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Update copyright lines with new year.
[simgrid.git] / src / mc / compare.cpp
index febf10b..c9a2579 100644 (file)
@@ -1,9 +1,9 @@
-/* Copyright (c) 2008-2019. The SimGrid Team. All rights reserved.          */
+/* Copyright (c) 2008-2020. The SimGrid Team. All rights reserved.          */
 
 /* This program is free software; you can redistribute it and/or modify it
  * under the terms of the license (GNU LGPL) which comes with this package. */
 
-/** \file compare.cpp Memory snapshooting and comparison                    */
+/** \file compare.cpp Memory snapshotting and comparison                    */
 
 #include "src/mc/mc_config.hpp"
 #include "src/mc/mc_private.hpp"
@@ -26,7 +26,7 @@ public:
   int fragment_ = 0;
 
   HeapLocation() = default;
-  HeapLocation(int block, int fragment = 0) : block_(block), fragment_(fragment) {}
+  explicit HeapLocation(int block, int fragment = 0) : block_(block), fragment_(fragment) {}
 
   bool operator==(HeapLocation const& that) const
   {
@@ -55,12 +55,12 @@ public:
 
 class ProcessComparisonState {
 public:
-  const std::vector<simgrid::mc::IgnoredHeapRegion>* to_ignore = nullptr;
+  const std::vector<IgnoredHeapRegion>* to_ignore = nullptr;
   std::vector<HeapArea> equals_to;
-  std::vector<simgrid::mc::Type*> types;
+  std::vector<Type*> types;
   std::size_t heapsize = 0;
 
-  void initHeapInformation(xbt_mheap_t heap, const std::vector<simgrid::mc::IgnoredHeapRegion>& i);
+  void initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i);
 };
 
 class StateComparator {
@@ -77,8 +77,8 @@ public:
     compared_pointers.clear();
   }
 
-  int initHeapInformation(xbt_mheap_t heap1, xbt_mheap_t heap2, const std::vector<simgrid::mc::IgnoredHeapRegion>& i1,
-                          const std::vector<simgrid::mc::IgnoredHeapRegion>& i2);
+  int initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
+                          const std::vector<IgnoredHeapRegion>& i1, const std::vector<IgnoredHeapRegion>& i2);
 
   template <int rank> HeapArea& equals_to_(std::size_t i, std::size_t j)
   {
@@ -123,11 +123,11 @@ public:
            this->equals_to_<2>(b2, f2).block_ == b1 && this->equals_to_<2>(b2, f2).fragment_ == f1;
   }
 
-  void match_equals(HeapLocationPairs* list);
+  void match_equals(const HeapLocationPairs* list);
 };
 
-}
-}
+} // namespace mc
+} // namespace simgrid
 
 /************************************************************************************/
 
@@ -151,12 +151,6 @@ static ssize_t heap_comparison_ignore_size(const std::vector<simgrid::mc::Ignore
   return -1;
 }
 
-static bool is_on_heap(const void* address)
-{
-  const xbt_mheap_t heap = mc_model_checker->process().get_heap();
-  return address >= heap->heapbase && address < heap->breakval;
-}
-
 static bool is_stack(const void *address)
 {
   for (auto const& stack : mc_model_checker->process().stack_areas())
@@ -177,20 +171,20 @@ static bool is_block_stack(int block)
 namespace simgrid {
 namespace mc {
 
-void StateComparator::match_equals(HeapLocationPairs* list)
+void StateComparator::match_equals(const HeapLocationPairs* list)
 {
   for (auto const& pair : *list) {
     if (pair[0].fragment_ != -1) {
-      this->equals_to_<1>(pair[0].block_, pair[0].fragment_) = simgrid::mc::HeapArea(pair[1].block_, pair[1].fragment_);
-      this->equals_to_<2>(pair[1].block_, pair[1].fragment_) = simgrid::mc::HeapArea(pair[0].block_, pair[0].fragment_);
+      this->equals_to_<1>(pair[0].block_, pair[0].fragment_) = HeapArea(pair[1].block_, pair[1].fragment_);
+      this->equals_to_<2>(pair[1].block_, pair[1].fragment_) = HeapArea(pair[0].block_, pair[0].fragment_);
     } else {
-      this->equals_to_<1>(pair[0].block_, 0) = simgrid::mc::HeapArea(pair[1].block_, pair[1].fragment_);
-      this->equals_to_<2>(pair[1].block_, 0) = simgrid::mc::HeapArea(pair[0].block_, pair[0].fragment_);
+      this->equals_to_<1>(pair[0].block_, 0) = HeapArea(pair[1].block_, pair[1].fragment_);
+      this->equals_to_<2>(pair[1].block_, 0) = HeapArea(pair[0].block_, pair[0].fragment_);
     }
   }
 }
 
