https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106129
--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Joseph Myers <js...@gcc.gnu.org>: https://gcc.gnu.org/g:8a8ee37a3325f1009034245676ef4e482c0444a2 commit r13-1368-g8a8ee37a3325f1009034245676ef4e482c0444a2 Author: Joseph Myers <jos...@codesourcery.com> Date: Thu Jun 30 16:41:40 2022 +0000 lto: Fix option merging [PR106129] The LTO merging of options from different input files was broken by: commit 227a2ecf663d69972b851f51f1934d18927b62cd Author: Martin Liska <mli...@suse.cz> Date: Fri Mar 12 11:53:47 2021 +0100 lto-wrapper: Use vec<cl_decoded_option> data type. Previously, find_and_merge_options would merge options it read into those in *opts. After this commit, options in *opts on entry to find_and_merge_options are ignored; the only merging that takes place is between multiple sets of options in the same input file that are read in the same call to this function (not sure how that case can occur at all). The effects include, for example, that if some objects are built with PIC enabled and others with it disabled, and the last LTO object processed has PIC enabled, the choice of PIC for the last object will result in the whole program being built as PIC, when the merging logic is intended to ensure that a mixture of PIC and non-PIC objects results in the whole program being built as non-PIC. Fix this with an extra argument to find_and_merge_options to determine whether merging should take place. This shows up a second issue with that commit (which I think wasn't actually intended to change code semantics at all): once merging is enabled again, the check for -Xassembler options became an infinite loop in the case where both inputs had -Xassembler options, with the same first option, so fix that loop to restore the previous semantics. Note that I'm not sure how LTO option merging might be tested in the testsuite (clearly there wasn't sufficient, if any, coverage to detect these bugs). Bootstrapped with no regressions for x86_64-pc-linux-gnu. PR lto/106129 * lto-wrapper.cc (find_option): Add argument start. (merge_and_complain): Loop over existing_opt_index and existing_opt2_index for Xassembler check. Update calls to find_option. (find_and_merge_options): Add argument first to determine whether to merge options with those passed in *opts. (run_gcc): Update calls to find_and_merge_options.
