540,10 +1540,9 @@ OptionsBase::ParseString(const char* name, nsCString& prop)
         return false;
     }
 
-    char* tmp = JS_EncodeString(mCx, value.toString());
+    JS::UniqueChars tmp = JS_EncodeString(mCx, value.toString());
     NS_ENSURE_TRUE(tmp, false);
-    prop.Assign(tmp, strlen(tmp));
+    prop.Assign(tmp.get(), strlen(tmp.get()));
-    js_free(tmp);
     return true;
 }
 

js/xpconnect/src/XPCComponents.cpp

@@ -15,7 +15,7 @@
 #include "nsContentUtils.h"
 #include "nsCycleCollector.h"
 #include "jsfriendapi.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/SavedFrameAPI.h"
 #include "js/StructuredClone.h"
 #include "mozilla/Attributes.h"
@@ -246,12 +246,12 @@ nsXPCComponents_Interfaces::Resolve(nsIXPConnectWrappedNative* wrapper,
     if (!JSID_IS_STRING(id))
         return NS_OK;
 
-    JSAutoByteString name;
     RootedString str(cx, JSID_TO_STRING(id));
+    JS::UniqueChars name = JS_EncodeString(cx, str);
 
     // we only allow interfaces by name here
-    if (name.encodeLatin1(cx, str) && name.ptr()[0] != '{') {
+    if (name && name[0] != '{') {
-        const nsXPTInterfaceInfo* info = nsXPTInterfaceInfo::ByName(name.ptr());
+        const nsXPTInterfaceInfo* info = nsXPTInterfaceInfo::ByName(name.get());
         if (!info)
             return NS_OK;
 
@@ -431,10 +431,10 @@ nsXPCComponents_InterfacesByID::Resolve(nsIXPConnectWrappedNative* wrapper,
     if (38 != JS_GetStringLength(str))
         return NS_OK;
 
-    JSAutoByteString utf8str;
+    JS::UniqueChars utf8str = JS_EncodeStringToUTF8(cx, str);
-    if (utf8str.encodeUtf8(cx, str)) {
+    if (utf8str) {
         nsID iid;
-        if (!iid.Parse(utf8str.ptr()))
+        if (!iid.Parse(utf8str.get()))
             return NS_OK;
 
         const nsXPTInterfaceInfo* info = nsXPTInterfaceInfo::ByIID(iid);
@@ -623,11 +623,13 @@ nsXPCComponents_Classes::Resolve(nsIXPConnectWrappedNative* wrapper,
     RootedId id(cx, idArg);
     RootedObject obj(cx, objArg);
 
-    JSAutoByteString name;
+    if (!JSID_IS_STRING(id))
-    if (JSID_IS_STRING(id) &&
+        return NS_OK;
-        name.encodeLatin1(cx, JSID_TO_STRING(id)) &&
+
-        name.ptr()[0] != '{') { // we only allow contractids here
+    JS::UniqueChars name = JS_EncodeString(cx, JSID_TO_STRING(id));
-        nsCOMPtr<nsIJSCID> nsid = nsJSCID::NewID(name.ptr());
+    if (name &&
+        name[0] != '{') { // we only allow contractids here
+        nsCOMPtr<nsIJSCID> nsid = nsJSCID::NewID(name.get());
         if (nsid) {
             nsXPConnect* xpc = nsXPConnect::XPConnect();
             RootedObject idobj(cx);
@@ -832,12 +834,12 @@ nsXPCComponents_ClassesByID::Resolve(nsIXPConnectWrappedNative* wrapper,
     if (!JSID_IS_STRING(id))
         return NS_OK;
 
-    JSAutoByteString name;
     RootedString str(cx, JSID_TO_STRING(id));
-    if (name.encodeLatin1(cx, str) && name.ptr()[0] == '{' &&
+    JS::UniqueChars name = JS_EncodeString(cx, str);
-        IsRegisteredCLSID(name.ptr())) // we only allow canonical CLSIDs here
+    if (name && name[0] == '{' &&
+        IsRegisteredCLSID(name.get())) // we only allow canonical CLSIDs here
     {
-        nsCOMPtr<nsIJSCID> nsid = nsJSCID::NewID(name.ptr());
+        nsCOMPtr<nsIJSCID> nsid = nsJSCID::NewID(name.get());
         if (nsid) {
             nsXPConnect* xpc = nsXPConnect::XPConnect();
             RootedObject idobj(cx);
@@ -998,14 +1000,16 @@ nsXPCComponents_Results::Resolve(nsIXPConnectWrappedNative* wrapper,
 {
     RootedObject obj(cx, objArg);
     RootedId id(cx, idArg);
-    JSAutoByteString name;
+    if (!JSID_IS_STRING(id))
+        return NS_OK;
 
