libtool defaults to filtering flags passed at link-time.
This brings the filtering in GCC's 'fork' of libtool into sync with
upstream libtool commit 22a7e547e9857fc94fe5bc7c921d9a4b49c09f8e.
In particular, this now allows some harmless diagnostic flags (especially
useful for things like -Werror=odr), more optimization flags, and some
Clang-specific options.
GCC's -flto documentation mentions:
> To use the link-time optimizer, -flto and optimization options should be
> specified at compile time and during the final link. It is recommended
> that you compile all the files participating in the same link with the
> same options and also specify those options at link time.
This allows compliance with that.
* ltmain.sh (func_mode_link): Allow various flags through filter.
---
We have been using this for a while now downstream.
H.J., please take a look.
I think this also explains
https://src.fedoraproject.org/rpms/binutils/blob/rawhide/f/binutils.spec#_947.
ltmain.sh | 46 ++++++++++++++++++++++++++++++++++------------
1 file changed, 34 insertions(+), 12 deletions(-)
diff --git a/ltmain.sh b/ltmain.sh
index 493e83c36f14..79cd7c57f42e 100644
--- a/ltmain.sh
+++ b/ltmain.sh
@@ -4966,19 +4966,41 @@ func_mode_link ()
arg="$func_quote_for_eval_result"
;;
- # -64, -mips[0-9] enable 64-bit mode on the SGI compiler
- # -r[0-9][0-9]* specifies the processor on the SGI compiler
- # -xarch=*, -xtarget=* enable 64-bit mode on the Sun compiler
- # +DA*, +DD* enable 64-bit mode on the HP compiler
- # -q* pass through compiler args for the IBM compiler
- # -m*, -t[45]*, -txscale* pass through architecture-specific
- # compiler args for GCC
- # -F/path gives path to uninstalled frameworks, gcc on darwin
- # -p, -pg, --coverage, -fprofile-* pass through profiling flag for GCC
- # @file GCC response files
- # -tp=* Portland pgcc target processor selection
+ # Flags to be passed through unchanged, with rationale:
+ # -64, -mips[0-9] enable 64-bit mode for the SGI compiler
+ # -r[0-9][0-9]* specify processor for the SGI compiler
+ # -xarch=*, -xtarget=* enable 64-bit mode for the Sun compiler
+ # +DA*, +DD* enable 64-bit mode for the HP compiler
+ # -q* compiler args for the IBM compiler
+ # -m*, -t[45]*, -txscale* architecture-specific flags for GCC
+ # -F/path path to uninstalled frameworks, gcc on darwin
+ # -p, -pg, --coverage, -fprofile-* profiling flags for GCC
+ # -fstack-protector* stack protector flags for GCC
+ # @file GCC response files
+ # -tp=* Portland pgcc target processor selection
+ # -O*, -g*, -flto*, -fwhopr*, -fuse-linker-plugin GCC link-time
optimization
+ # -specs=* GCC specs files
+ # -stdlib=* select c++ std lib with clang
+ # -fdiagnostics-color* simply affects output
+ # -frecord-gcc-switches used to verify flags were respected
+ # -fsanitize=* Clang/GCC memory and address sanitizer
+ # -fno-sanitize* Clang/GCC memory and address sanitizer
+ # -shared-libsan Link with shared sanitizer runtimes (Clang)
+ # -static-libsan Link with static sanitizer runtimes (Clang)
+ # -fuse-ld=* Linker select flags for GCC
+ # -rtlib=* select c runtime lib with clang
+ # --unwindlib=* select unwinder library with clang
+ # -f{file|debug|macro|profile}-prefix-map=* needed for lto linking
+ # -Wa,* Pass flags directly to the assembler
+ # -Werror, -Werror=* Report (specified) warnings as errors
-64|-mips[0-9]|-r[0-9][0-9]*|-xarch=*|-xtarget=*|+DA*|+DD*|-q*|-m*| \
- -t[45]*|-txscale*|-p|-pg|--coverage|-fprofile-*|-F*|@*|-tp=*)
+ -t[45]*|-txscale*|-p|-pg|--coverage|-fprofile-*|-F*|@*|-tp=*| \
+ -O*|-g*|-flto*|-fwhopr*|-fuse-linker-plugin|-fstack-protector*| \
+ -stdlib=*|-rtlib=*|--unwindlib=*| \
+ -specs=*|-fsanitize=*|-fno-sanitize*|-shared-libsan|-static-libsan| \
+
-ffile-prefix-map=*|-fdebug-prefix-map=*|-fmacro-prefix-map=*|-fprofile-prefix-map=*|
\
+ -fdiagnostics-color*|-frecord-gcc-switches| \
+ -fuse-ld=*|-Wa,*|-Werror|-Werror=*)
func_quote_for_eval "$arg"
arg="$func_quote_for_eval_result"
func_append compile_command " $arg"
--
2.45.2
