On 2016.05.03 at 16:42 +0200, Dhole wrote: > On 16-04-18 15:04:58, Markus Trippelsdorf wrote: > > A nice follow-up patch would be to set SOURCE_DATE_EPOCH to the current > > time during -fcompare-debug. This would avoid false positives like: > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70679 > > I've been working on a patch to implement that, but I can't manage to > reproduce the false positive from the link. Maybe the test code I'm > using compiles too fast. I'm not familiar with -fcompare-debug either. > > Could you provide me some code with instructions to reproduce this false > positive, to see if my patch is working as expected?
Just building LLVM is enough: markus@x4 llvm_build % time g++ -fcompare-debug -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -fPIC -fvisibility-inlines-hidden -Wall -W -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wno-missing-field-initializers -pedantic -Wno-long-long -Wno-maybe-uninitialized -Wdelete-non-virtual-dtor -Wno-comment -std=c++11 -O2 -pipe -Ilib/Support -I/home/trippels/llvm/lib/Support -Iinclude -I/home/trippels/llvm/include -UNDEBUG -fno-exceptions -fno-rtti -MMD -MT lib/Support/CMakeFiles/LLVMSupport.dir/CommandLine.cpp.o -MF lib/Support/CMakeFiles/LLVMSupport.dir/CommandLine.cpp.o.d -o lib/Support/CMakeFiles/LLVMSupport.dir/CommandLine.cpp.o -c /home/markus/llvm/lib/Support/CommandLine.cpp g++: error: /home/markus/llvm/lib/Support/CommandLine.cpp: -fcompare-debug failure g++ -fcompare-debug -DGTEST_HAS_RTTI=0 -D_DEBUG -D_GNU_SOURCE -fPIC -Wall 5.71s user 0.26s system 101% cpu 5.904 total -- Markus