-void ProcessComparisonState::initHeapInformation(xbt_mheap_t heap, const std::vector<simgrid::mc::IgnoredHeapRegion>& i)
+void ProcessComparisonState::initHeapInformation(const s_xbt_mheap_t* heap, const std::vector<IgnoredHeapRegion>& i)
 {
   auto heaplimit  = heap->heaplimit;
   this->heapsize  = heap->heapsize;
@@ -199,9 +193,9 @@ void ProcessComparisonState::initHeapInformation(xbt_mheap_t heap, const std::ve
   this->types.assign(heaplimit * MAX_FRAGMENT_PER_BLOCK, nullptr);
 }
 
-int StateComparator::initHeapInformation(xbt_mheap_t heap1, xbt_mheap_t heap2,
-                                         const std::vector<simgrid::mc::IgnoredHeapRegion>& i1,
-                                         const std::vector<simgrid::mc::IgnoredHeapRegion>& i2)
+int StateComparator::initHeapInformation(const s_xbt_mheap_t* heap1, const s_xbt_mheap_t* heap2,
+                                         const std::vector<IgnoredHeapRegion>& i1,
+                                         const std::vector<IgnoredHeapRegion>& i2)
 {
   if ((heap1->heaplimit != heap2->heaplimit) || (heap1->heapsize != heap2->heapsize))
     return -1;
@@ -216,7 +210,7 @@ int StateComparator::initHeapInformation(xbt_mheap_t heap1, xbt_mheap_t heap2,
 static inline Region* MC_get_heap_region(const Snapshot& snapshot)
 {
   for (auto const& region : snapshot.snapshot_regions_)
-    if (region->region_type() == simgrid::mc::RegionType::Heap)
+    if (region->region_type() == RegionType::Heap)
       return region.get();
   xbt_die("No heap region");
 }
@@ -224,10 +218,9 @@ static inline Region* MC_get_heap_region(const Snapshot& snapshot)
 static bool heap_area_differ(StateComparator& state, const void* area1, const void* area2, const Snapshot& snapshot1,
                              const Snapshot& snapshot2, HeapLocationPairs* previous, Type* type, int pointer_level);
 
-static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgrid::mc::Snapshot& snapshot1,
-                                const simgrid::mc::Snapshot& snapshot2)
+static bool mmalloc_heap_differ(StateComparator& state, const Snapshot& snapshot1, const Snapshot& snapshot2)
 {
-  const simgrid::mc::RemoteClient& process = mc_model_checker->process();
+  const RemoteClient& process = mc_model_checker->process();
 
   /* Check busy blocks */
   size_t i1 = 1;
@@ -236,8 +229,8 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
   malloc_info heapinfo_temp2;
   malloc_info heapinfo_temp2b;
 
-  simgrid::mc::Region* heap_region1 = MC_get_heap_region(snapshot1);
-  simgrid::mc::Region* heap_region2 = MC_get_heap_region(snapshot2);
+  const Region* heap_region1 = MC_get_heap_region(snapshot1);
+  const Region* heap_region2 = MC_get_heap_region(snapshot2);
 
   // This is the address of std_heap->heapinfo in the application process:
   void* heapinfo_address = &((xbt_mheap_t)process.heap_address)->heapinfo;
@@ -249,7 +242,6 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
       snapshot2.read<malloc_info*>(RemotePtr<malloc_info*>((std::uint64_t)heapinfo_address));
 
   while (i1 < state.heaplimit) {
-
     const malloc_info* heapinfo1 =
         (const malloc_info*)heap_region1->read(&heapinfo_temp1, &heapinfos1[i1], sizeof(malloc_info));
     const malloc_info* heapinfo2 =
@@ -260,15 +252,11 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
       continue;
     }
 
-    if (heapinfo1->type < 0) {
-      fprintf(stderr, "Unkown mmalloc block type.\n");
-      abort();
-    }
+    xbt_assert(heapinfo1->type >= 0, "Unkown mmalloc block type: %d", heapinfo1->type);
 
     void* addr_block1 = ((void*)(((ADDR2UINT(i1)) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase));
 
