From: George Bosilca <bosilca@cs.utk.edu>
Date: Mon, 4 Sep 2006 17:27:27 +0000 (+0000)
Subject: Make libltdl work when compiled with a C++ compiler.
X-Git-Tag: release-2-1b~250
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8a17ccd68d2075b6c6d94f2c2d35c4c9e60a4952;p=thirdparty%2Flibtool.git

Make libltdl work when compiled with a C++ compiler.

* libltdl/lt__alloc.c, libltdl/lt_dlloader.c, libltdl/ltdl.c,
libltdl/slist.c, libltdl/libltdl/lt__alloc.h,
libltdl/libltdl/lt_error.h, libltdl/libltdl/slist.h,
libltdl/loaders/dld_link.c, libltdl/loaders/dlopen.c,
libltdl/loaders/dyld.c, libltdl/loaders/load_add_on.c,
libltdl/loaders/loadlibrary.c, libltdl/loaders/preopen.c,
libltdl/loaders/shl_load.c, tests/stresstest.at,
tests/testsuite.at, tests/f77demo/foo.h, tests/fcdemo/foo.h,
tests/mdemo/foo.h, tests/mdemo/foo1.c, tests/mdemo/foo2.c,
tests/mdemo/main.c: Allow sources to be compiled by a C++
compiler: Cast appropriately, add C linkage for `get_vtable'
functions, do not use C++ keyword `delete'.
---

diff --git a/ChangeLog b/ChangeLog
index 380210877..73ad66038 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,21 @@
 2006-09-04  George Bosilca <bosilca@cs.utk.edu>
 	and Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
 
+	Make libltdl work when compiled with a C++ compiler.
+
+	* libltdl/lt__alloc.c, libltdl/lt_dlloader.c, libltdl/ltdl.c,
+	libltdl/slist.c, libltdl/libltdl/lt__alloc.h,
+	libltdl/libltdl/lt_error.h, libltdl/libltdl/slist.h,
+	libltdl/loaders/dld_link.c, libltdl/loaders/dlopen.c,
+	libltdl/loaders/dyld.c, libltdl/loaders/load_add_on.c,
+	libltdl/loaders/loadlibrary.c, libltdl/loaders/preopen.c,
+	libltdl/loaders/shl_load.c, tests/stresstest.at,
+	tests/testsuite.at, tests/f77demo/foo.h, tests/fcdemo/foo.h,
+	tests/mdemo/foo.h, tests/mdemo/foo1.c, tests/mdemo/foo2.c,
+	tests/mdemo/main.c: Allow sources to be compiled by a C++
+	compiler: Cast appropriately, add C linkage for `get_vtable'
+	functions, do not use C++ keyword `delete'.
+
 	* libltdl/config/ltmain.m4sh (func_mode_link): In the dlsym
 	file, define a type for the symbol list, and declare the list
 	`extern', so that it is extern even if compiled by a C++
diff --git a/libltdl/libltdl/lt__alloc.h b/libltdl/libltdl/lt__alloc.h
index b5c615715..6f95109fd 100644
--- a/libltdl/libltdl/lt__alloc.h
+++ b/libltdl/libltdl/lt__alloc.h
@@ -37,7 +37,7 @@ LT_BEGIN_C_DECLS
 #define MALLOC(tp, n)		(tp*) lt__malloc((n) * sizeof(tp))
 #define REALLOC(tp, mem, n)	(tp*) lt__realloc((mem), (n) * sizeof(tp))
 #define FREE(mem)					LT_STMT_START {	\
-	if (mem) (mem) = (free ((void *)mem), (void *) 0); 	} LT_STMT_END
+	if (mem) { free ((void *)mem); mem = NULL; }	} LT_STMT_END
 #define MEMREASSIGN(p, q)				LT_STMT_START {	\
 	if ((p) != (q)) { if (p) free (p); (p) = (q); (q) = 0; }	\
 								} LT_STMT_END
diff --git a/libltdl/libltdl/lt_error.h b/libltdl/libltdl/lt_error.h
index 8773770a4..8e417469e 100644
--- a/libltdl/libltdl/lt_error.h
+++ b/libltdl/libltdl/lt_error.h
@@ -69,8 +69,8 @@ enum {
 	LT_ERROR_MAX
 };
 
-/* Should be max of the error string lengths above */
-#define LT_ERROR_LEN_MAX (35)
+/* Should be max of the error string lengths above (plus one for C++) */
+#define LT_ERROR_LEN_MAX (36)
 
