[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 371 matching lines @@
 }
 
 Node* WasmGraphBuilder::Int32Constant(int32_t value) {
   return jsgraph()->Int32Constant(value);
 }
 
 Node* WasmGraphBuilder::Int64Constant(int64_t value) {
   return jsgraph()->Int64Constant(value);
 }
 
+void WasmGraphBuilder::StackCheck(wasm::WasmCodePosition position) {
+  // We do not generate stack checks for cctests.
+  if (module_ && !module_->instance->context.is_null()) {
+    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);
+
+    Diamond stack_check(graph(), jsgraph()->common(), check, BranchHint::kTrue);
+
+    Node* effect_true = *effect_;
+
+    Node* effect_false;
+    // Generate a call to the runtime if there is a stack overflow.

[titzer, 2016/08/18 10:55:09]

s/stack overflow/stack check failure/

Since, as mentioned in previous comment, the runtime uses stack checks to
interrupt running programs.

[ahaas, 2016/08/18 17:10:49]

Done.

+    {
+      // Use the module context to call the runtime to throw an exception.
+      Runtime::FunctionId f = Runtime::kStackGuard;
+      const Runtime::Function* fun = Runtime::FunctionForId(f);
+      CallDescriptor* desc = Linkage::GetRuntimeCallDescriptor(
+          jsgraph()->zone(), f, fun->nargs, Operator::kNoProperties,
+          CallDescriptor::kNoFlags);
+      // CEntryStubConstant nodes have to be created and cached in the main
+      // thread. At the moment this is only done for CEntryStubConstant(1).
+      Node* inputs[] = {
+          jsgraph()->CEntryStubConstant(fun->result_size),  // C entry
+          jsgraph()->ExternalConstant(
+              ExternalReference(f, jsgraph()->isolate())),  // ref
+          jsgraph()->Int32Constant(fun->nargs),             // arity
+          HeapConstant(module_->instance->context),         // context
+          *effect_,
+          stack_check.if_false};
+
+      Node* node =
+          graph()->NewNode(jsgraph()->common()->Call(desc),
+                           static_cast<int>(arraysize(inputs)), inputs);
+      effect_false = node;
+    }
+
+    Node* ephi = graph()->NewNode(jsgraph()->common()->EffectPhi(2),
+                                  effect_true, effect_false, stack_check.merge);
+
+    *control_ = stack_check.merge;
+    *effect_ = ephi;
+  }
+}
+
 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 2836 matching lines @@
                             function_->code_start_offset),
            compile_ms);
   }
 
   return code;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8