Prepare redirections for IEEE long double on powerpc64le

All functions that have a format string, which can consume a long double
argument, must have one version for each long double format supported on
a platform.  On powerpc64le, these functions currently have two versions
(i.e.: long double with the same format as double, and long double with
IBM Extended Precision format).  Support for a third long double format
option (i.e. long double with IEEE long double format) is being prepared
and all the aforementioned functions now have a third version (not yet
exported on the master branch, but the code is in).

For these functions to get selected (during build time), references to
them in user programs (or dependent libraries) must get redirected to
the aforementioned new versions of the functions.  This patch installs
the header magic required to perform such redirections.

Notice, however, that since the redirections only happen when
__LONG_DOUBLE_USES_FLOAT128 is set to 1, and no platform (including
powerpc64le) currently does it, no redirections actually happen.
Redirections and the exporting of the new functions will happen at the
same time (when powerpc64le adds ldbl-128ibm-compat to their Implies.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Reviewed-by: Paul E. Murphy <murphyp@linux.vnet.ibm.com>

2 files changed, 42 insertions, 20 deletions

diff --git a/libio/bits/stdio-ldbl.h b/libio/bits/stdio-ldbl.h
index 6626412fce..3bb9f7dd2c 100644
--- a/libio/bits/stdio-ldbl.h
+++ b/libio/bits/stdio-ldbl.h
@@ -27,9 +27,17 @@ __LDBL_REDIR_DECL (vfprintf)
 __LDBL_REDIR_DECL (vprintf)
 __LDBL_REDIR_DECL (vsprintf)
 #if !__GLIBC_USE (DEPRECATED_SCANF)
+# if defined __LDBL_COMPAT
 __LDBL_REDIR1_DECL (fscanf, __nldbl___isoc99_fscanf)
 __LDBL_REDIR1_DECL (scanf, __nldbl___isoc99_scanf)
 __LDBL_REDIR1_DECL (sscanf, __nldbl___isoc99_sscanf)
+# elif __LONG_DOUBLE_USES_FLOAT128 == 1
+__LDBL_REDIR1_DECL (fscanf, __isoc99_fscanfieee128)
+__LDBL_REDIR1_DECL (scanf, __isoc99_scanfieee128)
+__LDBL_REDIR1_DECL (sscanf, __isoc99_sscanfieee128)
+# else
+#  error bits/stdlib-ldbl.h included when no ldbl redirections are required.
+# endif
 #else
 __LDBL_REDIR_DECL (fscanf)
 __LDBL_REDIR_DECL (scanf)
@@ -43,9 +51,17 @@ __LDBL_REDIR_DECL (vsnprintf)
 
 #ifdef	__USE_ISOC99
 # if !__GLIBC_USE (DEPRECATED_SCANF)
+#  if defined __LDBL_COMPAT
 __LDBL_REDIR1_DECL (vfscanf, __nldbl___isoc99_vfscanf)
 __LDBL_REDIR1_DECL (vscanf, __nldbl___isoc99_vscanf)
 __LDBL_REDIR1_DECL (vsscanf, __nldbl___isoc99_vsscanf)
+#  elif __LONG_DOUBLE_USES_FLOAT128 == 1
+__LDBL_REDIR1_DECL (vfscanf, __isoc99_vfscanfieee128)
+__LDBL_REDIR1_DECL (vscanf, __isoc99_vscanfieee128)
+__LDBL_REDIR1_DECL (vsscanf, __isoc99_vsscanfieee128)
+#  else
+#   error bits/stdlib-ldbl.h included when no ldbl redirections are required.
+#  endif
 # else
 __LDBL_REDIR_DECL (vfscanf)
 __LDBL_REDIR_DECL (vsscanf)
@@ -60,33 +76,33 @@ __LDBL_REDIR_DECL (dprintf)
 
 #ifdef __USE_GNU
 __LDBL_REDIR_DECL (vasprintf)
-__LDBL_REDIR_DECL (__asprintf)
+__LDBL_REDIR2_DECL (asprintf)
 __LDBL_REDIR_DECL (asprintf)
 __LDBL_REDIR_DECL (obstack_printf)
 __LDBL_REDIR_DECL (obstack_vprintf)
 #endif
 
