Bug 1125371 - Silence some GCC-only warnings about uninitialized varaibles when building with --enable-optimize. r=jandem.

--HG--
extra : rebase_source : dae6430359a99e683639e740248d58899350c9e2

js/src/asmjs/AsmJSModule.cpp

@@ -1919,13 +1919,13 @@ class ModuleChars
 
   public:
     static uint32_t beginOffset(AsmJSParser &parser) {
-      return parser.pc->maybeFunction->pn_pos.begin;
+        return parser.pc->maybeFunction->pn_pos.begin;
     }
 
     static uint32_t endOffset(AsmJSParser &parser) {
-      TokenPos pos;
-      MOZ_ALWAYS_TRUE(parser.tokenStream.peekTokenPos(&pos));
-      return pos.end;
+        TokenPos pos(0, 0);  // initialize to silence GCC warning
+        MOZ_ALWAYS_TRUE(parser.tokenStream.peekTokenPos(&pos));
+        return pos.end;
     }
 };
 

js/src/asmjs/AsmJSValidate.cpp

@@ -635,6 +635,7 @@ class RetType
     RetType() : which_(Which(-1)) {}
     MOZ_IMPLICIT RetType(Which w) : which_(w) {}
     MOZ_IMPLICIT RetType(AsmJSCoercion coercion) {
+        which_ = Which(-1);  // initialize to silence GCC warning
         switch (coercion) {
           case AsmJS_ToInt32: which_ = Signed; break;
           case AsmJS_ToNumber: which_ = Double; break;
@@ -3031,7 +3032,7 @@ class FunctionCompiler
         uint32_t line, column;
         m_.tokenStream().srcCoords.lineNumAndColumnIndex(call.node_->pn_pos.begin, &line, &column);
 
-        CallSiteDesc::Kind kind;
+        CallSiteDesc::Kind kind = CallSiteDesc::Kind(-1);  // initialize to silence GCC warning
         switch (callee.which()) {
           case MAsmJSCall::Callee::Internal: kind = CallSiteDesc::Relative; break;
           case MAsmJSCall::Callee::Dynamic:  kind = CallSiteDesc::Register; break;
@@ -7292,7 +7293,7 @@ CheckChangeHeap(ModuleCompiler &m, ParseNode *fn, bool *validated)
     if (ParseNode *elseStmt = TernaryKid3(stmtIter))
         return m.fail(elseStmt, "unexpected else statement");
 
-    uint32_t mask, min, max;
+    uint32_t mask, min = 0, max;  // initialize min to silence GCC warning
     if (!CheckHeapLengthCondition(m, cond, newBufferName, &mask, &min, &max))
         return false;
 
@@ -7416,7 +7417,7 @@ CheckFunction(ModuleCompiler &m, LifoAlloc &lifo, MIRGenerator **mir, ModuleComp
     // the backing LifoAlloc after parsing/compiling each function.
     AsmJSParser::Mark mark = m.parser().mark();
 
-    ParseNode *fn;
+    ParseNode *fn = nullptr;  // initialize to silence GCC warning
     if (!ParseFunction(m, &fn))
         return false;
 

js/src/frontend/BytecodeEmitter.cpp

@@ -3101,6 +3101,7 @@ frontend::EmitFunctionScript(ExclusiveContext *cx, BytecodeEmitter *bce, ParseNo
         if (bce->script->bindingIsAliased(bi)) {
             ScopeCoordinate sc;
             sc.setHops(0);
+            sc.setSlot(0);  // initialize to silence GCC warning
             JS_ALWAYS_TRUE(LookupAliasedNameSlot(bce, bce->script, cx->names().arguments, &sc));
             if (!EmitAliasedVarOp(cx, JSOP_SETALIASEDVAR, sc, DontCheckLexical, bce))
                 return false;

js/src/jit/BaselineIC.cpp

@@ -7533,6 +7533,8 @@ ICGetPropCallDOMProxyNativeCompiler::getStub(ICStubSpace *space)
     Value expandoVal;
     if (kind == ICStub::GetProp_CallDOMProxyNative) {
         expandoVal = expandoSlot;
+        expandoAndGeneration = nullptr;  // initialize to silence GCC warning
+        generation = 0;  // initialize to silence GCC warning
     } else {
         MOZ_ASSERT(kind == ICStub::GetProp_CallDOMProxyWithGenerationNative);
         MOZ_ASSERT(!expandoSlot.isObject() && !expandoSlot.isUndefined());

js/src/jit/IonBuilder.cpp

@@ -7552,7 +7552,7 @@ IonBuilder::pushReferenceLoadFromTypedObject(MDefinition *typedObj,
 
     types::TemporaryTypeSet *observedTypes = bytecodeTypes(pc);
 