 /* These functions are only useful from inside custom module loaders. */
 LT_SCOPE int	lt_dladderror	(const char *diagnostic);
diff --git a/libltdl/libltdl/slist.h b/libltdl/libltdl/slist.h
index 4b47cda6d..80a570fb8 100644
--- a/libltdl/libltdl/slist.h
+++ b/libltdl/libltdl/slist.h
@@ -63,7 +63,7 @@ typedef int	SListCompare	(const SList *item1, const SList *item2,
 LT_SCOPE SList *slist_concat	(SList *head, SList *tail);
 LT_SCOPE SList *slist_cons	(SList *item, SList *slist);
 
-LT_SCOPE SList *slist_delete	(SList *slist, void (*delete) (void *item));
+LT_SCOPE SList *slist_delete	(SList *slist, void (*delete_fct) (void *item));
 LT_SCOPE void *	slist_remove	(SList **phead, SListCallback *find,
 				 void *matchdata);
 LT_SCOPE SList *slist_reverse	(SList *slist);
diff --git a/libltdl/loaders/dld_link.c b/libltdl/loaders/dld_link.c
index b93868d20..c7b283e23 100644
--- a/libltdl/loaders/dld_link.c
+++ b/libltdl/loaders/dld_link.c
@@ -36,7 +36,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    be fetched from the preloaded symbol list by lt_dlsym():  */
 #define get_vtable	dld_link_LTX_get_vtable
 
+LT_BEGIN_C_DECLS
 LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
+LT_END_C_DECLS
 
 
 /* Boilerplate code to set up the vtable for hooking this loader into
diff --git a/libltdl/loaders/dlopen.c b/libltdl/loaders/dlopen.c
index 95e7a07a8..3bd5bd3f7 100644
--- a/libltdl/loaders/dlopen.c
+++ b/libltdl/loaders/dlopen.c
@@ -36,7 +36,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    be fetched from the preloaded symbol list by lt_dlsym():  */
 #define get_vtable	dlopen_LTX_get_vtable
 
+LT_BEGIN_C_DECLS
 LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
+LT_END_C_DECLS
 
 
 /* Boilerplate code to set up the vtable for hooking this loader into
@@ -56,7 +58,7 @@ get_vtable (lt_user_data loader_data)
 
   if (!vtable)
     {
-      vtable = lt__zalloc (sizeof *vtable);
+      vtable = (lt_dlvtable *) lt__zalloc (sizeof *vtable);
     }
 
   if (vtable && !vtable->name)
diff --git a/libltdl/loaders/dyld.c b/libltdl/loaders/dyld.c
index c5f94f069..2138de6cf 100644
--- a/libltdl/loaders/dyld.c
+++ b/libltdl/loaders/dyld.c
@@ -1,5 +1,5 @@
 /* loader-dyld.c -- dynamic linking on darwin and OS X
-   Copyright (C) 1998, 1999, 2000, 2004 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2000, 2004, 2006 Free Software Foundation, Inc.
    Originally by Peter O'Gorman <peter@pogma.com>
 
    NOTE: The canonical source of this file is maintained with the
@@ -36,7 +36,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    be fetched from the preloaded symbol list by lt_dlsym():  */
 #define get_vtable	dyld_LTX_get_vtable
 
+LT_BEGIN_C_DECLS
 LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
+LT_END_C_DECLS
 
 
 /* Boilerplate code to set up the vtable for hooking this loader into
diff --git a/libltdl/loaders/load_add_on.c b/libltdl/loaders/load_add_on.c
index d67e3a20d..03a155798 100644
--- a/libltdl/loaders/load_add_on.c
+++ b/libltdl/loaders/load_add_on.c
@@ -36,7 +36,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    be fetched from the preloaded symbol list by lt_dlsym():  */
 #define get_vtable	load_add_on_LTX_get_vtable
 
+LT_BEGIN_C_DECLS
 LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
+LT_END_C_DECLS
 
 
 /* Boilerplate code to set up the vtable for hooking this loader into
diff --git a/libltdl/loaders/loadlibrary.c b/libltdl/loaders/loadlibrary.c
index 47b0e664b..49a33ec6c 100644
--- a/libltdl/loaders/loadlibrary.c
+++ b/libltdl/loaders/loadlibrary.c
@@ -1,5 +1,5 @@
 /* loader-loadlibrary.c --  dynamic linking for Win32
-   Copyright (C) 1998, 1999, 2000, 2004, 2005 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2000, 2004, 2005, 2006 Free Software Foundation, Inc.
    Originally by Thomas Tanner <tanner@ffii.org>
 
