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109 lines
4 KiB
C
109 lines
4 KiB
C
/* ss.c: STACK SCANNING
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*
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* $Id$
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* Copyright (c) 2001-2014 Ravenbrook Limited. See end of file for license.
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*
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* This scans the mutator's stack and fixes the registers that may
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* contain roots. See <design/stack-scan/>.
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*
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* This is a generic implementation, but it makes assumptions that,
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* while true on all the platforms we currently (version 1.115)
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* support, may not be true on all platforms. See
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* <design/stack-scan/#sol.platform>.
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*
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* .assume.desc: The stack is descending (and so stackHot is a lower
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* address than stackCold).
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*
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* .assume.full: The stack convention is "full" (and so we must scan
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* the word pointed to by stackHot but not the word pointed to by
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* stackCold).
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*/
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#include "mpm.h"
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SRCID(ss, "$Id$");
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/* StackHot -- capture a hot stack pointer
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*
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* On all supported platforms, the arguments are pushed on to the
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* stack by the caller below its other local data, so as long as
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* it does not use something like alloca, the address of the argument
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* is a hot stack pointer. See design.mps.ss.sol.stack.hot.
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*/
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ATTRIBUTE_NOINLINE
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void StackHot(void **stackOut)
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{
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*stackOut = &stackOut;
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}
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/* StackScan -- scan the mutator's stack and registers */
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Res StackScan(ScanState ss, void *stackCold,
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mps_area_scan_t scan_area, void *closure)
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{
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StackContextStruct scStruct;
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Arena arena;
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void *warmest;
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AVERT(ScanState, ss);
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arena = ss->arena;
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AVER(arena->stackWarm != NULL);
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warmest = arena->stackWarm;
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if (warmest == NULL) {
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/* Somehow missed saving the context at the entry point (see
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<design/stack-scan/#sol.entry-points.fragile>): do it now. */
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STACK_CONTEXT_SAVE(&scStruct);
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warmest = &scStruct;
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}
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AVER(warmest < stackCold); /* .assume.desc */
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return TraceScanArea(ss, warmest, stackCold, scan_area, closure);
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}
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/* C. COPYRIGHT AND LICENSE
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*
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* Copyright (C) 2001-2014 Ravenbrook Limited <http://www.ravenbrook.com/>.
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* All rights reserved. This is an open source license. Contact
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* Ravenbrook for commercial licensing options.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* 3. Redistributions in any form must be accompanied by information on how
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* to obtain complete source code for this software and any accompanying
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* software that uses this software. The source code must either be
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* included in the distribution or be available for no more than the cost
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* of distribution plus a nominal fee, and must be freely redistributable
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* under reasonable conditions. For an executable file, complete source
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* code means the source code for all modules it contains. It does not
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* include source code for modules or files that typically accompany the
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* major components of the operating system on which the executable file
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* runs.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
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* PURPOSE, OR NON-INFRINGEMENT, ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT HOLDERS AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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