1 /* Copyright (c) 2008-2023. The SimGrid Team. All rights reserved. */
3 /* This program is free software; you can redistribute it and/or modify it
4 * under the terms of the license (GNU LGPL) which comes with this package. */
6 /** \file compare.cpp Memory snapshotting and comparison */
8 #include "src/mc/mc_config.hpp"
9 #include "src/mc/mc_private.hpp"
10 #include "src/mc/sosp/Snapshot.hpp"
15 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_compare, mc, "Logging specific to mc_compare in mc");
17 namespace simgrid::mc {
19 /*********************************** Heap comparison ***********************************/
20 /***************************************************************************************/
27 HeapLocation() = default;
28 explicit HeapLocation(int block, int fragment = 0) : block_(block), fragment_(fragment) {}
30 bool operator==(HeapLocation const& that) const
32 return block_ == that.block_ && fragment_ == that.fragment_;
34 bool operator<(HeapLocation const& that) const
36 return std::make_pair(block_, fragment_) < std::make_pair(that.block_, that.fragment_);
40 using HeapLocationPair = std::array<HeapLocation, 2>;
41 using HeapLocationPairs = std::set<HeapLocationPair>;
43 class HeapArea : public HeapLocation {
47 explicit HeapArea(int block) : valid_(true) { block_ = block; }
48 HeapArea(int block, int fragment) : valid_(true)
55 class ProcessComparisonState {
57 const std::vector<IgnoredHeapRegion>* to_ignore = nullptr;
58 std::vector<HeapArea> equals_to;
59 std::vector<Type*> types;
60 std::size_t heapsize = 0;
62 void initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i);
65 class StateComparator {
67 s_xbt_mheap_t std_heap_copy;
68 std::size_t heaplimit;
69 std::array<ProcessComparisonState, 2> processStates;
71 std::unordered_set<std::pair<const void*, const void*>, simgrid::xbt::hash<std::pair<const void*, const void*>>>
76 compared_pointers.clear();
79 int initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
80 const std::vector<IgnoredHeapRegion>& i1, const std::vector<IgnoredHeapRegion>& i2);
82 template <int rank> HeapArea& equals_to_(std::size_t i, std::size_t j)
84 return processStates[rank - 1].equals_to[MAX_FRAGMENT_PER_BLOCK * i + j];
86 template <int rank> Type*& types_(std::size_t i, std::size_t j)
88 return processStates[rank - 1].types[MAX_FRAGMENT_PER_BLOCK * i + j];
91 template <int rank> HeapArea const& equals_to_(std::size_t i, std::size_t j) const
93 return processStates[rank - 1].equals_to[MAX_FRAGMENT_PER_BLOCK * i + j];
95 template <int rank> Type* const& types_(std::size_t i, std::size_t j) const
97 return processStates[rank - 1].types[MAX_FRAGMENT_PER_BLOCK * i + j];
100 /** Check whether two blocks are known to be matching
102 * @param b1 Block of state 1
103 * @param b2 Block of state 2
104 * @return if the blocks are known to be matching
106 bool blocksEqual(int b1, int b2) const
108 return this->equals_to_<1>(b1, 0).block_ == b2 && this->equals_to_<2>(b2, 0).block_ == b1;
111 /** Check whether two fragments are known to be matching
113 * @param b1 Block of state 1
114 * @param f1 Fragment of state 1
115 * @param b2 Block of state 2
116 * @param f2 Fragment of state 2
117 * @return if the fragments are known to be matching
119 int fragmentsEqual(int b1, int f1, int b2, int f2) const
121 return this->equals_to_<1>(b1, f1).block_ == b2 && this->equals_to_<1>(b1, f1).fragment_ == f2 &&
122 this->equals_to_<2>(b2, f2).block_ == b1 && this->equals_to_<2>(b2, f2).fragment_ == f1;
125 void match_equals(const HeapLocationPairs* list);
128 } // namespace simgrid::mc
130 /************************************************************************************/
132 static ssize_t heap_comparison_ignore_size(const std::vector<simgrid::mc::IgnoredHeapRegion>* ignore_list,
135 auto pos = std::lower_bound(ignore_list->begin(), ignore_list->end(), address,
136 [](auto const& reg, auto const* addr) { return reg.address < addr; });
137 return (pos != ignore_list->end() && pos->address == address) ? pos->size : -1;
140 static bool is_stack(const simgrid::mc::RemoteProcessMemory& process, const void* address)
142 auto const& stack_areas = process.stack_areas();
143 return std::any_of(stack_areas.begin(), stack_areas.end(),
144 [address](auto const& stack) { return stack.address == address; });
147 // TODO, this should depend on the snapshot?
