On Sat, Mar 3, 2012 at 00:35, FX <fxcoud...@gmail.com> wrote: > Hi all, > > I'll offer my first patch to the new 4.8 trunk. I noticed that the > -fbacktrace option and the GFORTRAN_ERROR_BACKTRACE environment variable are > somewhat inconsistently handled. Currently, the environment variabled doesn't > actually override the compilation option, as it should. So, I set to change > that (checking both options.backtrace and compile_options.backtrace instead > of only the latter) when I realized that we could improve this further by > moving the checking code: it is currently located in the set_options() > function, which is called from the main Fortran routine (call generated by > the front-end). This means that it's not triggered if the main program is C.
Good catch! > Full disclosure: I removed the function maybe_find_addr2line() because it's > not needed anymore now the code was regrouped. However, I'll note that I > don't understand why it was useful before, and that I think the comment on > top of it was wrong (variable "options" could be seen in the function, it was > just shadowed by the local function argument!). Thus, while I was at it, I > renamed the options argument to set_options(), just to make sure we didn't > have a problem of this sort in the future. I added it because, as you say, the argument "options" in set_options() prevented access to the global variable options, and I was lazy and considered a new function faster than renaming the argument. :) > The change was bootstrapped and regtested on x86_64-apple-darwin11, but is an > area not covered by the testsuite. I have manually checked that running > various types of abort, both in a pure Fortran code and a mixed C/Fortran > (with C main), with all combinations -fno-backtrace/GFORTRAN_ERROR_BACKTRACE, > behaved as expected. I don't think it will work if you have a C main program which then calls _gfortran_set_options() to enable backtracing per the mixed-language programming chapter in the manual. You probably need to move the setup code to a separate function which is called both from init and set_options. Also, in the patch as it stands now, you could make find_addr2line static and remove the prototype from libgfortran.h. That being said, I'd recommend moving both find_addr2line and the signal handler setup code to backtrace.c, and then do a bit of janitorial work checking which functions and variables can be made static. -- Janne Blomqvist
