re PR bootstrap/67363 (r227188 breaks build for mingw-w64)

	PR bootstrap/67363
	* configure.ac: Check if setenv and unsetenv are declared.
	* configure: Rebuild.
	* config.in: Rebuild.
	* system.h: Declare setenv and unsetenv if not declared.

From-SVN: r227666

gcc/ChangeLog

+2015-09-15  John David Anglin  <danglin@gcc.gnu.org>
+
+	PR bootstrap/67363
+	* configure.ac: Check if setenv and unsetenv are declared.
+	* configure: Rebuild.
+	* config.in: Rebuild.
+	* system.h: Declare setenv and unsetenv if not declared.
+
 2015-09-10  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	* config/rs6000/rs6000.c (swap_web_entry): Update preceding

gcc/config.in

@@ -934,6 +934,13 @@
 #endif
 
 
+/* Define to 1 if we found a declaration for 'setenv', otherwise define to 0.
+   */
+#ifndef USED_FOR_TARGET
+#undef HAVE_DECL_SETENV
+#endif
+
+
 /* Define to 1 if we found a declaration for 'setrlimit', otherwise define to
    0. */
 #ifndef USED_FOR_TARGET
@@ -1025,6 +1032,13 @@
 #endif
 
 
+/* Define to 1 if we found a declaration for 'unsetenv', otherwise define to
+   0. */
+#ifndef USED_FOR_TARGET
+#undef HAVE_DECL_UNSETENV
+#endif
+
+
 /* Define to 1 if we found a declaration for 'vasprintf', otherwise define to
    0. */
 #ifndef USED_FOR_TARGET

gcc/configure

@@ -10926,7 +10926,7 @@ _ACEOF
 
 for ac_func in getenv atol atoll asprintf sbrk abort atof getcwd getwd \
 	madvise stpcpy strnlen strsignal strverscmp \
-	strtol strtoul strtoll strtoull \
+	strtol strtoul strtoll strtoull setenv unsetenv \
 	errno snprintf vsnprintf vasprintf malloc realloc calloc \
 	free getopt clock getpagesize ffs clearerr_unlocked feof_unlocked   ferror_unlocked fflush_unlocked fgetc_unlocked fgets_unlocked   fileno_unlocked fprintf_unlocked fputc_unlocked fputs_unlocked   fread_unlocked fwrite_unlocked getchar_unlocked getc_unlocked   putchar_unlocked putc_unlocked
 do

gcc/configure.ac

@@ -1247,7 +1247,7 @@ AC_CHECK_DECLS([basename(const char*), strstr(const char*,const char*)], , ,[
 
 gcc_AC_CHECK_DECLS(getenv atol atoll asprintf sbrk abort atof getcwd getwd \
 	madvise stpcpy strnlen strsignal strverscmp \
-	strtol strtoul strtoll strtoull \
+	strtol strtoul strtoll strtoull setenv unsetenv \
 	errno snprintf vsnprintf vasprintf malloc realloc calloc \
 	free getopt clock getpagesize ffs gcc_UNLOCKED_FUNCS, , ,[
 #include "ansidecl.h"

gcc/system.h

@@ -465,6 +465,10 @@ extern char *getwd (char *);
 extern void *sbrk (int);
 #endif
 
+#if defined (HAVE_DECL_SETENV) && !HAVE_DECL_SETENV
+int setenv(const char *, const char *, int);
+#endif
+
 #if defined (HAVE_DECL_STRSTR) && !HAVE_DECL_STRSTR
 extern char *strstr (const char *, const char *);
 #endif
@@ -473,6 +477,10 @@ extern char *strstr (const char *, const char *);
 extern char *stpcpy (char *, const char *);
 #endif
 
+#if defined (HAVE_DECL_UNSETENV) && !HAVE_DECL_UNSETENV
+int unsetenv(const char *);
+#endif
+
 #ifdef __cplusplus
 }
 #endif