148 static bool is_block_stack(const simgrid::mc::RemoteProcessMemory& process, int block)
150 auto const& stack_areas = process.stack_areas();
151 return std::any_of(stack_areas.begin(), stack_areas.end(),
152 [block](auto const& stack) { return stack.block == block; });
155 namespace simgrid::mc {
157 void StateComparator::match_equals(const HeapLocationPairs* list)
159 for (auto const& pair : *list) {
160 if (pair[0].fragment_ != -1) {
161 this->equals_to_<1>(pair[0].block_, pair[0].fragment_) = HeapArea(pair[1].block_, pair[1].fragment_);
162 this->equals_to_<2>(pair[1].block_, pair[1].fragment_) = HeapArea(pair[0].block_, pair[0].fragment_);
164 this->equals_to_<1>(pair[0].block_, 0) = HeapArea(pair[1].block_, pair[1].fragment_);
165 this->equals_to_<2>(pair[1].block_, 0) = HeapArea(pair[0].block_, pair[0].fragment_);
170 void ProcessComparisonState::initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i)
172 auto heaplimit = heap->heaplimit;
173 this->heapsize = heap->heapsize;
174 this->to_ignore = &i;
175 this->equals_to.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, HeapArea());
176 this->types.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, nullptr);
179 int StateComparator::initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
180 const std::vector<IgnoredHeapRegion>& i1,
181 const std::vector<IgnoredHeapRegion>& i2)
183 if ((heap1->heaplimit != heap2->heaplimit) || (heap1->heapsize != heap2->heapsize))
185 this->heaplimit = heap1->heaplimit;
186 this->std_heap_copy = *mc_model_checker->get_remote_process_memory().get_heap();
187 this->processStates[0].initHeapInformation(heap1, i1);
188 this->processStates[1].initHeapInformation(heap2, i2);
192 // TODO, have a robust way to find it in O(1)
193 static inline Region* MC_get_heap_region(const Snapshot& snapshot)
195 for (auto const& region : snapshot.snapshot_regions_)
196 if (region->region_type() == RegionType::Heap)
198 xbt_die("No heap region");
201 static bool heap_area_differ(const RemoteProcessMemory& process, StateComparator& state, const void* area1,
202 const void* area2, const Snapshot& snapshot1, const Snapshot& snapshot2,
203 HeapLocationPairs* previous, Type* type, int pointer_level);
205 /* Compares the content of each heap fragment between the two states, at the bit level.
207 * This operation is costly (about 5 seconds per snapshots' pair to compare on a small program),
208 * but hard to optimize because our algorithm is too hackish.
210 * Going at bit level can trigger syntaxtic differences on states that are semantically equivalent.
212 * Padding bytes constitute the first source of such syntaxtic difference: Any malloced memory contains spaces that
213 * are not used to enforce the memory alignment constraints of the CPU. So, cruft of irrelevant changes could get
214 * added on these bits. But this case is handled properly, as any memory block is zeroed by mmalloc before being handled
215 * back, not only for calloc but also for malloc. So the memory interstices due to padding bytes are properly zeroed.
217 * Another source of such change comes from the order of mallocs, that may well change from one execution path to
218 * another. This will change the malloc fragment in which the data is stored and the pointer values (syntaxtic
219 * difference) while the semantic of the state remains the same.
221 * To fix this, this code relies on a hugly hack. When we see a difference during the bit-level comparison,
222 * we first check if it could be explained by a pointer-to-block difference. Ie, if when interpreting the memory
223 * area containing that difference as a pointer, I get the pointer to a valid fragment in the heap (in both snapshots).
225 * This is why we cannot pre-compute a bit-level hash of the heap content: we discover the pointers to other memory
226 * fragment when a difference is found during the bit-level exploration. Fixing this would require to save typing
227 * information about the memory fragments, which is something that could be done with https://github.com/tudasc/TypeART
228 * This would give us all pointers in the mallocated memory, allowing the graph traversal needed to precompute the hash.
230 * Using a hash without paying attention to malloc fragment reordering would lead to false negatives:
231 * semantically equivalent states would be detected as [syntaxically] different. It's of no importance for the
232 * state-equality reduction (we would re-explore semantically equivalent states), but it would endanger the soundness
233 * of the liveness model-checker, as state-equality is used to detect the loops that constitute the accepting states of
234 * the verified property. So we could miss counter-examples to the verified property. Not good. Not good at all.
236 static bool mmalloc_heap_differ(const RemoteProcessMemory& process, StateComparator& state, const Snapshot& snapshot1,
237 const Snapshot& snapshot2)
239 /* Check busy blocks */
242 malloc_info heapinfo_temp1;
243 malloc_info heapinfo_temp2;
244 malloc_info heapinfo_temp2b;
246 const Region* heap_region1 = MC_get_heap_region(snapshot1);
247 const Region* heap_region2 = MC_get_heap_region(snapshot2);
249 // This is the address of std_heap->heapinfo in the application process:
250 uint64_t heapinfo_address = process.heap_address.address() + offsetof(s_xbt_mheap_t, heapinfo);
252 // This is in snapshot do not use them directly:
253 const malloc_info* heapinfos1 = snapshot1.read(remote<malloc_info*>(heapinfo_address));
254 const malloc_info* heapinfos2 = snapshot2.read(remote<malloc_info*>(heapinfo_address));
256 while (i1 < state.heaplimit) {
257 const auto* heapinfo1 =
258 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[i1], sizeof(malloc_info)));
259 const auto* heapinfo2 =
260 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[i1], sizeof(malloc_info)));
262 if (heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type == MMALLOC_TYPE_HEAPINFO) { /* Free block */
267 xbt_assert(heapinfo1->type >= 0, "Unknown mmalloc block type: %d", heapinfo1->type);
269 void* addr_block1 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
271 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED) { /* Large block */
272 if (is_stack(process, addr_block1)) {
273 for (size_t k = 0; k < heapinfo1->busy_block.size; k++)
274 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
275 for (size_t k = 0; k < heapinfo2->busy_block.size; k++)
276 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
277 i1 += heapinfo1->busy_block.size;
281 if (state.equals_to_<1>(i1, 0).valid_) {
