[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, 10 insertions, 0 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py b/lldb/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py
index 8d260b235fc..6959f2ef75d 100644
--- a/lldb/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py
+++ b/lldb/packages/Python/lldbsuite/test/lang/objc/exceptions/TestObjCExceptions.py
@@ -23,6 +23,16 @@ class ObjCExceptionsTestCase(TestBase):
         target = self.dbg.CreateTarget(self.getBuildArtifact("a.out"))
         self.assertTrue(target, VALID_TARGET)
 
+        lldbutil.run_to_name_breakpoint(self, "objc_exception_throw")
+
+        self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,
+                    substrs=['stopped', 'stop reason = breakpoint'])
+
+        self.expect('thread exception', substrs=[
+                '(NSException *) exception = ',
+                'name: "ThrownException" - reason: "SomeReason"',
+            ])
+
         lldbutil.run_to_source_breakpoint(self, "// Set break point at this line.", lldb.SBFileSpec("main.m"))
 
         self.expect("thread list", STOPPED_DUE_TO_BREAKPOINT,