Author: jingham
Date: Thu Jun 19 13:25:51 2014
New Revision: 211289
URL: http://llvm.org/viewvc/llvm-project?rev=211289&view=rev
Log:
Switch over to using object_getClass to get the class of an object. Previously we were
directly accessing the isa pointer of a class object to get its meta-class, but the isa
pointers are not simple pointers on arm64, so this would cause the stepping to fail.
object_getClass does whatever magic needs doing in this case.
<rdar://problem/17239690>
Modified:
lldb/trunk/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.cpp
Modified: lldb/trunk/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.cpp?rev=211289&r1=211288&r2=211289&view=diff
==============================================================================
--- lldb/trunk/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.cpp (original)
+++ lldb/trunk/source/Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCTrampolineHandler.cpp Thu Jun 19 13:25:51 2014
@@ -50,6 +50,7 @@ extern \"C\"
{ \n\
extern void *class_getMethodImplementation(void *objc_class, void *sel); \n\
extern void *class_getMethodImplementation_stret(void *objc_class, void *sel); \n\
+ extern void * object_getClass (id object); \n\
extern void * sel_getUid(char *name); \n\
extern int printf(const char *format, ...); \n\
} \n\
@@ -101,20 +102,25 @@ extern \"C\" void * __lldb_objc_find_imp
} \n\
else \n\
{ \n\
+ // This code seems a little funny, but has its reasons... \n\
+ // The call to [object class] is here because if this is a class, and has not been called into \n\
+ // yet, we need to do something to force the class to initialize itself. \n\
+ // Then the call to object_getClass will actually return the correct class, either the class \n\
+ // if object is a class instance, or the meta-class if it is a class pointer. \n\
void *class_ptr = (void *) [(id) object class]; \n\
- if (class_ptr == object) \n\
+ return_struct.class_addr = (id) object_getClass((id) object); \n\
+ if (debug) \n\
{ \n\
- struct __lldb_objc_class *class_as_class_struct = (struct __lldb_objc_class *) class_ptr; \n\
- if (debug) \n\
- printf (\"Found a class object, need to return the meta class 0x%p -> 0x%p\\n\", \n\
- class_ptr, class_as_class_struct->isa); \n\
- return_struct.class_addr = class_as_class_struct->isa; \n\
- } \n\
- else \n\
- { \n\
- if (debug) \n\
- printf (\"[object class] returned: 0x%p.\\n\", class_ptr); \n\
- return_struct.class_addr = class_ptr; \n\
+ if (class_ptr == object) \n\
+ { \n\
+ printf (\"Found a class object, need to use the meta class %p -> %p\\n\", \n\
+ class_ptr, return_struct.class_addr); \n\
+ } \n\
+ else \n\
+ { \n\
+ printf (\"[object class] returned: %p object_getClass: %p.\\n\", \n\
+ class_ptr, return_struct.class_addr); \n\
+ } \n\
} \n\
} \n\
\n\
@@ -129,7 +135,7 @@ extern \"C\" void * __lldb_objc_find_imp
char *sel_name = (char *) ((__lldb_msg_ref *) sel)->sel; \n\
return_struct.sel_addr = sel_getUid (sel_name); \n\
if (debug) \n\
- printf (\"\\n*** Got fixed up selector: 0x%p for name %s.\\n\", \n\
+ printf (\"\\n*** Got fixed up selector: %p for name %s.\\n\", \n\
return_struct.sel_addr, sel_name); \n\
} \n\
} \n\
@@ -149,7 +155,7 @@ extern \"C\" void * __lldb_objc_find_imp
return_struct.sel_addr); \n\
} \n\
if (debug) \n\
- printf (\"\\n*** Returning implementation: 0x%p.\\n\", return_struct.impl_addr); \n\
+ printf (\"\\n*** Returning implementation: %p.\\n\", return_struct.impl_addr); \n\
\n\
return return_struct.impl_addr; \n\
} \n\
@@ -158,6 +164,7 @@ const char *AppleObjCTrampolineHandler::
extern \"C\" \n\
{ \n\
extern void *class_getMethodImplementation(void *objc_class, void *sel); \n\
+ extern void * object_getClass (id object); \n\
extern void * sel_getUid(char *name); \n\
extern int printf(const char *format, ...); \n\
} \n\
@@ -209,20 +216,25 @@ extern \"C\" void * __lldb_objc_find_imp
} \n\
else \n\
{ \n\
+ // This code seems a little funny, but has its reasons... \n\
+ // The call to [object class] is here because if this is a class, and has not been called into \n\
+ // yet, we need to do something to force the class to initialize itself. \n\
+ // Then the call to object_getClass will actually return the correct class, either the class \n\
+ // if object is a class instance, or the meta-class if it is a class pointer. \n\
void *class_ptr = (void *) [(id) object class]; \n\
- if (class_ptr == object) \n\
+ return_struct.class_addr = (id) object_getClass((id) object); \n\
+ if (debug) \n\
{ \n\
- struct __lldb_objc_class *class_as_class_struct = (struct __lldb_objc_class *) class_ptr; \n\
- if (debug) \n\
- printf (\"Found a class object, need to return the meta class 0x%p -> 0x%p\\n\", \n\
- class_ptr, class_as_class_struct->isa); \n\
- return_struct.class_addr = class_as_class_struct->isa; \n\
- } \n\
- else \n\
- { \n\
- if (debug) \n\
- printf (\"[object class] returned: 0x%p.\\n\", class_ptr); \n\
- return_struct.class_addr = class_ptr; \n\
+ if (class_ptr == object) \n\
+ { \n\
+ printf (\"Found a class object, need to return the meta class %p -> %p\\n\", \n\
+ class_ptr, return_struct.class_addr); \n\
+ } \n\
+ else \n\
+ { \n\
+ printf (\"[object class] returned: %p object_getClass: %p.\\n\", \n\
+ class_ptr, return_struct.class_addr); \n\
+ } \n\
} \n\
} \n\
\n\
@@ -237,7 +249,7 @@ extern \"C\" void * __lldb_objc_find_imp
char *sel_name = (char *) ((__lldb_msg_ref *) sel)->sel; \n\
return_struct.sel_addr = sel_getUid (sel_name); \n\
if (debug) \n\
- printf (\"\\n*** Got fixed up selector: 0x%p for name %s.\\n\", \n\
+ printf (\"\\n*** Got fixed up selector: %p for name %s.\\n\", \n\
return_struct.sel_addr, sel_name); \n\
} \n\
} \n\