289 /* Try first to associate to same block in the other heap */
290 if (heapinfo2->type == heapinfo1->type && state.equals_to_<2>(i1, 0).valid_ == 0) {
291 const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
292 if (not heap_area_differ(process, state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
293 for (size_t k = 1; k < heapinfo2->busy_block.size; k++)
294 state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
295 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
296 state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
298 i1 += heapinfo1->busy_block.size;
302 while (i2 < state.heaplimit && not equal) {
303 const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
310 const auto* heapinfo2b =
311 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info)));
313 if (heapinfo2b->type != MMALLOC_TYPE_UNFRAGMENTED) {
318 if (state.equals_to_<2>(i2, 0).valid_) {
323 if (not heap_area_differ(process, state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
324 for (size_t k = 1; k < heapinfo2b->busy_block.size; k++)
325 state.equals_to_<2>(i2 + k, 0) = HeapArea(i1, -1);
326 for (size_t k = 1; k < heapinfo1->busy_block.size; k++)
327 state.equals_to_<1>(i1 + k, 0) = HeapArea(i2, -1);
329 i1 += heapinfo1->busy_block.size;
335 XBT_DEBUG("Block %zu not found (size_used = %zu, addr = %p)", i1, heapinfo1->busy_block.busy_size, addr_block1);
338 } else { /* Fragmented block */
339 for (size_t j1 = 0; j1 < (size_t)(BLOCKSIZE >> heapinfo1->type); j1++) {
340 if (heapinfo1->busy_frag.frag_size[j1] == -1) /* Free fragment_ */
343 if (state.equals_to_<1>(i1, j1).valid_)
346 void* addr_frag1 = (char*)addr_block1 + (j1 << heapinfo1->type);
351 /* Try first to associate to same fragment_ in the other heap */
352 if (heapinfo2->type == heapinfo1->type && not state.equals_to_<2>(i1, j1).valid_) {
353 const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
354 const void* addr_frag2 = (const char*)addr_block2 + (j1 << heapinfo2->type);
355 if (not heap_area_differ(process, state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0))
359 while (i2 < state.heaplimit && not equal) {
360 const auto* heapinfo2b =
361 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info)));
363 if (heapinfo2b->type == MMALLOC_TYPE_FREE || heapinfo2b->type == MMALLOC_TYPE_HEAPINFO) {
368 // We currently do not match fragments with unfragmented blocks (maybe we should).
369 if (heapinfo2b->type == MMALLOC_TYPE_UNFRAGMENTED) {
374 xbt_assert(heapinfo2b->type >= 0, "Unknown mmalloc block type: %d", heapinfo2b->type);
376 for (size_t j2 = 0; j2 < (size_t)(BLOCKSIZE >> heapinfo2b->type); j2++) {
377 if (i2 == i1 && j2 == j1)
380 if (state.equals_to_<2>(i2, j2).valid_)
383 const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
384 const void* addr_frag2 = (const char*)addr_block2 + (j2 << heapinfo2b->type);
386 if (not heap_area_differ(process, state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr,
396 XBT_DEBUG("Block %zu, fragment_ %zu not found (size_used = %zd, address = %p)\n", i1, j1,
397 heapinfo1->busy_frag.frag_size[j1], addr_frag1);
405 /* All blocks/fragments are equal to another block/fragment_ ? */
406 for (size_t i = 1; i < state.heaplimit; i++) {
407 const auto* heapinfo1 =
408 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[i], sizeof(malloc_info)));
410 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo1->busy_block.busy_size > 0 &&
411 not state.equals_to_<1>(i, 0).valid_) {
412 XBT_DEBUG("Block %zu not found (size used = %zu)", i, heapinfo1->busy_block.busy_size);
416 if (heapinfo1->type <= 0)
418 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo1->type); j++)
419 if (i1 == state.heaplimit && heapinfo1->busy_frag.frag_size[j] > 0 && not state.equals_to_<1>(i, j).valid_) {
420 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)", i, j, heapinfo1->busy_frag.frag_size[j]);
425 for (size_t i = 1; i < state.heaplimit; i++) {
426 const auto* heapinfo2 =
427 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[i], sizeof(malloc_info)));
428 if (heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo2->busy_block.busy_size > 0 &&
429 not state.equals_to_<2>(i, 0).valid_) {
430 XBT_DEBUG("Block %zu not found (size used = %zu)", i,
431 heapinfo2->busy_block.busy_size);
435 if (heapinfo2->type <= 0)
438 for (size_t j = 0; j < (size_t)(BLOCKSIZE >> heapinfo2->type); j++)
439 if (i1 == state.heaplimit && heapinfo2->busy_frag.frag_size[j] > 0 && not state.equals_to_<2>(i, j).valid_) {
440 XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)",
441 i, j, heapinfo2->busy_frag.frag_size[j]);
451 * @param real_area1 Process address for state 1
452 * @param real_area2 Process address for state 2
453 * @param snapshot1 Snapshot of state 1
454 * @param snapshot2 Snapshot of state 2
457 * @param check_ignore
458 * @return true when different, false otherwise (same or unknown)
460 static bool heap_area_differ_without_type(const RemoteProcessMemory& process, StateComparator& state,
461 const void* real_area1, const void* real_area2, const Snapshot& snapshot1,
462 const Snapshot& snapshot2, HeapLocationPairs* previous, int size,
465 const Region* heap_region1 = MC_get_heap_region(snapshot1);
466 const Region* heap_region2 = MC_get_heap_region(snapshot2);
468 for (int i = 0; i < size; ) {
469 if (check_ignore > 0) {
470 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, (const char*)real_area1 + i);
472 ssize_t ignore2 = heap_comparison_ignore_size(state.processStates[1].to_ignore, (const char*)real_area2 + i);
473 if (ignore2 == ignore1) {
485 if (MC_snapshot_region_memcmp((const char*)real_area1 + i, heap_region1, (const char*)real_area2 + i, heap_region2,
487 int pointer_align = (i / sizeof(void *)) * sizeof(void *);
488 const void* addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + pointer_align)));
489 const void* addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + pointer_align)));
491 if (process.in_maestro_stack(remote(addr_pointed1)) && process.in_maestro_stack(remote(addr_pointed2))) {
492 i = pointer_align + sizeof(void *);
496 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)) {
497 // Both addresses are in the heap:
498 if (heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, nullptr, 0))
500 i = pointer_align + sizeof(void *);
513 * @param real_area1 Process address for state 1
514 * @param real_area2 Process address for state 2
515 * @param snapshot1 Snapshot of state 1
516 * @param snapshot2 Snapshot of state 2
519 * @param area_size either a byte_size or an elements_count (?)
