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author | Alex Coplan <alex.coplan@arm.com> | 2020-08-21 14:26:11 +0100 |
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committer | Alex Coplan <alex.coplan@arm.com> | 2020-08-21 14:26:11 +0100 |
commit | b46584d7836bee011facdf946fd7241c748d66f0 (patch) | |
tree | c413688a720f31abff580d02f4a0accd0276ff81 /lto-plugin | |
parent | e7d55c6b81733335d81e35f7c0116bbdffccb682 (diff) | |
download | gcc-b46584d7836bee011facdf946fd7241c748d66f0.zip gcc-b46584d7836bee011facdf946fd7241c748d66f0.tar.gz gcc-b46584d7836bee011facdf946fd7241c748d66f0.tar.bz2 |
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().
Diffstat (limited to 'lto-plugin')
0 files changed, 0 insertions, 0 deletions