From 310990651488c6255e6ac558d56b3ab79cde316e Mon Sep 17 00:00:00 2001
From: steve <steve>
Date: Mon, 17 Sep 2001 22:26:33 +0000
Subject: [PATCH]  Detect C name mangling for dlsym.

---
 vvp/config.h.in  | 31 +++++++++++++++++++++----
 vvp/configure.in | 59 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 4 deletions(-)

diff --git a/vvp/config.h.in b/vvp/config.h.in
index e8af9db44..94ed5ef26 100644
--- a/vvp/config.h.in
+++ b/vvp/config.h.in
@@ -19,12 +19,16 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT)
-#ident "$Id: config.h.in,v 1.7 2001/09/15 18:27:05 steve Exp $"
+#ident "$Id: config.h.in,v 1.8 2001/09/17 22:26:33 steve Exp $"
 #endif
 
 # define SIZEOF_UNSIGNED_LONG 0
 # define SIZEOF_UNSIGNED 0
 
+# undef NEED_LU
+# undef NEED_TU  
+# undef WLU
+# undef WTU
 # undef HAVE_DLFCN_H
 # undef HAVE_DL_H
 # undef HAVE_GETOPT_H
@@ -33,9 +37,6 @@
 
 # undef ENABLE_VVP_DEBUG
 
-# define LU ""
-# define TU ""
-
 #ifndef MODULE_DIR
 # define MODULE_DIR "."
 #endif
@@ -46,8 +47,30 @@
 
 # undef HAVE_TIMES
 
+
+/*
+ * When doing dynamic linking, we need a uniform way to identify the
+ * symbol. Some compilers put leading _, some trailing _. The
+ * configure script figures out which is the local convention and
+ * defines NEED_LU and NEED_TU as required.
+ */
+#ifdef NEED_LU
+#define LU "_"
+#else
+#define LU ""
+#endif
+
+#ifdef NEED_TU
+#define TU "_"
+#else
+#define TU ""
+#endif
+
 /*
  * $Log: config.h.in,v $
+ * Revision 1.8  2001/09/17 22:26:33  steve
+ *  Detect C name mangling for dlsym.
+ *
  * Revision 1.7  2001/09/15 18:27:05  steve
  *  Make configure detect malloc.h
  *
diff --git a/vvp/configure.in b/vvp/configure.in
index 1be691582..8bb84d640 100644
--- a/vvp/configure.in
+++ b/vvp/configure.in
@@ -93,4 +93,63 @@ esac
 AC_SUBST(EXTRALIBS)
 AC_MSG_RESULT($EXTRALIBS)
 
+#######################
+## test for underscores. The vpi module loader in vvm needs to know this
+## in order to know the name of the start symbol for the .vpi module.
+#######################
+
+AC_CYGWIN
+AC_EXEEXT
+AC_MINGW32
+
+
+WIN32=no
+AC_MSG_CHECKING("Checking for windows")
+if test "$CYGWIN" = "yes" -o "$MINGW32" = "yes"
+then
+    WIN32=yes
+fi
+AC_SUBST(WIN32)
+AC_MSG_RESULT($WIN32)
+AC_SUBST(EXEEXT)
+
+
+AC_MSG_CHECKING("for leading and/or trailing underscores")
+cat << EOF > underscore.c
+       void underscore(void){}
+EOF
+$CC -shared -c underscore.c > /dev/null 2>&1
+
+CC_LEADING_UNDERSCORE=no
+CC_TRAILING_UNDERSCORE=no
+
+output=`nm underscore.o|grep _underscore 2>&1`
+if test ! -z "$output" -a -z "$CYGWIN" -a -z "$MINGW32"; then
+  CC_LEADING_UNDERSCORE=yes
+  AC_DEFINE(NEED_LU)
+fi
+
+
+
+output=`nm underscore.o|grep underscore_ 2>&1`
+if test ! -z "$output"; then
+  CC_TRAILING_UNDERSCORE=yes
+  AC_DEFINE(NEED_TU)
+fi
+
+if test "$CC_LEADING_UNDERSCORE" = yes; then
+  AC_DEFINE(WLU)
+fi
+if test "$CC_TRAILING_UNDERSCORE" = yes; then
+  AC_DEFINE(WTU)
+fi
+
+rm underscore.c underscore.o
+
+AC_MSG_RESULT("$CC_LEADING_UNDERSCORE $CC_TRAILING_UNDERSCORE")
+
+#######################
+## end of test for underscores
+#######################
+
 AC_OUTPUT(Makefile)