[wasm] Add stack checks at the beginning of each function.

src/compiler/wasm-compiler.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/compiler/wasm-compiler.h"
 
 #include <memory>
 
 #include "src/isolate-inl.h"
 
@@ skipping 356 matching lines @@
 }
 
 Node* WasmGraphBuilder::Int32Constant(int32_t value) {
   return jsgraph()->Int32Constant(value);
 }
 
 Node* WasmGraphBuilder::Int64Constant(int64_t value) {
   return jsgraph()->Int64Constant(value);
 }
 
+void WasmGraphBuilder::InitStackCheck(wasm::WasmCodePosition position) {
+  Node* limit = graph()->NewNode(
+      jsgraph()->machine()->Load(MachineType::Pointer()),
+      jsgraph()->ExternalConstant(
+          ExternalReference::address_of_stack_limit(jsgraph()->isolate())),
+      jsgraph()->IntPtrConstant(0), *effect_, *control_);
+  Node* pointer = graph()->NewNode(jsgraph()->machine()->LoadStackPointer());
+
+  Node* check =
+      graph()->NewNode(jsgraph()->machine()->UintLessThan(), limit, pointer);
+  trap_->AddTrapIfFalse(wasm::kTrapStackOverflow, check, position);

[titzer, 2016/08/17 08:23:28]

We'll need to use the regular JS machinery here and not a WASM trap, since
V8/Blink may "request an interrupt" by changing the stack limit, which is not a
stack overflow.

[ahaas, 2016/08/17 09:18:43]

Done.

+}
+
 Node* WasmGraphBuilder::Binop(wasm::WasmOpcode opcode, Node* left, Node* right,
                               wasm::WasmCodePosition position) {
   const Operator* op;
   MachineOperatorBuilder* m = jsgraph()->machine();
   switch (opcode) {
     case wasm::kExprI32Add:
       op = m->Int32Add();
       break;
     case wasm::kExprI32Sub:
       op = m->Int32Sub();
@@ skipping 2840 matching lines @@
                             function_->code_start_offset),
            compile_ms);
   }
 
   return code;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8