Refactor strtod parsing of NaN payloads.

The nan* functions handle their string argument by constructing a
NAN(...) string on the stack as a VLA and passing it to strtod
functions.

This approach has problems discussed in bug 16961 and bug 16962: the
stack usage is unbounded, and it gives incorrect results in certain
cases where the argument is not a valid n-char-sequence.

The natural fix for both issues is to refactor the NaN payload parsing
out of strtod into a separate function that the nan* functions can
call directly, so that no temporary string needs constructing on the
stack at all.  This patch does that refactoring in preparation for
fixing those bugs (but without actually using the new functions from
nan* - which will also require exporting them from libc at version
GLIBC_PRIVATE).  This patch is not intended to change any user-visible
behavior, so no tests are added (fixes for the above bugs will of
course add tests for them).

This patch builds on my recent fixes for strtol and strtod issues in
Turkish locales.  Given those fixes, the parsing of NaN payloads is
locale-independent; thus, the new functions do not need to take a
locale_t argument.

Tested for x86_64, x86, mips64 and powerpc.

	* stdlib/strtod_nan.c: New file.
	* stdlib/strtod_nan_double.h: Likewise.
	* stdlib/strtod_nan_float.h: Likewise.
	* stdlib/strtod_nan_main.c: Likewise.
	* stdlib/strtod_nan_narrow.h: Likewise.
	* stdlib/strtod_nan_wide.h: Likewise.
	* stdlib/strtof_nan.c: Likewise.
	* stdlib/strtold_nan.c: Likewise.
	* sysdeps/ieee754/ldbl-128/strtod_nan_ldouble.h: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/strtod_nan_ldouble.h: Likewise.
	* sysdeps/ieee754/ldbl-96/strtod_nan_ldouble.h: Likewise.
	* wcsmbs/wcstod_nan.c: Likewise.
	* wcsmbs/wcstof_nan.c: Likewise.
	* wcsmbs/wcstold_nan.c: Likewise.
	* stdlib/Makefile (routines): Add strtof_nan, strtod_nan and
	strtold_nan.
	* wcsmbs/Makefile (routines): Add wcstod_nan, wcstold_nan and
	wcstof_nan.
	* include/stdlib.h (__strtof_nan): Declare and use
	libc_hidden_proto.
	(__strtod_nan): Likewise.
	(__strtold_nan): Likewise.
	(__wcstof_nan): Likewise.
	(__wcstod_nan): Likewise.
	(__wcstold_nan): Likewise.
	* include/wchar.h (____wcstoull_l_internal): Declare.
	* stdlib/strtod_l.c: Do not include <ieee754.h>.
	(____strtoull_l_internal): Remove declaration.
	(STRTOF_NAN): Define macro.
	(SET_MANTISSA): Remove macro.
	(STRTOULL): Likewise.
	(____STRTOF_INTERNAL): Use STRTOF_NAN to parse NaN payload.
	* stdlib/strtof_l.c (____strtoull_l_internal): Remove declaration.
	(STRTOF_NAN): Define macro.
	(SET_MANTISSA): Remove macro.
	* sysdeps/ieee754/ldbl-128/strtold_l.c (STRTOF_NAN): Define macro.
	(SET_MANTISSA): Remove macro.
	* sysdeps/ieee754/ldbl-128ibm/strtold_l.c (STRTOF_NAN): Define
	macro.
	(SET_MANTISSA): Remove macro.
	* sysdeps/ieee754/ldbl-64-128/strtold_l.c (STRTOF_NAN): Define
	macro.
	(SET_MANTISSA): Remove macro.
	* sysdeps/ieee754/ldbl-96/strtold_l.c (STRTOF_NAN): Define macro.
	(SET_MANTISSA): Remove macro.
	* wcsmbs/wcstod_l.c (____wcstoull_l_internal): Remove declaration.
	* wcsmbs/wcstof_l.c (____wcstoull_l_internal): Likewise.
	* wcsmbs/wcstold_l.c (____wcstoull_l_internal): Likewise.