    NOTE: The canonical source of this file is maintained with the
@@ -40,7 +40,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    be fetched from the preloaded symbol list by lt_dlsym():  */
 #define get_vtable	loadlibrary_LTX_get_vtable
 
+LT_BEGIN_C_DECLS
 LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
+LT_END_C_DECLS
 
 
 /* Boilerplate code to set up the vtable for hooking this loader into
@@ -62,7 +64,7 @@ get_vtable (lt_user_data loader_data)
 
   if (!vtable)
     {
-      vtable = lt__zalloc (sizeof *vtable);
+      vtable = (lt_dlvtable *) lt__zalloc (sizeof *vtable);
       iface_id = lt_dlinterface_register ("ltdl loadlibrary", NULL);
     }
 
@@ -202,7 +204,7 @@ vm_close (lt_user_data loader_data LT__UNUSED, lt_module module)
 {
   int errors = 0;
 
-  if (FreeLibrary(module) == 0)
+  if (FreeLibrary((HMODULE) module) == 0)
     {
       LT__SETERROR (CANNOT_CLOSE);
       ++errors;
@@ -217,7 +219,7 @@ vm_close (lt_user_data loader_data LT__UNUSED, lt_module module)
 static void *
 vm_sym (lt_user_data loader_data LT__UNUSED, lt_module module, const char *name)
 {
-  void *address = GetProcAddress (module, name);
+  void *address = (void *) GetProcAddress ((HMODULE) module, name);
 
   if (!address)
     {
diff --git a/libltdl/loaders/preopen.c b/libltdl/loaders/preopen.c
index e71c46f2d..dc2e92680 100644
--- a/libltdl/loaders/preopen.c
+++ b/libltdl/loaders/preopen.c
@@ -36,7 +36,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    be fetched from the preloaded symbol list by lt_dlsym():  */
 #define get_vtable	preopen_LTX_get_vtable
 
+LT_BEGIN_C_DECLS
 LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
+LT_END_C_DECLS
 
 
 /* Boilerplate code to set up the vtable for hooking this loader into
@@ -58,7 +60,7 @@ get_vtable (lt_user_data loader_data)
 
   if (!vtable)
     {
-      vtable = lt__zalloc (sizeof *vtable);
+      vtable = (lt_dlvtable *) lt__zalloc (sizeof *vtable);
     }
 
   if (vtable && !vtable->name)
@@ -259,7 +261,7 @@ add_symlist (const lt_dlsymlist *symlist)
   /* Don't add the same list twice:  */
   if (!lists)
     {
-      symlist_chain *tmp = lt__zalloc (sizeof *tmp);
+      symlist_chain *tmp = (symlist_chain *) lt__zalloc (sizeof *tmp);
 
       if (tmp)
 	{
diff --git a/libltdl/loaders/shl_load.c b/libltdl/loaders/shl_load.c
index bcdbc5632..e5d0e35f6 100644
--- a/libltdl/loaders/shl_load.c
+++ b/libltdl/loaders/shl_load.c
@@ -36,7 +36,9 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    be fetched from the preloaded symbol list by lt_dlsym():  */
 #define get_vtable	shl_load_LTX_get_vtable
 
+LT_BEGIN_C_DECLS
 LT_SCOPE lt_dlvtable *get_vtable (lt_user_data loader_data);
+LT_END_C_DECLS
 
 
 /* Boilerplate code to set up the vtable for hooking this loader into
diff --git a/libltdl/lt__alloc.c b/libltdl/lt__alloc.c
index 019e5e386..7cb8553b0 100644
--- a/libltdl/lt__alloc.c
+++ b/libltdl/lt__alloc.c
@@ -97,5 +97,5 @@ lt__memdup (void const *mem, size_t n)
 char *
 lt__strdup (const char *string)
 {
-  return lt__memdup (string, strlen (string) +1);
+  return (char *) lt__memdup (string, strlen (string) +1);
 }
diff --git a/libltdl/lt_dlloader.c b/libltdl/lt_dlloader.c
index 411b5e010..d8317dfd4 100644
--- a/libltdl/lt_dlloader.c
+++ b/libltdl/lt_dlloader.c
@@ -46,8 +46,8 @@ static	SList    *loaders		= 0;
 static void *
 loader_callback (SList *item, void *userdata)
 {
-  const lt_dlvtable *vtable = item->userdata;
-  const char *	    name    = userdata;
+  const lt_dlvtable *vtable = (const lt_dlvtable *) item->userdata;
+  const char *	    name    = (const char *) userdata;
 
   assert (vtable);
 
