Enable common subexpression optimization in GCC.

* lib/dirent.in.h (_GL_ATTRIBUTE_PURE): Define, like in string.in.h.
(alphasort): Declare with GCC attribute 'pure'.
* lib/stdlib.in.h (_GL_ATTRIBUTE_PURE): Define, like in string.in.h.
(atoll): Declare with GCC attribute 'pure'.
* lib/string.in.h (mbslen, mbsnlen, mbschr, mbsrchr, mbsstr,
mbscasecmp, mbsncasecmp, mbspcasecmp, mbscasestr, mbscspn, mbspbrk,
mbsspn, strverscmp): Declare with GCC attribute 'pure'.
* lib/wchar.in.h (_GL_ATTRIBUTE_PURE): Define, like in string.in.h.
(btowc, wctob, wcwidth, wmemchr, wmemcmp, wcslen, wcsnlen, wcscmp,
wcsncmp, wcscasecmp, wcsncasecmp, wcschr, wcsrchr, wcscspn, wcsspn,
wcspbrk, wcsstr, wcswidth): Declare with GCC attribute 'pure'.

diff --git a/ChangeLog b/ChangeLog
index 103cf74..55b242d 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,20 @@
 2012-03-24  Bruno Haible  <bruno@clisp.org>
 
+       Enable common subexpression optimization in GCC.
+       * lib/dirent.in.h (_GL_ATTRIBUTE_PURE): Define, like in string.in.h.
+       (alphasort): Declare with GCC attribute 'pure'.
+       * lib/stdlib.in.h (_GL_ATTRIBUTE_PURE): Define, like in string.in.h.
+       (atoll): Declare with GCC attribute 'pure'.
+       * lib/string.in.h (mbslen, mbsnlen, mbschr, mbsrchr, mbsstr,
+       mbscasecmp, mbsncasecmp, mbspcasecmp, mbscasestr, mbscspn, mbspbrk,
+       mbsspn, strverscmp): Declare with GCC attribute 'pure'.
+       * lib/wchar.in.h (_GL_ATTRIBUTE_PURE): Define, like in string.in.h.
+       (btowc, wctob, wcwidth, wmemchr, wmemcmp, wcslen, wcsnlen, wcscmp,
+       wcsncmp, wcscasecmp, wcsncasecmp, wcschr, wcsrchr, wcscspn, wcsspn,
+       wcspbrk, wcsstr, wcswidth): Declare with GCC attribute 'pure'.
+
+2012-03-24  Bruno Haible  <bruno@clisp.org>
+
        gnulib-tool: Avoid unintended error output from 'cmp'.
        * gnulib-tool (func_add_file, func_update_file, func_import): Use
        "cmp -s", not "cmp > /dev/null".

diff --git a/lib/dirent.in.h b/lib/dirent.in.h
index 808b360..cdbc5fd 100644 (file)
--- a/lib/dirent.in.h
+++ b/lib/dirent.in.h
@@ -55,6 +55,14 @@ typedef struct gl_directory DIR;
 # endif
 #endif
 
+/* The __attribute__ feature is available in gcc versions 2.5 and later.
+   The attribute __pure__ was added in gcc 2.96.  */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#else
+# define _GL_ATTRIBUTE_PURE /* empty */
+#endif
+
 /* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
 
 /* The definition of _GL_ARG_NONNULL is copied here.  */
@@ -229,6 +237,7 @@ _GL_WARN_ON_USE (scandir, "scandir is unportable - "
 # if !@HAVE_ALPHASORT@
 _GL_FUNCDECL_SYS (alphasort, int,
                   (const struct dirent **, const struct dirent **)
+                  _GL_ATTRIBUTE_PURE
                   _GL_ARG_NONNULL ((1, 2)));
 # endif
 /* Need to cast, because on glibc systems, the parameters are

diff --git a/lib/stdlib.in.h b/lib/stdlib.in.h
index e92a614..b546133 100644 (file)
--- a/lib/stdlib.in.h
+++ b/lib/stdlib.in.h
@@ -94,6 +94,14 @@ struct random_data
 # include <unistd.h>
 #endif
 
+/* The __attribute__ feature is available in gcc versions 2.5 and later.
+   The attribute __pure__ was added in gcc 2.96.  */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#else
+# define _GL_ATTRIBUTE_PURE /* empty */
+#endif
+
 /* The definition of _Noreturn is copied here.  */
 