1 files changed, 9 insertions, 39 deletions

diff --git a/stdlib/strtod_l.c b/stdlib/strtod_l.c
index 7307d98b24..21692914fd 100644
--- a/stdlib/strtod_l.c
+++ b/stdlib/strtod_l.c
@@ -20,8 +20,6 @@
 #include <xlocale.h>
 
 extern double ____strtod_l_internal (const char *, char **, int, __locale_t);
-extern unsigned long long int ____strtoull_l_internal (const char *, char **,
-						       int, int, __locale_t);
 
 /* Configuration part.  These macros are defined by `strtold.c',
    `strtof.c', `wcstod.c', `wcstold.c', and `wcstof.c' to produce the
@@ -33,27 +31,20 @@ extern unsigned long long int ____strtoull_l_internal (const char *, char **,
 # ifdef USE_WIDE_CHAR
 #  define STRTOF	wcstod_l
 #  define __STRTOF	__wcstod_l
+#  define STRTOF_NAN	__wcstod_nan
 # else
 #  define STRTOF	strtod_l
 #  define __STRTOF	__strtod_l
+#  define STRTOF_NAN	__strtod_nan
 # endif
 # define MPN2FLOAT	__mpn_construct_double
 # define FLOAT_HUGE_VAL	HUGE_VAL
-# define SET_MANTISSA(flt, mant) \
-  do { union ieee754_double u;						      \
-       u.d = (flt);							      \
-       u.ieee_nan.mantissa0 = (mant) >> 32;				      \
-       u.ieee_nan.mantissa1 = (mant);					      \
-       if ((u.ieee.mantissa0 | u.ieee.mantissa1) != 0)			      \
-	 (flt) = u.d;							      \
-  } while (0)
 #endif
 /* End of configuration part.  */
 
 #include <ctype.h>
 #include <errno.h>
 #include <float.h>
-#include <ieee754.h>
 #include "../locale/localeinfo.h"
 #include <locale.h>
 #include <math.h>
@@ -105,7 +96,6 @@ extern unsigned long long int ____strtoull_l_internal (const char *, char **,
 # define TOLOWER_C(Ch) __towlower_l ((Ch), _nl_C_locobj_ptr)
 # define STRNCASECMP(S1, S2, N) \
   __wcsncasecmp_l ((S1), (S2), (N), _nl_C_locobj_ptr)
-# define STRTOULL(S, E, B) ____wcstoull_l_internal ((S), (E), (B), 0, loc)
 #else
 # define STRING_TYPE char
 # define CHAR_TYPE char
@@ -117,7 +107,6 @@ extern unsigned long long int ____strtoull_l_internal (const char *, char **,
 # define TOLOWER_C(Ch) __tolower_l ((Ch), _nl_C_locobj_ptr)
 # define STRNCASECMP(S1, S2, N) \
   __strncasecmp_l ((S1), (S2), (N), _nl_C_locobj_ptr)
-# define STRTOULL(S, E, B) ____strtoull_l_internal ((S), (E), (B), 0, loc)
 #endif
 
 
@@ -649,33 +638,14 @@ ____STRTOF_INTERNAL (const STRING_TYPE *nptr, STRING_TYPE **endptr, int group,
 	  if (*cp == L_('('))
 	    {
 	      const STRING_TYPE *startp = cp;
-	      do
-		++cp;
-	      while ((*cp >= L_('0') && *cp <= L_('9'))
-		     || (*cp >= L_('A') && *cp <= L_('Z'))
-		     || (*cp >= L_('a') && *cp <= L_('z'))
-		     || *cp == L_('_'));
-
-	      if (*cp != L_(')'))
-		/* The closing brace is missing.  Only match the NAN
-		   part.  */
-		cp = startp;
+	      STRING_TYPE *endp;
+	      retval = STRTOF_NAN (cp + 1, &endp, L_(')'));
+	      if (*endp == L_(')'))
+		/* Consume the closing parenthesis.  */
+		cp = endp + 1;
 	      else
-		{
-		  /* This is a system-dependent way to specify the
-		     bitmask used for the NaN.  We expect it to be
-		     a number which is put in the mantissa of the
-		     number.  */
-		  STRING_TYPE *endp;
-		  unsigned long long int mant;
-
-		  mant = STRTOULL (startp + 1, &endp, 0);
-		  if (endp == cp)
-		    SET_MANTISSA (retval, mant);
-
-		  /* Consume the closing brace.  */
-		  ++cp;
-		}
+		/* Only match the NAN part.  */
+		cp = startp;
 	    }
 
 	  if (endptr != NULL)