libiberty: Fix build with GCC < 7

Tobias reported on IRC that the linker fails to build with GCC 4.8.5.
In configure I've tried to use everything actually used in the sha1.c
x86 hw implementation, but unfortunately I forgot about implicit function
declarations.  GCC before 7 did have <cpuid.h> header and bit_SHA define
and __get_cpuid function defined inline, but it didn't define
__get_cpuid_count, which compiled fine (and the configure test is
intentionally compile time only) due to implicit function declaration,
but then failed to link when linking the linker, because
__get_cpuid_count wasn't defined anywhere.

The following patch fixes that by using what autoconf uses in AC_CHECK_DECL
to make sure the functions are declared.

2023-12-05  Jakub Jelinek  <jakub@redhat.com>

	* configure.ac (HAVE_X86_SHA1_HW_SUPPORT): Verify __get_cpuid and
	__get_cpuid_count are not implicitly declared.
	* configure: Regenerated.

diff --git a/libiberty/configure b/libiberty/configure
index 10f38511463c85a181ea57e1c058f3cf35cde74b..5c69fee56c1075ec40be77d02734268af5bd333c 100755 (executable)
--- a/libiberty/configure
+++ b/libiberty/configure
@@ -7667,6 +7667,8 @@ void foo (__m128i *buf, unsigned int e, __m128i msg0, __m128i msg1)
 int bar (void)
 {
   unsigned int eax, ebx, ecx, edx;
+  (void) __get_cpuid;
+  (void) __get_cpuid_count;
   if (__get_cpuid_count (7, 0, &eax, &ebx, &ecx, &edx)
       && (ebx & bit_SHA) != 0
       && __get_cpuid (1, &eax, &ebx, &ecx, &edx)

diff --git a/libiberty/configure.ac b/libiberty/configure.ac
index 96a61934ffd095643cfb126b23b29b2d36a1b683..0888e6388965997693950e0c32de0edd3997304e 100644 (file)
--- a/libiberty/configure.ac
+++ b/libiberty/configure.ac
@@ -771,6 +771,8 @@ void foo (__m128i *buf, unsigned int e, __m128i msg0, __m128i msg1)
 int bar (void)
 {
   unsigned int eax, ebx, ecx, edx;
+  (void) __get_cpuid;
+  (void) __get_cpuid_count;
   if (__get_cpuid_count (7, 0, &eax, &ebx, &ecx, &edx)
       && (ebx & bit_SHA) != 0
       && __get_cpuid (1, &eax, &ebx, &ecx, &edx)