[lldb] Add GetCurrentException APIs to SBThread, add frame recognizer for objc_exception_throw for Obj-C runtimes

This adds new APIs and a command to deal with exceptions (mostly Obj-C exceptions): SBThread and Thread get GetCurrentException API, which returns an SBValue/ValueObjectSP with the current exception for a thread. "Current" means an exception that is currently being thrown, caught or otherwise processed. In this patch, we only know about the exception when in objc_exception_throw, but subsequent patches will expand this (and add GetCurrentExceptionBacktrace, which will return an SBThread/ThreadSP containing a historical thread backtrace retrieved from the exception object. Currently unimplemented, subsequent patches will implement this).

Extracting the exception from objc_exception_throw is implemented by adding a frame recognizer.

This also add a new sub-command "thread exception", which prints the current exception.

Differential Revision: https://reviews.llvm.org/D43886

llvm-svn: 347813

1 files changed, 5 insertions, 4 deletions

diff --git a/lldb/source/Target/StackFrameRecognizer.cpp b/lldb/source/Target/StackFrameRecognizer.cpp
index f3f090a2a03..152f4a198e2 100644
--- a/lldb/source/Target/StackFrameRecognizer.cpp
+++ b/lldb/source/Target/StackFrameRecognizer.cpp
@@ -49,8 +49,9 @@ ScriptedStackFrameRecognizer::RecognizeFrame(lldb::StackFrameSP frame) {
 
 class StackFrameRecognizerManagerImpl {
 public:
-  void AddRecognizer(StackFrameRecognizerSP recognizer, ConstString &module,
-                     ConstString &symbol, bool first_instruction_only) {
+  void AddRecognizer(StackFrameRecognizerSP recognizer,
+                     const ConstString &module, const ConstString &symbol,
+                     bool first_instruction_only) {
     m_recognizers.push_front({(uint32_t)m_recognizers.size(), false, recognizer, false, module, RegularExpressionSP(),
                               symbol, RegularExpressionSP(),
                               first_instruction_only});
@@ -152,8 +153,8 @@ StackFrameRecognizerManagerImpl &GetStackFrameRecognizerManagerImpl() {
 }
 
 void StackFrameRecognizerManager::AddRecognizer(
-    StackFrameRecognizerSP recognizer, ConstString &module, ConstString &symbol,
-    bool first_instruction_only) {
+    StackFrameRecognizerSP recognizer, const ConstString &module,
+    const ConstString &symbol, bool first_instruction_only) {
   GetStackFrameRecognizerManagerImpl().AddRecognizer(recognizer, module, symbol,
                                                      first_instruction_only);
 }