config.host (*-cygwin* |*-mingw* ): Add crtbegin.o, crtend.o to extra_parts.

ChangeLog/libgcc

2007-06-14  Danny Smith  <dannysmith@users.sourceforge.net>

	* config.host(*-cygwin* |*-mingw* ): Add crtbegin.o, crtend.o to
	extra_parts. Add config/i386/t-cygming to tmake_file. 
	* config/i386/t-cygming: New file with rules for crtbegin.o, crtend.o.


ChangeLog/gcc

2007-06-14  Danny Smith  <dannysmith@users.sourceforge.net>

	* config/i386/cygming.h (DWARF_FRAME_REGNUM): Define.
	(DWARF2_UNWIND_INFO): Override default if configured with
	SJLJ EH disabled.
	* config/i386/cygwin.h (STARTFILE_SPEC): Add crtbegin.o.
	(ENDFILE_SPEC): Add crtend.o.
	* config/i386/mingw32.h (STARTFILE_SEC): Add crtbegin.o.
	(ENDFILE_SPEC): Add crtend.o.
	(TARGET_USE_JCR_SECTION): Define.
	(MD_UNWIND_SUPPORT): Define for 32-bit target.

	* config/i386/cygming-crtbegin.c: New file.
	* config/i386/cygming-crtend.c: New file.

2007-06-14  Pascal Obry Pascal Obry  <obry@adacore.com>

	* config/i386/w32-unwind.h: New file.

From-SVN: r125696

10 files changed, 509 insertions, 9 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7f85af9b35a..ecb6746e2b0 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,22 @@
+2007-06-14  Danny Smith  <dannysmith@users.sourceforge.net>
+
+	* config/i386/cygming.h (DWARF_FRAME_REGNUM): Define.
+	(DWARF2_UNWIND_INFO): Override default if configured with
+	SJLJ EH disabled.
+	* config/i386/cygwin.h (STARTFILE_SPEC): Add crtbegin.o.
+	(ENDFILE_SPEC): Add crtend.o.
+	* config/i386/mingw32.h (STARTFILE_SEC): Add crtbegin.o.
+	(ENDFILE_SPEC): Add crtend.o.
+	(TARGET_USE_JCR_SECTION): Define.
+	(MD_UNWIND_SUPPORT): Define for 32-bit target.
+
+	* config/i386/cygming-crtbegin.c: New file.
+	* config/i386/cygming-crtend.c: New file.
+
+2007-06-14  Pascal Obry Pascal Obry  <obry@adacore.com>
+
+	* config/i386/w32-unwind.h: New file.
+
 2007-06-13  Eric Christopher  <echristo@apple.com>
 
