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authorKevin B Kenny <kennykb@acm.org>2005-06-23 19:48:26 (GMT)
committerKevin B Kenny <kennykb@acm.org>2005-06-23 19:48:26 (GMT)
commitca2c58dc87aed527aea5e80d39a72c95e537f41c (patch)
treedb1f99db3864102b1310d348031588f60b424620 /win/tclWinChan.c
parent10e79f4f5579a69921d990800c1ead43c1486443 (diff)
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bug 1225957
Diffstat (limited to 'win/tclWinChan.c')
-rw-r--r--win/tclWinChan.c202
1 files changed, 97 insertions, 105 deletions
diff --git a/win/tclWinChan.c b/win/tclWinChan.c
index c4ec930..db8b75b 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 1.42 2005/06/08 14:12:19 dkf Exp $
+ * RCS: @(#) $Id: tclWinChan.c,v 1.43 2005/06/23 19:48:50 kennykb Exp $
*/
#include "tclWinInt.h"
@@ -127,16 +127,24 @@ static Tcl_ChannelType fileChannelType = {
FileTruncateProc, /* Truncate proc. */
};
-#if defined(HAVE_NO_SEH) && defined(TCL_MEM_DEBUG)
-static void *INITIAL_ESP, *INITIAL_EBP, *INITIAL_HANDLER;
-static void *RESTORED_ESP, *RESTORED_EBP, *RESTORED_HANDLER;
-#endif /* HAVE_NO_SEH && TCL_MEM_DEBUG */
-
#ifdef HAVE_NO_SEH
-static __attribute__ ((cdecl)) EXCEPTION_DISPOSITION
-_except_makefilechannel_handler(struct _EXCEPTION_RECORD *ExceptionRecord,
- void *EstablisherFrame, struct _CONTEXT *ContextRecord,
- void *DispatcherContext);
+
+/*
+ * Unlike Borland and Microsoft, we don't register exception handlers
+ * by pushing registration records onto the runtime stack. Instead, we
+ * register them by creating an EXCEPTION_REGISTRATION within the activation
+ * record.
+ */
+
+typedef struct EXCEPTION_REGISTRATION {
+ struct EXCEPTION_REGISTRATION* link;
+ EXCEPTION_DISPOSITION (*handler)( struct _EXCEPTION_RECORD*, void*,
+ struct _CONTEXT*, void* );
+ void* ebp;
+ void* esp;
+ int status;
+} EXCEPTION_REGISTRATION;
+
#endif
/*
@@ -1049,6 +1057,9 @@ Tcl_MakeFileChannel(rawHandle, mode)
* and TCL_WRITABLE to indicate file
* mode. */
{
+#ifdef HAVE_NO_SEH
+ EXCEPTION_REGISTRATION registration;
+#endif
char channelName[16 + TCL_INTEGER_SPACE];
Tcl_Channel channel = NULL;
HANDLE handle = (HANDLE) rawHandle;
@@ -1137,81 +1148,93 @@ Tcl_MakeFileChannel(rawHandle, mode)
* of this duped handle which might throw EXCEPTION_INVALID_HANDLE.
*/
-#ifdef HAVE_NO_SEH
-# ifdef TCL_MEM_DEBUG
- __asm__ __volatile__ (
- "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 */
-
- __asm__ __volatile__ (
- "pushl %%ebp" "\n\t"
- "pushl %0" "\n\t"
- "pushl %%fs:0" "\n\t"
- "movl %%esp, %%fs:0"
- :
- : "r" (_except_makefilechannel_handler) );
- result = CloseHandle(dupedHandle);
- __asm__ __volatile__ (
- "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 $0, %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
+ result = 0;
+#ifndef HAVE_NO_SEH
+ __try {
+ CloseHandle(dupedHandle);
+ result = 1;
+ } __except (EXCEPTION_EXECUTE_HANDLER) {}
+#else
+ /*
+ * Don't have SEH available, do things the hard way.
+ * Note that this needs to be one block of asm, to avoid stack
+ * imbalance; also, it is illegal for one asm block to contain
+ * a jump to another.
