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-rw-r--r--m4/fpurge.m473
1 files changed, 73 insertions, 0 deletions
diff --git a/m4/fpurge.m4 b/m4/fpurge.m4
new file mode 100644
index 0000000..1a15454
--- /dev/null
+++ b/m4/fpurge.m4
@@ -0,0 +1,73 @@
+# fpurge.m4 serial 12
+dnl Copyright (C) 2007, 2009-2022 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_FPURGE],
+[
+ AC_REQUIRE([gl_STDIO_H_DEFAULTS])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+ AC_CHECK_HEADERS_ONCE([stdio_ext.h])
+ AC_CHECK_FUNCS_ONCE([fpurge])
+ AC_CHECK_FUNCS_ONCE([__fpurge])
+ AC_CHECK_DECLS([fpurge], , , [[#include <stdio.h>]])
+ if test "x$ac_cv_func_fpurge" = xyes; then
+ HAVE_FPURGE=1
+ # Detect BSD bug. Only cygwin 1.7 and musl are known to be immune.
+ AC_CACHE_CHECK([whether fpurge works], [gl_cv_func_fpurge_works],
+ [AC_RUN_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <stdio.h>
+]],
+ [[FILE *f = fopen ("conftest.txt", "w+");
+ if (!f)
+ return 1;
+ if (fputc ('a', f) != 'a')
+ { fclose (f); return 2; }
+ rewind (f);
+ if (fgetc (f) != 'a')
+ { fclose (f); return 3; }
+ if (fgetc (f) != EOF)
+ { fclose (f); return 4; }
+ if (fpurge (f) != 0)
+ { fclose (f); return 5; }
+ if (putc ('b', f) != 'b')
+ { fclose (f); return 6; }
+ if (fclose (f) != 0)
+ return 7;
+ if ((f = fopen ("conftest.txt", "r")) == NULL)
+ return 8;
+ if (fgetc (f) != 'a')
+ { fclose (f); return 9; }
+ if (fgetc (f) != 'b')
+ { fclose (f); return 10; }
+ if (fgetc (f) != EOF)
+ { fclose (f); return 11; }
+ if (fclose (f) != 0)
+ return 12;
+ if (remove ("conftest.txt") != 0)
+ return 13;
+ return 0;
+ ]])],
+ [gl_cv_func_fpurge_works=yes],
+ [gl_cv_func_fpurge_works=no],
+ [case "$host_os" in
+ # Guess yes on musl systems.
+ *-musl*) gl_cv_func_fpurge_works="guessing yes" ;;
+ # Otherwise obey --enable-cross-guesses.
+ *) gl_cv_func_fpurge_works="$gl_cross_guess_normal" ;;
+ esac
+ ])
+ ])
+ case "$gl_cv_func_fpurge_works" in
+ *yes) ;;
+ *) REPLACE_FPURGE=1 ;;
+ esac
+ else
+ HAVE_FPURGE=0
+ fi
+ if test "x$ac_cv_have_decl_fpurge" = xno; then
+ HAVE_DECL_FPURGE=0
+ fi
+])