[PATCH 26/31] Do not redirect calls to __GI_* symbols, when redirecting to *ieee128

["Gabriel F. T. Gomes" <gabriel at inconstante dot net dot br>]

From: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>

On platforms where long double has IEEE binary128 format as a third
option (initially, only powerpc64le), many exported functions are
redirected to their __*ieee128 equivalents.  This redirection is
provided by installed headers such as stdio-ldbl.h, and is supposed to
work correctly with user code.

However, during the build of glibc, similar redirections are employed,
in internal headers such as include/stdio.h, in order to avoid extra PLT
entries.  These redirections conflict with the redirections to
__*ieee128, and must be avoided during the build.  This patch protects
the second redirections with a test for __LONG_DOUBLE_USES_FLOAT128.
---
 include/err.h        |  3 +++
 include/stdio.h      | 14 ++++++++++++--
 include/sys/syslog.h |  5 +++++
 include/wchar.h      |  3 +++
 4 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/include/err.h b/include/err.h
index 7c05cd1dbb..4bfd0f1769 100644
--- a/include/err.h
+++ b/include/err.h
@@ -12,12 +12,15 @@ __vwarn_internal (const char *format, __gnuc_va_list ap,
 
 # ifndef _ISOMAC
 
+#if !defined __LONG_DOUBLE_USES_FLOAT128 \
+  || (defined __LONG_DOUBLE_USES_FLOAT128 && __LONG_DOUBLE_USES_FLOAT128 == 0)
 libc_hidden_proto (warn)
 libc_hidden_proto (warnx)
 libc_hidden_proto (vwarn)
 libc_hidden_proto (vwarnx)
 libc_hidden_proto (verr)
 libc_hidden_proto (verrx)
+#  endif
 
 # endif /* !_ISOMAC */
 #endif /* err.h */
diff --git a/include/stdio.h b/include/stdio.h
index bea2066cd1..8ec801c989 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -13,7 +13,10 @@ extern int __fcloseall (void) attribute_hidden;
 extern int __snprintf (char *__restrict __s, size_t __maxlen,
 		       const char *__restrict __format, ...)
      __attribute__ ((__format__ (__printf__, 3, 4)));
+#  if !defined __LONG_DOUBLE_USES_FLOAT128 \
+  || (defined __LONG_DOUBLE_USES_FLOAT128 && __LONG_DOUBLE_USES_FLOAT128 == 0)
 libc_hidden_proto (__snprintf)
+#  endif
 extern int __vfscanf (FILE *__restrict __s,
 		      const char *__restrict __format,
 		      __gnuc_va_list __arg)
@@ -72,7 +75,8 @@ libc_hidden_proto (__isoc99_vfscanf)
    Unfortunately, symbol redirection is not transitive, so the
    __REDIRECT in the public header does not link up with the above
    libc_hidden_proto.  Bridge the gap with a macro.  */
-#  if !__GLIBC_USE (DEPRECATED_SCANF)
+#  if !__GLIBC_USE (DEPRECATED_SCANF) \
+      && __LONG_DOUBLE_USES_FLOAT128 == 0
 #   undef sscanf
 #   define sscanf __isoc99_sscanf
 #  endif
@@ -150,7 +154,10 @@ libc_hidden_proto (__libc_readline_unlocked);
 extern const char *const _sys_errlist_internal[] attribute_hidden;
 extern int _sys_nerr_internal attribute_hidden;
 
+#if !defined __LONG_DOUBLE_USES_FLOAT128 \
+  || (defined __LONG_DOUBLE_USES_FLOAT128 && __LONG_DOUBLE_USES_FLOAT128 == 0)
 libc_hidden_proto (__asprintf)
+#endif
 #  if IS_IN (libc)
 extern FILE *_IO_new_fopen (const char*, const char*);
 #   define fopen(fname, mode) _IO_new_fopen (fname, mode)
@@ -171,13 +178,16 @@ extern int _IO_new_fgetpos (FILE *, __fpos_t *);
 #   define fgetpos(fp, posp) _IO_new_fgetpos (fp, posp)
 #  endif
 
-libc_hidden_proto (dprintf)
 extern __typeof (dprintf) __dprintf
      __attribute__ ((__format__ (__printf__, 2, 3)));
 libc_hidden_proto (__dprintf)
+#if !defined __LONG_DOUBLE_USES_FLOAT128 \
+  || (defined __LONG_DOUBLE_USES_FLOAT128 && __LONG_DOUBLE_USES_FLOAT128 == 0)
+libc_hidden_proto (dprintf)
 libc_hidden_proto (fprintf)
 libc_hidden_proto (vfprintf)
 libc_hidden_proto (sprintf)
+#endif
 libc_hidden_proto (fwrite)
 libc_hidden_proto (perror)
 libc_hidden_proto (remove)
diff --git a/include/sys/syslog.h b/include/sys/syslog.h
index 89d3479ebc..e10c58f6ef 100644
--- a/include/sys/syslog.h
+++ b/include/sys/syslog.h
@@ -3,7 +3,12 @@
 #include <misc/sys/syslog.h>
 #ifndef _ISOMAC
 
+#include <bits/floatn.h>
+
+#if !defined __LONG_DOUBLE_USES_FLOAT128 \
+  || (defined __LONG_DOUBLE_USES_FLOAT128 && __LONG_DOUBLE_USES_FLOAT128 == 0)
 libc_hidden_proto (syslog)
+#endif
 
 /* __vsyslog_internal uses the same mode_flags bits as
    __v*printf_internal; see libio/libioP.h.  */
diff --git a/include/wchar.h b/include/wchar.h
index 2cb44954fc..4875c9e84c 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -114,7 +114,10 @@ libc_hidden_proto (fputws_unlocked)
 libc_hidden_proto (putwc_unlocked)
 libc_hidden_proto (putwc)
 
+#if !defined __LONG_DOUBLE_USES_FLOAT128 \
+  || (defined __LONG_DOUBLE_USES_FLOAT128 && __LONG_DOUBLE_USES_FLOAT128 == 0)
 libc_hidden_proto (vswscanf)
+#endif
 
 libc_hidden_proto (mbrtowc)
 libc_hidden_proto (wcrtomb)
-- 
2.21.0