Support for precise stepping in functions compiled before debugging was started (step 2)

src/compiler.cc

Index: src/compiler.cc
diff --git a/src/compiler.cc b/src/compiler.cc
index ba6bb42bfa2862ad21932d47d1e82ea7b3b60f00..400fe0c36bfab37c70c3f5281a0d5f5e95a566be 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -59,7 +59,8 @@ CompilationInfo::CompilationInfo(Handle<Script> script)
       extension_(NULL),
       pre_parse_data_(NULL),
       supports_deoptimization_(false),
-      osr_ast_id_(AstNode::kNoNumber) {
+      osr_ast_id_(AstNode::kNoNumber),
+      compiling_for_debugging_(false) {
   Initialize(NONOPT);
 }
 
@@ -74,7 +75,8 @@ CompilationInfo::CompilationInfo(Handle<SharedFunctionInfo> shared_info)
       extension_(NULL),
       pre_parse_data_(NULL),
       supports_deoptimization_(false),
-      osr_ast_id_(AstNode::kNoNumber) {
+      osr_ast_id_(AstNode::kNoNumber),
+      compiling_for_debugging_(false) {
   Initialize(BASE);
 }
 
@@ -90,7 +92,8 @@ CompilationInfo::CompilationInfo(Handle<JSFunction> closure)
       extension_(NULL),
       pre_parse_data_(NULL),
       supports_deoptimization_(false),
-      osr_ast_id_(AstNode::kNoNumber) {
+      osr_ast_id_(AstNode::kNoNumber),
+      compiling_for_debugging_(false) {
   Initialize(BASE);
 }
 
@@ -308,9 +311,13 @@ static bool MakeCrankshaftCode(CompilationInfo* info) {
 
 
 static bool GenerateCode(CompilationInfo* info) {
-  return V8::UseCrankshaft() ?
-    MakeCrankshaftCode(info) :
-    FullCodeGenerator::MakeCode(info);
+  if (info->CompilingForDebugging()) {

[Kevin Millikin (Chromium), 2011/09/29 10:47:35]

You could piggyback on the existing test so the control flow through here
doesn't get too complicated conditions don't get too complicated:

return V8::UseCrankshaft() && !info->CompilingForDebugging()
    ? MakeCrankshaftCode(info)
    : FullCodeGenerator::MakeCode(info);

or 

return info->CompilingForDebugging() || !V8::UseCrankshaft()
    ? FullCodeGenerator::MakeCode(info)
    : MakeCrankshaftCode(info);

[Søren Thygesen Gjesse, 2011/09/30 08:33:22]

Done.

+    return FullCodeGenerator::MakeCode(info);
+  } else {
+    return V8::UseCrankshaft() ?
+        MakeCrankshaftCode(info) :
+        FullCodeGenerator::MakeCode(info);
+  }
 }