Bug 1283924 - Baldr: tidy how ModuleKind is set (r=sunfish)

MozReview-Commit-ID: 1pZf96RncII

--HG--
extra : rebase_source : a7304a5beb102008c23a5879d99f12e2b099311f

js/src/asmjs/AsmJS.cpp

@@ -310,7 +310,8 @@ struct js::AsmJSMetadata : Metadata, AsmJSMetadataCacheablePod
     }
 
     AsmJSMetadata()
-      : cacheResult(CacheResult::Miss),
+      : Metadata(ModuleKind::AsmJS),
+        cacheResult(CacheResult::Miss),
         srcStart(0),
         srcBodyStart(0),
         strict(false)

js/src/asmjs/WasmCode.h

@@ -419,9 +419,10 @@ class MetadataCacheablePod
     uint32_t              minMemoryLength;
     uint32_t              maxMemoryLength;
 
-    MetadataCacheablePod() {
+    explicit MetadataCacheablePod(ModuleKind kind) {
         mozilla::PodZero(this);
         startFuncIndex_ = NO_START_FUNCTION;
+        this->kind = kind;
     }
 
     bool hasStartFunction() const {
@@ -440,6 +441,7 @@ class MetadataCacheablePod
 
 struct Metadata : ShareableBase<Metadata>, MetadataCacheablePod
 {
+    explicit Metadata(ModuleKind kind = ModuleKind::Wasm) : MetadataCacheablePod(kind) {}
     virtual ~Metadata() {}
 
     MetadataCacheablePod& pod() { return *this; }

js/src/asmjs/WasmGenerator.cpp

@@ -100,6 +100,7 @@ bool
 ModuleGenerator::init(UniqueModuleGeneratorData shared, CompileArgs&& args,
                       Metadata* maybeAsmJSMetadata)
 {
+    shared_ = Move(shared);
     alwaysBaseline_ = args.alwaysBaseline;
 
     if (!exportedFuncs_.init())
@@ -109,20 +110,18 @@ ModuleGenerator::init(UniqueModuleGeneratorData shared, CompileArgs&& args,
 
     // asm.js passes in an AsmJSMetadata subclass to use instead.
     if (maybeAsmJSMetadata) {
-        MOZ_ASSERT(shared->kind == ModuleKind::AsmJS);
         metadata_ = maybeAsmJSMetadata;
+        MOZ_ASSERT(isAsmJS());
     } else {
         metadata_ = js_new<Metadata>();
         if (!metadata_)
             return false;
+        MOZ_ASSERT(!isAsmJS());
     }
 
-    metadata_->kind = shared->kind;
     metadata_->filename = Move(args.filename);
     metadata_->assumptions = Move(args.assumptions);
 
-    shared_ = Move(shared);
-
     // For asm.js, the Vectors in ModuleGeneratorData are max-sized reservations
     // and will be initialized in a linear order via init* functions as the
     // module is generated. For wasm, the Vectors are correctly-sized and