520 * @param check_ignore
521 * @param pointer_level
522 * @return true when different, false otherwise (same or unknown)
524 static bool heap_area_differ_with_type(const simgrid::mc::RemoteProcessMemory& process, StateComparator& state,
525 const void* real_area1, const void* real_area2, const Snapshot& snapshot1,
526 const Snapshot& snapshot2, HeapLocationPairs* previous, const Type* type,
527 int area_size, int check_ignore, int pointer_level)
529 // HACK: This should not happen but in practice, there are some
530 // DW_TAG_typedef without an associated DW_AT_type:
531 //<1><538832>: Abbrev Number: 111 (DW_TAG_typedef)
532 // <538833> DW_AT_name : (indirect string, offset: 0x2292f3): gregset_t
533 // <538837> DW_AT_decl_file : 98
534 // <538838> DW_AT_decl_line : 37
538 if (is_stack(process, real_area1) && is_stack(process, real_area2))
541 if (check_ignore > 0) {
542 ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, real_area1);
543 if (ignore1 > 0 && heap_comparison_ignore_size(state.processStates[1].to_ignore, real_area2) == ignore1)
548 const Type* subsubtype;
550 const void* addr_pointed1;
551 const void* addr_pointed2;
553 const Region* heap_region1 = MC_get_heap_region(snapshot1);
554 const Region* heap_region2 = MC_get_heap_region(snapshot2);
556 switch (type->type) {
557 case DW_TAG_unspecified_type:
560 case DW_TAG_base_type:
561 if (not type->name.empty() && type->name == "char") { /* String, hence random (arbitrary ?) size */
562 if (real_area1 == real_area2)
565 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, area_size) != 0;
567 if (area_size != -1 && type->byte_size != area_size)
570 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
573 case DW_TAG_enumeration_type:
574 if (area_size != -1 && type->byte_size != area_size)
576 return MC_snapshot_region_memcmp(real_area1, heap_region1, real_area2, heap_region2, type->byte_size) != 0;
579 case DW_TAG_const_type:
580 case DW_TAG_volatile_type:
581 return heap_area_differ_with_type(process, state, real_area1, real_area2, snapshot1, snapshot2, previous,
582 type->subtype, area_size, check_ignore, pointer_level);
584 case DW_TAG_array_type:
585 subtype = type->subtype;
586 switch (subtype->type) {
587 case DW_TAG_unspecified_type:
590 case DW_TAG_base_type:
591 case DW_TAG_enumeration_type:
592 case DW_TAG_pointer_type:
593 case DW_TAG_reference_type:
594 case DW_TAG_rvalue_reference_type:
595 case DW_TAG_structure_type:
596 case DW_TAG_class_type:
597 case DW_TAG_union_type:
598 if (subtype->full_type)
599 subtype = subtype->full_type;
600 elm_size = subtype->byte_size;
602 // TODO, just remove the type indirection?
603 case DW_TAG_const_type:
605 case DW_TAG_volatile_type:
606 subsubtype = subtype->subtype;
607 if (subsubtype->full_type)
608 subsubtype = subsubtype->full_type;
609 elm_size = subsubtype->byte_size;
614 for (int i = 0; i < type->element_count; i++) {
615 // TODO, add support for variable stride (DW_AT_byte_stride)
616 if (heap_area_differ_with_type(process, state, (const char*)real_area1 + (i * elm_size),
617 (const char*)real_area2 + (i * elm_size), snapshot1, snapshot2, previous,
618 type->subtype, subtype->byte_size, check_ignore, pointer_level))
623 case DW_TAG_reference_type:
624 case DW_TAG_rvalue_reference_type:
625 case DW_TAG_pointer_type:
626 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type) {
627 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
628 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
629 return (addr_pointed1 != addr_pointed2);
632 if (pointer_level <= 1) {
633 addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
634 addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
635 if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2))
636 return heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous,
637 type->subtype, pointer_level);
639 return (addr_pointed1 != addr_pointed2);
641 for (size_t i = 0; i < (area_size / sizeof(void*)); i++) {
642 addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + i * sizeof(void*))));
643 addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + i * sizeof(void*))));
644 bool differ = snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)
645 ? heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2,
646 previous, type->subtype, pointer_level)
647 : addr_pointed1 != addr_pointed2;
653 case DW_TAG_structure_type:
654 case DW_TAG_class_type:
656 type = type->full_type;
657 if (type->byte_size == 0)
659 if (area_size != -1 && type->byte_size != area_size) {
660 if (area_size <= type->byte_size || area_size % type->byte_size != 0)
662 for (size_t i = 0; i < (size_t)(area_size / type->byte_size); i++) {
663 if (heap_area_differ_with_type(process, state, (const char*)real_area1 + i * type->byte_size,
664 (const char*)real_area2 + i * type->byte_size, snapshot1, snapshot2, previous,
665 type, -1, check_ignore, 0))
669 for (const simgrid::mc::Member& member : type->members) {
670 // TODO, optimize this? (for the offset case)
671 const void* real_member1 = dwarf::resolve_member(real_area1, type, &member, &snapshot1);
672 const void* real_member2 = dwarf::resolve_member(real_area2, type, &member, &snapshot2);
673 if (heap_area_differ_with_type(process, state, real_member1, real_member2, snapshot1, snapshot2, previous,
674 member.type, -1, check_ignore, 0))
680 case DW_TAG_union_type:
681 return heap_area_differ_without_type(process, state, real_area1, real_area2, snapshot1, snapshot2, previous,
682 type->byte_size, check_ignore);
689 /** Infer the type of a part of the block from the type of the block
691 * TODO, handle DW_TAG_array_type as well as arrays of the object ((*p)[5], p[5])
693 * TODO, handle subfields ((*p).bar.foo, (*p)[5].bar…)
695 * @param type DWARF type ID of the root address
697 * @return DWARF type ID for given offset
699 static Type* get_offset_type(void* real_base_address, Type* type, int offset, int area_size, const Snapshot& snapshot)
701 // Beginning of the block, the inferred variable type if the type of the block:
705 switch (type->type) {
706 case DW_TAG_structure_type:
707 case DW_TAG_class_type:
709 type = type->full_type;
710 if (area_size != -1 && type->byte_size != area_size) {
711 if (area_size > type->byte_size && area_size % type->byte_size == 0)
717 for (const simgrid::mc::Member& member : type->members) {
718 if (member.has_offset_location()) {
719 // We have the offset, use it directly (shortcut):
720 if (member.offset() == offset)
723 void* real_member = dwarf::resolve_member(real_base_address, type, &member, &snapshot);
724 if ((char*)real_member - (char*)real_base_address == offset)
731 /* FIXME: other cases ? */
738 * @param area1 Process address for state 1
739 * @param area2 Process address for state 2
740 * @param snapshot1 Snapshot of state 1
741 * @param snapshot2 Snapshot of state 2
742 * @param previous Pairs of blocks already compared on the current path (or nullptr)
743 * @param type_id Type of variable
744 * @param pointer_level
745 * @return true when different, false otherwise (same or unknown)
747 static bool heap_area_differ(const RemoteProcessMemory& process, StateComparator& state, const void* area1,
748 const void* area2, const Snapshot& snapshot1, const Snapshot& snapshot2,
749 HeapLocationPairs* previous, Type* type, int pointer_level)
754 int check_ignore = 0;
762 Type* new_type1 = nullptr;
764 bool match_pairs = false;
766 // This is the address of std_heap->heapinfo in the application process:
767 uint64_t heapinfo_address = process.heap_address.address() + offsetof(s_xbt_mheap_t, heapinfo);
769 const malloc_info* heapinfos1 = snapshot1.read(remote<malloc_info*>(heapinfo_address));
770 const malloc_info* heapinfos2 = snapshot2.read(remote<malloc_info*>(heapinfo_address));
772 malloc_info heapinfo_temp1;
773 malloc_info heapinfo_temp2;
775 simgrid::mc::HeapLocationPairs current;
776 if (previous == nullptr) {
782 block1 = ((const char*)area1 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
783 block2 = ((const char*)area2 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
785 // If either block is a stack block:
786 if (is_block_stack(process, (int)block1) && is_block_stack(process, (int)block2)) {
787 previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}});
789 state.match_equals(previous);
793 // If either block is not in the expected area of memory:
794 if (((const char*)area1 < (const char*)state.std_heap_copy.heapbase) ||
795 (block1 > (ssize_t)state.processStates[0].heapsize) ||
796 ((const char*)area2 < (const char*)state.std_heap_copy.heapbase) ||
797 (block2 > (ssize_t)state.processStates[1].heapsize)) {
801 // Process address of the block:
802 void* real_addr_block1 = (ADDR2UINT(block1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
803 void* real_addr_block2 = (ADDR2UINT(block2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
807 type = type->full_type;
809 // This assume that for "boring" types (volatile ...) byte_size is absent:
810 while (type->byte_size == 0 && type->subtype != nullptr)
811 type = type->subtype;
814 if (type->type == DW_TAG_pointer_type ||
815 (type->type == DW_TAG_base_type && not type->name.empty() && type->name == "char"))
818 type_size = type->byte_size;
821 const Region* heap_region1 = MC_get_heap_region(snapshot1);
822 const Region* heap_region2 = MC_get_heap_region(snapshot2);
824 const auto* heapinfo1 =
825 static_cast<malloc_info*>(heap_region1->read(&heapinfo_temp1, &heapinfos1[block1], sizeof(malloc_info)));
826 const auto* heapinfo2 =
827 static_cast<malloc_info*>(heap_region2->read(&heapinfo_temp2, &heapinfos2[block2], sizeof(malloc_info)));
829 if ((heapinfo1->type == MMALLOC_TYPE_FREE || heapinfo1->type==MMALLOC_TYPE_HEAPINFO)
830 && (heapinfo2->type == MMALLOC_TYPE_FREE || heapinfo2->type ==MMALLOC_TYPE_HEAPINFO)) {
833 state.match_equals(previous);
837 if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED) {
840 // TODO, lookup variable type from block type as done for fragmented blocks
842 if (state.equals_to_<1>(block1, 0).valid_ && state.equals_to_<2>(block2, 0).valid_ &&
843 state.blocksEqual(block1, block2)) {
845 state.match_equals(previous);
849 if (type_size != -1 && type_size != (ssize_t)heapinfo1->busy_block.busy_size &&
850 type_size != (ssize_t)heapinfo2->busy_block.busy_size && type->name.empty()) {
852 state.match_equals(previous);
856 if (heapinfo1->busy_block.size != heapinfo2->busy_block.size ||
857 heapinfo1->busy_block.busy_size != heapinfo2->busy_block.busy_size)
860 if (not previous->insert(HeapLocationPair{{HeapLocation(block1, -1), HeapLocation(block2, -1)}}).second) {
862 state.match_equals(previous);
866 size = heapinfo1->busy_block.busy_size;
868 // Remember (basic) type inference.
