* data/c.m4 (b4_c_modern): New macro, with a new provision for _MSC_VER.

[bison.git] / data / c.m4

diff --git a/data/c.m4 b/data/c.m4
index a13725741da7bdebff879f7dfb396e85ed9b8909..d21941d6b466096211e8ceeb90c1f00a5cc4a5cc 100644 (file)
--- a/data/c.m4
+++ b/data/c.m4
@@ -248,11 +248,25 @@ m4_define([b4_token_enums_defines],
 ## --------------------------------------------- ##
 
 
 ## --------------------------------------------- ##
 
 

+# b4_modern_c
+# -----------
+# A predicate useful in #if to determine whether C is ancient or modern.
+#
+# If __STDC__ is defined, the compiler is modern.  IBM xlc 7.0 when run
+# as 'cc' doesn't define __STDC__ (or __STDC_VERSION__) for pedantic
+# reasons, but it defines __C99__FUNC__ so check that as well.
+# Microsoft C normally doesn't define these macros, but it defines _MSC_VER.
+# Consider a C++ compiler to be modern if it defines __cplusplus.  */
+#
+m4_define([b4_c_modern],
+  [[defined (__STDC__) || defined (__C99__FUNC__) || \
+       defined (__cplusplus) || defined (_MSC_VER)]])
+

 # b4_c_function_def(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
 # ----------------------------------------------------------
 # Declare the function NAME.
 m4_define([b4_c_function_def],
 # b4_c_function_def(NAME, RETURN-VALUE, [DECL1, NAME1], ...)
 # ----------------------------------------------------------
 # Declare the function NAME.
 m4_define([b4_c_function_def],

-[#if defined (__STDC__) || defined (__C99__FUNC__) || defined (__cplusplus)
+[#if b4_c_modern

 b4_c_ansi_function_def($@)
 #else
 $2
 b4_c_ansi_function_def($@)
 #else
 $2