 	* config/i386/darwin.h (PREFERRED_STACK_BOUNDARY): Don't let
diff --git a/gcc/config/i386/cygming-crtbegin.c b/gcc/config/i386/cygming-crtbegin.c
new file mode 100755
index 00000000000..f44f64a497b
--- /dev/null
+++ b/gcc/config/i386/cygming-crtbegin.c
@@ -0,0 +1,140 @@
+/* crtbegin object for windows32 targets.
+   Copyright (C) 2007  Free Software Foundation, Inc.
+
+   Contributed by Danny Smith <dannysmith@users.sourceforge.net>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file into combinations with other programs,
+and to distribute those combinations without any restriction coming
+from the use of this file.  (The General Public License restrictions
+do apply in other respects; for example, they cover modification of
+the file, and distribution when not linked into a combine
+executable.)
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA.  */
+
+/* Target machine header files require this define. */
+#define IN_LIBGCC2
+
+#include "auto-host.h"
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "unwind-dw2-fde.h"
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+#ifndef LIBGCC_SONAME
+#define LIBGCC_SONAME "libgcc_s.dll"
+#endif
+
+#ifndef LIBGCJ_SONAME
+#define LIBGCJ_SONAME "libgcj_s.dll"
+#endif
+
+
+/* Make the declarations weak.  This is critical for
+   _Jv_RegisterClasses because it lives in libgcj.a  */
+extern void __register_frame_info (const void *, struct object *)
+				   TARGET_ATTRIBUTE_WEAK;
+extern void *__deregister_frame_info (const void *)
+				      TARGET_ATTRIBUTE_WEAK;
+extern void _Jv_RegisterClasses (const void *) TARGET_ATTRIBUTE_WEAK;
+
+#if defined(HAVE_LD_RO_RW_SECTION_MIXING)
+# define EH_FRAME_SECTION_CONST const
+#else
+# define EH_FRAME_SECTION_CONST
+#endif
+
+/* Stick a label at the beginning of the frame unwind info so we can
+   register/deregister it with the exception handling library code.  */
+#if DWARF2_UNWIND_INFO
+static EH_FRAME_SECTION_CONST char __EH_FRAME_BEGIN__[]
+  __attribute__((section(EH_FRAME_SECTION_NAME), aligned(4)))
+  = { };
+
+static struct object obj;
+#endif
+
+#if TARGET_USE_JCR_SECTION
+static void *__JCR_LIST__[]
+  __attribute__ ((unused, section(JCR_SECTION_NAME), aligned(4)))
+  = { };
+#endif
+
+/* Pull in references from libgcc.a(unwind-dw2-fde.o) in the
+   startfile. These are referenced by a ctor and dtor in crtend.o.  */
+extern void __gcc_register_frame (void);
+extern void __gcc_deregister_frame (void);
+
+void
+__gcc_register_frame (void)
+{
+#if DWARF2_UNWIND_INFO
+/* Weak undefined symbols won't be pulled in from dlls; hence
+   we first test if the dll is already loaded and, if so,
+   get the symbol's address at run-time.  If the dll is not loaded,
+   fallback to weak linkage to static archive.  */
+
+  void (*register_frame_fn) (const void *, struct object *);
+  HANDLE h = GetModuleHandle (LIBGCC_SONAME);
+  if (h)
+    register_frame_fn = (void (*) (const void *, struct object *))
+			GetProcAddress (h, "__register_frame_info");
+  else 
+    register_frame_fn = __register_frame_info;
+  if (register_frame_fn)
+     register_frame_fn (__EH_FRAME_BEGIN__, &obj);
+#endif
+
+#if TARGET_USE_JCR_SECTION 
+  if (__JCR_LIST__[0])
+    {
+      void (*register_class_fn) (const void *);
+      HANDLE h = GetModuleHandle (LIBGCJ_SONAME);
+      if (h)
+	register_class_fn = (void (*) (const void *))
+			     GetProcAddress (h, "_Jv_RegisterClasses");
+      else
+	register_class_fn = _Jv_RegisterClasses;
+
+      if (register_class_fn)
+	register_class_fn (__JCR_LIST__);
+    }
+#endif
+}
+
+void
+__gcc_deregister_frame (void)
+{
+#if DWARF2_UNWIND_INFO
+  void *  (*deregister_frame_fn) (const void *);
+  HANDLE h = GetModuleHandle (LIBGCC_SONAME);
+  if (h)
+    deregister_frame_fn = (void* (*) (const void *))
+			  GetProcAddress (h, "__deregister_frame_info");
+  else 
+    deregister_frame_fn = __deregister_frame_info;
+  if (deregister_frame_fn)
+     deregister_frame_fn (__EH_FRAME_BEGIN__);
+#endif
+}
diff --git a/gcc/config/i386/cygming-crtend.c b/gcc/config/i386/cygming-crtend.c
new file mode 100755
index 00000000000..92e133099e4
--- /dev/null
+++ b/gcc/config/i386/cygming-crtend.c
@@ -0,0 +1,86 @@
+/* crtend object for windows32 targets.
+   Copyright (C) 2007  Free Software Foundation, Inc.
+
+   Contributed by Danny Smith <dannysmith@users.sourceforge.net>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file into combinations with other programs,
+and to distribute those combinations without any restriction coming
+from the use of this file.  (The General Public License restrictions
+do apply in other respects; for example, they cover modification of
+the file, and distribution when not linked into a combine
+executable.)
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA.  */
+
+/* Target machine header files require this define. */
+#define IN_LIBGCC2
+
+/* auto-host.h is needed by cygming.h for HAVE_GAS_WEAK and here
+   for HAVE_LD_RO_RW_SECTION_MIXING.  */  
+#include "auto-host.h"
+#include "tconfig.h"
+#include "tsystem.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "unwind-dw2-fde.h"
+
+#if defined(HAVE_LD_RO_RW_SECTION_MIXING)
+# define EH_FRAME_SECTION_CONST const
+#else
+# define EH_FRAME_SECTION_CONST
+#endif
+
+#if DWARF2_UNWIND_INFO
+/* Terminate the frame unwind info section with a 0 as a sentinel;
+   this would be the 'length' field in a real FDE.  */
+
+static EH_FRAME_SECTION_CONST int __FRAME_END__[]
+  __attribute__ ((unused,  section(EH_FRAME_SECTION_NAME),
+		  aligned(4)))
+  = { 0 };
+#endif
+
+#if TARGET_USE_JCR_SECTION
+/* Null terminate the .jcr section array.  */
+static void *__JCR_END__[1] 
+   __attribute__ ((unused, section(JCR_SECTION_NAME),
+		   aligned(sizeof(void *))))
+   = { 0 };
+#endif
+
+
+extern void __gcc_register_frame (void); 
+extern void __gcc_deregister_frame (void);
+
+static void register_frame_ctor (void) __attribute__ ((constructor (0)));
+static void deregister_frame_dtor (void) __attribute__ ((destructor (0)));
+
+
+static void
+register_frame_ctor (void)
+{
+  __gcc_register_frame ();
+}
+
+static void
+deregister_frame_dtor (void)
+{
+  __gcc_deregister_frame ();
+}
diff --git a/gcc/config/i386/cygming.h b/gcc/config/i386/cygming.h
index 9ce11b2dbe1..3f3ddd7ad68 100644
--- a/gcc/config/i386/cygming.h
+++ b/gcc/config/i386/cygming.h
@@ -51,6 +51,14 @@ Boston, MA 02110-1301, USA.  */
    : (write_symbols == DWARF2_DEBUG			\
       ? svr4_dbx_register_map[n] : dbx_register_map[n]))
 
