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-rw-r--r--src/Initialize.c60
-rw-r--r--src/Vendor.c21
2 files changed, 80 insertions, 1 deletions
diff --git a/src/Initialize.c b/src/Initialize.c
index c79ddc2..9ad6522 100644
--- a/src/Initialize.c
+++ b/src/Initialize.c
@@ -184,6 +184,66 @@ void _XtInherit()
#define _XtInherit __XtInherit
#endif
+
+#if defined(__CYGWIN__)
+/*
+ * The Symbol _XtInherit is used in two different manners.
+ * First it could be used as a generic function and second
+ * as an absolute address reference, which will be used to
+ * check the initialisation process of several other libraries.
+ * Because of this the symbol must be accessable by all
+ * client dll's and applications. In unix environments
+ * this is no problem, because the used shared libraries
+ * format (elf) supports this immediatly. Under Windows
+ * this isn't true, because a functions address in a dll
+ * is different from the same function in another dll or
+ * applications, because the used Portable Executable
+ * File adds a code stub to each client to provide the
+ * exported symbol name. This stub uses an indirect
+ * pointer to get the original symbol address, which is
+ * then jumped to, like in this example:
+ *
+ * --- client --- --- dll ----
+ * ...
+ * call foo
+ *
+ * foo: jmp (*_imp_foo) ----> foo: ....
+ * nop
+ * nop
+ *
+ * _imp_foo: .long <index of foo in dll export table, is
+ * set to the real address by the runtime linker>
+ *
+ * Now it is clear why the clients symbol foo isn't the same
+ * as in the dll and we can think about how to deal which
+ * this two above mentioned requirements, to export this
+ * symbol to all clients and to allow calling this symbol
+ * as a function. The solution I've used exports the
+ * symbol _XtInherit as data symbol, because global data
+ * symbols are exported to all clients. But how to deal
+ * with the second requirement, that this symbol should
+ * be used as function. The Trick is to build a little
+ * code stub in the data section in the exact manner as
+ * above explained. This is done with the assembler code
+ * below.
+ *
+ * Ralf Habacker
+ *
+ * References:
+ * msdn http://msdn.microsoft.com/msdnmag/issues/02/02/PE/PE.asp
+ * cygwin-xfree: http://www.cygwin.com/ml/cygwin-xfree/2003-10/msg00000.html
+ */
+
+asm (".data\n\
+ .globl __XtInherit \n\
+ __XtInherit: jmp *_y \n\
+ _y: .long ___XtInherit \n\
+ .text \n");
+
+#define _XtInherit __XtInherit
+#endif
+
+
void _XtInherit()
{
XtErrorMsg("invalidProcedure","inheritanceProc",XtCXtToolkitError,
diff --git a/src/Vendor.c b/src/Vendor.c
index 3b282dc..aa2e7a6 100644
--- a/src/Vendor.c
+++ b/src/Vendor.c
@@ -64,9 +64,11 @@ SOFTWARE.
*
***************************************************************************/
-#ifdef __UNIXOS2__
+#if defined(__UNIXOS2__) || defined(__CYGWIN__)
/* to fix the EditRes problem because of wrong linker semantics */
extern WidgetClass vendorShellWidgetClass;
+
+#if defined(__UNIXOS2__)
unsigned long _DLL_InitTerm(unsigned long mod,unsigned long flag)
{
switch (flag) {
@@ -82,6 +84,23 @@ unsigned long _DLL_InitTerm(unsigned long mod,unsigned long flag)
}
#endif
+#if defined(__CYGWIN__)
+int __stdcall
+DllMain(unsigned long mod_handle, unsigned long flag, void *routine)
+{
+ switch (flag)
+ {
+ case 1: /* DLL_PROCESS_ATTACH - process attach */
+ vendorShellWidgetClass = (WidgetClass)(&vendorShellClassRec);
+ break;
+ case 0: /* DLL_PROCESS_DETACH - process detach */
+ break;
+ }
+ return 1;
+}
+#endif
+#endif
+
externaldef(vendorshellclassrec) VendorShellClassRec vendorShellClassRec = {
{
/* superclass */ (WidgetClass) &wmShellClassRec,