-    if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED) {       /* Large block */
-
+    if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED) { /* Large block */
       if (is_stack(addr_block1)) {
         for (size_t k = 0; k < heapinfo1->busy_block.size; k++)
           state.equals_to_<1>(i1 + k, 0) = HeapArea(i1, -1);
@@ -288,7 +276,7 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
 
       /* Try first to associate to same block in the other heap */
       if (heapinfo2->type == heapinfo1->type && state.equals_to_<2>(i1, 0).valid_ == 0) {
-        void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
+        const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
         if (not heap_area_differ(state, addr_block1, addr_block2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
           for (size_t k = 1; k < heapinfo2->busy_block.size; k++)
             state.equals_to_<2>(i1 + k, 0) = HeapArea(i1, -1);
@@ -300,8 +288,7 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
       }
 
       while (i2 < state.heaplimit && not equal) {
-
-        void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
+        const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
 
         if (i2 == i1) {
           i2++;
@@ -329,7 +316,6 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
           equal = true;
           i1 += heapinfo1->busy_block.size;
         }
-
         i2++;
       }
 
@@ -337,11 +323,8 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
         XBT_DEBUG("Block %zu not found (size_used = %zu, addr = %p)", i1, heapinfo1->busy_block.busy_size, addr_block1);
         return true;
       }
-
-    } else {                    /* Fragmented block */
-
+    } else { /* Fragmented block */
       for (size_t j1 = 0; j1 < (size_t)(BLOCKSIZE >> heapinfo1->type); j1++) {
-
         if (heapinfo1->busy_frag.frag_size[j1] == -1) /* Free fragment_ */
           continue;
 
@@ -355,14 +338,13 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
 
         /* Try first to associate to same fragment_ in the other heap */
         if (heapinfo2->type == heapinfo1->type && not state.equals_to_<2>(i1, j1).valid_) {
-          void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
-          void* addr_frag2  = (void*)((char*)addr_block2 + (j1 << heapinfo2->type));
+          const void* addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
+          const void* addr_frag2  = (const char*)addr_block2 + (j1 << heapinfo2->type);
           if (not heap_area_differ(state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0))
             equal = true;
         }
 
         while (i2 < state.heaplimit && not equal) {
-
           const malloc_info* heapinfo2b =
               (const malloc_info*)heap_region2->read(&heapinfo_temp2b, &heapinfos2[i2], sizeof(malloc_info));
 
@@ -377,28 +359,23 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
             continue;
           }
 
-          if (heapinfo2b->type < 0) {
-            fprintf(stderr, "Unknown mmalloc block type.\n");
-            abort();
-          }
+          xbt_assert(heapinfo2b->type >= 0, "Unkown mmalloc block type: %d", heapinfo2b->type);
 
           for (size_t j2 = 0; j2 < (size_t)(BLOCKSIZE >> heapinfo2b->type); j2++) {
-
             if (i2 == i1 && j2 == j1)
               continue;
 
             if (state.equals_to_<2>(i2, j2).valid_)
               continue;
 
-            void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
-            void* addr_frag2  = (void*)((char*)addr_block2 + (j2 << heapinfo2b->type));
+            const void* addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase;
+            const void* addr_frag2  = (const char*)addr_block2 + (j2 << heapinfo2b->type);
 
             if (not heap_area_differ(state, addr_frag1, addr_frag2, snapshot1, snapshot2, nullptr, nullptr, 0)) {
               equal = true;
               break;
             }
           }
-
           i2++;
         }
 
@@ -408,7 +385,6 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
           return true;
         }
       }
-
       i1++;
     }
   }
@@ -453,7 +429,6 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
         return true;
       }
   }
-
   return false;
 }
 
