Issue #1691 - Part 5: Don't pre-create module metadata object when compiling. https://bugzilla.mozilla.org/show_bug.cgi?id=1489477

(cherry picked from commit d83bad49f6b03894548fbf85fc18ad7e8cc19a93)

js/src/frontend/FoldConstants.cpp

@@ -1914,7 +1914,6 @@ Fold(ExclusiveContext* cx, ParseNode** pnp, Parser<FullParseHandler>& parser, bo
 
       case PNK_CALL_IMPORT: {
         BinaryNode* node = &pn->as<BinaryNode>();
-        MOZ_ASSERT(pn->isArity(PN_BINARY));
         MOZ_ASSERT(node->left()->isKind(PNK_POSHOLDER));
         return Fold(cx, node->unsafeRightReference(), parser, inGenexpLambda);
       }

js/src/jit/BaselineCompiler.cpp

@@ -4695,17 +4695,27 @@ BaselineCompiler::emit_JSOP_JUMPTARGET()
     return true;
 }
 
+typedef JSObject* (*GetOrCreateModuleMetaObjectFn)(JSContext*, HandleObject);
+static const VMFunction GetOrCreateModuleMetaObjectInfo =
+    FunctionInfo<GetOrCreateModuleMetaObjectFn>(js::GetOrCreateModuleMetaObject,
+                                                "GetOrCreateModuleMetaObject");
+
 bool
 BaselineCompiler::emit_JSOP_IMPORTMETA()
 {
     RootedModuleObject module(cx, GetModuleObjectForScript(script));
     MOZ_ASSERT(module);
 
-    JSObject* metaObject = GetOrCreateModuleMetaObject(cx, module);
-    if (!metaObject)
-        return false;
+    frame.syncStack(0);
 
-    frame.push(ObjectValue(*metaObject));
+    prepareVMCall();
+    pushArg(ImmGCPtr(module));
+    if (!callVM(GetOrCreateModuleMetaObjectInfo)) {
+        return false;
+    }
+
+    masm.tagValue(JSVAL_TYPE_OBJECT, ReturnReg, R0);
+    frame.push(R0);
     return true;
 }
 

js/src/jit/CodeGenerator.cpp

@@ -2402,6 +2402,18 @@ CodeGenerator::visitNullarySharedStub(LNullarySharedStub* lir)
     }
 }
 
+typedef JSObject* (*GetOrCreateModuleMetaObjectFn)(JSContext*, HandleObject);
+static const VMFunction GetOrCreateModuleMetaObjectInfo =
+    FunctionInfo<GetOrCreateModuleMetaObjectFn>(js::GetOrCreateModuleMetaObject,
+                                                "GetOrCreateModuleMetaObject");
+
+void
+CodeGenerator::visitModuleMetadata(LModuleMetadata* lir)
+{
+    pushArg(ImmPtr(lir->mir()->module()));
+    callVM(GetOrCreateModuleMetaObjectInfo, lir);
+}
+
 typedef JSObject* (*StartDynamicModuleImportFn)(JSContext*, HandleValue, HandleValue);
 static const VMFunction StartDynamicModuleImportInfo =
     FunctionInfo<StartDynamicModuleImportFn>(js::StartDynamicModuleImport,

js/src/jit/CodeGenerator.h

@@ -442,6 +442,7 @@ class CodeGenerator final : public CodeGeneratorSpecific
 
     void visitRandom(LRandom* ins);
     void visitSignExtend(LSignExtend* ins);
+    void visitModuleMetadata(LModuleMetadata* lir);
     void visitDynamicImport(LDynamicImport* lir);
 
 #ifdef DEBUG

js/src/jit/IonBuilder.cpp

@@ -14259,13 +14259,10 @@ IonBuilder::jsop_importmeta()
     ModuleObject* module = GetModuleObjectForScript(script());
     MOZ_ASSERT(module);
 
-    // The object must have been created already when we compiled for baseline.
-    JSObject* metaObject = module->metaObject();
-    MOZ_ASSERT(metaObject);
-
-    pushConstant(ObjectValue(*metaObject));
-
-    return true;
+    MModuleMetadata* meta = MModuleMetadata::New(alloc(), module);
+    current->add(meta);
+    current->push(meta);
+    return resumeAfter(meta);
 }
 
 bool

js/src/jit/Lowering.cpp

@@ -2427,6 +2427,14 @@ LIRGenerator::visitNullarySharedStub(MNullarySharedStub* ins)
     assignSafepoint(lir, ins);
 }
 
+void
+LIRGenerator::visitModuleMetadata(MModuleMetadata* ins)
+{
+    LModuleMetadata* lir = new(alloc()) LModuleMetadata();
+    defineReturn(lir, ins);
+    assignSafepoint(lir, ins);
+}
+
 void
 LIRGenerator::visitDynamicImport(MDynamicImport* ins)
 {

js/src/jit/Lowering.h

@@ -334,6 +334,7 @@ class LIRGenerator : public LIRGeneratorSpecific
     void visitCheckIsCallable(MCheckIsCallable* ins);
     void visitCheckObjCoercible(MCheckObjCoercible* ins);
     void visitDebugCheckSelfHosted(MDebugCheckSelfHosted* ins);
+    void visitModuleMetadata(MModuleMetadata* ins);
     void visitDynamicImport(MDynamicImport* ins);
 };
 

js/src/jit/MIR.h

@@ -8379,6 +8379,33 @@ class MSubstr
     }
 };
 
+class MModuleMetadata : public MNullaryInstruction
+{
+    CompilerObject module_;
+
+    explicit MModuleMetadata(JSObject* module)
+      : module_(module)
+    {
+        setResultType(MIRType::Object);
+    }
+
+  public:
+    INSTRUCTION_HEADER(ModuleMetadata)
+    TRIVIAL_NEW_WRAPPERS
+
+    JSObject* module() const {
+      return module_;
+    }
+
+    AliasSet getAliasSet() const override {
+        return AliasSet::None();
+    }
+
+    bool appendRoots(MRootList& roots) const override {
+        return roots.append(module_);
+    }
+};
+
 class MDynamicImport : public MBinaryInstruction,
                        public BoxInputsPolicy::Data
 {

js/src/jit/MOpcodes.h

@@ -284,6 +284,7 @@ namespace jit {
     _(GlobalNameConflictsCheck)                                             \
     _(Debugger)                                                             \
     _(NewTarget)                                                            \
+    _(ModuleMetadata)                                                       \
     _(DynamicImport)                                                        \
     _(ArrowNewTarget)                                                       \
     _(CheckReturn)                                                          \

js/src/jit/shared/LIR-shared.h

@@ -4939,6 +4939,19 @@ class LNullarySharedStub : public LCallInstructionHelper<BOX_PIECES, 0, 0>
     }
 };
 
+class LModuleMetadata : public LCallInstructionHelper<1, 0, 0>
+{
+  public:
+    LIR_HEADER(ModuleMetadata)
+
+    const MModuleMetadata* mir() const {
+        return mir_->toModuleMetadata();
+    }
+
+    LModuleMetadata()
+    {}
+};
+
 class LDynamicImport : public LCallInstructionHelper<1, 2 * BOX_PIECES, 0>
 {
   public:

js/src/jit/shared/LOpcodes-shared.h

@@ -401,6 +401,7 @@
     _(GlobalNameConflictsCheck)     \
     _(Debugger)                     \
     _(NewTarget)                    \
+    _(ModuleMetadata)               \
     _(DynamicImport)                \
     _(ArrowNewTarget)               \
     _(CheckReturn)                  \