-    if (JSID_IS_STRING(id) && name.encodeLatin1(cx, JSID_TO_STRING(id))) {
+    JS::UniqueChars name = JS_EncodeString(cx, JSID_TO_STRING(id));
+    if (name) {
         const char* rv_name;
         const void* iter = nullptr;
         nsresult rv;
         while (nsXPCException::IterateNSResults(&rv, &rv_name, nullptr, &iter)) {
-            if (!strcmp(name.ptr(), rv_name)) {
+            if (!strcmp(name.get(), rv_name)) {
                 *resolvedp = true;
                 if (!JS_DefinePropertyById(cx, obj, id, (uint32_t)rv,
                                            JSPROP_ENUMERATE |
@@ -1161,15 +1165,17 @@ nsXPCComponents_ID::CallOrConstruct(nsIXPConnectWrappedNative* wrapper,
 
     // convert the first argument into a string and see if it looks like an id
 
-    JSString* jsstr;
+    JSString* jsstr = ToString(cx, args[0]);
-    JSAutoByteString bytes;
+    if (!jsstr)
-    nsID id;
+        return ThrowAndFail(NS_ERROR_XPC_BAD_ID_STRING, cx, _retval);
-
+
-    if (!(jsstr = ToString(cx, args[0])) ||
+    JS::UniqueChars bytes = JS_EncodeString(cx, jsstr);
-        !bytes.encodeLatin1(cx, jsstr) ||
+    if (!bytes)
-        !id.Parse(bytes.ptr())) {
+        return ThrowAndFail(NS_ERROR_XPC_BAD_ID_STRING, cx, _retval);
+
+    nsID id;
+    if (!id.Parse(bytes.get()))
         return ThrowAndFail(NS_ERROR_XPC_BAD_ID_STRING, cx, _retval);
-    }
 
     // make the new object and return it.
 
@@ -1382,7 +1388,8 @@ struct MOZ_STACK_CLASS ExceptionArgParser
         JSString* str = ToString(cx, v);
         if (!str)
            return false;
-        eMsg = messageBytes.encodeLatin1(cx, str);
+        messageBytes = JS_EncodeString(cx, str);
+        eMsg = messageBytes.get();
         return !!eMsg;
     }
 
@@ -1453,7 +1460,7 @@ struct MOZ_STACK_CLASS ExceptionArgParser
      */
 
     // If there's a non-default exception string, hold onto the allocated bytes.
-    JSAutoByteString messageBytes;
+    JS::UniqueChars messageBytes;
 
     // Various bits and pieces that are helpful to have around.
     JSContext* cx;
@@ -1871,12 +1878,17 @@ nsXPCComponents_Constructor::CallOrConstruct(nsIXPConnectWrappedNative* wrapper,
     nsCOMPtr<nsIJSCID> cClassID;
     nsCOMPtr<nsIJSIID> cInterfaceID;
     const char*        cInitializer = nullptr;
-    JSAutoByteString  cInitializerBytes;
+    JS::UniqueChars cInitializerBytes;
 
     if (args.length() >= 3) {
         // args[2] is an initializer function or property name
         RootedString str(cx, ToString(cx, args[2]));
-        if (!str || !(cInitializer = cInitializerBytes.encodeLatin1(cx, str)))
+        if (!str)
+            return ThrowAndFail(NS_ERROR_XPC_BAD_CONVERT_JS, cx, _retval);
+
+        cInitializerBytes = JS_EncodeString(cx, str);
+        cInitializer = cInitializerBytes.get();
+        if (!cInitializer)
             return ThrowAndFail(NS_ERROR_XPC_BAD_CONVERT_JS, cx, _retval);
     }
 

js/xpconnect/src/XPCConvert.cpp

@@ -21,7 +21,6 @@
 
 #include "jsapi.h"
 #include "jsfriendapi.h"
-#include "js/AutoByteString.h"
 #include "js/CharacterEncoding.h"
 
