Expose functionality to create a stack trace to internal vm code.

runtime/vm/object.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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 11790 matching lines @@
   const intptr_t len = NumberOfChecks();
   for (intptr_t i = 1; i < len; i++) {
     if (GetTargetAt(i) != first_target.raw()) {
       return false;
     }
   }
   return true;
 }
 
 
-RawICData* ICData::New(const Function& function,
+RawICData* ICData::New(const Function& caller_function,
                        const String& target_name,
                        const Array& arguments_descriptor,
                        intptr_t deopt_id,
                        intptr_t num_args_tested) {
-  ASSERT(!function.IsNull());
+  ASSERT(!caller_function.IsNull());
   ASSERT(!target_name.IsNull());
   ASSERT(!arguments_descriptor.IsNull());
   ASSERT(Object::icdata_class() != Class::null());
   ASSERT(num_args_tested >= 0);
   ICData& result = ICData::Handle();
   {
     // IC data objects are long living objects, allocate them in old generation.
     RawObject* raw = Object::Allocate(ICData::kClassId,
                                       ICData::InstanceSize(),
                                       Heap::kOld);
     NoGCScope no_gc;
     result ^= raw;
   }
-  result.set_function(function);
+  result.set_function(caller_function);
   result.set_target_name(target_name);
   result.set_arguments_descriptor(arguments_descriptor);
   result.set_deopt_id(deopt_id);
   result.set_num_args_tested(num_args_tested);
   result.set_deopt_reason(kDeoptUnknown);
   result.set_is_closure_call(false);
   // Number of array elements in one test entry.
   intptr_t len = result.TestEntryLength();
   // IC data array must be null terminated (sentinel entry).
   const Array& ic_data = Array::Handle(Array::New(len, Heap::kOld));
@@ skipping 6250 matching lines @@
     chars = isolate->current_zone()->Alloc<char>(len + 1);
     OS::SNPrint(chars, (len + 1), kFormatNoCol,
                 frame_index, function_name.ToCString(),
                 url.ToCString(), line);
   }
   frame_strings->Add(chars);
   return len;
 }
 
 
-const char* Stacktrace::ToCStringInternal(intptr_t* frame_index) const {
+const char* Stacktrace::ToCStringInternal(intptr_t* frame_index,
+                                          intptr_t max_frames) const {
   Isolate* isolate = Isolate::Current();
   Function& function = Function::Handle();
   Code& code = Code::Handle();
   // Iterate through the stack frames and create C string description
   // for each frame.
   intptr_t total_len = 0;
   GrowableArray<char*> frame_strings;
-  for (intptr_t i = 0; i < Length(); i++) {
+  for (intptr_t i = 0; (i < Length()) && (*frame_index < max_frames); i++) {
     function = FunctionAtFrame(i);
     if (function.IsNull()) {
       // Check if null function object indicates a stack trace overflow.
       if ((i < (Length() - 1)) &&
           (FunctionAtFrame(i + 1) != Function::null())) {
         const char* kTruncated = "...\n...\n";
         intptr_t truncated_len = strlen(kTruncated) + 1;
         char* chars = isolate->current_zone()->Alloc<char>(truncated_len);
         OS::SNPrint(chars, truncated_len, "%s", kTruncated);
         frame_strings.Add(chars);
       }
     } else if (function.is_visible() || FLAG_verbose_stacktrace) {
       code = CodeAtFrame(i);
       ASSERT(function.raw() == code.function());
       uword pc = code.EntryPoint() + Smi::Value(PcOffsetAtFrame(i));
       if (code.is_optimized() && expand_inlined()) {
         // Traverse inlined frames.
-        for (InlinedFunctionsIterator it(code, pc); !it.Done(); it.Advance()) {
+        for (InlinedFunctionsIterator it(code, pc);
+             !it.Done() && (*frame_index < max_frames); it.Advance()) {
           function = it.function();
           if (function.is_visible() || FLAG_verbose_stacktrace) {
             code = it.code();
             ASSERT(function.raw() == code.function());
             uword pc = it.pc();
             ASSERT(pc != 0);
             ASSERT(code.EntryPoint() <= pc);
             ASSERT(pc < (code.EntryPoint() + code.Size()));
             total_len += PrintOneStacktrace(
                 isolate, &frame_strings, pc, function, code, *frame_index);
+            (*frame_index)++;  // To account for inlined frames.
           }
-          (*frame_index)++;  // To account for inlined frames.
         }
       } else {
         total_len += PrintOneStacktrace(
             isolate, &frame_strings, pc, function, code, *frame_index);
         (*frame_index)++;
       }
     }
   }
 
   // Now concatenate the frame descriptions into a single C string.
@@ skipping 314 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintToJSONStream(JSONStream* stream, bool ref) const {
   Instance::PrintToJSONStream(stream, ref);
 }
 
 
 }  // namespace dart