Internal compiler error with Objective-C++ and -fobjc-gc

[llvmbot]

Bugzilla Link	844
Resolution	FIXED
Resolved on	Feb 22, 2010 12:43
Version	trunk
OS	MacOS X
Reporter	LLVM Bugzilla Contributor
CC	@lattner

Extended Description

The following Objective-C++ file causes a reproducible internal compiler error when compiled with
llvm-gcc4 revision 17 from svn://anonsvn.opensource.apple.com/svn/llvm/. The error is only
generated when -fobjc-gc is passed to g++. This occurs even when llvm-gcc4 is built without LLVM
support enabled.

I initially filed this bug with Apple at http://bugreporter.apple.com/ as rdar://problem/4622335,
but they asked that I file it over here.

test.mm

template void foo(T v) { snprintf(v); }

Steps to Reproduce:

1. Put the snippet above in test.mm
2. /path/to/llvm-gcc/bin/g++ -c -o test-no-objc-gc.o test.mm
3. /path/to/llvm-gcc/bin/g++ -c -fobjc-gc -o test-objc-gc.o test.mm

Expected Results:
I expect test-no-objc-gc.o to be created in step 2, and test-objc-gc.o in step 3.

Actual Results:
test-no-objc-gc.o is created in step 2, but step 3 results in an internal compiler error:

test.mm: In function ‘void foo(T)’:
test.mm:1: internal compiler error: Bus error
Please submit a full bug report,
with preprocessed source if appropriate.
See URL:http://developer.apple.com/bugreporter for instructions.

Regression:
This does not occur with:
i686-apple-darwin8-g++-4.0.1 (GCC) 4.0.1 (Apple Computer, Inc. build 5341)

[lattner]

This is definitely an llvm-gcc issue.

[llvmbot]

This is a regression in Apple internal gcc-4.0 compiler snap-shot that we are using as base for llvm-gcc.
It has been fixed in newer Apple internal gcc-4.0 compiler. Whenever we sync llvm-gcc with newer gcc,
we'll get the fix.

[lattner]

FYI, our goal is to do this sync shortly after WWDC occurs in early August.

-Chris

[llvmbot]

This is now fixed.