Hi everyone, Currently I'm looking into a wrong-code bug and would like to understand a certain optimization done by combine during local transformation. Without LTO I would simply debug cc1 and step through combine. However, with LTO enabled AFAIK I have to debug lto1 instead. In order to get the lto1 command line of interest according to https://gcc.gnu.org/legacy-ml/gcc/2009-11/msg00047.html I have to pass -Wl,-debug to gcc in order to get the command for collect2 to which itself I have to pass -plugin-opt=-debug in order to get the command for lto-wrapper. According to the aforementioned mail I should add option -debug to lto-wrapper, however, it appears to me that option -debug was removed. I gave options -v and -### a chance without luck, i.e., those only print the usual environment variables and afterwards a list of object files like
/tmp/ccPEIV35.ltrans0.ltrans.o /tmp/ccNmpKfS.debug.temp.o /tmp/cceiCIFg.debug.temp.o /tmp/ccZ4Qc7E.debug.temp.o ... but no lto1 command. Thus, how do you retrieve the lto1 command? While desperate I retrieved it manually via strace. However, the lto1 command refers to temporary files which have been erased meanwhile. I actually didn't expect that because I added -save-temps to all the intermediate commands which is also reflected in the environment variable COLLECT_GCC_OPTIONS. Thus, how do you keep temporary files? Cheers, Stefan
