From 22e4a74ff1e9bac5faa14e508579c64e647181a0 Mon Sep 17 00:00:00 2001
From: "oliver@apple.com"
 <oliver@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Date: Thu, 23 Feb 2012 23:18:05 +0000
Subject: [PATCH] Make Interpreter::getStackTrace be able to generate the line
 number for the top callframe if none is provided
 https://bugs.webkit.org/show_bug.cgi?id=79407

Reviewed by Gavin Barraclough.

Outside of exception handling, we don't know what our source line number is.  This
change allows us to pass -1 is as the initial line number, and get the correct line
number in the resultant stack trace.  We can't completely elide the initial line
number (yet) due to some idiosyncrasies of the exception handling machinery.

* interpreter/Interpreter.cpp:
(JSC::getLineNumberForCallFrame):
(JSC):
(JSC::Interpreter::getStackTrace):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@108681 268f45cc-cd09-0410-ab3c-d52691b4dbfc
---
 Source/JavaScriptCore/ChangeLog                   | 17 +++++++++++++++++
 Source/JavaScriptCore/interpreter/Interpreter.cpp | 22 ++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/Source/JavaScriptCore/ChangeLog b/Source/JavaScriptCore/ChangeLog
index 8099f61..cb388cb 100644
--- a/Source/JavaScriptCore/ChangeLog
+++ b/Source/JavaScriptCore/ChangeLog
@@ -1,3 +1,20 @@
+2012-02-23  Oliver Hunt  <oliver@apple.com>
+
+        Make Interpreter::getStackTrace be able to generate the line number for the top callframe if none is provided
+        https://bugs.webkit.org/show_bug.cgi?id=79407
+
+        Reviewed by Gavin Barraclough.
+
+        Outside of exception handling, we don't know what our source line number is.  This
+        change allows us to pass -1 is as the initial line number, and get the correct line
+        number in the resultant stack trace.  We can't completely elide the initial line
+        number (yet) due to some idiosyncrasies of the exception handling machinery.
+
+        * interpreter/Interpreter.cpp:
+        (JSC::getLineNumberForCallFrame):
+        (JSC):
+        (JSC::Interpreter::getStackTrace):
+
 2012-02-22  Filip Pizlo  <fpizlo@apple.com>
 
         DFG OSR exit value profiling should have graceful handling of local variables and arguments
diff --git a/Source/JavaScriptCore/interpreter/Interpreter.cpp b/Source/JavaScriptCore/interpreter/Interpreter.cpp
index eb6a29d..336f109 100644
--- a/Source/JavaScriptCore/interpreter/Interpreter.cpp
+++ b/Source/JavaScriptCore/interpreter/Interpreter.cpp
@@ -817,6 +817,25 @@ static void appendSourceToError(CallFrame* callFrame, ErrorInstance* exception,
     exception->putDirect(*globalData, globalData->propertyNames->message, jsString(globalData, message));
 }
 
+static int getLineNumberForCallFrame(CallFrame* callFrame)
+{
+    callFrame = callFrame->removeHostCallFrameFlag();
+    CodeBlock* codeBlock = callFrame->codeBlock();
+    if (!codeBlock)
+        return -1;
+#if ENABLE(INTERPRETER)
+    if (!globalData->canUseJIT())
+        return codeBlock->lineNumberForBytecodeOffset(callFrame->bytecodeOffsetForNonDFGCode() - 1);
+#endif
+#if ENABLE(JIT)
+#if ENABLE(DFG_JIT)
+    if (codeBlock->getJITType() == JITCode::DFGJIT)
+        return codeBlock->lineNumberForBytecodeOffset(codeBlock->codeOrigin(callFrame->codeOriginIndexForDFG()).bytecodeIndex);
+#endif
+    return codeBlock->lineNumberForBytecodeOffset(callFrame->bytecodeOffsetForNonDFGCode());
+#endif
+}
+
 static CallFrame* getCallerInfo(JSGlobalData* globalData, CallFrame* callFrame, int& lineNumber)
 {
     UNUSED_PARAM(globalData);
@@ -929,6 +948,9 @@ void Interpreter::getStackTrace(JSGlobalData* globalData, int line, Vector<Stack
     if (!callFrame || callFrame == CallFrame::noCaller()) 
         return;
 
+    if (line == -1)
+        line = getLineNumberForCallFrame(callFrame);
+    
     while (callFrame && callFrame != CallFrame::noCaller()) {
         UString sourceURL;
         if (callFrame->codeBlock()) {
-- 
2.7.4