 /* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
@@ -138,7 +146,9 @@ _GL_WARN_ON_USE (_Exit, "_Exit is unportable - "
 /* Parse a signed decimal integer.
    Returns the value of the integer.  Errors are not detected.  */
 # if !@HAVE_ATOLL@
-_GL_FUNCDECL_SYS (atoll, long long, (const char *string) _GL_ARG_NONNULL ((1)));
+_GL_FUNCDECL_SYS (atoll, long long, (const char *string)
+                                    _GL_ATTRIBUTE_PURE
+                                    _GL_ARG_NONNULL ((1)));
 # endif
 _GL_CXXALIAS_SYS (atoll, long long, (const char *string));
 _GL_CXXALIASWARN (atoll);

diff --git a/lib/string.in.h b/lib/string.in.h
index 02a119e..8cbe8cd 100644 (file)
--- a/lib/string.in.h
+++ b/lib/string.in.h
@@ -724,10 +724,14 @@ _GL_WARN_ON_USE (strtok_r, "strtok_r is unportable - "
 #  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 #   define mbslen rpl_mbslen
 #  endif
-_GL_FUNCDECL_RPL (mbslen, size_t, (const char *string) _GL_ARG_NONNULL ((1)));
+_GL_FUNCDECL_RPL (mbslen, size_t, (const char *string)
+                                  _GL_ATTRIBUTE_PURE
+                                  _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (mbslen, size_t, (const char *string));
 # else
-_GL_FUNCDECL_SYS (mbslen, size_t, (const char *string) _GL_ARG_NONNULL ((1)));
+_GL_FUNCDECL_SYS (mbslen, size_t, (const char *string)
+                                  _GL_ATTRIBUTE_PURE
+                                  _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_SYS (mbslen, size_t, (const char *string));
 # endif
 _GL_CXXALIASWARN (mbslen);
@@ -737,6 +741,7 @@ _GL_CXXALIASWARN (mbslen);
 /* Return the number of multibyte characters in the character string starting
    at STRING and ending at STRING + LEN.  */
 _GL_EXTERN_C size_t mbsnlen (const char *string, size_t len)
+     _GL_ATTRIBUTE_PURE
      _GL_ARG_NONNULL ((1));
 #endif
 