869 // The current data structure only allows us to do this for the whole block.
870 if (type != nullptr && area1 == real_addr_block1)
871 state.types_<1>(block1, 0) = type;
872 if (type != nullptr && area2 == real_addr_block2)
873 state.types_<2>(block2, 0) = type;
877 state.match_equals(previous);
881 if (heapinfo1->busy_block.ignore > 0 && heapinfo2->busy_block.ignore == heapinfo1->busy_block.ignore)
882 check_ignore = heapinfo1->busy_block.ignore;
884 } else if ((heapinfo1->type > 0) && (heapinfo2->type > 0)) { /* Fragmented block */
886 ssize_t frag1 = (ADDR2UINT(area1) % BLOCKSIZE) >> heapinfo1->type;
887 ssize_t frag2 = (ADDR2UINT(area2) % BLOCKSIZE) >> heapinfo2->type;
889 // Process address of the fragment_:
890 void* real_addr_frag1 = (char*)real_addr_block1 + (frag1 << heapinfo1->type);
891 void* real_addr_frag2 = (char*)real_addr_block2 + (frag2 << heapinfo2->type);
893 // Check the size of the fragments against the size of the type:
894 if (type_size != -1) {
895 if (heapinfo1->busy_frag.frag_size[frag1] == -1 || heapinfo2->busy_frag.frag_size[frag2] == -1) {
897 state.match_equals(previous);
901 if (type_size != heapinfo1->busy_frag.frag_size[frag1]
902 || type_size != heapinfo2->busy_frag.frag_size[frag2]) {
904 state.match_equals(previous);
909 // Check if the blocks are already matched together:
910 if (state.equals_to_<1>(block1, frag1).valid_ && state.equals_to_<2>(block2, frag2).valid_ &&
911 state.fragmentsEqual(block1, frag1, block2, frag2)) {
913 state.match_equals(previous);
916 // Compare the size of both fragments:
917 if (heapinfo1->busy_frag.frag_size[frag1] != heapinfo2->busy_frag.frag_size[frag2]) {
918 if (type_size == -1) {
920 state.match_equals(previous);
926 // Size of the fragment_:
927 size = heapinfo1->busy_frag.frag_size[frag1];
929 // Remember (basic) type inference.
930 // The current data structure only allows us to do this for the whole fragment_.
931 if (type != nullptr && area1 == real_addr_frag1)
932 state.types_<1>(block1, frag1) = type;
933 if (type != nullptr && area2 == real_addr_frag2)
934 state.types_<2>(block2, frag2) = type;
936 // The type of the variable is already known:
940 // Type inference from the block type.
941 else if (state.types_<1>(block1, frag1) != nullptr || state.types_<2>(block2, frag2) != nullptr) {
942 Type* new_type2 = nullptr;
944 offset1 = (const char*)area1 - (const char*)real_addr_frag1;
945 offset2 = (const char*)area2 - (const char*)real_addr_frag2;
947 if (state.types_<1>(block1, frag1) != nullptr && state.types_<2>(block2, frag2) != nullptr) {
948 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
949 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset1, size, snapshot2);
950 } else if (state.types_<1>(block1, frag1) != nullptr) {
951 new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
952 new_type2 = get_offset_type(real_addr_frag2, state.types_<1>(block1, frag1), offset2, size, snapshot2);
953 } else if (state.types_<2>(block2, frag2) != nullptr) {
954 new_type1 = get_offset_type(real_addr_frag1, state.types_<2>(block2, frag2), offset1, size, snapshot1);
955 new_type2 = get_offset_type(real_addr_frag2, state.types_<2>(block2, frag2), offset2, size, snapshot2);
958 state.match_equals(previous);
962 if (new_type1 != nullptr && new_type2 != nullptr && new_type1 != new_type2) {
964 while (type->byte_size == 0 && type->subtype != nullptr)
965 type = type->subtype;
966 new_size1 = type->byte_size;
969 while (type->byte_size == 0 && type->subtype != nullptr)
970 type = type->subtype;
971 new_size2 = type->byte_size;
975 state.match_equals(previous);
980 if (new_size1 > 0 && new_size1 == new_size2) {
985 if (offset1 == 0 && offset2 == 0 &&
986 not previous->insert(HeapLocationPair{{HeapLocation(block1, frag1), HeapLocation(block2, frag2)}}).second) {
988 state.match_equals(previous);
994 state.match_equals(previous);
998 if ((heapinfo1->busy_frag.ignore[frag1] > 0) &&
999 (heapinfo2->busy_frag.ignore[frag2] == heapinfo1->busy_frag.ignore[frag1]))
1000 check_ignore = heapinfo1->busy_frag.ignore[frag1];
1004 /* Start comparison */
1005 if (type ? heap_area_differ_with_type(process, state, area1, area2, snapshot1, snapshot2, previous, type, size,
1006 check_ignore, pointer_level)
1007 : heap_area_differ_without_type(process, state, area1, area2, snapshot1, snapshot2, previous, size,
1012 state.match_equals(previous);
1015 } // namespace simgrid::mc
1017 /************************** Snapshot comparison *******************************/
1018 /******************************************************************************/
1020 static bool areas_differ_with_type(const simgrid::mc::RemoteProcessMemory& process, simgrid::mc::StateComparator& state,
1021 const void* real_area1, const simgrid::mc::Snapshot& snapshot1,
1022 simgrid::mc::Region* region1, const void* real_area2,
1023 const simgrid::mc::Snapshot& snapshot2, simgrid::mc::Region* region2,
