Only define BOOST_NO_EXCEPTIONS if not already defined - fixes #4059.

[SVN r61791]

include/boost/config/compiler/borland.hpp

@@ -218,7 +218,7 @@
 //
 // check for exception handling support:
 //
-#if !defined(_CPPUNWIND) && !defined(BOOST_CPPUNWIND) && !defined(__EXCEPTIONS)
+#if !defined(_CPPUNWIND) && !defined(BOOST_CPPUNWIND) && !defined(__EXCEPTIONS) && !defined(BOOST_NO_EXCEPTIONS)
 #  define BOOST_NO_EXCEPTIONS
 #endif
 //

include/boost/config/compiler/clang.hpp

@@ -8,7 +8,7 @@
 
 // Clang compiler setup.
 
-#if __has_feature(cxx_exceptions)
+#if __has_feature(cxx_exceptions) && !defined(BOOST_NO_EXCEPTIONS)
 #else
 #  define BOOST_NO_EXCEPTIONS
 #endif

include/boost/config/compiler/codegear.hpp

@@ -131,7 +131,7 @@
 //
 // check for exception handling support:
 //
-#if !defined(_CPPUNWIND) && !defined(BOOST_CPPUNWIND) && !defined(__EXCEPTIONS)
+#if !defined(_CPPUNWIND) && !defined(BOOST_CPPUNWIND) && !defined(__EXCEPTIONS) && !defined(BOOST_NO_EXCEPTIONS)
 #  define BOOST_NO_EXCEPTIONS
 #endif
 //

include/boost/config/compiler/common_edg.hpp

@@ -44,7 +44,7 @@
 #endif 
 
 // See also kai.hpp which checks a Kai-specific symbol for EH
-# if !defined(__KCC) && !defined(__EXCEPTIONS)
+# if !defined(__KCC) && !defined(__EXCEPTIONS) && !defined(BOOST_NO_EXCEPTIONS)
 #     define BOOST_NO_EXCEPTIONS
 # endif
 

include/boost/config/compiler/digitalmars.hpp

@@ -51,7 +51,7 @@
 
 
 // check for exception handling support:
-#ifndef _CPPUNWIND
+#if !defined(_CPPUNWIND) && !defined(BOOST_NO_EXCEPTIONS)
 #  define BOOST_NO_EXCEPTIONS
 #endif
 

include/boost/config/compiler/gcc.hpp

@@ -81,7 +81,7 @@
 #define BOOST_NO_COMPLETE_VALUE_INITIALIZATION
 #endif
 
-#ifndef __EXCEPTIONS
+#if !defined(__EXCEPTIONS) && !defined(BOOST_NO_EXCEPTIONS)
 # define BOOST_NO_EXCEPTIONS
 #endif
 

include/boost/config/compiler/kai.hpp

@@ -17,7 +17,7 @@
 #   endif
 
 // see also common_edg.hpp which needs a special check for __KCC
-# if !defined(_EXCEPTIONS)
+# if !defined(_EXCEPTIONS) && !defined(BOOST_NO_EXCEPTIONS)
 #     define BOOST_NO_EXCEPTIONS
 # endif
 

include/boost/config/compiler/metrowerks.hpp

@@ -48,7 +48,7 @@
 #   define BOOST_NO_INTRINSIC_WCHAR_T
 #endif
 
-#if !__option(exceptions)
+#if !__option(exceptions) && !defined(BOOST_NO_EXCEPTIONS)
 #   define BOOST_NO_EXCEPTIONS
 #endif
 

include/boost/config/compiler/visualc.hpp

@@ -115,7 +115,7 @@
 
 //   
 // check for exception handling support:   
-#ifndef _CPPUNWIND 
+#if !defined(_CPPUNWIND) && !defined(BOOST_NO_EXCEPTIONS)
 #  define BOOST_NO_EXCEPTIONS   
 #endif