@@ -750,10 +755,12 @@ _GL_EXTERN_C size_t mbsnlen (const char *string, size_t len)
 #   define mbschr rpl_mbschr /* avoid collision with HP-UX function */
 #  endif
 _GL_FUNCDECL_RPL (mbschr, char *, (const char *string, int c)
+                                  _GL_ATTRIBUTE_PURE
                                   _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (mbschr, char *, (const char *string, int c));
 # else
 _GL_FUNCDECL_SYS (mbschr, char *, (const char *string, int c)
+                                  _GL_ATTRIBUTE_PURE
                                   _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_SYS (mbschr, char *, (const char *string, int c));
 # endif
@@ -770,10 +777,12 @@ _GL_CXXALIASWARN (mbschr);
 #   define mbsrchr rpl_mbsrchr /* avoid collision with system function */
 #  endif
 _GL_FUNCDECL_RPL (mbsrchr, char *, (const char *string, int c)
+                                   _GL_ATTRIBUTE_PURE
                                    _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (mbsrchr, char *, (const char *string, int c));
 # else
 _GL_FUNCDECL_SYS (mbsrchr, char *, (const char *string, int c)
+                                   _GL_ATTRIBUTE_PURE
                                    _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_SYS (mbsrchr, char *, (const char *string, int c));
 # endif
@@ -786,6 +795,7 @@ _GL_CXXALIASWARN (mbsrchr);
    Unlike strstr(), this function works correctly in multibyte locales with
    encodings different from UTF-8.  */
 _GL_EXTERN_C char * mbsstr (const char *haystack, const char *needle)
+     _GL_ATTRIBUTE_PURE
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -797,6 +807,7 @@ _GL_EXTERN_C char * mbsstr (const char *haystack, const char *needle)
    different lengths!
    Unlike strcasecmp(), this function works correctly in multibyte locales.  */
 _GL_EXTERN_C int mbscasecmp (const char *s1, const char *s2)
+     _GL_ATTRIBUTE_PURE
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -811,6 +822,7 @@ _GL_EXTERN_C int mbscasecmp (const char *s1, const char *s2)
    Unlike strncasecmp(), this function works correctly in multibyte locales.
    But beware that N is not a byte count but a character count!  */
 _GL_EXTERN_C int mbsncasecmp (const char *s1, const char *s2, size_t n)
+     _GL_ATTRIBUTE_PURE
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -824,6 +836,7 @@ _GL_EXTERN_C int mbsncasecmp (const char *s1, const char *s2, size_t n)
    Unlike strncasecmp(), this function works correctly in multibyte
    locales.  */
 _GL_EXTERN_C char * mbspcasecmp (const char *string, const char *prefix)
+     _GL_ATTRIBUTE_PURE
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -834,6 +847,7 @@ _GL_EXTERN_C char * mbspcasecmp (const char *string, const char *prefix)
    strlen (haystack) < strlen (needle) !
    Unlike strcasestr(), this function works correctly in multibyte locales.  */
 _GL_EXTERN_C char * mbscasestr (const char *haystack, const char *needle)
+     _GL_ATTRIBUTE_PURE
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -844,6 +858,7 @@ _GL_EXTERN_C char * mbscasestr (const char *haystack, const char *needle)
    if none exists.
    Unlike strcspn(), this function works correctly in multibyte locales.  */
 _GL_EXTERN_C size_t mbscspn (const char *string, const char *accept)
+     _GL_ATTRIBUTE_PURE
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -857,10 +872,12 @@ _GL_EXTERN_C size_t mbscspn (const char *string, const char *accept)
 #   define mbspbrk rpl_mbspbrk /* avoid collision with HP-UX function */
 #  endif
 _GL_FUNCDECL_RPL (mbspbrk, char *, (const char *string, const char *accept)
+                                   _GL_ATTRIBUTE_PURE
                                    _GL_ARG_NONNULL ((1, 2)));
 _GL_CXXALIAS_RPL (mbspbrk, char *, (const char *string, const char *accept));
 # else
 _GL_FUNCDECL_SYS (mbspbrk, char *, (const char *string, const char *accept)
+                                   _GL_ATTRIBUTE_PURE
                                    _GL_ARG_NONNULL ((1, 2)));
 _GL_CXXALIAS_SYS (mbspbrk, char *, (const char *string, const char *accept));
 # endif
@@ -874,6 +891,7 @@ _GL_CXXALIASWARN (mbspbrk);
    if none exists.
    Unlike strspn(), this function works correctly in multibyte locales.  */
 _GL_EXTERN_C size_t mbsspn (const char *string, const char *reject)
+     _GL_ATTRIBUTE_PURE
      _GL_ARG_NONNULL ((1, 2));
 #endif
 
@@ -993,6 +1011,7 @@ _GL_WARN_ON_USE (strsignal, "strsignal is unportable - "
 #if @GNULIB_STRVERSCMP@
 # if !@HAVE_STRVERSCMP@
 _GL_FUNCDECL_SYS (strverscmp, int, (const char *, const char *)
+                                   _GL_ATTRIBUTE_PURE
                                    _GL_ARG_NONNULL ((1, 2)));
 # endif
 _GL_CXXALIAS_SYS (strverscmp, int, (const char *, const char *));

diff --git a/lib/wchar.in.h b/lib/wchar.in.h
index 34d2c29..11beb5a 100644 (file)
--- a/lib/wchar.in.h
+++ b/lib/wchar.in.h
@@ -83,6 +83,14 @@
 #ifndef _@GUARD_PREFIX@_WCHAR_H
 #define _@GUARD_PREFIX@_WCHAR_H
 
+/* The __attribute__ feature is available in gcc versions 2.5 and later.
+   The attribute __pure__ was added in gcc 2.96.  */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#else
+# define _GL_ATTRIBUTE_PURE /* empty */
+#endif
+
 /* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
 
