On Sat, 2015-05-09 at 18:28 -0500, Victor Rodriguez wrote:
I am trying to build the kernel 4.0 with gcc 5 . But I found the following problem :
builtin-report.c comparison of constant ‘-1’ with boolean expression is always false
THe problem is that gcc5 has new warnings:
A new command-line option -Wbool-compare has been added for the C and C++ compilers, which warns about boolean expressions compared with an integer value different from true/false. https://gcc.gnu.org/gcc-5/changes.html
I think the problem is actually that the code is broken. See commit fefd2d9619de ("perf report: Fix branch stack mode cannot be set") in linux-next which links to http://lkml.kernel.org/r/1423967617-28879-1-git-send-email-hekuang@huawei.co... .
I was checking the Makefile of tools/perf/ anda aprently they became every warning into an error. Werror
(tools/perf/Makefile.perf has this line # Define WERROR=0 to disable treating any warnings as errors. Perhaps that might help you get past this build error. I don't know, I never tried it. But the best thing here seems to use that patch. I guess it should eventually show up in the v4.0.y-stable tree.)
Now I wonder if someone is working on this changes so I can take their pathces.
Do you know any easy way that GCC use to avoid this kind of problems
All the help is more than welcome
Hope this helps, Paul Bolle