math: add LDBL_CLASSIFY_COMPAT support

If a platform does not define "long-double-fcts = yes" in its
Makefiles and it does define __NO_LONG_DOUBLE_MATH in its installed
headers, it will currently create exported symbols for __finitel,
__isinfl, and __isnanl that can't be reached from userspace by
correct use of the finite(), isinf(), or isnan() macros in <math.h>.

To avoid this situation, by default for such platforms we now no
longer export these symbols, thus causing appropriate link-time
errors.  However, for platforms that previously exported these
symbols, we continue to do so as compat symbols; this is enabled
by adding LDBL_CLASSIFY_COMPAT to math_private.h for the platform.

For tile, remove the now-unnecessary exports of those functions from
libc and libm.

1 files changed, 4 insertions, 0 deletions

diff --git a/sysdeps/microblaze/math_private.h b/sysdeps/microblaze/math_private.h
index 73e59df5b9..d82e8bf820 100644
--- a/sysdeps/microblaze/math_private.h
+++ b/sysdeps/microblaze/math_private.h
@@ -26,6 +26,10 @@
 #define libc_feholdexcept_setround(env, exc)   ({ (void) (env); 0; })
 #define libc_feupdateenv_test(env, exc)        ({ (void) (env); 0; })
 
+/* Enable __finitel, __isinfl, and __isnanl for binary compatibility
+   when built without long double support. */
+#define LDBL_CLASSIFY_COMPAT 1
+
 #include_next <math_private.h>
 
 #define feraiseexcept(excepts)                 ({ 0; })