 /* The definition of _GL_ARG_NONNULL is copied here.  */
@@ -135,11 +143,11 @@ typedef int rpl_mbstate_t;
 #   undef btowc
 #   define btowc rpl_btowc
 #  endif
-_GL_FUNCDECL_RPL (btowc, wint_t, (int c));
+_GL_FUNCDECL_RPL (btowc, wint_t, (int c) _GL_ATTRIBUTE_PURE);
 _GL_CXXALIAS_RPL (btowc, wint_t, (int c));
 # else
 #  if !@HAVE_BTOWC@
-_GL_FUNCDECL_SYS (btowc, wint_t, (int c));
+_GL_FUNCDECL_SYS (btowc, wint_t, (int c) _GL_ATTRIBUTE_PURE);
 #  endif
 _GL_CXXALIAS_SYS (btowc, wint_t, (int c));
 # endif
@@ -160,12 +168,12 @@ _GL_WARN_ON_USE (btowc, "btowc is unportable - "
 #   undef wctob
 #   define wctob rpl_wctob
 #  endif
-_GL_FUNCDECL_RPL (wctob, int, (wint_t wc));
+_GL_FUNCDECL_RPL (wctob, int, (wint_t wc) _GL_ATTRIBUTE_PURE);
 _GL_CXXALIAS_RPL (wctob, int, (wint_t wc));
 # else
 #  if !defined wctob && !@HAVE_DECL_WCTOB@
 /* wctob is provided by gnulib, or wctob exists but is not declared.  */
-_GL_FUNCDECL_SYS (wctob, int, (wint_t wc));
+_GL_FUNCDECL_SYS (wctob, int, (wint_t wc) _GL_ATTRIBUTE_PURE);
 #  endif
 _GL_CXXALIAS_SYS (wctob, int, (wint_t wc));
 # endif
@@ -426,12 +434,12 @@ _GL_WARN_ON_USE (wcsnrtombs, "wcsnrtombs is unportable - "
 #   undef wcwidth
 #   define wcwidth rpl_wcwidth
 #  endif
-_GL_FUNCDECL_RPL (wcwidth, int, (wchar_t));
+_GL_FUNCDECL_RPL (wcwidth, int, (wchar_t) _GL_ATTRIBUTE_PURE);
 _GL_CXXALIAS_RPL (wcwidth, int, (wchar_t));
 # else
 #  if !@HAVE_DECL_WCWIDTH@
 /* wcwidth exists but is not declared.  */
-_GL_FUNCDECL_SYS (wcwidth, int, (wchar_t));
+_GL_FUNCDECL_SYS (wcwidth, int, (wchar_t) _GL_ATTRIBUTE_PURE);
 #  endif
 _GL_CXXALIAS_SYS (wcwidth, int, (wchar_t));
 # endif
@@ -448,7 +456,8 @@ _GL_WARN_ON_USE (wcwidth, "wcwidth is unportable - "
 /* Search N wide characters of S for C.  */
 #if @GNULIB_WMEMCHR@
 # if !@HAVE_WMEMCHR@
-_GL_FUNCDECL_SYS (wmemchr, wchar_t *, (const wchar_t *s, wchar_t c, size_t n));
+_GL_FUNCDECL_SYS (wmemchr, wchar_t *, (const wchar_t *s, wchar_t c, size_t n)
+                                      _GL_ATTRIBUTE_PURE);
 # endif
   /* On some systems, this function is defined as an overloaded function:
        extern "C++" {
@@ -479,7 +488,8 @@ _GL_WARN_ON_USE (wmemchr, "wmemchr is unportable - "
 #if @GNULIB_WMEMCMP@
 # if !@HAVE_WMEMCMP@
 _GL_FUNCDECL_SYS (wmemcmp, int,
-                  (const wchar_t *s1, const wchar_t *s2, size_t n));
+                  (const wchar_t *s1, const wchar_t *s2, size_t n)
+                  _GL_ATTRIBUTE_PURE);
 # endif
 _GL_CXXALIAS_SYS (wmemcmp, int,
                   (const wchar_t *s1, const wchar_t *s2, size_t n));
@@ -549,7 +559,7 @@ _GL_WARN_ON_USE (wmemset, "wmemset is unportable - "
 /* Return the number of wide characters in S.  */
 #if @GNULIB_WCSLEN@
 # if !@HAVE_WCSLEN@
-_GL_FUNCDECL_SYS (wcslen, size_t, (const wchar_t *s));
+_GL_FUNCDECL_SYS (wcslen, size_t, (const wchar_t *s) _GL_ATTRIBUTE_PURE);
 # endif
 _GL_CXXALIAS_SYS (wcslen, size_t, (const wchar_t *s));
