Messages in this thread | | | From | Fangrui Song <> | Date | Sun, 5 Nov 2023 12:50:16 -0800 | Subject | Re: [PATCH v1 09/14] DCE/DSE: inhibit .size directive for SHF_GROUP |
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On Fri, Nov 3, 2023 at 9:01 AM Yuan Tan <tanyuan@tinylab.org> wrote: > > .size directive fails in some functions with SHF_GROUP, this is not > really required for normal building, inhibit it to silence the compiling > failures with SHF_GROUP. > > Signed-off-by: Yuan Tan <tanyuan@tinylab.org> > Signed-off-by: Zhangjin Wu <falcon@tinylab.org> > --- > Makefile | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/Makefile b/Makefile > index a4e522b747cb..f67b6e8d2c45 100644 > --- a/Makefile > +++ b/Makefile > @@ -936,6 +936,9 @@ endif > # `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0). > ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION > KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections > +ifdef CONFIG_SECTION_SHF_GROUP_SUPPORT > +KBUILD_CFLAGS_KERNEL += -finhibit-size-directive > +endif > KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y > LDFLAGS_vmlinux += --gc-sections > ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION_DEBUG > -- > 2.34.1 >
Clang doesn't support -finhibit-size-directive, so this would break Clang builds.
GCC has had this option since 1992, but it is not used in the wild. https://gcc.gnu.org/onlinedocs/gcc/Code-Gen-Options.html#index-finhibit-size-directive says
> ... This option is used when compiling crtstuff.c; you should not need to use it for anything else.
What problem have you seen with .size directives (st_size field in symbol table entries)?
% cat a.c int v; void f() {} % diff -u0 <(gcc -S a.c -o -) <(gcc -S -finhibit-size-directive a.c -o -) --- /proc/self/fd/11 2023-11-05 12:42:51.298618475 -0800 +++ /proc/self/fd/15 2023-11-05 12:42:51.298618475 -0800 @@ -7 +6,0 @@ - .size v, 4 @@ -27 +25,0 @@ - .size f, .-f
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