+
+/* Map gcc register number to DWARF 2 CFA column number. For 32 bit
+   target, always use the svr4_dbx_register_map for DWARF .eh_frame
+   even if we don't use DWARF .debug_frame. */
+#undef DWARF_FRAME_REGNUM
+#define DWARF_FRAME_REGNUM(n) TARGET_64BIT \
+	? dbx64_register_map[(n)] : svr4_dbx_register_map[(n)] 
+
 /* Use section relative relocations for debugging offsets.  Unlike
    other targets that fake this by putting the section VMA at 0, PE
    won't allow it.  */
@@ -279,12 +287,15 @@ do {							\
 #undef ASM_COMMENT_START
 #define ASM_COMMENT_START " #"
 
-/* DWARF2 Unwinding doesn't work with exception handling yet.  To make
-   it work, we need to build a libgcc_s.dll, and dcrt0.o should be
-   changed to call __register_frame_info/__deregister_frame_info.  */
 #ifndef DWARF2_UNWIND_INFO
+/* If configured with --disable-sjlj-exceptions, use DWARF2, else
+   default to SJLJ  */
+#if defined (CONFIG_SJLJ_EXCEPTIONS) && !CONFIG_SJLJ_EXCEPTIONS
+#define DWARF2_UNWIND_INFO 1
+#else
 #define DWARF2_UNWIND_INFO 0
 #endif
+#endif
 
 /* Don't assume anything about the header files.  */
 #define NO_IMPLICIT_EXTERN_C
diff --git a/gcc/config/i386/cygwin.h b/gcc/config/i386/cygwin.h
index 22e0af2db99..8eb480ec2ae 100644
--- a/gcc/config/i386/cygwin.h
+++ b/gcc/config/i386/cygwin.h
@@ -38,11 +38,12 @@ Boston, MA 02110-1301, USA.  */
   %{shared|mdll: %{mno-cygwin:dllcrt2%O%s}}\
   %{!shared: %{!mdll: %{!mno-cygwin:crt0%O%s} %{mno-cygwin:crt2%O%s}\
   %{pg:gcrt0%O%s}}}\
-"
+  crtbegin.o%s"
 
 #undef ENDFILE_SPEC
 #define ENDFILE_SPEC \
-  "%{ffast-math|funsafe-math-optimizations:crtfastmath.o%s}"
+  "%{ffast-math|funsafe-math-optimizations:crtfastmath.o%s}\
+   crtend.o%s"
 
 /* Normally, -lgcc is not needed since everything in it is in the DLL, but we
    want to allow things to be added to it when installing new versions of
diff --git a/gcc/config/i386/mingw32.h b/gcc/config/i386/mingw32.h
index 1145b13b3cb..2b129ecf9e1 100644
--- a/gcc/config/i386/mingw32.h
+++ b/gcc/config/i386/mingw32.h
@@ -84,11 +84,13 @@ Boston, MA 02110-1301, USA.  */
 
