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Publish minor changes to readme and configure files in main directory. Main directory and code directory licence texts are now fully updated. Copied from Perforce Change: 196994
99 lines
3.3 KiB
C
99 lines
3.3 KiB
C
/* ss.c: STACK SCANNING
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*
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* $Id$
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* Copyright (c) 2001-2020 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. <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. <design/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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/* Avoid the error "variable might be clobbered by 'longjmp'" from
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GCC by specifying volatile. See job004113. */
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void * volatile 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
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<design/stack-scan#.sol.entry-points.fragile>: do it now. */
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warmest = &scStruct;
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STACK_CONTEXT_SAVE(&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) 2001-2020 Ravenbrook Limited <http://www.ravenbrook.com/>.
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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
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* distribution.
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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 AND FITNESS FOR A
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* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* 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
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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