1024 const simgrid::mc::Type* type, int pointer_level)
1026 const simgrid::mc::Type* subtype;
1027 const simgrid::mc::Type* subsubtype;
1030 xbt_assert(type != nullptr);
1031 switch (type->type) {
1032 case DW_TAG_unspecified_type:
1035 case DW_TAG_base_type:
1036 case DW_TAG_enumeration_type:
1037 case DW_TAG_union_type:
1038 return MC_snapshot_region_memcmp(real_area1, region1, real_area2, region2, type->byte_size) != 0;
1039 case DW_TAG_typedef:
1040 case DW_TAG_volatile_type:
1041 case DW_TAG_const_type:
1042 return areas_differ_with_type(process, state, real_area1, snapshot1, region1, real_area2, snapshot2, region2,
1043 type->subtype, pointer_level);
1044 case DW_TAG_array_type:
1045 subtype = type->subtype;
1046 switch (subtype->type) {
1047 case DW_TAG_unspecified_type:
1050 case DW_TAG_base_type:
1051 case DW_TAG_enumeration_type:
1052 case DW_TAG_pointer_type:
1053 case DW_TAG_reference_type:
1054 case DW_TAG_rvalue_reference_type:
1055 case DW_TAG_structure_type:
1056 case DW_TAG_class_type:
1057 case DW_TAG_union_type:
1058 if (subtype->full_type)
1059 subtype = subtype->full_type;
1060 elm_size = subtype->byte_size;
1062 case DW_TAG_const_type:
1063 case DW_TAG_typedef:
1064 case DW_TAG_volatile_type:
1065 subsubtype = subtype->subtype;
1066 if (subsubtype->full_type)
1067 subsubtype = subsubtype->full_type;
1068 elm_size = subsubtype->byte_size;
1073 for (int i = 0; i < type->element_count; i++) {
1074 size_t off = i * elm_size;
1075 if (areas_differ_with_type(process, state, (const char*)real_area1 + off, snapshot1, region1,
1076 (const char*)real_area2 + off, snapshot2, region2, type->subtype, pointer_level))
1080 case DW_TAG_pointer_type:
1081 case DW_TAG_reference_type:
1082 case DW_TAG_rvalue_reference_type: {
1083 const void* addr_pointed1 = MC_region_read_pointer(region1, real_area1);
1084 const void* addr_pointed2 = MC_region_read_pointer(region2, real_area2);
1086 if (type->subtype && type->subtype->type == DW_TAG_subroutine_type)
1087 return (addr_pointed1 != addr_pointed2);
1088 if (addr_pointed1 == nullptr && addr_pointed2 == nullptr)
1090 if (addr_pointed1 == nullptr || addr_pointed2 == nullptr)
1092 if (not state.compared_pointers.insert(std::make_pair(addr_pointed1, addr_pointed2)).second)
1097 // Some cases are not handled here:
1098 // * the pointers lead to different areas (one to the heap, the other to the RW segment ...)
1099 // * a pointer leads to the read-only segment of the current object
1100 // * a pointer lead to a different ELF object
1102 if (snapshot1.on_heap(addr_pointed1)) {
1103 if (not snapshot2.on_heap(addr_pointed2))
1105 // The pointers are both in the heap:
1106 return simgrid::mc::heap_area_differ(process, state, addr_pointed1, addr_pointed2, snapshot1, snapshot2,
1107 nullptr, type->subtype, pointer_level);
1109 } else if (region1->contain(simgrid::mc::remote(addr_pointed1))) {
1110 // The pointers are both in the current object R/W segment:
1111 if (not region2->contain(simgrid::mc::remote(addr_pointed2)))
1113 if (not type->type_id)
1114 return (addr_pointed1 != addr_pointed2);
1116 return areas_differ_with_type(process, state, addr_pointed1, snapshot1, region1, addr_pointed2, snapshot2,
1117 region2, type->subtype, pointer_level);
1119 // TODO, We do not handle very well the case where
1120 // it belongs to a different (non-heap) region from the current one.
1122 return (addr_pointed1 != addr_pointed2);
1125 case DW_TAG_structure_type:
1126 case DW_TAG_class_type:
1127 for (const simgrid::mc::Member& member : type->members) {
1128 const void* member1 = simgrid::dwarf::resolve_member(real_area1, type, &member, &snapshot1);
1129 const void* member2 = simgrid::dwarf::resolve_member(real_area2, type, &member, &snapshot2);
1130 simgrid::mc::Region* subregion1 = snapshot1.get_region(member1, region1); // region1 is hinted
1131 simgrid::mc::Region* subregion2 = snapshot2.get_region(member2, region2); // region2 is hinted
1132 if (areas_differ_with_type(process, state, member1, snapshot1, subregion1, member2, snapshot2, subregion2,
1133 member.type, pointer_level))
1137 case DW_TAG_subroutine_type:
1140 XBT_VERB("Unknown case: %d", type->type);
1147 static bool global_variables_differ(const simgrid::mc::RemoteProcessMemory& process,
1148 simgrid::mc::StateComparator& state,
1149 const simgrid::mc::ObjectInformation* object_info, simgrid::mc::Region* r1,
1150 simgrid::mc::Region* r2, const simgrid::mc::Snapshot& snapshot1,
1151 const simgrid::mc::Snapshot& snapshot2)
1153 xbt_assert(r1 && r2, "Missing region.");
1155 const std::vector<simgrid::mc::Variable>& variables = object_info->global_variables;
1157 for (simgrid::mc::Variable const& current_var : variables) {
1158 // If the variable is not in this object, skip it:
1159 // We do not expect to find a pointer to something which is not reachable
1160 // by the global variables.