 _GL_CXXALIASWARN (wcslen);
@@ -565,7 +575,8 @@ _GL_WARN_ON_USE (wcslen, "wcslen is unportable - "
 /* Return the number of wide characters in S, but at most MAXLEN.  */
 #if @GNULIB_WCSNLEN@
 # if !@HAVE_WCSNLEN@
-_GL_FUNCDECL_SYS (wcsnlen, size_t, (const wchar_t *s, size_t maxlen));
+_GL_FUNCDECL_SYS (wcsnlen, size_t, (const wchar_t *s, size_t maxlen)
+                                   _GL_ATTRIBUTE_PURE);
 # endif
 _GL_CXXALIAS_SYS (wcsnlen, size_t, (const wchar_t *s, size_t maxlen));
 _GL_CXXALIASWARN (wcsnlen);
@@ -684,7 +695,8 @@ _GL_WARN_ON_USE (wcsncat, "wcsncat is unportable - "
 /* Compare S1 and S2.  */
 #if @GNULIB_WCSCMP@
 # if !@HAVE_WCSCMP@
-_GL_FUNCDECL_SYS (wcscmp, int, (const wchar_t *s1, const wchar_t *s2));
+_GL_FUNCDECL_SYS (wcscmp, int, (const wchar_t *s1, const wchar_t *s2)
+                               _GL_ATTRIBUTE_PURE);
 # endif
 _GL_CXXALIAS_SYS (wcscmp, int, (const wchar_t *s1, const wchar_t *s2));
 _GL_CXXALIASWARN (wcscmp);
@@ -701,7 +713,8 @@ _GL_WARN_ON_USE (wcscmp, "wcscmp is unportable - "
 #if @GNULIB_WCSNCMP@
 # if !@HAVE_WCSNCMP@
 _GL_FUNCDECL_SYS (wcsncmp, int,
-                  (const wchar_t *s1, const wchar_t *s2, size_t n));
+                  (const wchar_t *s1, const wchar_t *s2, size_t n)
+                  _GL_ATTRIBUTE_PURE);
 # endif
 _GL_CXXALIAS_SYS (wcsncmp, int,
                   (const wchar_t *s1, const wchar_t *s2, size_t n));
@@ -718,7 +731,8 @@ _GL_WARN_ON_USE (wcsncmp, "wcsncmp is unportable - "
 /* Compare S1 and S2, ignoring case.  */
 #if @GNULIB_WCSCASECMP@
 # if !@HAVE_WCSCASECMP@
-_GL_FUNCDECL_SYS (wcscasecmp, int, (const wchar_t *s1, const wchar_t *s2));
+_GL_FUNCDECL_SYS (wcscasecmp, int, (const wchar_t *s1, const wchar_t *s2)
+                                   _GL_ATTRIBUTE_PURE);
 # endif
 _GL_CXXALIAS_SYS (wcscasecmp, int, (const wchar_t *s1, const wchar_t *s2));
 _GL_CXXALIASWARN (wcscasecmp);
@@ -735,7 +749,8 @@ _GL_WARN_ON_USE (wcscasecmp, "wcscasecmp is unportable - "
 #if @GNULIB_WCSNCASECMP@
 # if !@HAVE_WCSNCASECMP@
 _GL_FUNCDECL_SYS (wcsncasecmp, int,
-                  (const wchar_t *s1, const wchar_t *s2, size_t n));
+                  (const wchar_t *s1, const wchar_t *s2, size_t n)
+                  _GL_ATTRIBUTE_PURE);
 # endif
 _GL_CXXALIAS_SYS (wcsncasecmp, int,
                   (const wchar_t *s1, const wchar_t *s2, size_t n));
@@ -803,7 +818,8 @@ _GL_WARN_ON_USE (wcsdup, "wcsdup is unportable - "
 /* Find the first occurrence of WC in WCS.  */
 #if @GNULIB_WCSCHR@
 # if !@HAVE_WCSCHR@
-_GL_FUNCDECL_SYS (wcschr, wchar_t *, (const wchar_t *wcs, wchar_t wc));
+_GL_FUNCDECL_SYS (wcschr, wchar_t *, (const wchar_t *wcs, wchar_t wc)
+                                     _GL_ATTRIBUTE_PURE);
 # endif
   /* On some systems, this function is defined as an overloaded function:
        extern "C++" {
@@ -832,7 +848,8 @@ _GL_WARN_ON_USE (wcschr, "wcschr is unportable - "
