Bug 1305097: Enhance error reporting from the ToAST transformation; r=luke

js/src/asmjs/WasmBinary.cpp

@@ -40,6 +40,7 @@ Decoder::fail(const char* msg, ...) {
 
 bool
 Decoder::fail(UniqueChars msg) {
+    MOZ_ASSERT(error_);
     UniqueChars strWithOffset(JS_smprintf("at offset %zu: %s", currentOffset(), msg.get()));
     if (!strWithOffset)
         return false;

js/src/asmjs/WasmBinary.h

@@ -770,7 +770,7 @@ class Decoder
     static const size_t ExprLimit = 2 * UINT8_MAX - 1;
 
   public:
-    Decoder(const uint8_t* begin, const uint8_t* end, UniqueChars* error = nullptr)
+    Decoder(const uint8_t* begin, const uint8_t* end, UniqueChars* error)
       : beg_(begin),
         end_(end),
         cur_(begin),

js/src/asmjs/WasmBinaryToAST.cpp

@@ -46,16 +46,20 @@ struct AstDecodeStackItem
     ExprType type;
 
     explicit AstDecodeStackItem()
-        : expr(nullptr),
-          terminationKind(AstDecodeTerminationKind::Unknown),
-          type(ExprType::Limit) {}
-    explicit AstDecodeStackItem(AstDecodeTerminationKind terminationKind,
-                                ExprType type)
-        : expr(nullptr), terminationKind(terminationKind), type(type) {}
+      : expr(nullptr),
+        terminationKind(AstDecodeTerminationKind::Unknown),
+        type(ExprType::Limit)
+    {}
+    explicit AstDecodeStackItem(AstDecodeTerminationKind terminationKind, ExprType type)
+      : expr(nullptr),
+        terminationKind(terminationKind),
+        type(type)
+    {}
     explicit AstDecodeStackItem(AstExpr* expr)
-        : expr(expr),
-          terminationKind(AstDecodeTerminationKind::Unknown),
-          type(ExprType::Limit) {}
+     : expr(expr),
+       terminationKind(AstDecodeTerminationKind::Unknown),
+       type(ExprType::Limit)
+    {}
 };
 
 // We don't define a Value type because ExprIter doesn't push void values, which
@@ -97,7 +101,8 @@ class AstDecodeContext
     ExprType retType_;
 
   public:
-    AstDecodeContext(JSContext* cx, LifoAlloc& lifo, Decoder& d, AstModule& module, bool generateNames)
+    AstDecodeContext(JSContext* cx, LifoAlloc& lifo, Decoder& d, AstModule& module,
+                     bool generateNames)
      : cx(cx),
        lifo(lifo),
        d(d),
@@ -1469,7 +1474,6 @@ AstDecodeFunctionSection(AstDecodeContext& c)
     if (numDecls > MaxFuncs)
         return c.d.fail("too many functions");
 
-
     if (!c.funcSigs().resize(numDecls))
         return false;
 
@@ -2147,6 +2151,8 @@ wasm::BinaryToAst(JSContext* cx, const uint8_t* bytes, uint32_t length,
         return false;
     }
 
+    MOZ_ASSERT(!error, "unreported error in decoding");
+
     *module = result;
     return true;
 }

js/src/asmjs/WasmBinaryToAST.h

@@ -28,7 +28,8 @@ namespace js {
 namespace wasm {
 
 bool
-BinaryToAst(JSContext* cx, const uint8_t* bytes, uint32_t length, LifoAlloc& lifo, AstModule** module);
+BinaryToAst(JSContext* cx, const uint8_t* bytes, uint32_t length, LifoAlloc& lifo,
+            AstModule** module);
 
 } // end wasm namespace
 } // end js namespace

js/src/asmjs/WasmBinaryToExperimentalText.cpp

@@ -129,7 +129,8 @@ struct WasmPrintContext
     uint32_t currentFuncIndex;
     PrintOperatorPrecedence currentPrecedence;
 
-    WasmPrintContext(JSContext* cx, AstModule* module, WasmPrintBuffer& buffer, const ExperimentalTextFormatting& f, GeneratedSourceMap* wasmSourceMap_)
+    WasmPrintContext(JSContext* cx, AstModule* module, WasmPrintBuffer& buffer,
+                     const ExperimentalTextFormatting& f, GeneratedSourceMap* wasmSourceMap_)
       : cx(cx),
         module(module),
         buffer(buffer),

js/src/jit-test/tests/wasm/to-text-experimental.js

@@ -1,6 +1,8 @@
 // |jit-test| test-also-wasm-baseline
 load(libdir + "wasm.js");
 
+assertErrorMessage(() => wasmBinaryToText(wasmTextToBinary(`(module (func (result i32) (f32.const 13.37)))`), 'experimental'), WebAssembly.CompileError, /type mismatch/);
+
 function runTest(code, expected) {
   var binary = wasmTextToBinary(code);
   var s = wasmBinaryToText(binary, "experimental");

js/src/jit-test/tests/wasm/to-text.js

@@ -9,6 +9,8 @@ try {
 }
 assertEq(caught, true);
 
+assertErrorMessage(() => wasmBinaryToText(wasmTextToBinary(`(module (func (result i32) (f32.const 13.37)))`)), WebAssembly.CompileError, /type mismatch/);
+
 function runTest(code) {
   var expected = wasmTextToBinary(code);
   var s = wasmBinaryToText(expected);