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.

11 files changed, 256 insertions, 48 deletions

diff --git a/stdlib/Makefile b/stdlib/Makefile
index 10d9406..d7ae165 100644
--- a/stdlib/Makefile
+++ b/stdlib/Makefile
@@ -50,6 +50,7 @@ routines	:=							      \
 	strtol_l strtoul_l strtoll_l strtoull_l				      \
 	strtof strtod strtold						      \
 	strtof_l strtod_l strtold_l					      \
+	strtof_nan strtod_nan strtold_nan				      \
 	system canonicalize						      \
 	a64l l64a							      \
 	rpmatch strfmon strfmon_l getsubopt xpg_basename fmtmsg		      \
diff --git a/stdlib/strtod_l.c b/stdlib/strtod_l.c
index 7307d98..2169291 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)
diff --git a/stdlib/strtod_nan.c b/stdlib/strtod_nan.c
new file mode 100644
index 0000000..2a0a89f
--- /dev/null
+++ b/stdlib/strtod_nan.c
@@ -0,0 +1,24 @@
+/* Convert string for NaN payload to corresponding NaN.  Narrow
+   strings, double.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <strtod_nan_narrow.h>
+#include <strtod_nan_double.h>
+
+#define STRTOD_NAN __strtod_nan
+#include <strtod_nan_main.c>
diff --git a/stdlib/strtod_nan_double.h b/stdlib/strtod_nan_double.h
new file mode 100644
index 0000000..f5bdb03
--- /dev/null
+++ b/stdlib/strtod_nan_double.h
@@ -0,0 +1,30 @@
+/* Convert string for NaN payload to corresponding NaN.  For double.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define FLOAT		double
+#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)
diff --git a/stdlib/strtod_nan_float.h b/stdlib/strtod_nan_float.h
new file mode 100644
index 0000000..4c52de8
--- /dev/null
+++ b/stdlib/strtod_nan_float.h
@@ -0,0 +1,29 @@
+/* Convert string for NaN payload to corresponding NaN.  For float.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define	FLOAT		float
+#define SET_MANTISSA(flt, mant)			\
+  do						\
+    {						\
+      union ieee754_float u;			\
+      u.f = (flt);				\
+      u.ieee_nan.mantissa = (mant);		\
+      if (u.ieee.mantissa != 0)			\
+	(flt) = u.f;				\
+    }						\
+  while (0)
diff --git a/stdlib/strtod_nan_main.c b/stdlib/strtod_nan_main.c
new file mode 100644
index 0000000..bc37a63
--- /dev/null
+++ b/stdlib/strtod_nan_main.c
@@ -0,0 +1,63 @@
+/* Convert string for NaN payload to corresponding NaN.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <ieee754.h>
+#include <locale.h>
+#include <math.h>
+#include <stdlib.h>
+#include <wchar.h>
+
+
+/* If STR starts with an optional n-char-sequence as defined by ISO C
+   (a sequence of ASCII letters, digits and underscores), followed by
+   ENDC, return a NaN whose payload is set based on STR.  Otherwise,
+   return a default NAN.  If ENDPTR is not NULL, set *ENDPTR to point
+   to the character after the initial n-char-sequence.  */
+
+internal_function
+FLOAT
+STRTOD_NAN (const STRING_TYPE *str, STRING_TYPE **endptr, STRING_TYPE endc)
+{
+  const STRING_TYPE *cp = str;
+
+  while ((*cp >= L_('0') && *cp <= L_('9'))
+	 || (*cp >= L_('A') && *cp <= L_('Z'))
+	 || (*cp >= L_('a') && *cp <= L_('z'))
+	 || *cp == L_('_'))
+    ++cp;
+
+  FLOAT retval = NAN;
+  if (*cp != endc)
+    goto out;
+
+  /* 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 (str, &endp, 0);
+  if (endp == cp)
+    SET_MANTISSA (retval, mant);
+
+ out:
+  if (endptr != NULL)
+    *endptr = (STRING_TYPE *) cp;
+  return retval;
+}
+libc_hidden_def (STRTOD_NAN)
diff --git a/stdlib/strtod_nan_narrow.h b/stdlib/strtod_nan_narrow.h
new file mode 100644
index 0000000..bd77045
--- /dev/null
+++ b/stdlib/strtod_nan_narrow.h
@@ -0,0 +1,22 @@
+/* Convert string for NaN payload to corresponding NaN.  Narrow strings.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define STRING_TYPE char
+#define L_(Ch) Ch
+#define STRTOULL(S, E, B) ____strtoull_l_internal ((S), (E), (B), 0,	\
+						   _nl_C_locobj_ptr)
diff --git a/stdlib/strtod_nan_wide.h b/stdlib/strtod_nan_wide.h
new file mode 100644
index 0000000..783fbf4
--- /dev/null
+++ b/stdlib/strtod_nan_wide.h
@@ -0,0 +1,22 @@
+/* Convert string for NaN payload to corresponding NaN.  Wide strings.
+   Copyright (C) 1997-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#define STRING_TYPE wchar_t
+#define L_(Ch) L##Ch
+#define STRTOULL(S, E, B) ____wcstoull_l_internal ((S), (E), (B), 0,	\
+						   _nl_C_locobj_ptr)
diff --git a/stdlib/strtof_l.c b/stdlib/strtof_l.c
index 2a8646a..491256f 100644
--- a/stdlib/strtof_l.c
+++ b/stdlib/strtof_l.c
@@ -20,26 +20,19 @@
 #include <xlocale.h>
 
