On Tue, Nov 01, 2011 at 08:23:56PM +0200, Janne Blomqvist wrote: > Hi, > > the attached patch changes the backtracing functionality, which is > used to print a stack trace before aborting when something goes > belly-up, to use the stack unwinding functionality provided by libgcc > instead of using the glibc backtrace_symbols and backtrace_symbols_fd > functions, or the "pstack" utility which is available on some systems > (Solaris?). There are some nice benefits of this: > > - It should work on all targets, not only those which use glibc or pstack. > > - It gets the correct line numbers, whereas the backtrace_symbols_fd > output was usually (but not always) offset by one. This is probably > related to the use of _Unwind_GetIPInfo and in some cases decrementing > the IP. > > - Based on some googling, it's a bit unclear whether backtrace() > and/or backtrace_symbols_fd() actually are async-signal-safe due to > usage of dlsym/dladdr and such. > > It still uses addr2line if available to print out function and file > names and line numbers. If addr2line is not found on the path during > program startup, it resorts to printing out the addresses only. > > Regtested on x86_64-unknown-linux-gnu, Ok for trunk? > > 2011-11-01 Janne Blomqvist <j...@gcc.gnu.org> > > PR fortran/46686 > * configure.ac: Don't check execinfo.h, backtrace, > backtrace_symbols_fd. Check execve instead of execvp. Call > GCC_CHECK_UNWIND_GETIPINFO. > * runtime/backtrace.c: Don't include unused headers, include > limits.h and unwind.h. > (CAN_FORK): Check execve instead of execvp. > (GLIBC_BACKTRACE): Remove. > (bt_header): Conform to gdb backtrace format. > (struct bt_state): New struct. > (trace_function): New function. > (show_backtrace): Use _Unwind_Backtrace from libgcc instead of > glibc backtrace functions.
OK. -- Steve