@@ -469,24 +444,21 @@ static bool mmalloc_heap_differ(simgrid::mc::StateComparator& state, const simgr
  * @param check_ignore
  * @return true when different, false otherwise (same or unknown)
  */
-static bool heap_area_differ_without_type(simgrid::mc::StateComparator& state, const void* real_area1,
-                                          const void* real_area2, const simgrid::mc::Snapshot& snapshot1,
-                                          const simgrid::mc::Snapshot& snapshot2, HeapLocationPairs* previous, int size,
-                                          int check_ignore)
+static bool heap_area_differ_without_type(StateComparator& state, const void* real_area1, const void* real_area2,
+                                          const Snapshot& snapshot1, const Snapshot& snapshot2,
+                                          HeapLocationPairs* previous, int size, int check_ignore)
 {
-  const simgrid::mc::RemoteClient& process = mc_model_checker->process();
-  simgrid::mc::Region* heap_region1  = MC_get_heap_region(snapshot1);
-  simgrid::mc::Region* heap_region2  = MC_get_heap_region(snapshot2);
+  const RemoteClient& process = mc_model_checker->process();
+  const Region* heap_region1  = MC_get_heap_region(snapshot1);
+  const Region* heap_region2  = MC_get_heap_region(snapshot2);
 
   for (int i = 0; i < size; ) {
-
     if (check_ignore > 0) {
       ssize_t ignore1 = heap_comparison_ignore_size(state.processStates[0].to_ignore, (const char*)real_area1 + i);
       if (ignore1 != -1) {
         ssize_t ignore2 = heap_comparison_ignore_size(state.processStates[1].to_ignore, (const char*)real_area2 + i);
         if (ignore2 == ignore1) {
           if (ignore1 == 0) {
-            check_ignore--;
             return false;
           } else {
             i = i + ignore2;
@@ -499,30 +471,26 @@ static bool heap_area_differ_without_type(simgrid::mc::StateComparator& state, c
 
     if (MC_snapshot_region_memcmp((const char*)real_area1 + i, heap_region1, (const char*)real_area2 + i, heap_region2,
                                   1) != 0) {
-
       int pointer_align = (i / sizeof(void *)) * sizeof(void *);
-      const void* addr_pointed1 = snapshot1.read(remote((void**)((const char*)real_area1 + pointer_align)));
-      const void* addr_pointed2 = snapshot2.read(remote((void**)((const char*)real_area2 + pointer_align)));
+      const void* addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + pointer_align)));
+      const void* addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + pointer_align)));
 
       if (process.in_maestro_stack(remote(addr_pointed1)) && process.in_maestro_stack(remote(addr_pointed2))) {
         i = pointer_align + sizeof(void *);
         continue;
       }
 
-      if (is_on_heap(addr_pointed1) && is_on_heap(addr_pointed2)) {
+      if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)) {
         // Both addresses are in the heap:
         if (heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, nullptr, 0))
           return true;
         i = pointer_align + sizeof(void *);
         continue;
       }
-
       return true;
     }
-
     i++;
   }
-
   return false;
 }
 
@@ -540,12 +508,12 @@ static bool heap_area_differ_without_type(simgrid::mc::StateComparator& state, c
  * @param pointer_level
  * @return               true when different, false otherwise (same or unknown)
  */
-static bool heap_area_differ_with_type(simgrid::mc::StateComparator& state, const void* real_area1,
-                                       const void* real_area2, const simgrid::mc::Snapshot& snapshot1,
-                                       const simgrid::mc::Snapshot& snapshot2, HeapLocationPairs* previous,
-                                       simgrid::mc::Type* type, int area_size, int check_ignore, int pointer_level)
+static bool heap_area_differ_with_type(StateComparator& state, const void* real_area1, const void* real_area2,
+                                       const Snapshot& snapshot1, const Snapshot& snapshot2,
+                                       HeapLocationPairs* previous, const Type* type, int area_size, int check_ignore,
+                                       int pointer_level)
 {
-  // HACK: This should not happen but in pratice, there are some
+  // HACK: This should not happen but in practice, there are some
   // DW_TAG_typedef without an associated DW_AT_type:
   //<1><538832>: Abbrev Number: 111 (DW_TAG_typedef)
   //    <538833>   DW_AT_name        : (indirect string, offset: 0x2292f3): gregset_t
@@ -563,14 +531,14 @@ static bool heap_area_differ_with_type(simgrid::mc::StateComparator& state, cons
       return false;
   }
 
-  simgrid::mc::Type* subtype;
-  simgrid::mc::Type* subsubtype;
+  const Type* subtype;
+  const Type* subsubtype;
   int elm_size;
   const void* addr_pointed1;
   const void* addr_pointed2;
 