 #undef STARTFILE_SPEC
 #define STARTFILE_SPEC "%{shared|mdll:dllcrt2%O%s} \
-  %{!shared:%{!mdll:crt2%O%s}} %{pg:gcrt2%O%s}"
+  %{!shared:%{!mdll:crt2%O%s}} %{pg:gcrt2%O%s} \
+  crtbegin.o%s"
 
 #undef ENDFILE_SPEC
 #define ENDFILE_SPEC \
-  "%{ffast-math|funsafe-math-optimizations:crtfastmath.o%s}"
+  "%{ffast-math|funsafe-math-optimizations:crtfastmath.o%s} \
+  crtend.o%s"
 
 /* Override startfile prefix defaults.  */
 #ifndef STANDARD_STARTFILE_PREFIX_1
@@ -141,3 +143,11 @@ do {						         \
 /* mingw32 atexit function is safe to use in shared libraries.  Use it
    to register C++ static destructors.  */
 #define TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT hook_bool_void_true
+
+/* JCR_SECTION works on mingw32.  */
+#undef TARGET_USE_JCR_SECTION
+#define TARGET_USE_JCR_SECTION 1
+
+#if !TARGET_64BIT
+#define MD_UNWIND_SUPPORT "config/i386/w32-unwind.h"
+#endif
diff --git a/gcc/config/i386/w32-unwind.h b/gcc/config/i386/w32-unwind.h
new file mode 100755
index 00000000000..61e42997a61
--- /dev/null
+++ b/gcc/config/i386/w32-unwind.h
@@ -0,0 +1,215 @@
+/* Definitions for Dwarf2 EH unwind support for Windows32 targets 
+   Copyright (C) 2007
+   Free Software Foundation, Inc.
+   Contributed by Pascal Obry  <obry@adacore.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
+
+In addition to the permissions in the GNU General Public License, the
+Free Software Foundation gives you unlimited permission to link the
+compiled version of this file with other programs, and to distribute
+those programs without any restriction coming from the use of this
+file.  (The General Public License restrictions do apply in other
+respects; for example, they cover modification of the file, and
+distribution when not linked into another program.)
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA.  */
+
+/* This file implements the md_fallback_frame_state_for routine for
+   Windows, triggered when the GCC table based unwinding process hits a
+   frame for which no unwind info has been registered. This typically
+   occurs when raising an exception from a signal handler, because the
+   handler is actually called from the OS kernel.
+
+   The basic idea is to detect that we are indeed trying to unwind past a
+   signal handler and to fill out the GCC internal unwinding structures for
+   the OS kernel frame as if it had been directly called from the
+   interrupted context.
+
+   This is all assuming that the code to set the handler asked the kernel
+   to pass a pointer to such context information.
+
+   There is three main parts.
+
+   1) The first thing to do is to check if we are in a signal context. If
+      not we can just return as there is nothing to do. We are probably on
+      some foreign code for which no unwind frame can be found. If this is
+      a call from the Windows signal handler, then:
+
+   2) We must get the signal context information. 
+
+      * With the standard exception filter:
+
+      This is on Windows pointed to by an EXCEPTION_POINTERS. We know that
+      the signal handle will call an UnhandledExceptionFilter with this
+      parameter. The spec for this routine is:
+
+         LONG WINAPI UnhandledExceptionFilter(struct _EXCEPTION_POINTERS*);
+
+      So the pointer to struct _EXCEPTION_POINTERS must be somewhere on the
+      stack.
+
+      This was found experimentally to always be at offset 0 of the context
+      frame in all cases handled by this implementation.
+
+      * With the SEH exception handler:
+
+      In this case the signal context is directly on the stack as the SEH
+      exception handler has the following prototype:
+
+         DWORD
+         SEH_error_handler (PEXCEPTION_RECORD ExceptionRecord,
+                            PVOID EstablisherFrame,
+                            PCONTEXT ContextRecord,
+                            PVOID DispatcherContext)
+
+      This was found experimentally to always be at offset 56 of the
+      context frame in all cases handled by this implementation.
+
+   3) When we have the signal context we just have to save some registers
+      and set the return address based on the program counter (Eip).
+
+   Note that this implementation follows closely the same principles as the
+   GNU/Linux and OSF ones.  */
+
+#define WIN32_MEAN_AND_LEAN
+#include <windows.h>
+/* Patterns found experimentally to be on a Windows signal handler  */
+
+/* In a standard exception filter  */
+
+#define SIG_PAT1 \
+      (pc_[-2] == 0xff && pc_[-1] == 0xd0     /* call %eax           */ \
+      && pc_[0] == 0x83 && pc_[1] == 0xf8)    /* cmp 0xdepl,%eax     */
+
+#define SIG_PAT2 \
+        (pc_[-5] == 0xe8 && pc_[-4] == 0x68   /* call (depl16)       */ \
+         && pc_[0] == 0xc3)                   /* ret                 */