+ */
+
__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) {
- Tcl_Panic("ESP restored incorrectly");
- }
- if (INITIAL_EBP != RESTORED_EBP) {
- Tcl_Panic("EBP restored incorrectly");
- }
- if (INITIAL_HANDLER != RESTORED_HANDLER) {
- Tcl_Panic("HANDLER restored incorrectly");
- }
-# endif /* TCL_MEM_DEBUG */
- if (result == 0) {
/*
- * The handle failed to close. The original is therefore
- * invalid.
+ * Pick up parameters before messing with the stack
*/
- return NULL;
- }
+ "movl %[dupedHandle], %%ebx" "\n\t"
-#else
- __try {
- result = CloseHandle(dupedHandle);
- } __except (EXCEPTION_EXECUTE_HANDLER) {
/*
- * Definately an invalid handle. So, therefore, the original
- * is invalid also.
+ * Construct an EXCEPTION_REGISTRATION to protect the
+ * call to CloseHandle
*/
+ "leal %[registration], %%edx" "\n\t"
+ "movl %%fs:0, %%eax" "\n\t"
+ "movl %%eax, 0x0(%%edx)" "\n\t" /* link */
+ "leal 1f, %%eax" "\n\t"
+ "movl %%eax, 0x4(%%edx)" "\n\t" /* handler */
+ "movl %%ebp, 0x8(%%edx)" "\n\t" /* ebp */
+ "movl %%esp, 0xc(%%edx)" "\n\t" /* esp */
+ "movl $0, 0x10(%%edx)" "\n\t" /* status */
+
+ /* Link the EXCEPTION_REGISTRATION on the chain */
+
+ "movl %%edx, %%fs:0" "\n\t"
+
+ /* Call CloseHandle( dupedHandle ) */
+
+ "pushl %%ebx" "\n\t"
+ "call _CloseHandle@4" "\n\t"
+
+ /*
+ * Come here on normal exit. Recover the EXCEPTION_REGISTRATION
+ * and put a TRUE status return into it.
+ */
+
+ "movl %%fs:0, %%edx" "\n\t"
+ "movl $1, %%eax" "\n\t"
+ "movl %%eax, 0x10(%%edx)" "\n\t"
+ "jmp 2f" "\n"
+
+ /*
+ * Come here on an exception. Recover the EXCEPTION_REGISTRATION
+ */
+
+ "1:" "\t"
+ "movl %%fs:0, %%edx" "\n\t"
+ "movl 0x8(%%edx), %%edx" "\n\t"
+
+ /*
+ * Come here however we exited. Restore context from the
+ * EXCEPTION_REGISTRATION in case the stack is unbalanced.
+ */
+
+ "2:" "\t"
+ "movl 0xc(%%edx), %%esp" "\n\t"
+ "movl 0x8(%%edx), %%ebp" "\n\t"
+ "movl 0x0(%%edx), %%eax" "\n\t"
+ "movl %%eax, %%fs:0" "\n\t"
+
+ :
+ /* No outputs */
+ :
+ [registration] "m" (registration),
+ [dupedHandle] "m" (dupedHandle)
+ :
+ "%eax", "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory"
+ );
+ result = registration.status;
+#endif
+ if (result == FALSE) {
return NULL;
}
-#endif /* HAVE_NO_SEH */
/* Fall through, the handle is valid. */
@@ -1229,37 +1252,6 @@ Tcl_MakeFileChannel(rawHandle, mode)
/*
*----------------------------------------------------------------------
*
- * _except_makefilechannel_handler --
- *
- * SEH exception handler for Tcl_MakeFileChannel.
- *
- * Results:
- * See Tcl_MakeFileChannel.
- *
- * Side effects:
- * See Tcl_MakeFileChannel.
- *
- *----------------------------------------------------------------------
- */
-#ifdef HAVE_NO_SEH
-static
-__attribute__ ((cdecl))
-EXCEPTION_DISPOSITION
-_except_makefilechannel_handler(
- struct _EXCEPTION_RECORD *ExceptionRecord,
- void *EstablisherFrame,
- struct _CONTEXT *ContextRecord,
- void *DispatcherContext)
-{
- __asm__ __volatile__ (
- "jmp makefilechannel_reentry");
- return 0; /* Function does not return */
-}
-#endif
-
-/*
- *----------------------------------------------------------------------
- *
* TclpGetDefaultStdChannel --
*
* Constructs a channel for the specified standard OS handle.