-  simgrid::mc::Region* heap_region1 = MC_get_heap_region(snapshot1);
-  simgrid::mc::Region* heap_region2 = MC_get_heap_region(snapshot2);
+  const Region* heap_region1 = MC_get_heap_region(snapshot1);
+  const Region* heap_region2 = MC_get_heap_region(snapshot2);
 
   switch (type->type) {
     case DW_TAG_unspecified_type:
@@ -651,7 +619,7 @@ static bool heap_area_differ_with_type(simgrid::mc::StateComparator& state, cons
       if (pointer_level <= 1) {
         addr_pointed1 = snapshot1.read(remote((void* const*)real_area1));
         addr_pointed2 = snapshot2.read(remote((void* const*)real_area2));
-        if (is_on_heap(addr_pointed1) && is_on_heap(addr_pointed2))
+        if (snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2))
           return heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous, type->subtype,
                                   pointer_level);
         else
@@ -660,7 +628,7 @@ static bool heap_area_differ_with_type(simgrid::mc::StateComparator& state, cons
       for (size_t i = 0; i < (area_size / sizeof(void*)); i++) {
         addr_pointed1 = snapshot1.read(remote((void* const*)((const char*)real_area1 + i * sizeof(void*))));
         addr_pointed2 = snapshot2.read(remote((void* const*)((const char*)real_area2 + i * sizeof(void*))));
-        bool differ   = is_on_heap(addr_pointed1) && is_on_heap(addr_pointed2)
+        bool differ   = snapshot1.on_heap(addr_pointed1) && snapshot2.on_heap(addr_pointed2)
                           ? heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, previous,
                                              type->subtype, pointer_level)
                           : addr_pointed1 != addr_pointed2;
@@ -673,6 +641,8 @@ static bool heap_area_differ_with_type(simgrid::mc::StateComparator& state, cons
     case DW_TAG_class_type:
       if (type->full_type)
         type = type->full_type;
+      if (type->byte_size == 0)
+        return false;
       if (area_size != -1 && type->byte_size != area_size) {
         if (area_size <= type->byte_size || area_size % type->byte_size != 0)
           return false;
@@ -683,10 +653,10 @@ static bool heap_area_differ_with_type(simgrid::mc::StateComparator& state, cons
             return true;
         }
         } else {
-          for (simgrid::mc::Member& member : type->members) {
+          for (const simgrid::mc::Member& member : type->members) {
             // TODO, optimize this? (for the offset case)
-            void* real_member1 = simgrid::dwarf::resolve_member(real_area1, type, &member, &snapshot1);
-            void* real_member2 = simgrid::dwarf::resolve_member(real_area2, type, &member, &snapshot2);
+            const void* real_member1 = dwarf::resolve_member(real_area1, type, &member, &snapshot1);
+            const void* real_member2 = dwarf::resolve_member(real_area2, type, &member, &snapshot2);
             if (heap_area_differ_with_type(state, real_member1, real_member2, snapshot1, snapshot2, previous,
                                            member.type, -1, check_ignore, 0))
               return true;
@@ -701,7 +671,6 @@ static bool heap_area_differ_with_type(simgrid::mc::StateComparator& state, cons
     default:
       THROW_IMPOSSIBLE;
   }
-  return false;
 }
 
 /** Infer the type of a part of the block from the type of the block
@@ -714,16 +683,13 @@ static bool heap_area_differ_with_type(simgrid::mc::StateComparator& state, cons
  * @param  area_size
  * @return                    DWARF type ID for given offset
  */
-static simgrid::mc::Type* get_offset_type(void* real_base_address, simgrid::mc::Type* type, int offset, int area_size,
-                                          const simgrid::mc::Snapshot& snapshot)
+static Type* get_offset_type(void* real_base_address, Type* type, int offset, int area_size, const Snapshot& snapshot)
 {
-
-  // Beginning of the block, the infered variable type if the type of the block:
+  // Beginning of the block, the inferred variable type if the type of the block:
   if (offset == 0)
     return type;
 
   switch (type->type) {
-
   case DW_TAG_structure_type:
   case DW_TAG_class_type:
     if (type->full_type)
@@ -735,13 +701,13 @@ static simgrid::mc::Type* get_offset_type(void* real_base_address, simgrid::mc::
         return nullptr;
     }
 
