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f6fafa150d
Also fix some bugs in related code, and improve the related debugging
infrastructure.
-------------------
runtime/mercury_stacks.[ch]:
Fix bug 314 for temp frames created by nondet procedures. The fix will
probably also work for *det* procedures that create temp frames on the
nondet stack, but I can't think of a way to test that, because det
procedures create such frames only in very specific circumstances,
and I cannot think of a way to nest a recursive call inside those
circumstances.
The problem was that when we were creating new temp frames on
the nondet stack, we did not check whether the current nondet stack segment
had room for them. We now do.
The stack trace tracing code needs to know the size of each nondet stack
frame, since it uses the size to classify frames as temp or ordinary.
The size is given by the difference in address between the address of the
frame and the address of the previous frame. This difference would yield
an incorrect size and hence an incorrect frame classification if a temp
frame were allowed to have a frame on a different segment as its
immediate predecessor.
We prevent this by putting an ordinary (i.e. non-temp) frame at the bottom
of every new nondet stack segment as a sentinel. We hand-build this frame,
since it is not an "ordinary" ordinary frame. It is not created by a call,
so it has no meaningful success continuation, and since it does not make
any calls, no other frame's success continuation can point to it either.
If backtracking reaches this sentinel frame, we use this fact to free
all the segments beyond the one the sentinel frame is in, but keep the
frame the sentinel frame is in, since we are likely to need it again.
Document the reason why MR_incr_sp_leaf() does not have to check
whether a new stack segment is needed. (See the fix to llds_out_instr.m
below.)
runtime/mercury_stack_trace.[ch]:
When traversing the nondet stack, treat the sentinel frame specially.
We have to, since it is an ordinary frame (i.e. it is not a temp frame),
but it is not an "ordinary" ordinary frame: it does not make calls,
and hence calls cannot return to it, and it does not return to any
other frame either. It therefore does not have the layout structures
(label and proc) that the nondet stack traversal expects to find.
Fix an old bug: the nondet stack traversal used a simple directional
pointer comparison to check whether it has reached the bottom of the nondet
stack. This is NOT guaranteed to work in the presence of stack segments:
depending on exactly what addresses new stack segments get, a stack frame
can have an address BELOW the address of the initial stack frame
even if it is logically ABOVE that stack frame.
Another old bug was that a difference between two pointers, which could
be 64 bit, was stored in an int, which could be 32 bit.
The nondet stack traversal code used a similar directional comparison
to implement optionally stopping at an arbitrary point on the nondet stack.
Fixing this facility (the limit_addr parameter of MR_dump_nondet_stack)
while preserving reasonable efficiency would not be trivial, but it would
also be pointless, since the facility is not actually used. This diff
deletes the parameter instead.
Move some loop invariant code out of its loop.
trace/mercury_trace_cmd_developer.c:
trace/mercury_trace_external.c:
Don't pass the now-deleted parameter to mercury_stack_trace.c.
runtime/mercury_wrapper.c:
Record the zone of the initial nondet stack frame, since the fix
of mercury_stack_trace.c needs that info, and it is much more efficient
to set it up just once.
tests/hard_coded/bug314.{m,exp}:
The regression test for this bug.
tests/hard_coded/Mercury.options:
Compile the new test case with the options it needs.
tests/hard_coded/Mmakefile:
Enable the new test case.
-------------------
runtime/mercury_wrapper.c:
The compiler knows the number of words in a stack frame it is creating,
not necessarily the number of bytes (though it could put bounds on that
from the number of tag bits). Since this size must sync with the runtime,
change the runtime's variable holding this size to also be in words.
Note that similar changes would also be beneficial for other sizes.
compiler/llds_out_instr.m:
Conform to the change in mercury_wrapper.c, fixing an old bug
(mercury_wrapper.c reserved 128 BYTES for leaf procedures, but
llds_out_instr.m was using that space for procedures whose frames
were up to 128 WORDS in size.)
compiler/mercury_memory.c:
Conform to the change in mercury_wrapper.c.
