[wasm] Enable wasm frame inspection for debugging

test/mjsunit/wasm/frame-inspection.js

+// 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.
+
+// Flags: --expose-wasm --expose-debug-as debug
+
+load("test/mjsunit/wasm/wasm-constants.js");
+load("test/mjsunit/wasm/wasm-module-builder.js");
+
+Debug = debug.Debug
+
+var exception = null;
+var break_count = 0;
+
+const expected_num_frames = 5;
+const expected_wasm_frames = [false, true, true, false, false];
+const expected_wasm_positions = [0, 1, 2, 0, 0];
+const expected_function_names = ["call_debugger", "wasm_2", "wasm_1", "testFrameInspection", ""];
+
+function listener(event, exec_state, event_data, data) {
+  if (event != Debug.DebugEvent.Break) return;
+  ++break_count;
+  try {
+    var break_id = exec_state.break_id;
+    var frame_count = exec_state.frameCount();
+    assertEquals(expected_num_frames, frame_count);
+
+    for (var i = 0; i < frame_count; ++i) {
+      var frame = exec_state.frame(i);
+      assertEquals(expected_wasm_frames[i], !frame.func().resolved());
+      var wasm_script = null;
+      if (expected_wasm_frames[i]) {
+        var script = frame.details().script();
+        assertNotNull(script);
+        if (wasm_script === null) wasm_script = script;

[ahaas, 2016/06/17 07:25:44]

what's the purpose of this if?

[Clemens Hammacher, 2016/06/17 14:01:46]

You are right, it's pointless :)
I removed it.

+        assertEquals(wasm_script, script);
+        assertEquals(expected_wasm_positions[i], frame.details().sourcePosition());
+        var loc = script.locationFromPosition(frame.details().sourcePosition());
+        assertEquals(expected_wasm_positions[i], loc.column);
+        assertEquals(expected_wasm_positions[i], loc.position);
+      }
+      assertEquals(expected_function_names[i], frame.func().name());
+    }
+  } catch (e) {
+    exception = e;
+  }
+};
+
+var builder = new WasmModuleBuilder();
+
+// wasm_1 calls wasm_2 on offset 2.
+// wasm_2 calls call_debugger on offset 1.
+
+builder.addImport("func", kSig_v_v);
+
+builder.addFunction("wasm_1", kSig_v_v)
+  .addBody([kExprNop, kExprCallFunction, kArity0, 1])
+  .exportAs("main");
+
+builder.addFunction("wasm_2", kSig_v_v)
+  .addBody([kExprCallImport, kArity0, 0]);
+
+function call_debugger() {
+  debugger;
+}
+
+var module = builder.instantiate({func: call_debugger});
+
+(function testFrameInspection() {
+  Debug.setListener(listener);
+  module.exports.main();
+  Debug.setListener(null);
+
+  assertEquals(1, break_count);
+  if (exception) throw exception;
+})();