I have a project for Mac OS X 10.5 that I'm building on 10.6 using Xcode 3.2. When I use GCC 4.2 for Debug build and hit a breakpoint, Xcode debugger displays local variable information normally. If I choose LLVM GCC 4.2 or Clang LLVM, when I hit breakpoint, local symbols are not available, and GDB says No symbol 'self' in current context if I try to print self or any other local symbol. In all cases Generate debug info option is set. The Debug configuration is set to $(NATIVE_ARCH) and 10.5 SDK, Build active architecture only option is set. When GDB starts, I can see it is being configured as x86_64-apple-darwin. I must be missing something obvious. How do I make GDB show local symbols when using a LLVM compiler?
views:
1308answers:
5
A:
GDB from FSF only added support for JIT code very recently.
I don't know whether Apple-supplied GDB has support for it at all (do you get reasonable stack traces?). If it does, this support is (apparently) incomplete.
Employed Russian
2009-09-04 02:18:57
What makes you think this has anything to do with JIT, or that Apple would ship a gdb that doesn't fully work with the compiler they wrote?
2009-09-04 03:01:54
Stack looks correct, shows all my functions. It's local vars that are missing.
glebd
2009-09-04 09:29:09
But llvm can generate native code, not bytecode.
osgx
2010-02-08 17:01:53
+3
A:
This may help. Try turning off "Link-Time Optimization" in the project's build options. That fixed a problem I had with missing debug symbols.
In fact, that fixed a bunch of weird problems I was having with Clang. I'd say that feature is just too bleeding edge to use yet.
dodgio
2009-11-21 01:38:18
+4
A:
Make sure you're building with Dwarf symbols and no optimization. llvm is a new back-end, and not all of its optimized codegen is hooked up to debug symbol generation yet.
cdespinosa
2009-11-21 05:59:26
+5
A:
For those not familiar, a little more detail to cdespinosa's answer, which worked for me, and which I voted up.
- From the Xcode menu, select Project > Edit Project Settings...
- Choose the Build tab
- In the search box type "Optimization Level", choose that field, and select None.
- Next search for "Debug Information Format", choose that field, and select "DWARF" or "DWARF with dSYM".
Would have put this in comments to his post if I had the privs. ;)
This cost me some serious time, and was frankly kind of sloppy on Apple's part, but in general I can't complain.
Clay Bridges
2010-02-23 03:29:16
A:
I was having this problem and solved it by putting a tick next to the menu item: "Project > Set Active Build Configuration > Debug". Previously, the "Release" option was selected. Locals started showing up in the debugger for my project from then on.
SpaceMonkey
2010-05-05 04:05:17