diff options
Diffstat (limited to 'm4/stdbool.m4')
| -rw-r--r-- | m4/stdbool.m4 | 31 |
1 files changed, 29 insertions, 2 deletions
diff --git a/m4/stdbool.m4 b/m4/stdbool.m4 index dcb5793..43fbe28 100644 --- a/m4/stdbool.m4 +++ b/m4/stdbool.m4 @@ -1,6 +1,6 @@ # Check for stdbool.h that conforms to C99. -dnl Copyright (C) 2002-2005 Free Software Foundation, Inc. +dnl Copyright (C) 2002-2006 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. @@ -74,11 +74,38 @@ AC_DEFUN([AC_HEADER_STDBOOL], _Bool n[m]; char o[sizeof n == m * sizeof n[0] ? 1 : -1]; char p[-1 - (_Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1]; + #if defined __xlc__ || defined __GNUC__ + /* Catch a bug in IBM AIX xlc compiler version 6.0.0.0 + reported by James Lemley on 2005-10-05; see + http://lists.gnu.org/archive/html/bug-coreutils/2005-10/msg00086.html + This test is not quite right, since xlc is allowed to + reject this program, as the initializer for xlcbug is + not one of the forms that C requires support for. + However, doing the test right would require a run-time + test, and that would make cross-compilation harder. + Let us hope that IBM fixes the xlc bug, and also adds + support for this kind of constant expression. In the + meantime, this test will reject xlc, which is OK, since + our stdbool.h substitute should suffice. We also test + this with GCC, where it should work, to detect more + quickly whether someone messes up the test in the + future. */ + char digs[] = "0123456789"; + int xlcbug = 1 / (&(digs + 5)[-2 + (bool) 1] == &digs[4] ? 1 : -1); + #endif + /* Catch a bug in an HP-UX C compiler. See + http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html + http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html + */ + _Bool q = true; + _Bool *pq = &q; ], [ + *pq |= q; + *pq |= ! q; /* Refer to every declared value, to avoid compiler optimizations. */ return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l - + !m + !n + !o + !p); + + !m + !n + !o + !p + !q + !pq); ], [ac_cv_header_stdbool_h=yes], [ac_cv_header_stdbool_h=no])]) |