[wasm] Initial signal handler

src/trap-handler/v8-api.cc

+// Copyright 2016 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 <signal.h>
+#include <stdlib.h>
+
+#include "include/v8.h"
+#include "src/trap-handler/trap-handler-internal.h"

[jochen (gone - plz use gerrit), 2017/01/02 07:35:08]

this should either go into src/api.cc or src/api/trap-handler.cc

[Eric Holk, 2017/01/10 23:10:48]

I'd like to keep the signal handling code all under src/trap-handler to
facilitate easy auditing. I added stubs to src/api.cc that call into
src/trap-handler though. Does that work?

+
+namespace {
+
+void HandleSignal(int signum, siginfo_t* info, void* arg) {
+  if (!v8::V8::MaybeHandleFault(signum, info, arg)) {
+    abort();
+  }
+}
+}  // namespace
+
+namespace v8 {
+
+bool V8::MaybeHandleFault(int signum, void* info, void* context) {
+  return v8::internal::trap_handler::MaybeHandleFault(signum, info, context);
+}
+
+bool V8::RegisterDefaultSignalHandler() {
+  struct sigaction action;
+  action.sa_sigaction = HandleSignal;
+  action.sa_flags = SA_SIGINFO;
+  sigemptyset(&action.sa_mask);
+  return sigaction(SIGSEGV, &action, nullptr) == 0;
+}
+
+}  // namespace v8