D39317 made clang use .init_array when no gcc installations is found.
This change changes all gcc installations to use .init_array .
GCC 4.7 by default stopped providing .ctors/.dtors compatible crt files,
and stopped emitting .ctors for __attribute__((constructor)).
.init_array should always work.
FreeBSD rules are moved to FreeBSD.cpp to make Generic_ELF rules clean.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D71434
Very few ELF platforms still use .ctors/.dtors now. Linux (glibc: 1999-07),
DragonFlyBSD, FreeBSD (2012-03) and Solaris have supported .init_array
for many years. Some architectures like AArch64/RISC-V default to
.init_array . GNU ld and gold can even convert .ctors to .init_array .
It makes more sense to flip the CC1 default, and only uses
-fno-use-init-array on platforms that don't support .init_array .
For example, OpenBSD did not support DT_INIT_ARRAY before Aug 2016
(86fa57a279)
I may miss some ELF platforms that still use .ctors, but their
maintainers can easily diagnose such problems.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D71393
Summary:
It seems a bad idea to change the default in the middle of a release
branch due to possible changes in global ctor / dtor ordering between
.ctors and .init_array. With FreeBSD 11.0's release imminent lets change
the default now for FreeBSD 12 (the current development stream) and
later.
FreeBSD rtld has supported .init_array / .fini_array for many years. As
of Jan 1 2017 all supported FreeBSD releases and branches will have
support.
Reviewers: dim, brooks, arichardson
Reviewed By: dim, brooks, arichardson
Subscribers: bsdjhb, krytarowski, emaste, cfe-commits
Differential Revision: https://reviews.llvm.org/D24867
llvm-svn: 336008
clang currently uses .init_array instead of .ctors on Linux if it detects gcc
4.7+. Make it so that it also uses .init_array if no gcc installation is found
at all – if there's no old gcc, there's nothing we need to be compatible with.
icecc for example runs clang in a very small chroot, so before this change
clang would use .ctors if run under icecc. And lld currently silently mislinks
inputs with .ctors sections, so before this clang + icecc + lld would produce
broken binaries. (But this seems like a good change independent of that lld
bug.)
https://reviews.llvm.org/D39317
llvm-svn: 316713
For some regression tests the path to the right toolchain is specified using the -sysroot switch. However, if clang was configured with a custom gcc toolchain (either by using GCC_INSTALL_PREFIX in cmake or the equivalent configure command), the path to the custom gcc toolchain path takes precedence to the one specified by sysroot. This causes several regression tests to fail as they will be using an unexpected path. This patch fixes this issue by adding --gcc-toolchain='' to all tests that rely on that. The empty string causes the driver to pick the path from sysroot instead.
llvm-svn: 225182
Previously, this flag to CC1 was never exposed at the clang driver
layer, and if you happened to enable it (by being on Android or GCC 4.7
platform), you couldn't *disable* it, because there was no 'no' variant.
The whole thing was confusingly implemented.
Now, the target-specific flag processing gets the driver arg list, and
we use standard hasFlag with a default based on the GCC version and/or
Android platform. The user can still pass the 'no-' variant to forcibly
disable the flag, or pass the positive variant to clang itself to enable
the flag.
The test has also been substantially cleaned up and extended to cover
these use cases.
llvm-svn: 168473
The dynamic linker of Android does not support .ctors/.dtors.
We should emit .init_array and .fini_array regardless the
gcc version.
NOTE: This patch does not affect the ARM backend, because
it is required to generate .init_array and .fini_array
for program targeting ARM AAPCS and AEABI.
llvm-svn: 168309
option. On the driver, check if we are using libraries from gcc 4.7 or newer
and if so pass -fuse-init-array to the frontend.
The crtbegin*.o files in gcc 4.7 no longer call the constructors listed in
.ctors, so we have to use .init_array.
llvm-svn: 158694
Fangrui Song