[turbofan] Support initial step-in through debugger statement.

This adapts the debugger so that the first break event starting the
stepping process can come from optimized code. TurboFan supports a
debugger statement and hence can be the top-most frame whenever the
Debug::HandleDebugBreak handler is triggered.

R=yangguo@chromium.org
TEST=mjsunit/debug,cctest/test-debug

Review URL: https://codereview.chromium.org/1038613002

Cr-Commit-Position: refs/heads/master@{#27447}

src/debug.cc

@@ -1264,8 +1264,12 @@ void Debug::PrepareStep(StepAction step_action,
     return;
   }
 
+  List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
+  frames_it.frame()->Summarize(&frames);
+  FrameSummary summary = frames.first();
+
   // Get the debug info (create it if it does not exist).
-  Handle<JSFunction> function(frame->function());
+  Handle<JSFunction> function(summary.function());
   Handle<SharedFunctionInfo> shared(function->shared());
   if (!EnsureDebugInfo(shared, function)) {
     // Return if ensuring debug info failed.
@@ -1281,7 +1285,7 @@ void Debug::PrepareStep(StepAction step_action,
 
   // PC points to the instruction after the current one, possibly a break
   // location as well. So the "- 1" to exclude it from the search.
-  Address call_pc = frame->pc() - 1;
+  Address call_pc = summary.pc() - 1;
   BreakLocation location =
       BreakLocation::FromAddress(debug_info, ALL_BREAK_LOCATIONS, call_pc);
 
@@ -1348,7 +1352,7 @@ void Debug::PrepareStep(StepAction step_action,
 
     // Remember source position and frame to handle step next.
     thread_local_.last_statement_position_ =
-        debug_info->code()->SourceStatementPosition(frame->pc());
+        debug_info->code()->SourceStatementPosition(summary.pc());
     thread_local_.last_fp_ = frame->UnpaddedFP();
   } else {
     // If there's restarter frame on top of the stack, just get the pointer
@@ -1420,7 +1424,7 @@ void Debug::PrepareStep(StepAction step_action,
       // Object::Get/SetPropertyWithAccessor, otherwise the step action will be
       // propagated on the next Debug::Break.
       thread_local_.last_statement_position_ =
-          debug_info->code()->SourceStatementPosition(frame->pc());
+          debug_info->code()->SourceStatementPosition(summary.pc());
       thread_local_.last_fp_ = frame->UnpaddedFP();
     }
 

src/runtime/runtime-debug.cc

@@ -1552,9 +1552,11 @@ RUNTIME_FUNCTION(Runtime_GetStepInPositions) {
   JavaScriptFrameIterator frame_it(isolate, id);
   RUNTIME_ASSERT(!frame_it.done());
 
-  JavaScriptFrame* frame = frame_it.frame();
+  List<FrameSummary> frames(FLAG_max_inlining_levels + 1);
+  frame_it.frame()->Summarize(&frames);
+  FrameSummary summary = frames.first();
 
-  Handle<JSFunction> fun = Handle<JSFunction>(frame->function());
+  Handle<JSFunction> fun = Handle<JSFunction>(summary.function());
   Handle<SharedFunctionInfo> shared = Handle<SharedFunctionInfo>(fun->shared());
 
   if (!isolate->debug()->EnsureDebugInfo(shared, fun)) {
@@ -1565,7 +1567,7 @@ RUNTIME_FUNCTION(Runtime_GetStepInPositions) {
 
   // Find range of break points starting from the break point where execution
   // has stopped.
-  Address call_pc = frame->pc() - 1;
+  Address call_pc = summary.pc() - 1;
   List<BreakLocation> locations;
   BreakLocation::FromAddressSameStatement(debug_info, ALL_BREAK_LOCATIONS,
                                           call_pc, &locations);
@@ -1575,7 +1577,7 @@ RUNTIME_FUNCTION(Runtime_GetStepInPositions) {
   int index = 0;
   for (BreakLocation location : locations) {
     bool accept;
-    if (location.pc() > frame->pc()) {
+    if (location.pc() > summary.pc()) {
       accept = true;
     } else {
       StackFrame::Id break_frame_id = isolate->debug()->break_frame_id();

test/cctest/cctest.status

@@ -102,11 +102,6 @@
   # BUG(3742).
   'test-mark-compact/MarkCompactCollector': [PASS, ['arch==arm', NO_VARIANTS]],
 
-  # TODO(jarin/mstarzinger): Investigate debugger issues with TurboFan.
-  'test-debug/DebugStepNatives': [PASS, NO_VARIANTS],
-  'test-debug/DebugStepFunctionApply': [PASS, NO_VARIANTS],
-  'test-debug/DebugStepFunctionCall': [PASS, NO_VARIANTS],
-
   # TODO(jarin): Cannot lazy-deoptimize from conversions before comparisons.
   'test-js-typed-lowering/OrderCompareEffects': [SKIP],
 

test/mjsunit/debug-step-turbofan.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --turbo-filter=g --allow-natives-syntax
+// Flags: --expose-debug-as debug --turbo-filter=g --allow-natives-syntax
 
 // Test that Debug::PrepareForBreakPoints can deal with turbofan code (g)
 // on the stack.  Without deoptimization support, we will not be able to

test/mjsunit/mjsunit.status

@@ -96,24 +96,12 @@
   'debug-evaluate-locals': [PASS, NO_VARIANTS],
   'debug-liveedit-check-stack': [PASS, NO_VARIANTS],  # only in no-snap mode.
   'debug-liveedit-double-call': [PASS, NO_VARIANTS],
-  'debug-step-stub-callfunction': [PASS, NO_VARIANTS],
   'debug-set-variable-value': [PASS, NO_VARIANTS],
-  'debug-stepin-accessor': [PASS, NO_VARIANTS],
-  'debug-stepin-builtin': [PASS, NO_VARIANTS],
-  'debug-stepin-constructor': [PASS, NO_VARIANTS],
-  'debug-stepin-function-call': [PASS, NO_VARIANTS],
-  'debug-stepin-positions': [PASS, NO_VARIANTS],
-  'debug-stepin-property-function-call': [PASS, NO_VARIANTS],
-  'debug-stepnext-do-while': [PASS, NO_VARIANTS],
   'debug-stepout-scope-part1': [PASS, NO_VARIANTS],
   'debug-stepout-scope-part2': [PASS, NO_VARIANTS],
   'debug-stepout-scope-part3': [PASS, NO_VARIANTS],
-  'debug-scripts-request': [PASS, NO_VARIANTS],
-  'es6/debug-stepin-microtasks': [PASS, NO_VARIANTS],
-  'es6/debug-stepnext-for': [PASS, NO_VARIANTS],
   'es6/debug-evaluate-blockscopes': [PASS, NO_VARIANTS],
   'regress/regress-crbug-259300': [PASS, NO_VARIANTS],
-  'es6/regress/regress-468661': [PASS, NO_VARIANTS],
 
   ##############################################################################
   # Too slow in debug mode with --stress-opt mode.