+
+/* In a Win32 SEH handler  */
+
+#define SIG_SEH1 \
+        (pc_[-5] == 0xe8                      /* call addr           */ \
+         && pc_[0] == 0x83 && pc_[1] == 0xc4  /* add 0xval,%esp      */ \
+         && pc_[3] == 0xb8)                   /* mov 0xval,%eax      */
+
+#define SIG_SEH2 \
+        (pc_[-5] == 0x8b && pc_[-4] == 0x4d   /* mov depl(%ebp),%ecx */ \
+         && pc_[0] == 0x64 && pc_[1] == 0x8b) /* mov %fs:(0),<reg>   */ \
+
+/* In the GCC alloca (stack probing)  */
+
+#define SIG_ALLOCA \
+          (pc_[-1] == 0x83                    /* orl $0x0,(%ecx)     */ \
+	   && pc_[0] == 0x9 && pc_[1] == 0                              \
+	   && pc_[2] == 0x2d && pc_[3] == 0   /* subl $0x1000,%eax   */ \
+	   && pc_[4] == 0x10 && pc_[5] == 0)
+
+
+#define MD_FALLBACK_FRAME_STATE_FOR i386_w32_fallback_frame_state
+
+static _Unwind_Reason_Code
+i386_w32_fallback_frame_state (struct _Unwind_Context *context, 
+			       _Unwind_FrameState *fs)
+
+{
+  void * ctx_ra_  = (void *)(context->ra);  /* return address */
+  void * ctx_cfa_ = (void *)(context->cfa); /* context frame address */
+  unsigned char * pc_ = (unsigned char *) ctx_ra_;
+
+  /* In the test below we look for two specific patterns found
+     experimentally to be in the Windows signal handler.  */
+
+  if (SIG_PAT1 || SIG_PAT2 || SIG_SEH1 || SIG_SEH2)
+    {
+      PEXCEPTION_POINTERS weinfo_;
+      PCONTEXT proc_ctx_;
+      long new_cfa_;
+
+      if (SIG_SEH1) 
+	proc_ctx_ = (PCONTEXT) (*(int*)(ctx_cfa_ + 56));
+      else if (SIG_SEH2)
+	proc_ctx_ = (PCONTEXT) (*(int*)(ctx_cfa_ + 8));
+      else
+	{
+	  weinfo_ = (PEXCEPTION_POINTERS) (*(int*)ctx_cfa_);
+	  proc_ctx_ = weinfo_->ContextRecord;
+	}
+
+      /* The new context frame address is the stack pointer.  */
+
+      new_cfa_ = proc_ctx_->Esp;
+      fs->regs.cfa_how = CFA_REG_OFFSET;
+      fs->regs.cfa_reg = __builtin_dwarf_sp_column();
+      fs->regs.cfa_offset = new_cfa_ - (long) ctx_cfa_;
+
+      /* Save some registers.  */
+
+      fs->regs.reg[0].how = REG_SAVED_OFFSET;
+      fs->regs.reg[0].loc.offset = (long)&proc_ctx_->Eax - new_cfa_;
+      fs->regs.reg[3].how = REG_SAVED_OFFSET;
+      fs->regs.reg[3].loc.offset = (long)&proc_ctx_->Ebx - new_cfa_;
+      fs->regs.reg[1].how = REG_SAVED_OFFSET;
+      fs->regs.reg[1].loc.offset = (long)&proc_ctx_->Ecx - new_cfa_;
+      fs->regs.reg[2].how = REG_SAVED_OFFSET;
+      fs->regs.reg[2].loc.offset = (long)&proc_ctx_->Edx - new_cfa_;
+      fs->regs.reg[6].how = REG_SAVED_OFFSET;
+      fs->regs.reg[6].loc.offset = (long)&proc_ctx_->Esi - new_cfa_;
+      fs->regs.reg[7].how = REG_SAVED_OFFSET;
+      fs->regs.reg[7].loc.offset = (long)&proc_ctx_->Edi - new_cfa_;
+      fs->regs.reg[9].how = REG_SAVED_OFFSET;
+      fs->regs.reg[9].loc.offset = (long)&proc_ctx_->Eip - new_cfa_;
+      fs->regs.reg[4].how = REG_SAVED_OFFSET;
+      fs->regs.reg[4].loc.offset = (long)&proc_ctx_->Ebp - new_cfa_;
+
+      /* Set the return address to Eip + 1. As we can be called multiple
+	 times we use another register for this.  */
+      
+      proc_ctx_->Dr0 = proc_ctx_->Eip + 1;
+      fs->regs.reg[8].how = REG_SAVED_OFFSET;
+      fs->regs.reg[8].loc.offset = (long)&proc_ctx_->Dr0 - new_cfa_;
+      fs->retaddr_column = 8;
+      return _URC_NO_REASON;
+    }
+
+  /* Unwinding through _alloca, propagating from a trap triggered by
+     one of it's probes prior to the real SP adjustment. The only
+     operations of interest performed is "pushl %ecx", followed by
+     ecx clobbering.  */
+
+  else if (SIG_ALLOCA) 
+    {
+      /* Only one push between entry in _alloca and the probe trap.  */ 
+      long new_cfa_ = (long) ctx_cfa_ + 4;
+
+      fs->regs.cfa_how = CFA_REG_OFFSET;
+      fs->regs.cfa_reg = __builtin_dwarf_sp_column();
+      fs->regs.cfa_offset = new_cfa_ - (long) ctx_cfa_;
+
+      /* The saved value of %ecx is at CFA - 4 */
+      fs->regs.reg[1].how = REG_SAVED_OFFSET;
+      fs->regs.reg[1].loc.offset = -4;
+
+      /* and what is stored at the CFA is the return address.  */
+      fs->retaddr_column = 8;
+      fs->regs.reg[8].how = REG_SAVED_OFFSET;
+      fs->regs.reg[8].loc.offset = 0;
+ 
+      return _URC_NO_REASON;
+    }
+  else
+    return _URC_END_OF_STACK;
+}
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index fdcdd2f48ba..9cdf81e8eb8 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,10 @@
+2007-06-14  Danny Smith  <dannysmith@users.sourceforge.net>
+
+	* config.host(*-cygwin* |*-mingw* ): Add crtbegin.o, crtend.o to
+	extra_parts. Add config/i386/t-cygming to tmake_file. 
+	* config/i386/t-cygming: New file with rules for crtbegin.o, crtend.o.
+
+
 2007-05-29  Zuxy Meng  <zuxy.meng@gmail.com>
             Danny Smith  <dannysmith@users.sourceforge.net>
 
