Running:
$ valgrind ./xgcc -B. -c test.c -march=native
on aarch64 shows a use-after-free in host_detect_local_cpu due
to the std::string result of aarch64_get_extension_string_for_isa_flags
only living until immediately after a c_str call.
This leads to corrupt "-march=" values being passed to cc1.
This patch fixes the use-after-free, though it appears to also need
Tamar's patch here:
https://gcc.gnu.org/ml/gcc-patches/2018-12/msg01302.html
in order to generate valid values for cc1. This may have worked by
accident in the past, if the corrupt "-march=" value happened to be
0-terminated in the "right" place; with this patch it now appears
to reliably break without Tamar's patch.
gcc/ChangeLog:
PR driver/89014
* config/aarch64/driver-aarch64.c (host_detect_local_cpu): Fix
use-after-free of the result of
aarch64_get_extension_string_for_isa_flags.
From-SVN: r268189
