[wasm][asm.js] Ensure final validation phase runs.

src/asmjs/asm-wasm-builder.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 // Required to get M_E etc. in MSVC.
 #if defined(_WIN32)
 #define _USE_MATH_DEFINES
 #endif
@@ skipping 49 matching lines @@
         builder_(new (zone) WasmModuleBuilder(zone)),
         current_function_builder_(nullptr),
         literal_(literal),
         isolate_(isolate),
         zone_(zone),
         info_(info),
         ast_value_factory_(ast_value_factory),
         script_(script),
         typer_(typer),
         typer_failed_(false),
+        typer_finished_(false),
         breakable_blocks_(zone),
         foreign_variables_(zone),
         init_function_(nullptr),
         foreign_init_function_(nullptr),
         function_tables_(ZoneHashMap::kDefaultHashMapCapacity,
                          ZoneAllocationPolicy(zone)),
         imported_function_table_(this),
         parent_binop_(nullptr) {
     InitializeAstVisitor(isolate);
   }
@@ skipping 35 matching lines @@
   bool Build() {
     InitializeInitFunction();
     if (!typer_->ValidateBeforeFunctionsPhase()) {
       return false;
     }
     DCHECK(!HasStackOverflow());
     VisitFunctionLiteral(literal_);
     if (HasStackOverflow()) {
       return false;
     }
+    if (!typer_finished_) {
+      typer_->FailWithMessage("Module missing export section.");
+      typer_failed_ = true;
+    }
     if (typer_failed_) {
       return false;
     }
     BuildForeignInitFunction();
     return true;
   }
 
   void VisitVariableDeclaration(VariableDeclaration* decl) {}
 
   void VisitFunctionDeclaration(FunctionDeclaration* decl) {
@@ skipping 180 matching lines @@
   void VisitContinueStatement(ContinueStatement* stmt) {
     DoBreakOrContinue(stmt->target(), true);
   }
 
   void VisitBreakStatement(BreakStatement* stmt) {
     DoBreakOrContinue(stmt->target(), false);
   }
 
   void VisitReturnStatement(ReturnStatement* stmt) {
     if (scope_ == kModuleScope) {
+      if (typer_finished_) {
+        typer_->FailWithMessage("Module has multiple returns.");
+        typer_failed_ = true;
+        return;
+      }
       if (!typer_->ValidateAfterFunctionsPhase()) {
         typer_failed_ = true;
         return;
       }
+      typer_finished_ = true;
       scope_ = kExportScope;
       RECURSE(Visit(stmt->expression()));
       scope_ = kModuleScope;
     } else if (scope_ == kFuncScope) {
       RECURSE(Visit(stmt->expression()));
       current_function_builder_->Emit(kExprReturn);
     } else {
       UNREACHABLE();
     }
   }
@@ skipping 1601 matching lines @@
   WasmModuleBuilder* builder_;
   WasmFunctionBuilder* current_function_builder_;
   FunctionLiteral* literal_;
   Isolate* isolate_;
   Zone* zone_;
   CompilationInfo* info_;
   AstValueFactory* ast_value_factory_;
   Handle<Script> script_;
   AsmTyper* typer_;
   bool typer_failed_;
+  bool typer_finished_;
   ZoneVector<std::pair<BreakableStatement*, bool>> breakable_blocks_;
   ZoneVector<ForeignVariable> foreign_variables_;
   WasmFunctionBuilder* init_function_;
   WasmFunctionBuilder* foreign_init_function_;
   uint32_t next_table_index_;
   ZoneHashMap function_tables_;
   ImportedFunctionTable imported_function_table_;
   // Remember the parent node for reporting the correct location for ToNumber
   // conversions after calls.
   BinaryOperation* parent_binop_;
@@ skipping 23 matching lines @@
   impl.builder_->WriteAsmJsOffsetTable(*asm_offsets_buffer);
   return {module_buffer, asm_offsets_buffer, success};
 }
 
 const char* AsmWasmBuilder::foreign_init_name = "__foreign_init__";
 const char* AsmWasmBuilder::single_function_name = "__single_function__";
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8