 /* Find the last occurrence of WC in WCS.  */
 #if @GNULIB_WCSRCHR@
 # if !@HAVE_WCSRCHR@
-_GL_FUNCDECL_SYS (wcsrchr, wchar_t *, (const wchar_t *wcs, wchar_t wc));
+_GL_FUNCDECL_SYS (wcsrchr, wchar_t *, (const wchar_t *wcs, wchar_t wc)
+                                      _GL_ATTRIBUTE_PURE);
 # endif
   /* On some systems, this function is defined as an overloaded function:
        extern "C++" {
@@ -862,7 +879,8 @@ _GL_WARN_ON_USE (wcsrchr, "wcsrchr is unportable - "
    of wide characters not in REJECT.  */
 #if @GNULIB_WCSCSPN@
 # if !@HAVE_WCSCSPN@
-_GL_FUNCDECL_SYS (wcscspn, size_t, (const wchar_t *wcs, const wchar_t *reject));
+_GL_FUNCDECL_SYS (wcscspn, size_t, (const wchar_t *wcs, const wchar_t *reject)
+                                   _GL_ATTRIBUTE_PURE);
 # endif
 _GL_CXXALIAS_SYS (wcscspn, size_t, (const wchar_t *wcs, const wchar_t *reject));
 _GL_CXXALIASWARN (wcscspn);
@@ -879,7 +897,8 @@ _GL_WARN_ON_USE (wcscspn, "wcscspn is unportable - "
    of wide characters in ACCEPT.  */
 #if @GNULIB_WCSSPN@
 # if !@HAVE_WCSSPN@
-_GL_FUNCDECL_SYS (wcsspn, size_t, (const wchar_t *wcs, const wchar_t *accept));
+_GL_FUNCDECL_SYS (wcsspn, size_t, (const wchar_t *wcs, const wchar_t *accept)
+                                  _GL_ATTRIBUTE_PURE);
 # endif
 _GL_CXXALIAS_SYS (wcsspn, size_t, (const wchar_t *wcs, const wchar_t *accept));
 _GL_CXXALIASWARN (wcsspn);
@@ -896,7 +915,8 @@ _GL_WARN_ON_USE (wcsspn, "wcsspn is unportable - "
 #if @GNULIB_WCSPBRK@
 # if !@HAVE_WCSPBRK@
 _GL_FUNCDECL_SYS (wcspbrk, wchar_t *,
-                  (const wchar_t *wcs, const wchar_t *accept));
+                  (const wchar_t *wcs, const wchar_t *accept)
+                  _GL_ATTRIBUTE_PURE);
 # endif
   /* On some systems, this function is defined as an overloaded function:
        extern "C++" {
@@ -928,7 +948,8 @@ _GL_WARN_ON_USE (wcspbrk, "wcspbrk is unportable - "
 #if @GNULIB_WCSSTR@
 # if !@HAVE_WCSSTR@
 _GL_FUNCDECL_SYS (wcsstr, wchar_t *,
-                  (const wchar_t *haystack, const wchar_t *needle));
+                  (const wchar_t *haystack, const wchar_t *needle)
+                  _GL_ATTRIBUTE_PURE);
 # endif
   /* On some systems, this function is defined as an overloaded function:
        extern "C++" {
@@ -982,11 +1003,13 @@ _GL_WARN_ON_USE (wcstok, "wcstok is unportable - "
 #   undef wcswidth
 #   define wcswidth rpl_wcswidth
 #  endif
-_GL_FUNCDECL_RPL (wcswidth, int, (const wchar_t *s, size_t n));
+_GL_FUNCDECL_RPL (wcswidth, int, (const wchar_t *s, size_t n)
+                                 _GL_ATTRIBUTE_PURE);
 _GL_CXXALIAS_RPL (wcswidth, int, (const wchar_t *s, size_t n));
 # else
 #  if !@HAVE_WCSWIDTH@
-_GL_FUNCDECL_SYS (wcswidth, int, (const wchar_t *s, size_t n));
+_GL_FUNCDECL_SYS (wcswidth, int, (const wchar_t *s, size_t n)
+                                 _GL_ATTRIBUTE_PURE);
 #  endif
 _GL_CXXALIAS_SYS (wcswidth, int, (const wchar_t *s, size_t n));
 # endif