mirror of
git://git.sv.gnu.org/emacs.git
synced 2025-12-17 11:20:39 -08:00
205 lines
6.8 KiB
C
205 lines
6.8 KiB
C
/* sc.h: STACK CONTEXT
|
|
*
|
|
* $Id$
|
|
* Copyright (c) 2012 Ravenbrook Limited. See end of file for license.
|
|
*
|
|
* Provides a context to hold the registers and stack pointer
|
|
*
|
|
* This file provide wrappers for using setjmp or some similar mechanism
|
|
* to save the current callee-saves on the stack.
|
|
*
|
|
* See http://info.ravenbrook.com/mail/2012/08/03/14-36-35/0/ and the rest of
|
|
* the thread for the origin of the idea.
|
|
*
|
|
* TODO: Make StackScan take a StackContext
|
|
*/
|
|
|
|
#ifndef sc_h
|
|
#define sc_h
|
|
|
|
#include "mpm.h"
|
|
|
|
|
|
/* StackContext -- holds the registers including a stack pointer
|
|
*
|
|
* This contains the callee-save registers and the stack pointer.
|
|
*
|
|
* This is used to save the registers after or on entry to the arena so that
|
|
* they can be scanned.
|
|
*/
|
|
|
|
/* STACK_CONTEXT_SAVE - save the callee-saves and stack pointer
|
|
*
|
|
* This macro saves the callee-saves and stack pointer for the
|
|
* current function into the passed StackContext. The StackContext
|
|
* is no longer valid after the function returns.
|
|
*
|
|
* This needs to be a macro because the compiler may need to do
|
|
* setjmp magic.
|
|
*/
|
|
|
|
/* StackContextStackTop - return the stack top from the stack context.
|
|
*
|
|
* We assume the stack is full. In other words the stack top points at
|
|
* a word that contains a potential Ref.
|
|
*/
|
|
|
|
|
|
/* Mac OS X on 32-bit Intel built with Clang or GCC */
|
|
|
|
#if defined(MPS_PF_XCI3LL) || defined(MPS_PF_XCI3GC)
|
|
|
|
#include <setjmp.h>
|
|
|
|
typedef struct StackContextStruct {
|
|
jmp_buf jumpBuffer;
|
|
} StackContextStruct;
|
|
|
|
/* See the implementation of _setjmp in
|
|
* <http://www.opensource.apple.com/source/Libc/Libc-825.24/i386/sys/_setjmp.s> */
|
|
|
|
#define JB_ESP 36 /* offset into the jmp_buf in bytes as defined in _setjmp.s */
|
|
|
|
#define STACK_CONTEXT_SAVE(sc) ((void)_setjmp((sc)->jumpBuffer))
|
|
|
|
#define StackContextSP(sc) ((Addr *)(sc)->jumpBuffer[JB_ESP/sizeof(int)])
|
|
|
|
/* On MacOS X the stackPointer can end up pointing above the StackContext
|
|
* which we assume to be stored on the stack because it is no longer
|
|
* needed once we have _longjmp()ed back. So take the minimum of the
|
|
* SP and the base of the StackContext structure. */
|
|
#define StackContextStackTop(sc) \
|
|
(StackContextSP(sc) < (Addr*)(sc) ? StackContextSP(sc) : (Addr*)(sc))
|
|
|
|
|
|
/* Mac OS X on 64-bit Intel build with Clang or GCC */
|
|
|
|
#elif defined(MPS_PF_XCI6LL) || defined(MPS_PF_XCI6GC)
|
|
|
|
#include <setjmp.h>
|
|
|
|
/* We could use getcontext() from libunwind but that produces
|
|
* deprecation warnings. See
|
|
* <http://stackoverflow.com/questions/3592914/how-can-i-implement-cooperative-lightweight-threading-with-c-on-mac-os-x>
|
|
*/
|
|
|
|
typedef struct StackContextStruct {
|
|
jmp_buf jumpBuffer;
|
|
} StackContextStruct;
|
|
|
|
/* See the implementation of _setjmp in
|
|
* <http://www.opensource.apple.com/source/Libc/Libc-825.24/x86_64/sys/_setjmp.s> */
|
|
|
|
#define STACK_CONTEXT_SAVE(sc) ((void)_setjmp((sc)->jumpBuffer))
|
|
|
|
#define JB_RSP 16 /* offset into the jmp_buf in bytes as defined in _setjmp.s */
|
|
|
|
/* jmp_buf is an int[] but the stack pointer is 8 bytes so we need a cast */
