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

src/compiler/wasm-compiler.cc

Index: src/compiler/wasm-compiler.cc
diff --git a/src/compiler/wasm-compiler.cc b/src/compiler/wasm-compiler.cc
index b457efec4ec3e0e34ddd7305b16f1539a29fc631..93f7a78eed3183af122a040c18688a4d27e0fcb0 100644
--- a/src/compiler/wasm-compiler.cc
+++ b/src/compiler/wasm-compiler.cc
@@ -374,6 +374,19 @@ 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;