This is the mail archive of the binutils@sourceware.org mailing list for the binutils project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: gprof does not work with libc_p libraries in ubuntu?


Hi Mark,

I've tried some experiments with the latest Ubuntu and I can't seem to
properly link in the gprof'd standard libraries. The standard gprof'd
libraries aren't linked in when I do:

gcc -g -pg -o testme testme.c

Then when I try to link them in I get:

gcc -g -pg -o testme testme.c -lc_p
testme
Floating point exception (core dumped)

I assume that if you compile without "-pg" that your application then runs without generating a floating point exception ?


The most likely cause for this is the C library's profiling hook code. If you run the pap inside GDB you should be able to track down where the fault is occurring. Alternatively you have run across a compiler bug and the compiler is generating bad code when the -pg switch is used. (in which case this ought to be reported on the gcc list).

Then when I try to remove standard libs, I get a link error (can't
find _Unwind_resume):

gcc -g -pg -o testme testme.c -nodefaultlibs -lc_p -lgcc

Not surprising really since you are preventing the gcc program from adding the necessary standard libraries to the linker command line. Try running the same command without "-nodefaultlibs" but with "-v" added and then compare the linker command line that gcc generates with the one you were using above.


Cheers
  Nick



Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]