diff --git a/libgcc/config.host b/libgcc/config.host
index 3e0cb47903c..79039abc8e1 100644
--- a/libgcc/config.host
+++ b/libgcc/config.host
@@ -370,8 +370,8 @@ i[4567]86-wrs-vxworks|i[4567]86-wrs-vxworksae)
 i[34567]86-*-pe)
 	;;
 i[34567]86-*-cygwin* | i[34567]86-*-mingw*)
-	extra_parts="crtfastmath.o"
-	tmake_file="i386/t-crtfm"
+	extra_parts="crtbegin.o crtend.o crtfastmath.o"
+	tmake_file="i386/t-cygming i386/t-crtfm"
 	;;
 x86_64-*-mingw*)
 	;;
diff --git a/libgcc/config/i386/t-cygming b/libgcc/config/i386/t-cygming
new file mode 100755
index 00000000000..048cadbd5a1
--- /dev/null
+++ b/libgcc/config/i386/t-cygming
@@ -0,0 +1,11 @@
+CUSTOM_CRTSTUFF = yes
+
+crtbegin.o: $(gcc_srcdir)/config/i386/cygming-crtbegin.c
+	$(crt_compile) -fno-omit-frame-pointer  -c \
+	$(gcc_srcdir)/config/i386/cygming-crtbegin.c
+
+# We intentionally use a implementation-reserved init priority of 0,
+# so allow the warning.
+crtend.o: $(gcc_srcdir)/config/i386/cygming-crtend.c
+	$(crt_compile) -fno-omit-frame-pointer -Wno-error -c \
+	$(gcc_srcdir)/config/i386/cygming-crtend.c