[wasm] Generate correct locations for error messages

src/isolate.cc

 // Copyright 2012 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/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 1527 matching lines @@
   Handle<Name> key = factory()->stack_trace_symbol();
   Handle<Object> property =
       JSReceiver::GetDataProperty(Handle<JSObject>::cast(exception), key);
   if (!property->IsJSArray()) return false;
   Handle<JSArray> simple_stack_trace = Handle<JSArray>::cast(property);
 
   Handle<FrameArray> elements(FrameArray::cast(simple_stack_trace->elements()));
 
   const int frame_count = elements->FrameCount();
   for (int i = 0; i < frame_count; i++) {
-    if (elements->IsWasmFrame(i)) {
-      // TODO(clemensh): Handle wasm frames if they ever need handling here.
-      continue;
-    }
-
-    if (elements->IsAsmJsWasmFrame(i)) {
+    if (elements->IsWasmFrame(i) || elements->IsAsmJsWasmFrame(i)) {
       Handle<WasmCompiledModule> compiled_module(
           WasmInstanceObject::cast(elements->WasmInstance(i))
               ->get_compiled_module());
       int func_index = elements->WasmFunctionIndex(i)->value();
       int code_offset = elements->Offset(i)->value();
-      int byte_pos = elements->Code(i)->SourcePosition(code_offset);
-      int source_pos = WasmCompiledModule::GetAsmJsSourcePosition(
-          compiled_module, func_index, byte_pos);
+      // TODO(wasm): Clean this up (bug 5007).
+      int pos = code_offset < 0
+                    ? (-1 - code_offset)
+                    : elements->Code(i)->SourcePosition(code_offset);
+      if (elements->IsAsmJsWasmFrame(i)) {
+        // For asm.js frames, make an additional translation step to get the
+        // asm.js source position.
+        pos = WasmCompiledModule::GetAsmJsSourcePosition(compiled_module,
+                                                         func_index, pos);
+      } else {
+        // For pure wasm, make the function-local position module-relative by
+        // adding the function offset.
+        pos += compiled_module->GetFunctionOffset(func_index);
+      }
       Handle<Script> script = compiled_module->script();
 
-      *target = MessageLocation(script, source_pos, source_pos + 1);
+      *target = MessageLocation(script, pos, pos + 1);
       return true;
     }
 
     Handle<JSFunction> fun = handle(elements->Function(i), this);
     if (!fun->shared()->IsSubjectToDebugging()) continue;
 
     Object* script = fun->shared()->script();
     if (script->IsScript() &&
         !(Script::cast(script)->source()->IsUndefined(this))) {
       AbstractCode* abstract_code = elements->Code(i);
@@ skipping 1941 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8