https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63854
--- Comment #33 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Alex Coplan <acop...@gcc.gnu.org>: https://gcc.gnu.org/g:b46584d7836bee011facdf946fd7241c748d66f0 commit r11-2799-gb46584d7836bee011facdf946fd7241c748d66f0 Author: Alex Coplan <alex.cop...@arm.com> Date: Fri Aug 21 14:26:11 2020 +0100 driver: Fix several memory leaks [PR63854] This patch fixes several memory leaks in the driver, all of which relate to the handling of static specs. We introduce functions set_static_spec_{shared,owned}() which are used to enforce proper memory management when updating the strings in the static_specs table. This is achieved by making use of the alloc_p field in the table entries. Similarly to set_spec(), each time we update an entry, we check whether alloc_p is set, and free the old value if so. We then set alloc_p correctly based on whether we "own" this memory or whether we're just taking a pointer to a shared string which we shouldn't free. The following table shows the number of leaks found by AddressSanitizer when running a minimal libgccjit program on AArch64. The test program does the whole libgccjit compilation cycle in a loop (including acquiring and releasing the context), and the table below shows the number of leaks for different iterations of that loop. +--------------+-----+-----+------+---------------+ | # of runs > | 1 | 2 | 3 | Leaks per run | +--------------+-----+-----+------+---------------+ | Before patch | 463 | 940 | 1417 | 477 | +--------------+-----+-----+------+---------------+ | After patch | 416 | 846 | 1276 | 430 | +--------------+-----+-----+------+---------------+ gcc/ChangeLog: PR jit/63854 * gcc.c (set_static_spec): New. (set_static_spec_owned): New. (set_static_spec_shared): New. (driver::maybe_putenv_COLLECT_LTO_WRAPPER): Use set_static_spec_owned() to take ownership of lto_wrapper_file such that it gets freed in driver::finalize. (driver::maybe_run_linker): Use set_static_spec_shared() to ensure that we don't try and free() the static string "ld", also ensuring that any previously-allocated string in linker_name_spec is freed. Likewise with argv0. (driver::finalize): Use set_static_spec_shared() when resetting specs that previously had allocated strings; remove if(0) around call to free().
