Hi, Willy
[...] before:
// ppc64le $ size nolibc-test text data bss dec hex filename 27916 8 80 28004 6d64 nolibc-test // mips $ size nolibc-test text data bss dec hex filename 23276 64 64 23404 5b6c nolibc-testafter:
// ppc64le $ size nolibc-test text data bss dec hex filename 27736 8 80 27824 6cb0 nolibc-test // mips $ size nolibc-test text data bss dec hex filename 23036 64 64 23164 5a7c nolibc-testSuggested-by: Willy Tarreau w@1wt.eu Link: https://lore.kernel.org/lkml/20230806095846.GB10627@1wt.eu/ Link: https://lore.kernel.org/lkml/20230806134348.GA19145@1wt.eu/ Signed-off-by: Zhangjin Wu falcon@tinylab.org
v2 here is further fix up argument with 'const' in the type and also support "void *" argument, v1 is [1].
Tested on many architectures (i386, x86_64, mips, ppc64) and gcc version (from gcc 4.8-13.1.0), compiles well without any warning and errors and also with smaller size.
tools/include/nolibc/sys.h | 52 ++++++++++++++++++++++++++++++-------- 1 file changed, 41 insertions(+), 11 deletions(-)
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index 56f63eb48a1b..9c7448ae19e2 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -35,15 +35,45 @@
- (src/internal/syscall_ret.c) and glibc (sysdeps/unix/sysv/linux/sysdep.h)
*/ -static __inline__ __attribute__((unused, always_inline)) -long __sysret(unsigned long ret) -{
- if (ret >= (unsigned long)-MAX_ERRNO) {
SET_ERRNO(-(long)ret);return -1;- }
- return ret;
-} +/*
- Whether 'type' is a signed type or an unsigned type. Supports scalar types,
- bool and also pointer types. (from include/linux/compiler.h)
- */
+#define __is_signed_type(type) (((type)(-1)) < (type)1)
+/* __auto_type is used instead of __typeof__ to workaround the build error
- 'error: assignment of read-only variable' when the argument has 'const' in
- the type, but __auto_type is a new feature from newer version and it only
- work with 'const' from gcc 11.0 (__GXX_ABI_VERSION = 1016)
- */
+#if __GXX_ABI_VERSION < 1016 +#define __typeofdecl(arg) long +#define __typeofconv1(arg) (long) +#define __typeofconv2(arg) (long) +#else +#define __typeofdecl(arg) __auto_type +#define __typeofconv1(arg) +#define __typeofconv2(arg) (__typeof__(arg)) +#endif
With nolibc-test, we did more tests.
for ppc64le (long better):
// __auto_type $ size nolibc-test text data bss dec hex filename 27736 8 80 27824 6cb0 nolibc-test
// long $ size nolibc-test text data bss dec hex filename 27612 8 80 27700 6c34 nolibc-test
for ppc64 (long better):
// __auto_type $ size nolibc-test text data bss dec hex filename 27136 1880 80 29096 71a8 nolibc-test
// long $ size nolibc-test text data bss dec hex filename 27012 1880 80 28972 712c nolibc-test
A further test on x86_64 (__auto_type better):
// __auto_type $ size nolibc-test text data bss dec hex filename 22206 8 88 22302 571e nolibc-test
// long $ size nolibc-test text data bss dec hex filename 22347 8 88 22443 57ab nolibc-test
And i386 (almost the same):
// __auto_type $ size nolibc-test text data bss dec hex filename 19718 4 52 19774 4d3e nolibc-test
// long $ size nolibc-test text data bss dec hex filename 19717 4 52 19773 4d3d nolibc-test
arm64 (__auto_type better): // __auto_type $ size nolibc-test text data bss dec hex filename 25764 8 80 25852 64fc nolibc-test
// long $ size nolibc-test text data bss dec hex filename 26004 8 80 26092 65ec nolibc-test
arm (the same):
// __auto_type $ size nolibc-test text data bss dec hex filename 19595 0 52 19647 4cbf nolibc-test
// long $ size nolibc-test text data bss dec hex filename 19595 0 52 19647 4cbf nolibc-test
riscv64 (__auto_type better):
// __auto_type $ size nolibc-test text data bss dec hex filename 21814 8 80 21902 558e nolibc-test
// long $ size nolibc-test text data bss dec hex filename 21912 8 80 22000 55f0 nolibc-test
s390 (__auto_type better):
// __auto_type $ size nolibc-test text data bss dec hex filename 22302 0 80 22382 576e nolibc-test
// long $ size nolibc-test text data bss dec hex filename 22438 0 80 22518 57f6 nolibc-test
As a summary, in nolibc-test, for 32-bit architectures, __auto_type has the same as long, for 64-bit architecture, __auto_type has less size than long, only ppc64/ppc64le has reverse result.
BR, Zhangjin
+#define __sysret(arg) \ +({ \
- __typeofdecl(arg) __sysret_arg = __typeofconv1(arg)(arg); \
- if (__is_signed_type(__typeof__(arg))) { \
if (__sysret_arg < 0) { \SET_ERRNO(-(long)__sysret_arg); \__sysret_arg = __typeofconv2(arg)(-1L); \} \- } else { \
if ((unsigned long)__sysret_arg >= (unsigned long)-MAX_ERRNO) { \SET_ERRNO(-(long)__sysret_arg); \__sysret_arg = __typeofconv2(arg)(-1L); \} \- } \
- (__typeof__(arg))__sysret_arg; \
+}) /* Functions in this file only describe syscalls. They're declared static so
- that the compiler usually decides to inline them while still being allowed
@@ -94,7 +124,7 @@ void *sbrk(intptr_t inc) if (ret && sys_brk(ret + inc) == ret + inc) return ret + inc;
- return (void *)__sysret(-ENOMEM);
- return __sysret((void *)-ENOMEM);
} @@ -682,7 +712,7 @@ void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd, static __attribute__((unused)) void *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset) {
- return (void *)__sysret((unsigned long)sys_mmap(addr, length, prot, flags, fd, offset));
- return __sysret(sys_mmap(addr, length, prot, flags, fd, offset));
} static __attribute__((unused)) -- 2.25.1