1161 if ((char*)current_var.address < object_info->start_rw || (char*)current_var.address > object_info->end_rw)
1164 const simgrid::mc::Type* bvariable_type = current_var.type;
1165 if (areas_differ_with_type(process, state, current_var.address, snapshot1, r1, current_var.address, snapshot2, r2,
1166 bvariable_type, 0)) {
1167 XBT_VERB("Global variable %s (%p) is different between snapshots", current_var.name.c_str(), current_var.address);
1175 static bool local_variables_differ(const simgrid::mc::RemoteProcessMemory& process, simgrid::mc::StateComparator& state,
1176 const simgrid::mc::Snapshot& snapshot1, const simgrid::mc::Snapshot& snapshot2,
1177 const_mc_snapshot_stack_t stack1, const_mc_snapshot_stack_t stack2)
1179 if (stack1->local_variables.size() != stack2->local_variables.size()) {
1180 XBT_VERB("Different number of local variables");
1184 for (unsigned int cursor = 0; cursor < stack1->local_variables.size(); cursor++) {
1185 const_local_variable_t current_var1 = &stack1->local_variables[cursor];
1186 const_local_variable_t current_var2 = &stack2->local_variables[cursor];
1187 if (current_var1->name != current_var2->name || current_var1->subprogram != current_var2->subprogram ||
1188 current_var1->ip != current_var2->ip) {
1189 // TODO, fix current_varX->subprogram->name to include name if DW_TAG_inlined_subprogram
1190 XBT_VERB("Different name of variable (%s - %s) or frame (%s - %s) or ip (%lu - %lu)", current_var1->name.c_str(),
1191 current_var2->name.c_str(), current_var1->subprogram->name.c_str(),
1192 current_var2->subprogram->name.c_str(), current_var1->ip, current_var2->ip);
1196 if (areas_differ_with_type(process, state, current_var1->address, snapshot1,
1197 snapshot1.get_region(current_var1->address), current_var2->address, snapshot2,
1198 snapshot2.get_region(current_var2->address), current_var1->type, 0)) {
1199 XBT_VERB("Local variable %s (%p - %p) in frame %s is different between snapshots", current_var1->name.c_str(),
1200 current_var1->address, current_var2->address, current_var1->subprogram->name.c_str());
1207 namespace simgrid::mc {
1209 bool Snapshot::operator==(const Snapshot& other)
1211 // TODO, make this a field of ModelChecker or something similar
1212 static StateComparator state_comparator;
1214 const RemoteProcessMemory& process = mc_model_checker->get_remote_process_memory();
1216 if (hash_ != other.hash_) {
1217 XBT_VERB("(%ld - %ld) Different hash: 0x%" PRIx64 "--0x%" PRIx64, this->num_state_, other.num_state_, this->hash_,
1221 XBT_VERB("(%ld - %ld) Same hash: 0x%" PRIx64, this->num_state_, other.num_state_, this->hash_);
1223 /* TODO: re-enable the quick filter of counting enabled processes in each snapshots */
1225 /* Compare size of stacks */
1226 for (unsigned long i = 0; i < this->stacks_.size(); i++) {
1227 size_t size_used1 = this->stack_sizes_[i];
1228 size_t size_used2 = other.stack_sizes_[i];
1229 if (size_used1 != size_used2) {
1230 XBT_VERB("(%ld - %ld) Different size used in stacks: %zu - %zu", num_state_, other.num_state_, size_used1,
1236 /* Init heap information used in heap comparison algorithm */
1237 const s_xbt_mheap_t* heap1 = static_cast<xbt_mheap_t>(this->read_bytes(
1238 alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), process.heap_address, ReadOptions::lazy()));
1239 const s_xbt_mheap_t* heap2 = static_cast<xbt_mheap_t>(other.read_bytes(
1240 alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), process.heap_address, ReadOptions::lazy()));
1241 if (state_comparator.initHeapInformation(heap1, heap2, this->to_ignore_, other.to_ignore_) == -1) {
1242 XBT_VERB("(%ld - %ld) Different heap information", this->num_state_, other.num_state_);
1246 /* Stacks comparison */
1247 for (unsigned int cursor = 0; cursor < this->stacks_.size(); cursor++) {
1248 const_mc_snapshot_stack_t stack1 = &this->stacks_[cursor];
1249 const_mc_snapshot_stack_t stack2 = &other.stacks_[cursor];
1251 if (local_variables_differ(process, state_comparator, *this, other, stack1, stack2)) {
1252 XBT_VERB("(%ld - %ld) Different local variables between stacks %u", this->num_state_, other.num_state_,
1258 size_t regions_count = this->snapshot_regions_.size();
1259 if (regions_count != other.snapshot_regions_.size())
1262 for (size_t k = 0; k != regions_count; ++k) {
1263 Region* region1 = this->snapshot_regions_[k].get();
1264 Region* region2 = other.snapshot_regions_[k].get();
1267 if (region1->region_type() != RegionType::Data)
1270 xbt_assert(region1->region_type() == region2->region_type());
1271 xbt_assert(region1->object_info() == region2->object_info());
1272 xbt_assert(region1->object_info());
1274 /* Compare global variables */
1275 if (global_variables_differ(process, state_comparator, region1->object_info(), region1, region2, *this, other)) {
1276 std::string const& name = region1->object_info()->file_name;
1277 XBT_VERB("(%ld - %ld) Different global variables in %s", this->num_state_, other.num_state_, name.c_str());
1282 XBT_VERB(" Compare heap...");
1284 if (mmalloc_heap_differ(process, state_comparator, *this, other)) {
1285 XBT_VERB("(%ld - %ld) Different heap (mmalloc_heap_differ)", this->num_state_, other.num_state_);
1289 XBT_VERB("(%ld - %ld) No difference found", this->num_state_, other.num_state_);
1293 } // namespace simgrid::mc