-    MInstruction *load;
+    MInstruction *load = nullptr;  // initialize to silence GCC warning
     BarrierKind barrier = PropertyReadNeedsTypeBarrier(analysisContext, constraints(),
                                                        typedObj, name, observedTypes);
 
@@ -11634,7 +11634,7 @@ IonBuilder::storeReferenceTypedObjectValue(MDefinition *typedObj,
     size_t alignment = ReferenceTypeDescr::alignment(type);
     loadTypedObjectElements(typedObj, byteOffset, alignment, &elements, &scaledOffset, &adjustment);
 
-    MInstruction *store;
+    MInstruction *store = nullptr;  // initialize to silence GCC warning
     switch (type) {
       case ReferenceTypeDescr::TYPE_ANY:
         if (NeedsPostBarrier(info(), value))

js/src/jit/LiveRangeAllocator.cpp

@@ -47,7 +47,7 @@ Requirement::toString() const
     char *cursor = buf;
     char *end = cursor + sizeof(buf);
 
-    int n;
+    int n = -1;  // initialize to silence GCC warning
     switch (kind()) {
       case NONE:
         return "none";

js/src/jit/MCallOptimize.cpp

@@ -2574,7 +2574,7 @@ IonBuilder::inlineConstructSimdObject(CallInfo &callInfo, SimdTypeDescr *descr)
         return InliningStatus_NotInlined;
 
     // Generic constructor of SIMD valuesX4.
-    MIRType simdType;
+    MIRType simdType = MIRType(-1);  // initialize to silence GCC warning
     switch (descr->type()) {
       case SimdTypeDescr::TYPE_INT32:
         simdType = MIRType_Int32x4;

js/src/jit/x64/Lowering-x64.cpp

@@ -171,7 +171,7 @@ LIRGeneratorX64::visitAsmJSStoreHeap(MAsmJSStoreHeap *ins)
                            ? useRegisterAtStart(ptr)
                            : useRegisterOrNonNegativeConstantAtStart(ptr);
 
-    LAsmJSStoreHeap *lir;
+    LAsmJSStoreHeap *lir = nullptr;  // initialize to silence GCC warning
     switch (ins->viewType()) {
       case Scalar::Int8:
       case Scalar::Uint8:

js/src/jsstr.cpp

@@ -182,7 +182,7 @@ str_escape(JSContext *cx, unsigned argc, Value *vp)
         return false;
 
     ScopedJSFreePtr<Latin1Char> newChars;
-    uint32_t newLength;
+    uint32_t newLength = 0;  // initialize to silence GCC warning
     if (str->hasLatin1Chars()) {
         AutoCheckCannotGC nogc;
         newChars = Escape(cx, str->latin1Chars(nogc), str->length(), &newLength);

js/src/vm/String.cpp

@@ -485,8 +485,8 @@ js::ConcatStrings(ExclusiveContext *cx,
                         ? JSInlineString::lengthFits<Latin1Char>(wholeLength)
                         : JSInlineString::lengthFits<char16_t>(wholeLength);
     if (canUseInline && cx->isJSContext()) {
-        Latin1Char *latin1Buf;
-        char16_t *twoByteBuf;
+        Latin1Char *latin1Buf = nullptr;  // initialize to silence GCC warning
+        char16_t *twoByteBuf = nullptr;  // initialize to silence GCC warning
         JSInlineString *str = isLatin1
             ? AllocateInlineString<allowGC>(cx, wholeLength, &latin1Buf)
             : AllocateInlineString<allowGC>(cx, wholeLength, &twoByteBuf);