|
|
/* FIXME: possible aliasing problem */
|
|
#define StackContextSP(sc) \
|
|
(*(Addr **)((char *)(sc)->jumpBuffer+JB_RSP))
|
|
|
|
/* On MacOS X the stackPointer can end up pointing above the StackContext
|
|
* which we assume to be stored on the stack because it is no longer
|
|
* needed once we have _longjmp()ed back. So take the minimum of the
|
|
* SP and the base of the StackContext structure. */
|
|
#define StackContextStackTop(sc) \
|
|
(StackContextSP(sc) < (Addr*)(sc) ? StackContextSP(sc) : (Addr*)(sc))
|
|
|
|
|
|
/* Windows on 32-bit Intel with Microsoft Visual Studio */
|
|
|
|
#elif defined(MPS_PF_W3I3MV)
|
|
|
|
#include <setjmp.h>
|
|
|
|
typedef struct StackContextStruct {
|
|
jmp_buf jumpBuffer;
|
|
} StackContextStruct;
|
|
|
|
#define STACK_CONTEXT_SAVE(sc) ((void)setjmp((sc)->jumpBuffer))
|
|
|
|
#define StackContextStackTop(sc) \
|
|
((Addr *)((_JUMP_BUFFER *)(sc)->jumpBuffer)->Esp)
|
|
|
|
|
|
/* Windows on 64-bit Intel with Microsoft Visual Studio */
|
|
|
|
#elif defined(MPS_PF_W3I6MV)
|
|
|
|
#include <setjmp.h>
|
|
|
|
typedef struct StackContextStruct {
|
|
jmp_buf jumpBuffer;
|
|
} StackContextStruct;
|
|
|
|
#define STACK_CONTEXT_SAVE(sc) ((void)setjmp((sc)->jumpBuffer))
|
|
|
|
#define StackContextStackTop(sc) \
|
|
((Addr *)((_JUMP_BUFFER *)(sc)->jumpBuffer)->Rsp)
|
|
|
|
|
|
#else
|
|
|
|
/* TODO: implement this on other platforms in a safer way.
|
|
* Potentially the callee saves from the calling function could be spilled
|
|
* underneath the jmp_buf so returning the address of the jmp_buf for the
|
|
* stack top is not completely safe.
|
|
*/
|
|
|
|
#include <setjmp.h>
|
|
|
|
typedef struct StackContextStruct {
|
|
jmp_buf jumpBuffer;
|
|
} StackContextStruct;
|
|
|
|
#define STACK_CONTEXT_SAVE(sc) ((void)setjmp((sc)->jumpBuffer))
|
|
|
|
#define StackContextStackTop(sc) ((Addr *)(sc)->jumpBuffer)
|
|
|
|
|
|
#endif /* platform defines */
|
|
|
|
#endif /* sc_h */
|
|
|
|
|
|
/* C. COPYRIGHT AND LICENSE
|
|
*
|
|
* Copyright (C) 2001-2012 Ravenbrook Limited <http://www.ravenbrook.com/>.
|
|
* All rights reserved. This is an open source license. Contact
|
|
* Ravenbrook for commercial licensing options.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are
|
|
* met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
*
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* 3. Redistributions in any form must be accompanied by information on how
|
|
* to obtain complete source code for this software and any accompanying
|
|
* software that uses this software. The source code must either be
|
|
* included in the distribution or be available for no more than the cost
|
|
* of distribution plus a nominal fee, and must be freely redistributable
|
|
* under reasonable conditions. For an executable file, complete source
|
|
* code means the source code for all modules it contains. It does not
|
|
* include source code for modules or files that typically accompany the
|
|
* major components of the operating system on which the executable file
|
|
* runs.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
|
|
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
|
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
|
|
* PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
|
|
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
|
|
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|