@@ -111,7 +111,7 @@ lt_dlloader_next (lt_dlloader loader)
 const lt_dlvtable *
 lt_dlloader_get	(lt_dlloader loader)
 {
-  return loader ? ((SList *) loader)->userdata : 0;
+  return (const lt_dlvtable *) (loader ? ((SList *) loader)->userdata : 0);
 }
 
 
@@ -155,7 +155,8 @@ lt_dlloader_remove (char *name)
     }
 
   /* If we got this far, remove the loader from our global list.  */
-  return slist_unbox (slist_remove (&loaders, loader_callback, name));
+  return (lt_dlvtable *)
+      slist_unbox ((SList *) slist_remove (&loaders, loader_callback, name));
 }
 
 
diff --git a/libltdl/ltdl.c b/libltdl/ltdl.c
index 0e57473b1..46badfb3e 100644
--- a/libltdl/ltdl.c
+++ b/libltdl/ltdl.c
@@ -159,7 +159,8 @@ lt__alloc_die_callback (void)
 static int
 loader_init_callback (lt_dlhandle handle)
 {
-  return loader_init (lt_dlsym (handle, "get_vtable"), 0);
+  lt_get_vtable *vtable_func = (lt_get_vtable *) lt_dlsym (handle, "get_vtable");
+  return loader_init (vtable_func, 0);
 }
 #endif /* HAVE_LIBDLLOADER */
 
@@ -195,7 +196,9 @@ loader_init (lt_get_vtable *vtable_func, lt_user_data data)
 #define get_vtable		preopen_LTX_get_vtable
 #define preloaded_symbols	LT_CONC3(lt_, LTDLOPEN, _LTX_preloaded_symbols)
 
+LT_BEGIN_C_DECLS
 LT_SCOPE const lt_dlvtable *	get_vtable (lt_user_data data);
+LT_END_C_DECLS
 #ifdef HAVE_LIBDLLOADER
 extern lt_dlsymlist		preloaded_symbols;
 #endif
@@ -289,9 +292,9 @@ lt_dlexit (void)
 	}
 
       /* close all loaders */
-      for (loader = lt_dlloader_next (NULL); loader;)
+      for (loader = (lt_dlloader *) lt_dlloader_next (NULL); loader;)
 	{
-	  lt_dlloader *next   = lt_dlloader_next (loader);
+	  lt_dlloader *next   = (lt_dlloader *) lt_dlloader_next (loader);
 	  lt_dlvtable *vtable = (lt_dlvtable *) lt_dlloader_get (loader);
 
 	  if ((vtable = lt_dlloader_remove ((char *) vtable->name)))
@@ -340,7 +343,7 @@ tryall_dlopen (lt_dlhandle *phandle, const char *filename)
       goto done;
     }
 
-  handle = *phandle;
+  handle = (lt__handle *) *phandle;
   if (filename)
     {
       /* Comment out the check of file permissions using access.
@@ -371,7 +374,7 @@ tryall_dlopen (lt_dlhandle *phandle, const char *filename)
     const lt_dlvtable *vtable = 0;
     lt_dlloader *loader = 0;
 
-    while ((loader = lt_dlloader_next (loader)))
+    while ((loader = (lt_dlloader *) lt_dlloader_next (loader)))
       {
 	vtable = lt_dlloader_get (loader);
 	handle->module = (*vtable->module_open) (vtable->dlloader_data,
@@ -1321,7 +1324,7 @@ try_dlopen (lt_dlhandle *phandle, const char *filename)
       ((lt__handle *) *phandle)->info.ref_count	= 1;
       MEMREASSIGN (((lt__handle *) *phandle)->info.name, name);
 
-      ((lt__handle *) *phandle)->next	= handles;
+      ((lt__handle *) *phandle)->next	= (lt__handle *) handles;
       handles				= *phandle;
     }
 
@@ -2033,7 +2036,7 @@ typedef struct {
 lt_dlinterface_id
 lt_dlinterface_register (const char *id_string, lt_dlhandle_interface *iface)
 {
-  lt__interface_id *interface_id = lt__malloc (sizeof *interface_id);
+  lt__interface_id *interface_id = (lt__interface_id *) lt__malloc (sizeof *interface_id);
 