 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
-__LDBL_REDIR_DECL (__sprintf_chk)
-__LDBL_REDIR_DECL (__vsprintf_chk)
+__LDBL_REDIR2_DECL (sprintf_chk)
+__LDBL_REDIR2_DECL (vsprintf_chk)
 # if defined __USE_ISOC99 || defined __USE_UNIX98
-__LDBL_REDIR_DECL (__snprintf_chk)
-__LDBL_REDIR_DECL (__vsnprintf_chk)
+__LDBL_REDIR2_DECL (snprintf_chk)
+__LDBL_REDIR2_DECL (vsnprintf_chk)
 # endif
 # if __USE_FORTIFY_LEVEL > 1
-__LDBL_REDIR_DECL (__fprintf_chk)
-__LDBL_REDIR_DECL (__printf_chk)
-__LDBL_REDIR_DECL (__vfprintf_chk)
-__LDBL_REDIR_DECL (__vprintf_chk)
+__LDBL_REDIR2_DECL (fprintf_chk)
+__LDBL_REDIR2_DECL (printf_chk)
+__LDBL_REDIR2_DECL (vfprintf_chk)
+__LDBL_REDIR2_DECL (vprintf_chk)
 #  ifdef __USE_XOPEN2K8
-__LDBL_REDIR_DECL (__dprintf_chk)
-__LDBL_REDIR_DECL (__vdprintf_chk)
+__LDBL_REDIR2_DECL (dprintf_chk)
+__LDBL_REDIR2_DECL (vdprintf_chk)
 #  endif
 #  ifdef __USE_GNU
-__LDBL_REDIR_DECL (__asprintf_chk)
-__LDBL_REDIR_DECL (__vasprintf_chk)
-__LDBL_REDIR_DECL (__obstack_printf_chk)
-__LDBL_REDIR_DECL (__obstack_vprintf_chk)
+__LDBL_REDIR2_DECL (asprintf_chk)
+__LDBL_REDIR2_DECL (vasprintf_chk)
+__LDBL_REDIR2_DECL (obstack_printf_chk)
+__LDBL_REDIR2_DECL (obstack_vprintf_chk)
 #  endif
 # endif
 #endif
diff --git a/libio/stdio.h b/libio/stdio.h
index 5a10a4d3ee..18e29752c4 100644
--- a/libio/stdio.h
+++ b/libio/stdio.h
@@ -400,9 +400,12 @@ extern int sscanf (const char *__restrict __s,
 		   const char *__restrict __format, ...) __THROW;
 
 /* For historical reasons, the C99-compliant versions of the scanf
-   functions are at alternative names.  When __LDBL_COMPAT is in
-   effect, this is handled in bits/stdio-ldbl.h.  */
-#if !__GLIBC_USE (DEPRECATED_SCANF) && !defined __LDBL_COMPAT
+   functions are at alternative names.  When __LDBL_COMPAT or
+   __LONG_DOUBLE_USES_FLOAT128 are in effect, this is handled in
+   bits/stdio-ldbl.h.  */
+#include <bits/floatn.h>
+#if !__GLIBC_USE (DEPRECATED_SCANF) && !defined __LDBL_COMPAT \
+    && __LONG_DOUBLE_USES_FLOAT128 == 0
 # ifdef __REDIRECT
 extern int __REDIRECT (fscanf, (FILE *__restrict __stream,
 				const char *__restrict __format, ...),
@@ -447,7 +450,8 @@ extern int vsscanf (const char *__restrict __s,
 
 /* Same redirection as above for the v*scanf family.  */
 # if !__GLIBC_USE (DEPRECATED_SCANF)
-#  if defined __REDIRECT && !defined __LDBL_COMPAT
+#  if defined __REDIRECT && !defined __LDBL_COMPAT \
+      && __LONG_DOUBLE_USES_FLOAT128 == 0
 extern int __REDIRECT (vfscanf,
 		       (FILE *__restrict __s,
 			const char *__restrict __format, __gnuc_va_list __arg),
@@ -866,7 +870,9 @@ extern int __overflow (FILE *, int);
 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
 # include <bits/stdio2.h>
 #endif
-#ifdef __LDBL_COMPAT
+
+#include <bits/floatn.h>
+#if defined __LDBL_COMPAT || __LONG_DOUBLE_USES_FLOAT128 == 1
 # include <bits/stdio-ldbl.h>
 #endif