 extern float ____strtof_l_internal (const char *, char **, int, __locale_t);
-extern unsigned long long int ____strtoull_l_internal (const char *, char **,
-						       int, int, __locale_t);
 
 #define	FLOAT		float
 #define	FLT		FLT
 #ifdef USE_WIDE_CHAR
 # define STRTOF		wcstof_l
 # define __STRTOF	__wcstof_l
+# define STRTOF_NAN	__wcstof_nan
 #else
 # define STRTOF		strtof_l
 # define __STRTOF	__strtof_l
+# define STRTOF_NAN	__strtof_nan
 #endif
 #define	MPN2FLOAT	__mpn_construct_float
 #define	FLOAT_HUGE_VAL	HUGE_VALF
-#define SET_MANTISSA(flt, mant) \
-  do { union ieee754_float u;						      \
-       u.f = (flt);							      \
-       u.ieee_nan.mantissa = (mant);					      \
-       if (u.ieee.mantissa != 0)					      \
-	 (flt) = u.f;							      \
-  } while (0)
 
 #include "strtod_l.c"
diff --git a/stdlib/strtof_nan.c b/stdlib/strtof_nan.c
new file mode 100644
index 0000000..b971310
--- /dev/null
+++ b/stdlib/strtof_nan.c
@@ -0,0 +1,24 @@
+/* Convert string for NaN payload to corresponding NaN.  Narrow
+   strings, float.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <strtod_nan_narrow.h>
+#include <strtod_nan_float.h>
+
+#define STRTOD_NAN __strtof_nan
+#include <strtod_nan_main.c>
diff --git a/stdlib/strtold_nan.c b/stdlib/strtold_nan.c
new file mode 100644
index 0000000..dd43032
--- /dev/null
+++ b/stdlib/strtold_nan.c
@@ -0,0 +1,30 @@
+/* Convert string for NaN payload to corresponding NaN.  Narrow
+   strings, long double.
+   Copyright (C) 2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+
+/* This function is unused if long double and double have the same
+   representation.  */
+#ifndef __NO_LONG_DOUBLE_MATH
+# include <strtod_nan_narrow.h>
+# include <strtod_nan_ldouble.h>
+
+# define STRTOD_NAN __strtold_nan
+# include <strtod_nan_main.c>
+#endif