Bug 1242342: Set return type accordingly to the compilation mode; r=luke

js/src/asmjs/WasmBinary.h

@@ -724,6 +724,7 @@ typedef Vector<uint32_t, 0, SystemAllocPolicy> Uint32Vector;
 class FuncBytecode
 {
     // Function metadata
+    ModuleKind kind_;
     const DeclaredSig& sig_;
     ValTypeVector locals_;
     uint32_t lineOrBytecode_;
@@ -742,8 +743,10 @@ class FuncBytecode
                  ValTypeVector&& locals,
                  uint32_t lineOrBytecode,
                  Uint32Vector&& callSiteLineNums,
-                 unsigned generateTime)
-      : sig_(sig),
+                 unsigned generateTime,
+                 ModuleKind kind)
+      : kind_(kind),
+        sig_(sig),
         locals_(Move(locals)),
         lineOrBytecode_(lineOrBytecode),
         callSiteLineNums_(Move(callSiteLineNums)),
@@ -764,6 +767,7 @@ class FuncBytecode
     ValType localType(size_t i) const { return locals_[i]; }
 
     unsigned generateTime() const { return generateTime_; }
+    bool isAsmJS() const { return kind_ == ModuleKind::AsmJS; }
 };
 
 typedef UniquePtr<FuncBytecode> UniqueFuncBytecode;

js/src/asmjs/WasmGenerator.cpp

@@ -488,7 +488,8 @@ ModuleGenerator::finishFuncDef(uint32_t funcIndex, unsigned generateTime, Functi
                                      Move(fg->locals_),
                                      fg->lineOrBytecode_,
                                      Move(fg->callSiteLineNums_),
-                                     generateTime);
+                                     generateTime,
+                                     module_->kind);
     if (!func)
         return false;
 

js/src/asmjs/WasmIonCompile.cpp

@@ -2579,7 +2579,7 @@ EmitRet(FunctionCompiler& f)
         return true;
     }
 
-    MDefinition *def = nullptr;
+    MDefinition* def;
     if (!EmitExpr(f, ret, &def))
         return false;
     f.returnExpr(def);
@@ -2992,12 +2992,20 @@ wasm::IonCompileFunction(IonCompileTask* task)
             return false;
 
         MDefinition* last = nullptr;
-        while (!f.done()) {
-            if (!EmitExprStmt(f, &last))
+        if (func.isAsmJS()) {
+            while (!f.done()) {
+                if (!EmitExprStmt(f, &last))
+                    return false;
+            }
+        } else {
+            if (!EmitExpr(f, f.sig().ret(), &last))
                 return false;
+            MOZ_ASSERT(f.done());
         }
 
-        if (IsVoid(f.sig().ret()) || !last)
+        MOZ_ASSERT(IsVoid(f.sig().ret()) || f.inDeadCode() || last);
+
+        if (IsVoid(f.sig().ret()))
             f.returnVoid();
         else
             f.returnExpr(last);

js/src/asmjs/WasmModule.h

@@ -348,14 +348,6 @@ UsesHeap(HeapUsage heapUsage)
     return bool(heapUsage);
 }
 
-// A Module can either be asm.js or wasm.
-
-enum ModuleKind
-{
-    Wasm,
-    AsmJS
-};
-
 // ModuleCacheablePod holds the trivially-memcpy()able serializable portion of
 // ModuleData.
 

js/src/asmjs/WasmTypes.h

@@ -41,6 +41,14 @@ using mozilla::Move;
 using mozilla::DebugOnly;
 using mozilla::MallocSizeOf;
 
+// A Module can either be asm.js or wasm.
+
+enum ModuleKind
+{
+    Wasm,
+    AsmJS
+};
+
 // The ValType enum represents the WebAssembly "value type", which are used to
 // specify the type of locals and parameters.