   /* If lt__malloc fails, it will LT__SETERROR (NO_MEMORY), which
      can then be detected with lt_dlerror() if we return 0.  */
diff --git a/libltdl/slist.c b/libltdl/slist.c
index 8cd855183..84af3f1d8 100644
--- a/libltdl/slist.c
+++ b/libltdl/slist.c
@@ -48,14 +48,14 @@ static SList *	slist_sort_merge    (SList *left, SList *right,
 	...
 */
 SList *
-slist_delete (SList *head, void (*delete) (void *item))
+slist_delete (SList *head, void (*delete_fct) (void *item))
 {
-  assert (delete);
+  assert (delete_fct);
 
   while (head)
     {
       SList *next = head->next;
-      (*delete) (head);
+      (*delete_fct) (head);
       head = next;
     }
 
@@ -340,7 +340,7 @@ slist_sort (SList *slist, SListCompare *compare, void *userdata)
 SList *
 slist_box (const void *userdata)
 {
-  SList *item = malloc (sizeof *item);
+  SList *item = (SList *) malloc (sizeof *item);
 
   if (item)
     {
diff --git a/tests/f77demo/foo.h b/tests/f77demo/foo.h
index 1468912b4..b39255a48 100644
--- a/tests/f77demo/foo.h
+++ b/tests/f77demo/foo.h
@@ -1,5 +1,5 @@
 /* foo.h -- interface to fortran and C libraries
-   Copyright (C) 1998-1999 Free Software Foundation, Inc.
+   Copyright (C) 1998-1999, 2006 Free Software Foundation, Inc.
    This file is part of GNU Libtool.
 
 This program is free software; you can redistribute it and/or modify
@@ -41,7 +41,10 @@ extern int fwrapper(int);
  * Note that fortran passes args by reference, so
  * you need to provide pointers to your ints.
  */
-extern void F77_FUNC(fsub,FSUB)(int *arg, int *res);
-
+extern
+#ifdef __cplusplus
+"C"
+#endif
+void F77_FUNC(fsub,FSUB)(int *arg, int *res);
 
 #endif
diff --git a/tests/fcdemo/foo.h b/tests/fcdemo/foo.h
index e62e00493..9fd410351 100644
--- a/tests/fcdemo/foo.h
+++ b/tests/fcdemo/foo.h
@@ -41,7 +41,11 @@ extern int fwrapper(int);
  * Note that fortran passes args by reference, so
  * you need to provide pointers to your ints.
  */
-extern void FC_FUNC(fsub,FSUB)(int *arg, int *res);
+extern
+#ifdef __cplusplus
+"C"
+#endif
+void FC_FUNC(fsub,FSUB)(int *arg, int *res);
 
 
 #endif
diff --git a/tests/mdemo/foo.h b/tests/mdemo/foo.h
index 106f937b8..59eac5e23 100644
--- a/tests/mdemo/foo.h
+++ b/tests/mdemo/foo.h
@@ -1,5 +1,5 @@
 /* foo.h -- interface to the libfoo* libraries
-   Copyright (C) 1998-1999 Free Software Foundation, Inc.
+   Copyright (C) 1998-1999, 2006 Free Software Foundation, Inc.
    Originally by Thomas Tanner <tanner@ffii.org>
    This file is part of GNU Libtool.
 
@@ -22,6 +22,19 @@ USA. */
 #ifndef _FOO_H_
 #define _FOO_H_ 1
 
+/* __BEGIN_DECLS should be used at the beginning of your declarations,
+   so that C++ compilers don't mangle their names.  Use __END_DECLS at
+   the end of C declarations. */
+#undef __BEGIN_DECLS
+#undef __END_DECLS
+#ifdef __cplusplus
+# define __BEGIN_DECLS extern "C" {
+# define __END_DECLS }
+#else
+# define __BEGIN_DECLS /* empty */
+# define __END_DECLS /* empty */
+#endif
+
 /* Silly constants that the functions return. */
 #define HELLO_RET 0xe110
 #define FOO_RET 0xf00
diff --git a/tests/mdemo/foo1.c b/tests/mdemo/foo1.c
index c7300c0b7..0f960eb38 100644
--- a/tests/mdemo/foo1.c
+++ b/tests/mdemo/foo1.c
@@ -41,6 +41,7 @@ _foo1_helper()
 }
 
