1 files changed, 51 insertions, 4 deletions
diff --git a/ares/m4/cares-compilers.m4 b/ares/m4/cares-compilers.m4
index 897c2ad89..80f4d1b49 100644
--- a/ares/m4/cares-compilers.m4
+++ b/ares/m4/cares-compilers.m4
@@ -1,7 +1,7 @@
 #***************************************************************************
 # $Id$
 #
-# Copyright (C) 2008 by Daniel Stenberg et al
+# Copyright (C) 2009 by Daniel Stenberg et al
 #
 # Permission to use, copy, modify, and distribute this software and its
 # documentation for any purpose and without fee is hereby granted, provided
@@ -16,7 +16,7 @@
 #***************************************************************************
 
 # File version for 'aclocal' use. Keep it a single number.
-# serial 48
+# serial 49
 
 
 dnl CARES_CHECK_COMPILER
@@ -374,8 +374,8 @@ dnl -------------------------------------------------
 dnl Changes standard include paths present in CFLAGS
 dnl and CPPFLAGS into isystem include paths. This is
 dnl done to prevent GNUC from generating warnings on
-dnl headers from these locations, even though this is
-dnl not reliable on ancient GNUC versions.
+dnl headers from these locations, although on ancient
+dnl GNUC versions these warnings are not silenced.
 
 AC_DEFUN([CARES_CONVERT_INCLUDE_TO_ISYSTEM], [
   AC_REQUIRE([CARES_SHFUNC_SQUEEZE])dnl
@@ -1121,6 +1121,53 @@ AC_DEFUN([CARES_CHECK_PROG_CC], [
 ])
 
 
+dnl CARES_CHECK_COMPILER_HALT_ON_ERROR
+dnl -------------------------------------------------
+dnl Verifies if the compiler actually halts after the
+dnl compilation phase without generating any object
+dnl code file, when the source compiles with errors.
+
+AC_DEFUN([CARES_CHECK_COMPILER_HALT_ON_ERROR], [
+  AC_MSG_CHECKING([if compiler halts on compilation errors])
+  AC_COMPILE_IFELSE([
+    AC_LANG_PROGRAM([[
+    ]],[[
+      force compilation error
+    ]])
+  ],[
+    AC_MSG_RESULT([no])
+    AC_MSG_ERROR([compiler does not halt on compilation errors.])
+  ],[
+    AC_MSG_RESULT([yes])
+  ])
+])
+
+
+dnl CARES_CHECK_COMPILER_ARRAY_SIZE_NEGATIVE
+dnl -------------------------------------------------
+dnl Verifies if the compiler actually halts after the
+dnl compilation phase without generating any object
+dnl code file, when the source code tries to define a
+dnl type for a constant array with negative dimension.
+
+AC_DEFUN([CARES_CHECK_COMPILER_ARRAY_SIZE_NEGATIVE], [
+  AC_REQUIRE([CARES_CHECK_COMPILER_HALT_ON_ERROR])dnl
+  AC_MSG_CHECKING([if compiler halts on negative sized arrays])
+  AC_COMPILE_IFELSE([
+    AC_LANG_PROGRAM([[
+      typedef char bad_t[sizeof(char) == sizeof(int) ? -1 : -1 ];
+    ]],[[
+      bad_t dummy;
+    ]])
+  ],[
+    AC_MSG_RESULT([no])
+    AC_MSG_ERROR([compiler does not halt on negative sized arrays.])
+  ],[
+    AC_MSG_RESULT([yes])
+  ])
+])
+
+
 dnl CARES_VAR_MATCH (VARNAME, VALUE)
 dnl -------------------------------------------------
 dnl Verifies if shell variable VARNAME contains VALUE.