Bug 1839396 part 17 - Make QuoteString and JSONQuoteString infallible. r=mgaudet

The previous patch reimplemented QuoteString to use a `StringSegmentRange`,
which should avoid mutating the inner parts of `JSRope`, while remaining fast on
`JSAtom`-s.

As the StringSegmentRange does not need to allocate with `ensureLinear`, then
all the failures are reported by the `put` functions using the `GenericPrinter`
mechanism, and the `release` functions of `Sprinter` would report the failure if
any.

Thus, there is no need for retuning a boolean value anymore from `QuoteString`
and `JSONQuoteString`, while this is still necessary to check the returned value
variant of `QuoteString` which returns `UniqueChars` by using the `release`
function of `Sprinter`.

Differential Revision: https://phabricator.services.mozilla.com/D183759

js/public/Printer.h

@@ -333,18 +333,18 @@ extern JS_PUBLIC_API JS::UniqueChars QuoteString(JSContext* cx, JSString* str,
 
 // Appends the quoted string to the given Sprinter. Follows the same semantics
 // as QuoteString from above.
-extern JS_PUBLIC_API bool QuoteString(Sprinter* sp, JSString* str,
+extern JS_PUBLIC_API void QuoteString(Sprinter* sp, JSString* str,
                                       char quote = '\0');
 
 // Appends the quoted string to the given Sprinter. Follows the same
 // Appends the JSON quoted string to the given Sprinter.
-extern JS_PUBLIC_API bool JSONQuoteString(Sprinter* sp, JSString* str);
+extern JS_PUBLIC_API void JSONQuoteString(Sprinter* sp, JSString* str);
 
 // Internal implementation code for QuoteString methods above.
 enum class QuoteTarget { String, JSON };
 
 template <QuoteTarget target, typename CharT>
-bool JS_PUBLIC_API QuoteString(Sprinter* sp,
+void JS_PUBLIC_API QuoteString(Sprinter* sp,
                                const mozilla::Range<const CharT> chars,
                                char quote = '\0');
 

js/src/builtin/temporal/TemporalFields.cpp

@@ -137,9 +137,7 @@ static JS::UniqueChars QuoteString(JSContext* cx, const char* str) {
   }
   mozilla::Range range(reinterpret_cast<const Latin1Char*>(str),
                        std::strlen(str));
-  if (!QuoteString<QuoteTarget::String>(&sprinter, range)) {
-    return nullptr;
-  }
+  QuoteString<QuoteTarget::String>(&sprinter, range);
   return sprinter.release();
 }
 

js/src/frontend/ParserAtom.cpp

@@ -1004,9 +1004,7 @@ UniqueChars ToPrintableStringImpl(mozilla::Range<CharT> str,
   if (!sprinter.init()) {
     return nullptr;
   }
-  if (!QuoteString<QuoteTarget::String>(&sprinter, str, quote)) {
-    return nullptr;
-  }
+  QuoteString<QuoteTarget::String>(&sprinter, str, quote);
   return sprinter.release();
 }
 

js/src/vm/BytecodeUtil.cpp

@@ -2183,7 +2183,8 @@ bool ExpressionDecompiler::write(JSString* str) {
 }
 
 bool ExpressionDecompiler::quote(JSString* s, char quote) {
-  return QuoteString(&sprinter, s, quote);
+  QuoteString(&sprinter, s, quote);
+  return true;
 }
 
 JSAtom* ExpressionDecompiler::loadAtom(jsbytecode* pc) {
@@ -2605,9 +2606,7 @@ size_t JS::GetPCCountScriptCount(JSContext* cx) {
 [[nodiscard]] static bool JSONStringProperty(Sprinter& sp, JSONPrinter& json,
                                              const char* name, JSString* str) {
   json.beginStringProperty(name);
-  if (!JSONQuoteString(&sp, str)) {
-    return false;
-  }
+  JSONQuoteString(&sp, str);
   json.endStringProperty();
   return true;
 }

js/src/vm/Printer.cpp

@@ -349,7 +349,7 @@ static const char JSONEscapeMap[] = {
 };
 
 template <QuoteTarget target, typename CharT>
-JS_PUBLIC_API bool QuoteString(Sprinter* sp,
+JS_PUBLIC_API void QuoteString(Sprinter* sp,
                                const mozilla::Range<const CharT> chars,
                                char quote) {
   MOZ_ASSERT_IF(target == QuoteTarget::JSON, quote == '\0');
@@ -370,23 +370,21 @@ JS_PUBLIC_API bool QuoteString(Sprinter* sp,
   if (quote) {
     sp->putChar(quote);
   }
-
-  return true;
 }
 
-template JS_PUBLIC_API bool QuoteString<QuoteTarget::String, Latin1Char>(
+template JS_PUBLIC_API void QuoteString<QuoteTarget::String, Latin1Char>(
     Sprinter* sp, const mozilla::Range<const Latin1Char> chars, char quote);
 
-template JS_PUBLIC_API bool QuoteString<QuoteTarget::String, char16_t>(
+template JS_PUBLIC_API void QuoteString<QuoteTarget::String, char16_t>(
     Sprinter* sp, const mozilla::Range<const char16_t> chars, char quote);
 
-template JS_PUBLIC_API bool QuoteString<QuoteTarget::JSON, Latin1Char>(
+template JS_PUBLIC_API void QuoteString<QuoteTarget::JSON, Latin1Char>(
     Sprinter* sp, const mozilla::Range<const Latin1Char> chars, char quote);
 
-template JS_PUBLIC_API bool QuoteString<QuoteTarget::JSON, char16_t>(
+template JS_PUBLIC_API void QuoteString<QuoteTarget::JSON, char16_t>(
     Sprinter* sp, const mozilla::Range<const char16_t> chars, char quote);
 
-JS_PUBLIC_API bool QuoteString(Sprinter* sp, JSString* str,
+JS_PUBLIC_API void QuoteString(Sprinter* sp, JSString* str,
                                char quote /*= '\0' */) {
   MOZ_ASSERT(sp->maybeCx);
   if (quote) {
@@ -398,8 +396,6 @@ JS_PUBLIC_API bool QuoteString(Sprinter* sp, JSString* str,
   if (quote) {
     sp->putChar(quote);
   }
-
-  return true;
 }
 
 JS_PUBLIC_API UniqueChars QuoteString(JSContext* cx, JSString* str,
@@ -408,18 +404,15 @@ JS_PUBLIC_API UniqueChars QuoteString(JSContext* cx, JSString* str,
   if (!sprinter.init()) {
     return nullptr;
   }
-  if (!QuoteString(&sprinter, str, quote)) {
-    return nullptr;
-  }
+  QuoteString(&sprinter, str, quote);
   return sprinter.release();
 }
 
-JS_PUBLIC_API bool JSONQuoteString(Sprinter* sp, JSString* str) {
+JS_PUBLIC_API void JSONQuoteString(Sprinter* sp, JSString* str) {
   MOZ_ASSERT(sp->maybeCx);
   JSONEscape esc;
   EscapePrinter ep(*sp, esc);
   ep.putString(sp->maybeCx, str);
-  return true;
 }
 
 Fprinter::Fprinter(FILE* fp) : file_(nullptr), init_(false) { init(fp); }