Handle optimized code blocks in debugger stack trace

runtime/vm/debugger.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/debugger.h"
 
 #include "include/dart_api.h"
 
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
@@ skipping 121 matching lines @@
 void CodeBreakpoint::VisitObjectPointers(ObjectPointerVisitor* visitor) {
   visitor->VisitPointer(reinterpret_cast<RawObject**>(&function_));
 }
 
 
 ActivationFrame::ActivationFrame(uword pc, uword fp, uword sp,
                                  const Context& ctx)
     : pc_(pc), fp_(fp), sp_(sp),
       ctx_(Context::ZoneHandle(ctx.raw())),
       function_(Function::ZoneHandle()),
+      code_(Code::ZoneHandle()),
       token_pos_(-1),
       pc_desc_index_(-1),
       line_number_(-1),
       context_level_(-1),
       vars_initialized_(false),
       var_descriptors_(LocalVarDescriptors::ZoneHandle()),
       desc_indices_(8),
       pc_desc_(PcDescriptors::ZoneHandle()) {
 }
 
 
+const Code& ActivationFrame::DartCode() {
+  if (code_.IsNull()) {
+    Isolate* isolate = Isolate::Current();
+    ASSERT(isolate != NULL);
+    code_ = Code::LookupCode(pc_);
+  }
+  return code_;
+}
+
+
 const Function& ActivationFrame::DartFunction() {
   if (function_.IsNull()) {
-    Isolate* isolate = Isolate::Current();
-    ASSERT(isolate != NULL);
-    const Code& code = Code::Handle(Code::LookupCode(pc_));
-    function_ = code.function();
+    function_ = DartCode().function();
   }
   return function_;
 }
 
 
 void Debugger::SignalIsolateEvent(EventType type) {
   if (event_handler_ != NULL) {
     Debugger* debugger = Isolate::Current()->debugger();
     ASSERT(debugger != NULL);
     DebuggerEvent event;
@@ skipping 59 matching lines @@
 
 RawLibrary* ActivationFrame::Library() {
   const Function& func = DartFunction();
   const Class& cls = Class::Handle(func.Owner());
   return cls.library();
 }
 
 
 void ActivationFrame::GetPcDescriptors() {
   if (pc_desc_.IsNull()) {
-    const Function& func = DartFunction();
-    ASSERT(!func.HasOptimizedCode());
-    Code& code = Code::Handle(func.unoptimized_code());
+    const Code& code = DartCode();
     ASSERT(!code.IsNull());
     pc_desc_ = code.pc_descriptors();
     ASSERT(!pc_desc_.IsNull());
   }
 }
 
 
 // Compute token_pos_ and pc_desc_index_.
 intptr_t ActivationFrame::TokenPos() {
   if (token_pos_ < 0) {
@@ skipping 25 matching lines @@
   if (line_number_ < 0) {
     const Script& script = Script::Handle(SourceScript());
     intptr_t ignore_column;
     script.GetTokenLocation(TokenPos(), &line_number_, &ignore_column);
   }
   return line_number_;
 }
 
 
 void ActivationFrame::GetVarDescriptors() {
-  if (!var_descriptors_.IsNull()) {
-    return;
+  if (var_descriptors_.IsNull()) {
+    const Code& code = DartCode();
+    var_descriptors_ = code.var_descriptors();
+    ASSERT(!var_descriptors_.IsNull());
   }
-  ASSERT(!DartFunction().HasOptimizedCode());
-  const Code& code = Code::Handle(DartFunction().unoptimized_code());
-  var_descriptors_ = code.var_descriptors();
-  ASSERT(!var_descriptors_.IsNull());
 }
 
 
 // Calculate the context level at the current token index of the frame.
 intptr_t ActivationFrame::ContextLevel() {
   if (context_level_ < 0) {
     context_level_ = 0;
     intptr_t pc_desc_idx = PcDescIndex();
     ASSERT(!pc_desc_.IsNull());
     if (pc_desc_.DescriptorKind(pc_desc_idx) == PcDescriptors::kReturn) {
@@ skipping 39 matching lines @@
   // Caller uses same context chain.
   return ctx_.raw();
 }
 
 
 void ActivationFrame::GetDescIndices() {
   if (vars_initialized_) {
     return;
   }
   GetVarDescriptors();
-  // TODO(hausner): Consider replacing this GrowableArray.
+
+  // We don't trust variable descriptors in optimized code.
+  // Rather than potentially displaying incorrect values, we
+  // pretend that there are no variables in the frame.
+  // We should be more clever about this in the future.
+  if (DartCode().is_optimized()) {
+    vars_initialized_ = true;
+    return;
+  }
+
   GrowableArray<String*> var_names(8);
   intptr_t activation_token_pos = TokenPos();
   intptr_t var_desc_len = var_descriptors_.Length();
   for (int cur_idx = 0; cur_idx < var_desc_len; cur_idx++) {
     ASSERT(var_names.length() == desc_indices_.length());
     RawLocalVarDescriptors::VarInfo var_info;
     var_descriptors_.GetInfo(cur_idx, &var_info);
     if ((var_info.kind != RawLocalVarDescriptors::kStackVar) &&
         (var_info.kind != RawLocalVarDescriptors::kContextVar)) {
       continue;
@@ skipping 1277 matching lines @@
 }
 
 
 void Debugger::RegisterCodeBreakpoint(CodeBreakpoint* bpt) {
   ASSERT(bpt->next() == NULL);
   bpt->set_next(code_breakpoints_);
   code_breakpoints_ = bpt;
 }
 
 }  // namespace dart