[asm.js] [wasm] Store function start position for stack check

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 158 matching lines @@
       if (new_func_scope != nullptr) {
         DCHECK_EQ(new_func_scope, decl->scope()->inner_scope());
         if (!decl->scope()->RemoveInnerScope(new_func_scope)) {
           UNREACHABLE();
         }
       }
       return;
     }
     current_function_builder_ = LookupOrInsertFunction(decl->proxy()->var());
     scope_ = kFuncScope;
+
+    // Record start of the function, used as position for the stack check.
+    current_function_builder_->SetAsmFunctionStartPosition(
+        decl->fun()->start_position());
+
     RECURSE(Visit(decl->fun()));
     decl->set_fun(old_func);
     if (new_func_scope != nullptr) {
       DCHECK_EQ(new_func_scope, decl->scope()->inner_scope());
       if (!decl->scope()->RemoveInnerScope(new_func_scope)) {
         UNREACHABLE();
       }
     }
     scope_ = kModuleScope;
     current_function_builder_ = nullptr;
@@ skipping 1790 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