Fix i686 build with GCC 9 [committed]

[Joseph Myers <joseph at codesourcery dot com>]

This patch fixes the glibc build for i686 with current mainline GCC,
where there are warnings about inconsistent attributes for aliases in
certain files defining libm IFUNCs.

In three of the files, the aliases were defined in terms of internal
symbols such as __sinf, and copied attributes from file-local
declarations of those functions which lacked the nothrow attribute.
Since the nothrow attribute is present on the declarations from
<math.h> (which include declarations of those __-prefixed functions),
the natural fix was to include <math.h> in those files, replacing the
local declarations.

In the other three files, a more complicated __hidden_ver1 call was
involved in the warnings.  <math.h> has not been included at this
point and, furthermore, it is included indirectly only later in the
source file after macros have been defined to remap a function name
therein.  So there isn't an obvious declaration from which to copy the
attribute and it seems simplest and safest just to add __THROW to the
hidden_ver1 calls.

Tested for i686 (build-many-glibcs.py compilers build for
x86_64-linux-gnu with GCC mainline; full testsuite run with GCC 7).  
Committed.

2018-11-12  Joseph Myers  <joseph@codesourcery.com>

	* sysdeps/i386/i686/fpu/multiarch/e_expf.c [SHARED]: Use __THROW
	with __hidden_ver1 call.
	* sysdeps/i386/i686/fpu/multiarch/e_log2f.c [SHARED]: Likewise.
	* sysdeps/i386/i686/fpu/multiarch/e_logf.c [SHARED]: Likewise.
	* sysdeps/i386/i686/fpu/multiarch/s_cosf.c: Include <math.h>.
	(__cosf): Do not declare here.
	* sysdeps/i386/i686/fpu/multiarch/s_sincosf.c: Include <math.h>.
	(__sincosf): Do not declare here.
	* sysdeps/i386/i686/fpu/multiarch/s_sinf.c: Include <math.h>.
	(__sinf): Do not declare here.

diff --git a/sysdeps/i386/i686/fpu/multiarch/e_expf.c b/sysdeps/i386/i686/fpu/multiarch/e_expf.c
index 1f7c35701b..d11ca309a7 100644
--- a/sysdeps/i386/i686/fpu/multiarch/e_expf.c
+++ b/sysdeps/i386/i686/fpu/multiarch/e_expf.c
@@ -26,7 +26,7 @@ libc_ifunc_redirected (__redirect_expf, __expf, IFUNC_SELECTOR ());
 #include <libm-alias-float.h>
 #ifdef SHARED
 __hidden_ver1 (__expf_ia32, __GI___expf, __redirect_expf)
-  __attribute__ ((visibility ("hidden")));
+  __attribute__ ((visibility ("hidden"))) __THROW;
 
 # include <shlib-compat.h>
 versioned_symbol (libm, __expf, expf, GLIBC_2_27);
diff --git a/sysdeps/i386/i686/fpu/multiarch/e_log2f.c b/sysdeps/i386/i686/fpu/multiarch/e_log2f.c
index 3dacaa609e..9c11536604 100644
--- a/sysdeps/i386/i686/fpu/multiarch/e_log2f.c
+++ b/sysdeps/i386/i686/fpu/multiarch/e_log2f.c
@@ -26,7 +26,7 @@ libc_ifunc_redirected (__redirect_log2f, __log2f, IFUNC_SELECTOR ());
 #include <libm-alias-float.h>
 #ifdef SHARED
 __hidden_ver1 (__log2f_ia32, __GI___log2f, __redirect_log2f)
-  __attribute__ ((visibility ("hidden")));
+  __attribute__ ((visibility ("hidden"))) __THROW;
 
 # include <shlib-compat.h>
 versioned_symbol (libm, __log2f, log2f, GLIBC_2_27);
diff --git a/sysdeps/i386/i686/fpu/multiarch/e_logf.c b/sysdeps/i386/i686/fpu/multiarch/e_logf.c
index 1ce90e2e05..070e8b7175 100644
--- a/sysdeps/i386/i686/fpu/multiarch/e_logf.c
+++ b/sysdeps/i386/i686/fpu/multiarch/e_logf.c
@@ -26,7 +26,7 @@ libc_ifunc_redirected (__redirect_logf, __logf, IFUNC_SELECTOR ());
 #include <libm-alias-float.h>
 #ifdef SHARED
 __hidden_ver1 (__logf_ia32, __GI___logf, __redirect_logf)
-  __attribute__ ((visibility ("hidden")));
+  __attribute__ ((visibility ("hidden"))) __THROW;
 
 # include <shlib-compat.h>
 versioned_symbol (libm, __logf, logf, GLIBC_2_27);
diff --git a/sysdeps/i386/i686/fpu/multiarch/s_cosf.c b/sysdeps/i386/i686/fpu/multiarch/s_cosf.c
index a4556a478d..52951186cc 100644
--- a/sysdeps/i386/i686/fpu/multiarch/s_cosf.c
+++ b/sysdeps/i386/i686/fpu/multiarch/s_cosf.c
@@ -18,10 +18,10 @@
 
 #include <init-arch.h>
 #include <libm-alias-float.h>
+#include <math.h>
 
 extern float __cosf_sse2 (float);
 extern float __cosf_ia32 (float);
-float __cosf (float);
 
 libm_ifunc (__cosf, HAS_CPU_FEATURE (SSE2) ? __cosf_sse2 : __cosf_ia32);
 libm_alias_float (__cos, cos);
diff --git a/sysdeps/i386/i686/fpu/multiarch/s_sincosf.c b/sysdeps/i386/i686/fpu/multiarch/s_sincosf.c
index 5f21f5c0ed..164c97ba7b 100644
--- a/sysdeps/i386/i686/fpu/multiarch/s_sincosf.c
+++ b/sysdeps/i386/i686/fpu/multiarch/s_sincosf.c
@@ -18,10 +18,10 @@
 
 #include <init-arch.h>
 #include <libm-alias-float.h>
+#include <math.h>
 
 extern void __sincosf_sse2 (float, float *, float *);
 extern void __sincosf_ia32 (float, float *, float *);
-void __sincosf (float, float *, float *);
 
 libm_ifunc (__sincosf,
 	    HAS_CPU_FEATURE (SSE2) ? __sincosf_sse2 : __sincosf_ia32);
diff --git a/sysdeps/i386/i686/fpu/multiarch/s_sinf.c b/sysdeps/i386/i686/fpu/multiarch/s_sinf.c
index 80a7ffaa1e..c69976b2ec 100644
--- a/sysdeps/i386/i686/fpu/multiarch/s_sinf.c
+++ b/sysdeps/i386/i686/fpu/multiarch/s_sinf.c
@@ -18,10 +18,10 @@
 
 #include <init-arch.h>
 #include <libm-alias-float.h>
+#include <math.h>
 
 extern float __sinf_sse2 (float);
 extern float __sinf_ia32 (float);
-float __sinf (float);
 
 libm_ifunc (__sinf, HAS_CPU_FEATURE (SSE2) ? __sinf_sse2 : __sinf_ia32);
 libm_alias_float (__sin, sin);

-- 
Joseph S. Myers
joseph@codesourcery.com