 #include "mozilla/dom/BindingUtils.h"
@@ -1333,11 +1332,11 @@ XPCConvert::JSValToXPCException(MutableHandleValue s,
             // extract the report and build an xpcexception from that
             const JSErrorReport* report;
             if (nullptr != (report = JS_ErrorFromException(cx, obj))) {
-                JSAutoByteString toStringResult;
+                JS::UniqueChars toStringResult;
                 RootedString str(cx, ToString(cx, s));
                 if (str)
-                    toStringResult.encodeUtf8(cx, str);
+                    toStringResult = JS_EncodeStringToUTF8(cx, str);
-                return JSErrorToXPCException(toStringResult.ptr(), ifaceName,
+                return JSErrorToXPCException(toStringResult.get(), ifaceName,
                                              methodName, report, exceptn);
             }
 
@@ -1352,12 +1351,12 @@ XPCConvert::JSValToXPCException(MutableHandleValue s,
             if (!str)
                 return NS_ERROR_FAILURE;
 
-            JSAutoByteString strBytes(cx, str);
+            JS::UniqueChars strBytes = JS_EncodeString(cx, str);
             if (!strBytes)
                 return NS_ERROR_FAILURE;
 
             return ConstructException(NS_ERROR_XPC_JS_THREW_JS_OBJECT,
-                                      strBytes.ptr(), ifaceName, methodName,
+                                      strBytes.get(), ifaceName, methodName,
                                       nullptr, exceptn, cx, s.address());
         }
     }
@@ -1420,10 +1419,10 @@ XPCConvert::JSValToXPCException(MutableHandleValue s,
 
     JSString* str = ToString(cx, s);
     if (str) {
-        JSAutoByteString strBytes(cx, str);
+        JS::UniqueChars strBytes = JS_EncodeString(cx, str);
         if (!!strBytes) {
             return ConstructException(NS_ERROR_XPC_JS_THREW_STRING,
-                                      strBytes.ptr(), ifaceName, methodName,
+                                      strBytes.get(), ifaceName, methodName,
                                       nullptr, exceptn, cx, s.address());
         }
     }

js/xpconnect/src/XPCShellImpl.cpp

@@ -7,7 +7,7 @@
 #include "nsXULAppAPI.h"
 #include "jsapi.h"
 #include "jsfriendapi.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/CompilationAndEvaluation.h"
 #include "js/Printf.h"
 #include "mozilla/ChaosMode.h"
@@ -250,8 +250,8 @@ ReadLine(JSContext* cx, unsigned argc, Value* vp)
     }
 
     /* Get a line from the infile */
-    JSAutoByteString strBytes(cx, str);
+    JS::UniqueChars strBytes = JS_EncodeString(cx, str);
-    if (!strBytes || !GetLine(cx, buf, gInFile, strBytes.ptr()))
+    if (!strBytes || !GetLine(cx, buf, gInFile, strBytes.get()))
         return false;
 
     /* Strip newline character added by GetLine() */
@@ -288,13 +288,13 @@ Print(JSContext* cx, unsigned argc, Value* vp)
         if (!str)
             return false;
 
-        JSAutoByteString utf8str;
+        JS::UniqueChars utf8str = JS_EncodeStringToUTF8(cx, str);
-        if (!utf8str.encodeUtf8(cx, str))
+        if (!utf8str)
             return false;
 
         if (i)
             utf8output.Append(' ');
-        utf8output.Append(utf8str.ptr(), utf8str.length());
+        utf8output.Append(utf8str.get(), strlen(utf8str.get()));
     }
     utf8output.Append('\n');
     fputs(utf8output.get(), gOutFile);
@@ -315,12 +315,12 @@ Dump(JSContext* cx, unsigned argc, Value* vp)
     if (!str)
         return false;
 
-    JSAutoByteString utf8str;
+    JS::UniqueChars utf8str = JS_EncodeStringToUTF8(cx, str);
-    if (!utf8str.encodeUtf8(cx, str))
+    if (!utf8str)
         return false;
 
