* win/tclWin32Dll.c (TclpCheckStackSpace, squelch_warnings):

	* win/tclWinChan.c (Tcl_MakeFileChannel, squelch_warnings):
	* win/tclWinFCmd.c (DoRenameFile, DoCopyFile, squelch_warnings):
	Re-implement inline ASM SEH handlers for gcc.
	The esp and ebp registers are now saved on the
	stack instead of in global variables so that
	the code is thread safe. Add additional checks
	when TCL_MEM_DEBUG is defined to be sure the
	values were recovered from the stack properly.
	Remove squelch_warnings functions and add
	a dummy call in the handler methods to squelch
	compiler warnings.

1 files changed, 55 insertions, 39 deletions

diff --git a/win/tclWinChan.c b/win/tclWinChan.c
index 9ba2f64..c377245 100644
--- a/win/tclWinChan.c
+++ b/win/tclWinChan.c
@@ -9,7 +9,7 @@
  * See the file "license.terms" for information on usage and redistribution
  * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tclWinChan.c,v 1.28 2003/01/16 19:01:59 mdejong Exp $
+ * RCS: @(#) $Id: tclWinChan.c,v 1.29 2003/01/25 14:11:32 mdejong Exp $
  */
 
 #include "tclWinInt.h"
@@ -121,10 +121,14 @@ static Tcl_ChannelType fileChannelType = {
     FileWideSeekProc,		/* Wide seek proc. */
 };
 
-#ifdef HAVE_NO_SEH
-static void *ESP;
-static void *EBP;
-#endif /* HAVE_NO_SEH */
+#if defined(HAVE_NO_SEH) && defined(TCL_MEM_DEBUG)
+static void *INITIAL_ESP,
+            *INITIAL_EBP,
+            *INITIAL_HANDLER,
+            *RESTORED_ESP,
+            *RESTORED_EBP,
+            *RESTORED_HANDLER;
+#endif /* HAVE_NO_SEH && TCL_MEM_DEBUG */
 
 
 /*
@@ -1049,34 +1053,59 @@ Tcl_MakeFileChannel(rawHandle, mode)
 	 */
 
 #ifdef HAVE_NO_SEH
+# ifdef TCL_MEM_DEBUG
         __asm__ __volatile__ (
-                "movl  %esp, _ESP" "\n\t"
-                "movl  %ebp, _EBP");
-
-        __asm__ __volatile__ (
-                "pushl $__except_makefilechannel_handler" "\n\t"
-                "pushl %fs:0" "\n\t"
-                "mov   %esp, %fs:0");
+            "movl %%esp,  %0" "\n\t"
+            "movl %%ebp,  %1" "\n\t"
+            "movl %%fs:0, %2" "\n\t"
+            : "=m"(INITIAL_ESP),
+              "=m"(INITIAL_EBP),
+              "=r"(INITIAL_HANDLER) );
+# endif /* TCL_MEM_DEBUG */
 
         result = 0;
+
+        __asm__ __volatile__ (
+            "pushl %ebp" "\n\t"
+            "pushl $__except_makefilechannel_handler" "\n\t"
+            "pushl %fs:0" "\n\t"
+            "movl  %esp, %fs:0");
 #else
 	__try {
 #endif /* HAVE_NO_SEH */
 	    CloseHandle(dupedHandle);
 #ifdef HAVE_NO_SEH
         __asm__ __volatile__ (
-                "jmp   makefilechannel_pop" "\n"
-                "makefilechannel_reentry:" "\n\t"
-                "movl  _ESP, %esp" "\n\t"
-                "movl  _EBP, %ebp");
-
-        result = 1;  /* True when exception was raised */
-
-        __asm__ __volatile__ (
-                "makefilechannel_pop:" "\n\t"
-                "mov   (%esp), %eax" "\n\t"
-                "mov   %eax, %fs:0" "\n\t"
-                "add   $8, %esp");
+            "jmp  makefilechannel_pop" "\n"
+        "makefilechannel_reentry:" "\n\t"
+            "movl %%fs:0, %%eax" "\n\t"
+            "movl 0x8(%%eax), %%esp" "\n\t"
+            "movl 0x8(%%esp), %%ebp" "\n"
+            "movl $1, %0" "\n"
+        "makefilechannel_pop:" "\n\t"
+            "movl (%%esp), %%eax" "\n\t"
+            "movl %%eax, %%fs:0" "\n\t"
+            "add  $12, %%esp" "\n\t"
+            : "=m"(result)
+            :
+            : "%eax");
+
+# ifdef TCL_MEM_DEBUG
+    __asm__ __volatile__ (
+            "movl  %%esp,  %0" "\n\t"
+            "movl  %%ebp,  %1" "\n\t"
+            "movl  %%fs:0, %2" "\n\t"
+            : "=m"(RESTORED_ESP),
+              "=m"(RESTORED_EBP),
+              "=r"(RESTORED_HANDLER) );
+
+    if (INITIAL_ESP != RESTORED_ESP)
+        panic("ESP restored incorrectly");
+    if (INITIAL_EBP != RESTORED_EBP)
+        panic("EBP restored incorrectly");
+    if (INITIAL_HANDLER != RESTORED_HANDLER)
+        panic("HANDLER restored incorrectly");
+# endif /* TCL_MEM_DEBUG */
 
         if (result)
             return NULL;
@@ -1116,6 +1145,8 @@ _except_makefilechannel_handler(
 {
     __asm__ __volatile__ (
             "jmp makefilechannel_reentry");
+    /* Nuke compiler warning about unused static function */
+    _except_makefilechannel_handler(NULL, NULL, NULL, NULL);
     return 0; /* Function does not return */
 }
 #endif
@@ -1314,18 +1345,3 @@ TclWinFlushDirtyChannels ()
 	}
     }
 }
-
-#ifdef HAVE_NO_SEH
-/*
- * This method exists only to stop the compiler from emitting
- * warnings about variables and methods accessed only from asm.
- */
-static void squelch_warnings()
-{
-    void *ptr;
-    ptr = _except_makefilechannel_handler;
-    ESP = 0;
-    EBP = 0;
-    squelch_warnings();
-}
-#endif /* HAVE_NO_SEH */