| Message ID | 20241231182649.1811734-6-adhemerval.zanella@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | More fixes for building tests with clang | expand |
On Wed, Jan 1, 2025 at 2:27 AM Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote: > > The __ifunc_resolver macro expands to: > > extern __typeof (__redirect_name) name __attribute__ ((ifunc ("iname_ifunc"))); > static __typeof (__redirect_name) *name_ifunc (void) { [...] }; > > And although NAME_IFUNC is and alias for NAME, clang still emits > an 'unused function 'name_ifunc' [-Werror,-Wunused-function]' Why didn't I see it on x86-64 with non-fortify build? > warning. The static is used to avoid name pollution on static > linkage. > --- > elf/ifuncmain9.c | 4 ++++ > elf/tst-ifunc-fault-lazy.c | 4 ++++ > include/libc-symbols.h | 6 +++++- > 3 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/elf/ifuncmain9.c b/elf/ifuncmain9.c > index 654beeadfe..f102b140bd 100644 > --- a/elf/ifuncmain9.c > +++ b/elf/ifuncmain9.c > @@ -22,6 +22,7 @@ > > #include <stdbool.h> > #include <stdio.h> > +#include <libc-diag.h> > > #if __GNUC_PREREQ (5, 5) > /* Do not use the test framework, so that the process setup is not > @@ -41,6 +42,8 @@ implementation (void) > return random_constant; > } > > +DIAG_PUSH_NEEDS_COMMENT_CLANG; > +DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); > static __typeof__ (implementation) * > inhibit_stack_protector > resolver (void) > @@ -50,6 +53,7 @@ resolver (void) > } > > static int magic (void) __attribute__ ((ifunc ("resolver"))); > +DIAG_POP_NEEDS_COMMENT_CLANG; > > int > main (void) > diff --git a/elf/tst-ifunc-fault-lazy.c b/elf/tst-ifunc-fault-lazy.c > index 5157c6cc6c..04448b2b15 100644 > --- a/elf/tst-ifunc-fault-lazy.c > +++ b/elf/tst-ifunc-fault-lazy.c > @@ -21,6 +21,7 @@ > relocations. */ > > #include <config.h> > +#include <libc-diag.h> > > #ifdef HAVE_GCC_IFUNC > > @@ -34,6 +35,8 @@ implementation (void) > *p = 0; > } > > +DIAG_PUSH_NEEDS_COMMENT_CLANG; > +DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); > static __typeof__ (implementation) * > resolver (void) > { > @@ -42,6 +45,7 @@ resolver (void) > *p = 0; > return implementation; > } > +DIAG_POP_NEEDS_COMMENT_CLANG; > > static void magic (void) __attribute__ ((ifunc ("resolver"))); > > diff --git a/include/libc-symbols.h b/include/libc-symbols.h > index 56ae61015d..9fe047f4d3 100644 > --- a/include/libc-symbols.h > +++ b/include/libc-symbols.h > @@ -86,6 +86,7 @@ > > /* Obtain the definition of symbol_version_reference. */ > #include <libc-symver.h> > +#include <libc-diag.h> > > /* When PIC is defined and SHARED isn't defined, we are building PIE > by default. */ > @@ -671,7 +672,10 @@ for linking") > # define __ifunc_args(type_name, name, expr, init, ...) \ > extern __typeof (type_name) name __attribute__ \ > ((ifunc (#name "_ifunc"))); \ > - __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__) > + DIAG_PUSH_NEEDS_COMMENT_CLANG; \ > + DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); \ > + __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__); \ > + DIAG_POP_NEEDS_COMMENT_CLANG; > > # define __ifunc_args_hidden(type_name, name, expr, init, ...) \ > __ifunc_args (type_name, name, expr, init, __VA_ARGS__) > -- > 2.43.0 >
On 31/12/24 18:01, H.J. Lu wrote: > On Wed, Jan 1, 2025 at 2:27 AM Adhemerval Zanella > <adhemerval.zanella@linaro.org> wrote: >> >> The __ifunc_resolver macro expands to: >> >> extern __typeof (__redirect_name) name __attribute__ ((ifunc ("iname_ifunc"))); >> static __typeof (__redirect_name) *name_ifunc (void) { [...] }; >> >> And although NAME_IFUNC is and alias for NAME, clang still emits >> an 'unused function 'name_ifunc' [-Werror,-Wunused-function]' > > Why didn't I see it on x86-64 with non-fortify build? I am not sure, from your cover letter to initially support clang as testing compiler you aimed to support clang-19; while for this patchset I tried with a clang-18 provided by ubuntu-24. I will check if this related to clang version. > >> warning. The static is used to avoid name pollution on static >> linkage. >> --- >> elf/ifuncmain9.c | 4 ++++ >> elf/tst-ifunc-fault-lazy.c | 4 ++++ >> include/libc-symbols.h | 6 +++++- >> 3 files changed, 13 insertions(+), 1 deletion(-) >> >> diff --git a/elf/ifuncmain9.c b/elf/ifuncmain9.c >> index 654beeadfe..f102b140bd 100644 >> --- a/elf/ifuncmain9.c >> +++ b/elf/ifuncmain9.c >> @@ -22,6 +22,7 @@ >> >> #include <stdbool.h> >> #include <stdio.h> >> +#include <libc-diag.h> >> >> #if __GNUC_PREREQ (5, 5) >> /* Do not use the test framework, so that the process setup is not >> @@ -41,6 +42,8 @@ implementation (void) >> return random_constant; >> } >> >> +DIAG_PUSH_NEEDS_COMMENT_CLANG; >> +DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); >> static __typeof__ (implementation) * >> inhibit_stack_protector >> resolver (void) >> @@ -50,6 +53,7 @@ resolver (void) >> } >> >> static int magic (void) __attribute__ ((ifunc ("resolver"))); >> +DIAG_POP_NEEDS_COMMENT_CLANG; >> >> int >> main (void) >> diff --git a/elf/tst-ifunc-fault-lazy.c b/elf/tst-ifunc-fault-lazy.c >> index 5157c6cc6c..04448b2b15 100644 >> --- a/elf/tst-ifunc-fault-lazy.c >> +++ b/elf/tst-ifunc-fault-lazy.c >> @@ -21,6 +21,7 @@ >> relocations. */ >> >> #include <config.h> >> +#include <libc-diag.h> >> >> #ifdef HAVE_GCC_IFUNC >> >> @@ -34,6 +35,8 @@ implementation (void) >> *p = 0; >> } >> >> +DIAG_PUSH_NEEDS_COMMENT_CLANG; >> +DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); >> static __typeof__ (implementation) * >> resolver (void) >> { >> @@ -42,6 +45,7 @@ resolver (void) >> *p = 0; >> return implementation; >> } >> +DIAG_POP_NEEDS_COMMENT_CLANG; >> >> static void magic (void) __attribute__ ((ifunc ("resolver"))); >> >> diff --git a/include/libc-symbols.h b/include/libc-symbols.h >> index 56ae61015d..9fe047f4d3 100644 >> --- a/include/libc-symbols.h >> +++ b/include/libc-symbols.h >> @@ -86,6 +86,7 @@ >> >> /* Obtain the definition of symbol_version_reference. */ >> #include <libc-symver.h> >> +#include <libc-diag.h> >> >> /* When PIC is defined and SHARED isn't defined, we are building PIE >> by default. */ >> @@ -671,7 +672,10 @@ for linking") >> # define __ifunc_args(type_name, name, expr, init, ...) \ >> extern __typeof (type_name) name __attribute__ \ >> ((ifunc (#name "_ifunc"))); \ >> - __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__) >> + DIAG_PUSH_NEEDS_COMMENT_CLANG; \ >> + DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); \ >> + __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__); \ >> + DIAG_POP_NEEDS_COMMENT_CLANG; >> >> # define __ifunc_args_hidden(type_name, name, expr, init, ...) \ >> __ifunc_args (type_name, name, expr, init, __VA_ARGS__) >> -- >> 2.43.0 >> > >
On Wed, Jan 1, 2025 at 2:27 AM Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote: > > The __ifunc_resolver macro expands to: > > extern __typeof (__redirect_name) name __attribute__ ((ifunc ("iname_ifunc"))); > static __typeof (__redirect_name) *name_ifunc (void) { [...] }; > > And although NAME_IFUNC is and alias for NAME, clang still emits > an 'unused function 'name_ifunc' [-Werror,-Wunused-function]' > warning. The static is used to avoid name pollution on static > linkage. > --- > elf/ifuncmain9.c | 4 ++++ > elf/tst-ifunc-fault-lazy.c | 4 ++++ > include/libc-symbols.h | 6 +++++- > 3 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/elf/ifuncmain9.c b/elf/ifuncmain9.c > index 654beeadfe..f102b140bd 100644 > --- a/elf/ifuncmain9.c > +++ b/elf/ifuncmain9.c > @@ -22,6 +22,7 @@ > > #include <stdbool.h> > #include <stdio.h> > +#include <libc-diag.h> > > #if __GNUC_PREREQ (5, 5) > /* Do not use the test framework, so that the process setup is not > @@ -41,6 +42,8 @@ implementation (void) > return random_constant; > } > > +DIAG_PUSH_NEEDS_COMMENT_CLANG; > +DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); These are needed for Clang 18. > static __typeof__ (implementation) * > inhibit_stack_protector > resolver (void) > @@ -50,6 +53,7 @@ resolver (void) > } > > static int magic (void) __attribute__ ((ifunc ("resolver"))); > +DIAG_POP_NEEDS_COMMENT_CLANG; > > int > main (void) > diff --git a/elf/tst-ifunc-fault-lazy.c b/elf/tst-ifunc-fault-lazy.c > index 5157c6cc6c..04448b2b15 100644 > --- a/elf/tst-ifunc-fault-lazy.c > +++ b/elf/tst-ifunc-fault-lazy.c > @@ -21,6 +21,7 @@ > relocations. */ > > #include <config.h> > +#include <libc-diag.h> > > #ifdef HAVE_GCC_IFUNC > > @@ -34,6 +35,8 @@ implementation (void) > *p = 0; > } > > +DIAG_PUSH_NEEDS_COMMENT_CLANG; > +DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); > static __typeof__ (implementation) * > resolver (void) > { > @@ -42,6 +45,7 @@ resolver (void) > *p = 0; > return implementation; > } > +DIAG_POP_NEEDS_COMMENT_CLANG; > > static void magic (void) __attribute__ ((ifunc ("resolver"))); > > diff --git a/include/libc-symbols.h b/include/libc-symbols.h > index 56ae61015d..9fe047f4d3 100644 > --- a/include/libc-symbols.h > +++ b/include/libc-symbols.h > @@ -86,6 +86,7 @@ > > /* Obtain the definition of symbol_version_reference. */ > #include <libc-symver.h> > +#include <libc-diag.h> > > /* When PIC is defined and SHARED isn't defined, we are building PIE > by default. */ > @@ -671,7 +672,10 @@ for linking") > # define __ifunc_args(type_name, name, expr, init, ...) \ > extern __typeof (type_name) name __attribute__ \ > ((ifunc (#name "_ifunc"))); \ > - __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__) > + DIAG_PUSH_NEEDS_COMMENT_CLANG; \ > + DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); \ > + __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__); \ > + DIAG_POP_NEEDS_COMMENT_CLANG; Drop ths. It isn't needed for glibc testing. > # define __ifunc_args_hidden(type_name, name, expr, init, ...) \ > __ifunc_args (type_name, name, expr, init, __VA_ARGS__) > -- > 2.43.0 >
diff --git a/elf/ifuncmain9.c b/elf/ifuncmain9.c index 654beeadfe..f102b140bd 100644 --- a/elf/ifuncmain9.c +++ b/elf/ifuncmain9.c @@ -22,6 +22,7 @@ #include <stdbool.h> #include <stdio.h> +#include <libc-diag.h> #if __GNUC_PREREQ (5, 5) /* Do not use the test framework, so that the process setup is not @@ -41,6 +42,8 @@ implementation (void) return random_constant; } +DIAG_PUSH_NEEDS_COMMENT_CLANG; +DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); static __typeof__ (implementation) * inhibit_stack_protector resolver (void) @@ -50,6 +53,7 @@ resolver (void) } static int magic (void) __attribute__ ((ifunc ("resolver"))); +DIAG_POP_NEEDS_COMMENT_CLANG; int main (void) diff --git a/elf/tst-ifunc-fault-lazy.c b/elf/tst-ifunc-fault-lazy.c index 5157c6cc6c..04448b2b15 100644 --- a/elf/tst-ifunc-fault-lazy.c +++ b/elf/tst-ifunc-fault-lazy.c @@ -21,6 +21,7 @@ relocations. */ #include <config.h> +#include <libc-diag.h> #ifdef HAVE_GCC_IFUNC @@ -34,6 +35,8 @@ implementation (void) *p = 0; } +DIAG_PUSH_NEEDS_COMMENT_CLANG; +DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); static __typeof__ (implementation) * resolver (void) { @@ -42,6 +45,7 @@ resolver (void) *p = 0; return implementation; } +DIAG_POP_NEEDS_COMMENT_CLANG; static void magic (void) __attribute__ ((ifunc ("resolver"))); diff --git a/include/libc-symbols.h b/include/libc-symbols.h index 56ae61015d..9fe047f4d3 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -86,6 +86,7 @@ /* Obtain the definition of symbol_version_reference. */ #include <libc-symver.h> +#include <libc-diag.h> /* When PIC is defined and SHARED isn't defined, we are building PIE by default. */ @@ -671,7 +672,10 @@ for linking") # define __ifunc_args(type_name, name, expr, init, ...) \ extern __typeof (type_name) name __attribute__ \ ((ifunc (#name "_ifunc"))); \ - __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__) + DIAG_PUSH_NEEDS_COMMENT_CLANG; \ + DIAG_IGNORE_NEEDS_COMMENT_CLANG (13, "-Wunused-function"); \ + __ifunc_resolver (type_name, name, expr, init, static, __VA_ARGS__); \ + DIAG_POP_NEEDS_COMMENT_CLANG; # define __ifunc_args_hidden(type_name, name, expr, init, ...) \ __ifunc_args (type_name, name, expr, init, __VA_ARGS__)
The __ifunc_resolver macro expands to: extern __typeof (__redirect_name) name __attribute__ ((ifunc ("iname_ifunc"))); static __typeof (__redirect_name) *name_ifunc (void) { [...] }; And although NAME_IFUNC is and alias for NAME, clang still emits an 'unused function 'name_ifunc' [-Werror,-Wunused-function]' warning. The static is used to avoid name pollution on static linkage. --- elf/ifuncmain9.c | 4 ++++ elf/tst-ifunc-fault-lazy.c | 4 ++++ include/libc-symbols.h | 6 +++++- 3 files changed, 13 insertions(+), 1 deletion(-)