 #ifdef ANDROID
-    __android_log_print(ANDROID_LOG_INFO, "Gecko", "%s", utf8str.ptr());
+    __android_log_print(ANDROID_LOG_INFO, "Gecko", "%s", utf8str.get());
 #endif
 #ifdef XP_WIN
     if (IsDebuggerPresent()) {
@@ -330,7 +330,7 @@ Dump(JSContext* cx, unsigned argc, Value* vp)
         OutputDebugStringW(wstr.get());
     }
 #endif
-    fputs(utf8str.ptr(), gOutFile);
+    fputs(utf8str.get(), gOutFile);
     fflush(gOutFile);
     return true;
 }
@@ -353,21 +353,21 @@ Load(JSContext* cx, unsigned argc, Value* vp)
         str = ToString(cx, args[i]);
         if (!str)
             return false;
-        JSAutoByteString filename(cx, str);
+        JS::UniqueChars filename = JS_EncodeString(cx, str);
         if (!filename)
             return false;
-        FILE* file = fopen(filename.ptr(), "r");
+        FILE* file = fopen(filename.get(), "r");
         if (!file) {
-            filename.clear();
+            filename = JS_EncodeStringToUTF8(cx, str);
-            if (!filename.encodeUtf8(cx, str))
+            if (!filename)
                 return false;
             JS_ReportErrorUTF8(cx, "cannot open file '%s' for reading",
-                               filename.ptr());
+                               filename.get());
             return false;
         }
         JS::CompileOptions options(cx);
         options.setUTF8(true)
-               .setFileAndLine(filename.ptr(), 1)
+               .setFileAndLine(filename.get(), 1)
                .setIsRunOnce(true);
         JS::Rooted<JSScript*> script(cx);
         JS::Rooted<JSObject*> global(cx, JS::CurrentGlobalOrNull(cx));
@@ -479,25 +479,25 @@ Options(JSContext* cx, unsigned argc, Value* vp)
     ContextOptions oldContextOptions = ContextOptionsRef(cx);
 
     RootedString str(cx);
-    JSAutoByteString opt;
+    JS::UniqueChars opt;
     for (unsigned i = 0; i < args.length(); ++i) {
         str = ToString(cx, args[i]);
         if (!str)
             return false;
 
-        opt.clear();
+        opt = JS_EncodeStringToUTF8(cx, str);
-        if (!opt.encodeUtf8(cx, str))
+        if (!opt)
             return false;
 
-        if (strcmp(opt.ptr(), "strict") == 0)
+        if (strcmp(opt.get(), "strict") == 0)
             ContextOptionsRef(cx).toggleExtraWarnings();
-        else if (strcmp(opt.ptr(), "werror") == 0)
+        else if (strcmp(opt.get(), "werror") == 0)
             ContextOptionsRef(cx).toggleWerror();
-        else if (strcmp(opt.ptr(), "strict_mode") == 0)
+        else if (strcmp(opt.get(), "strict_mode") == 0)
             ContextOptionsRef(cx).toggleStrictMode();
         else {
             JS_ReportErrorUTF8(cx, "unknown option name '%s'. The valid names are "
-                               "strict, werror, and strict_mode.", opt.ptr());
+                               "strict, werror, and strict_mode.", opt.get());
             return false;
         }
     }
@@ -726,11 +726,11 @@ ProcessLine(AutoJSAPI& jsapi, const char* buffer, int startline)
     RootedString str(cx);
     if (!(str = ToString(cx, result)))
         return false;
-    JSAutoByteString bytes;
+    JS::UniqueChars bytes = JS_EncodeString(cx, str);
-    if (!bytes.encodeLatin1(cx, str))
+    if (!bytes)
         return false;
 
-    fprintf(gOutFile, "%s\n", bytes.ptr());
+    fprintf(gOutFile, "%s\n", bytes.get());
     return true;
 }
 

js/xpconnect/src/XPCThrower.cpp

@@ -8,7 +8,7 @@
 
 #include "xpcprivate.h"
 #include "XPCWrapper.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/Printf.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/dom/DOMException.h"
@@ -164,10 +164,13 @@ XPCThrower::Verbosify(XPCCallContext& ccx,
     if (ccx.HasInterfaceAndMember()) {
         XPCNativeInterface* iface = ccx.GetInterface();
         jsid id = ccx.GetMember()->GetName();
-        JSAutoByteString bytes;
+        const char* name;
-        const char* name = JSID_IS_VOID(id) ? "Unknown" : bytes.encodeLatin1(ccx, JSID_TO_STRING(id));
+        JS::UniqueChars bytes;
-        if (!name) {
+        if (!JSID_IS_VOID(id)) {
-            name = "";
+            bytes = JS_EncodeString(ccx, JSID_TO_STRING(id));
+            name = bytes ? bytes.get() : "";
+        } else {
+            name = "Unknown";
         }
         sz = JS_smprintf("%s [%s.%s]", *psz, iface->GetNameString(), name).release();
     }

js/xpconnect/src/XPCWrappedNativeJSOps.cpp

@@ -10,7 +10,7 @@
 #include "xpc_make_class.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/Preferences.h"
-#include "js/AutoByteString.h"
+#include "js/CharacterEncoding.h"
 #include "js/Class.h"
 #include "js/Printf.h"
 