-------------------
runtime/mercury_memory_zones.h:
Instead of starting to use EVERY zone at a different offset, do this
only for the INITIAL zones in each memory area, since only on these
is it useful. When the program first starts up, it WILL be using
the initial parts of the det stack, nondet stack and heap, so it is
useful to make sure that these do not collide in the cache. However,
when we allocate e.g. the second zone in e.g. the nondet stack, we are
no more likely to be beating on the initial part of any segment
of the det stack than on any other part of such segments.
If a new debug macro, MR_DEBUG_STACK_SEGMENTS_SET_SIZE is set (to an int),
use only that many words in each segment. This allows the segment switchover
code to be exercised and debugged with smaller test cases.
runtime/mercury_conf_param.h:
Document the MR_DEBUG_STACK_SEGMENTS_SET_SIZE macro.
Convert this file to four-space indentation with tabs expanded.
-------------------
runtime/mercury_overflow.h:
Make abort messages from overflows and underflows more useful by including
more information.
runtime/mercury_overflow.c:
Add a new function to help with the better abort messages.
Since this file did not exist before, create it.
runtime/Mmakefile:
Add the new source file to the list of source files.
-------------------
runtime/mercury_debug.[ch]:
Fix problems with the formatting of the debugging output from existing
functions.
Add new functions for dumping info about memory zones.
Factor out some common code.
Convert the header file to four-space indentation.
-------------------
runtime/mercury_grade.c:
Generate an error if stack segments are specified together with stack
extension
-------------------
trace/.gitignore:
util/.gitignore:
tests/debugger/.gitignore:
List some more files.
-------------------
runtime/mercury_context.c:
runtime/mercury_engine.[ch]:
runtime/mercury_misc.h:
compiler/notes/failure.html:
Fix white space.
145 lines
6.5 KiB
C
145 lines
6.5 KiB
C
/*
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** vim: ts=4 sw=4 expandtab
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*/
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/*
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** Copyright (C) 1995-1998,2000-2001, 2005-2006 The University of Melbourne.
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** This file may only be copied under the terms of the GNU Library General
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** Public License - see the file COPYING.LIB in the Mercury distribution.
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*/
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/* mercury_overflow.h - definitions for overflow checks */
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#ifndef MERCURY_OVERFLOW_H
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#define MERCURY_OVERFLOW_H
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#include "mercury_types.h"
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#include "mercury_memory_zones.h"
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/*
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** If maxfr is not in any of the zones of the nondet stack, abort the program,
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** with the abort message including the message in `error', and (if not NULL)
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** the location in `where'.
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**
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** If maxfr *is* in one of the zones of the nondet stack, then update
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** its MR_zone_max field if maxfr exceeds it, since the MR_zone_max field
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** should always hold the highest address used in the zone so far.
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*/
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extern void MR_nondetstack_inclusion_check(MR_Word *maxfr,
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const char *error, const char *where);
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typedef enum {
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MR_OVERFLOW_ZONE_DETSTACK,
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MR_OVERFLOW_ZONE_NONDETSTACK,
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MR_OVERFLOW_ZONE_HEAP,
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MR_OVERFLOW_ZONE_OTHER
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} MR_OverflowZone;
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/*
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** Output a message about a zone error to standard error and abort.
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** This function is for fatal zone underflow and overflow errors
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** in the Mercury runtime.
