/* ss.h: STACK SCANNING
*
* $Id: //info.ravenbrook.com/project/mps/master/code/ss.h#20 $
* Copyright (c) 2001-2020 Ravenbrook Limited. See end of file for license.
*
* This module saves the mutator context on entry to the MPS, and
* provides functions for decoding the context and scanning the root
* registers. <design/stack-scan>.
*/
#ifndef ss_h
#define ss_h
#include "mpm.h"
/* StackContext -- some of the mutator's state
*
* The jumpBuffer is used to capture most of the mutator's state on
* entry to the MPS, but can't capture it all. See
* <design/stack-scan#.sol.setjmp.scan>.
*/
#include <setjmp.h>
typedef struct StackContextStruct {
jmp_buf jumpBuffer;
} StackContextStruct;
/* StackHot -- capture a hot stack pointer
*
* Sets *stackOut to a stack pointer that includes the current frame.
*/
void StackHot(void **stackOut);
/* STACK_CONTEXT_BEGIN -- save context */
#define STACK_CONTEXT_BEGIN(arena) \
BEGIN \
StackContextStruct _sc; \
STACK_CONTEXT_SAVE(&_sc); \
AVER(arena->stackWarm == NULL); \
StackHot(&arena->stackWarm); \
AVER(arena->stackWarm < (void *)&_sc); /* <code/ss.c#assume.desc> */ \
BEGIN
/* STACK_CONTEXT_END -- clear context */
#define STACK_CONTEXT_END(arena) \
END; \
AVER(arena->stackWarm != NULL); \
arena->stackWarm = NULL; \
END
/* STACK_CONTEXT_SAVE -- save the callee-saves and stack pointer */
#if defined(MPS_OS_XC)
/* We call _setjmp rather than setjmp because we can be confident what
* it does via the source code at
* <https://opensource.apple.com/source/Libc/Libc-825.24/i386/sys/_setjmp.s>,
* and because _setjmp saves only the register set and the stack while
* setjmp also saves the signal mask, which we don't care about. See
* _setjmp(2). */
#define STACK_CONTEXT_SAVE(sc) ((void)_setjmp((sc)->jumpBuffer))
#else /* other platforms */
#define STACK_CONTEXT_SAVE(sc) ((void)setjmp((sc)->jumpBuffer))
#endif /* platform defines */
/* StackScan -- scan the mutator's stack and registers
*
* This must be called between STACK_CONTEXT_BEGIN and
* STACK_CONTEXT_END.
*/
extern Res StackScan(ScanState ss, void *stackCold,
mps_area_scan_t scan_area, void *closure);
#endif /* ss_h */
/* C. COPYRIGHT AND LICENSE
*
* Copyright (C) 2001-2020 Ravenbrook Limited <https://www.ravenbrook.com/>.
*
* 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.
*
* 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 AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR 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.
*/