@@ -289,20 +289,37 @@ DefinePropertyIfFound(XPCCallContext& ccx,
         // interface and add a tearoff as necessary.
 
         if (wrapperToReflectInterfaceNames) {
-            JSAutoByteString name;
+            JS::UniqueChars name;
             RefPtr<XPCNativeInterface> iface2;
             XPCWrappedNativeTearOff* to;
             RootedObject jso(ccx);
             nsresult rv = NS_OK;
 
-            if (JSID_IS_STRING(id) &&
+            bool defineProperty = false;
-                name.encodeLatin1(ccx, JSID_TO_STRING(id)) &&
+            do {
-                (iface2 = XPCNativeInterface::GetNewOrUsed(name.ptr())) &&
+                if (!JSID_IS_STRING(id))
-                nullptr != (to = wrapperToReflectInterfaceNames->
+                    break;
-                           FindTearOff(iface2, true, &rv)) &&
-                nullptr != (jso = to->GetJSObject()))
 
-            {
+                name = JS_EncodeString(ccx, JSID_TO_STRING(id));
+                if (!name)
+                    break;
+
+                iface2 = XPCNativeInterface::GetNewOrUsed(name.get());
+                if (!iface2)
+                    break;
+
+                to = wrapperToReflectInterfaceNames->FindTearOff(iface2, true, &rv);
+                if (!to)
+                    break;
+
+                jso = to->GetJSObject();
+                if (!jso)
+                    break;
+
+                defineProperty = true;
+            } while (false);
+
+            if (defineProperty) {
                 AutoResolveName arn(ccx, id);
                 if (resolved)
                     *resolved = true;

toolkit/recordreplay/ipc/JSControl.cpp

@@ -6,6 +6,7 @@
 
 #include "JSControl.h"
 
+#include "js/CharacterEncoding.h"
 #include "js/Conversions.h"
 #include "js/JSON.h"
 #include "ChildInternal.h"
@@ -802,12 +803,11 @@ RecordReplay_Dump(JSContext* aCx, unsigned aArgc, Value* aVp)
     if (!str) {
       return false;
     }
-    char* cstr = JS_EncodeString(aCx, str);
+    JS::UniqueChars cstr = JS_EncodeString(aCx, str);
     if (!cstr) {
       return false;
     }
-    Print("%s", cstr);
+    Print("%s", cstr.get());
-    JS_free(aCx, cstr);
   }
 
   args.rval().setUndefined();

tools/fuzzing/messagemanager/MessageManagerFuzzer.cpp

@@ -9,6 +9,7 @@
 #include "FuzzingTraits.h"
 #include "jsapi.h"
 #include "jsfriendapi.h"
+#include "js/CharacterEncoding.h"
 #include "prenv.h"
 #include "MessageManagerFuzzer.h"
 #include "mozilla/ErrorResult.h"
@@ -195,9 +196,10 @@ MessageManagerFuzzer::MutateValue(JSContext* aCx,
     }
     JSString* str = JS_NewStringCopyZ(aCx, x.get());
     aOutMutationValue.set(JS::StringValue(str));
+    JS::UniqueChars valueChars = JS_EncodeString(aCx, aValue.toString());
     MSGMGR_FUZZER_LOG("%*s! Mutated value of type |string|: '%s' to '%s'",
                       aRecursionCounter * 4, "",
-                      JS_EncodeString(aCx, aValue.toString()), x.get());
+                      valueChars.get(), x.get());
     return true;
   }
 
@@ -258,9 +260,10 @@ MessageManagerFuzzer::Mutate(JSContext* aCx,
   /* Mutated and successfully written to StructuredCloneData object. */
   if (isMutated) {
     JS::RootedString str(aCx, JS_ValueToSource(aCx, scdMutationContent));
+    JS::UniqueChars strChars = JS_EncodeStringToUTF8(aCx, str);
     MSGMGR_FUZZER_LOG("Mutated '%s' Message: %s",
                       NS_ConvertUTF16toUTF8(aMessageName).get(),
-                      JS_EncodeStringToUTF8(aCx, str));
+                      strChars.get());
   }
 
   return true;