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*/
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MR_NO_RETURN(extern void \
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MR_fatal_zone_error(MR_OverflowZone ptr_kind,
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const char *ptr_name, const void *ptr,
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const char *zone_name,
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const MR_MemoryZone *zone, const MR_MemoryZones *zones,
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const char *error, const char *where));
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#ifndef MR_CHECK_FOR_OVERFLOW
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#define MR_heap_overflow_check() ((void) 0)
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#define MR_detstack_overflow_check() ((void) 0)
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#define MR_detstack_overflow_check_msg(x) ((void) 0)
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#define MR_detstack_underflow_check() ((void) 0)
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#define MR_detstack_underflow_check_msg(x) ((void) 0)
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#define MR_nondetstack_overflow_check() ((void) 0)
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#define MR_nondetstack_overflow_check_msg(x) ((void) 0)
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#define MR_nondetstack_underflow_check() ((void) 0)
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#define MR_nondetstack_underflow_check_msg(x) ((void) 0)
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#else /* MR_CHECK_FOR_OVERFLOW */
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#include "mercury_regs.h"
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#include "mercury_misc.h" /* for MR_fatal_error() */
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#define MR_heap_overflow_check() \
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( \
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MR_IF (MR_hp >= MR_ENGINE(MR_eng_heap_zone)->MR_zone_top,( \
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MR_fatal_error("heap overflow") \
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)), \
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MR_IF (MR_hp > MR_ENGINE(MR_eng_heap_zone)->MR_zone_max,( \
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MR_ENGINE(MR_eng_heap_zone)->MR_zone_max = MR_hp \
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)), \
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(void)0 \
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)
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#define MR_detstack_overflow_check() \
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( \
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MR_IF (MR_sp >= MR_CONTEXT(MR_ctxt_detstack_zone)->MR_zone_top,( \
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MR_fatal_error("stack overflow") \
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)), \
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MR_IF (MR_sp > MR_CONTEXT(MR_ctxt_detstack_zone)->MR_zone_max,( \
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MR_CONTEXT(MR_ctxt_detstack_zone)->MR_zone_max = MR_sp \
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)), \
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(void)0 \
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)
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#define MR_detstack_overflow_check_msg(where) \
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( \
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MR_IF (MR_sp >= MR_CONTEXT(MR_ctxt_detstack_zone)->MR_zone_top,( \
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MR_fatal_error("stack overflow: " where) \
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)), \
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MR_IF (MR_sp > MR_CONTEXT(MR_ctxt_detstack_zone)->MR_zone_max,( \
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MR_CONTEXT(MR_ctxt_detstack_zone)->MR_zone_max = MR_sp \
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)), \
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(void)0 \
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)
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#define MR_detstack_underflow_check() \
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( \
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MR_IF (MR_sp < MR_CONTEXT(MR_ctxt_detstack_zone)->MR_zone_min,( \
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MR_fatal_error("stack underflow") \
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)), \
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(void)0 \
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)
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#define MR_detstack_underflow_check_msg(where) \
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( \
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MR_IF (MR_sp < MR_CONTEXT(MR_ctxt_detstack_zone)->MR_zone_min,( \
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MR_fatal_error("stack underflow: " where) \
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)), \
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(void)0 \
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)
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/*
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** Checking for overflow and underflow on the nondet stack is not as simple
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** as on the det stack. Since it is OK for MR_maxfr to be in a segment that
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** is NOT currently the top nondet stack segment (see the comment on
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** MR_new_nondetstack_segment to see why), we have check whether MR_maxfr
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** is in *any* of the segments that currently belong to the nondet stack.
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**
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** MR_nondetstack_inclusion_check will set the MR_zone_max field of a zone
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** if MR_maxfr exceeds it. It will test for this even during underflow checks,
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** since testing whether the current check is for underflow would probably
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** take just as long.
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*/
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#define MR_nondetstack_overflow_check() \
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MR_nondetstack_inclusion_check(MR_maxfr, "nondetstack overflow", NULL)
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#define MR_nondetstack_overflow_check_msg(where) \
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MR_nondetstack_inclusion_check(MR_maxfr, "nondetstack overflow", where)
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#define MR_nondetstack_underflow_check() \
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MR_nondetstack_inclusion_check(MR_maxfr, "nondetstack underflow", NULL)
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#define MR_nondetstack_underflow_check_msg(where) \
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MR_nondetstack_inclusion_check(MR_maxfr, "nondetstack underflow", where)
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#endif /* MR_CHECK_FOR_OVERFLOW */
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#endif /* not MERCURY_OVERFLOW_H */
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