This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC 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: Regression: incorrect line numbers in debug info since 4.5+


On 25 June 2012 17:15, Peter A. Felvegi wrote:
> Hello,
>
> I found out while single stepping a new template function in gdb that gcc
> generates bad/inaccurate line numbers in the debug info. Optimization was
> turned off, but the execution jumped strangely, see below. gcc-4.4 and the
> current clang produced the expected results, gcc 4.5, 4.6, 4.7, 4.8 all had
> problems. The code was factored out from a proof-of-concept hack.

Which version of GDB?

As documented at http://gcc.gnu.org/gcc-4.5/changes.html

GCC now generates unwind info also for epilogues. DWARF debuginfo
generated by GCC now uses more features of DWARF3 than before, and
also some DWARF4 features. GDB older than 7.0 is not able to handle
either of these, so to debug GCC 4.5 generated binaries or libraries
GDB 7.0 or later is needed. You can disable use of DWARF4 features
with the -gdwarf-3 -gstrict-dwarf options, or use -gdwarf-2
-gstrict-dwarf to restrict GCC to just DWARF2, but epilogue unwind
info is emitted unconditionally whenever unwind info is emitted.


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