 /* exported functions */
+__BEGIN_DECLS
 
 int
 foo1()
@@ -55,3 +56,5 @@ hello()
   printf ("** This is foolib 1 **\n");
   return HELLO_RET;
 }
+
+__END_DECLS
diff --git a/tests/mdemo/foo2.c b/tests/mdemo/foo2.c
index d1d85d5eb..301e3cb10 100644
--- a/tests/mdemo/foo2.c
+++ b/tests/mdemo/foo2.c
@@ -41,6 +41,7 @@ _foo2_helper()
 }
 
 /* exported functions */
+__BEGIN_DECLS
 
 int
 foo2()
@@ -55,3 +56,5 @@ hello()
   printf ("** This is foolib 2 **\n");
   return HELLO_RET;
 }
+
+__END_DECLS
diff --git a/tests/mdemo/main.c b/tests/mdemo/main.c
index 38524f0ff..a73caac88 100644
--- a/tests/mdemo/main.c
+++ b/tests/mdemo/main.c
@@ -23,6 +23,10 @@ USA. */
 #include <stdio.h>
 #include <string.h>
 
+LT_BEGIN_C_DECLS
+extern int myfunc (void);
+LT_END_C_DECLS
+
 int
 test_dl (char *filename)
 {
diff --git a/tests/stresstest.at b/tests/stresstest.at
index af06d251a..4f7abaf65 100644
--- a/tests/stresstest.at
+++ b/tests/stresstest.at
@@ -30,10 +30,17 @@ mkdir sub sub2 sub3 2>/dev/null
 
 AT_DATA(a.c,
 [[/* all kinds of data items */
+#ifdef __cplusplus
+extern "C" {
+#endif
 int v1;
 static int v2;
 int v3 = 0;
 int v4 = 1;
+extern const int v5, v6;
+extern const char *v7;
+extern const char v8[];
+extern int (*const v12) (void);
 const int v5 = 0;
 const int v6 = 1;
 const char* v7 = "\01foo";
@@ -47,6 +54,9 @@ typedef struct { int arr[1000]; } large;
 large v13;
 large v14 = { { 0 } };
 large v15 = { { 1 } };
+#ifdef __cplusplus
+}
+#endif
 ]])
 
 AT_DATA(asyms,
@@ -73,7 +83,11 @@ int ab = 1;
 ]])
 
 AT_DATA(main.c,
-[[extern int v1;
+[[
+#ifdef __cplusplus
+extern "C" {
+#endif
+extern int v1;
 extern int v3, v4;
 extern const int v5, v6;
 extern const char* v7;
@@ -82,6 +96,9 @@ extern int v9(void);
 extern int (*v10) (void);
 extern int (*v11) (void);
 extern int (*const v12) (void);
+#ifdef __cplusplus
+}
+#endif
 
 typedef struct { int arr[1000]; } large;
 extern large v13, v14, v15;
@@ -96,7 +113,10 @@ int main(void)
 ]])
 
 AT_DATA(dlself.c,
-[[extern int v1;
+[[#ifdef __cplusplus
+extern "C" {
+#endif
+extern int v1;
 extern int v3, v4;
 extern const int v5, v6;
 extern const char* v7;
@@ -119,6 +139,9 @@ extern int (*w10) (void);
 extern int (*w11) (void);
 extern int (*const w12) (void);
 extern large w13, w14, w15;
+#ifdef __cplusplus
+}
+#endif
 
 int main(void)
 {
@@ -131,6 +154,9 @@ int main(void)
 }
 
 
+#ifdef __cplusplus
+extern "C" {
+#endif
 int w1;
 static int w2;
 int w3 = 0;
@@ -146,6 +172,9 @@ int (*const w12) (void) = w9;
 large w13;
 large w14 = { { 0 } };
 large w15 = { { 1 } };
+#ifdef __cplusplus
+}
+#endif
 ]])
 
 AT_DATA(dlselfsyms,
diff --git a/tests/testsuite.at b/tests/testsuite.at
index ab11e5c68..da39d3171 100644
--- a/tests/testsuite.at
+++ b/tests/testsuite.at
@@ -167,7 +167,10 @@ AT_CHECK([test -n "[$]$1" || (exit 77)])
 # is omitted, then no Makefile is created.
 m4_define([_LTDL_PROJECT_FILES],
 [AT_DATA([module.c],
-[[const char *
+[[#ifdef __cplusplus
+extern "C"
+#endif
+const char *
 hello (void)
 {
   return "Hello!";