-    for (simgrid::mc::Member& member : type->members) {
+    for (const simgrid::mc::Member& member : type->members) {
       if (member.has_offset_location()) {
         // We have the offset, use it directly (shortcut):
         if (member.offset() == offset)
           return member.type;
       } else {
-        void* real_member = simgrid::dwarf::resolve_member(real_base_address, type, &member, &snapshot);
+        void* real_member = dwarf::resolve_member(real_base_address, type, &member, &snapshot);
         if ((char*)real_member - (char*)real_base_address == offset)
           return member.type;
       }
@@ -751,7 +717,6 @@ static simgrid::mc::Type* get_offset_type(void* real_base_address, simgrid::mc::
   default:
     /* FIXME: other cases ? */
     return nullptr;
-
   }
 }
 
@@ -766,9 +731,8 @@ static simgrid::mc::Type* get_offset_type(void* real_base_address, simgrid::mc::
  * @param pointer_level
  * @return true when different, false otherwise (same or unknown)
  */
-static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* area1, const void* area2,
-                             const simgrid::mc::Snapshot& snapshot1, const simgrid::mc::Snapshot& snapshot2,
-                             HeapLocationPairs* previous, simgrid::mc::Type* type, int pointer_level)
+static bool heap_area_differ(StateComparator& state, const void* area1, const void* area2, const Snapshot& snapshot1,
+                             const Snapshot& snapshot2, HeapLocationPairs* previous, Type* type, int pointer_level)
 {
   const simgrid::mc::RemoteClient& process = mc_model_checker->process();
 
@@ -783,8 +747,8 @@ static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* ar
   int new_size1 = -1;
   int new_size2 = -1;
 
-  simgrid::mc::Type* new_type1 = nullptr;
-  simgrid::mc::Type* new_type2 = nullptr;
+  Type* new_type1 = nullptr;
+  Type* new_type2 = nullptr;
 
   bool match_pairs = false;
 
@@ -804,8 +768,8 @@ static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* ar
   }
 
   // Get block number:
-  block1 = ((char*)area1 - (char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
-  block2 = ((char*)area2 - (char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
+  block1 = ((const char*)area1 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
+  block2 = ((const char*)area2 - (const char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1;
 
   // If either block is a stack block:
   if (is_block_stack((int) block1) && is_block_stack((int) block2)) {
@@ -816,8 +780,9 @@ static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* ar
   }
 
   // If either block is not in the expected area of memory:
-  if (((char*)area1 < (char*)state.std_heap_copy.heapbase) || (block1 > (ssize_t)state.processStates[0].heapsize) ||
-      (block1 < 1) || ((char*)area2 < (char*)state.std_heap_copy.heapbase) ||
+  if (((const char*)area1 < (const char*)state.std_heap_copy.heapbase) ||
+      (block1 > (ssize_t)state.processStates[0].heapsize) || (block1 < 1) ||
+      ((const char*)area2 < (const char*)state.std_heap_copy.heapbase) ||
       (block2 > (ssize_t)state.processStates[1].heapsize) || (block2 < 1)) {
     return true;
   }
@@ -840,11 +805,10 @@ static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* ar
       type_size = -1;
     else
       type_size = type->byte_size;
-
   }
 
-  simgrid::mc::Region* heap_region1 = MC_get_heap_region(snapshot1);
-  simgrid::mc::Region* heap_region2 = MC_get_heap_region(snapshot2);
+  const Region* heap_region1 = MC_get_heap_region(snapshot1);
+  const Region* heap_region2 = MC_get_heap_region(snapshot2);
 
   const malloc_info* heapinfo1 =
       (const malloc_info*)heap_region1->read(&heapinfo_temp1, &heapinfos1[block1], sizeof(malloc_info));
@@ -904,12 +868,10 @@ static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* ar
       return false;
     }
 
-    if (heapinfo1->busy_block.ignore > 0
-        && heapinfo2->busy_block.ignore == heapinfo1->busy_block.ignore)
+    if (heapinfo1->busy_block.ignore > 0 && heapinfo2->busy_block.ignore == heapinfo1->busy_block.ignore)
       check_ignore = heapinfo1->busy_block.ignore;
 
   } else if ((heapinfo1->type > 0) && (heapinfo2->type > 0)) {      /* Fragmented block */
-
     // Fragment number:
     ssize_t frag1 = ((uintptr_t)(ADDR2UINT(area1) % (BLOCKSIZE))) >> heapinfo1->type;
     ssize_t frag2 = ((uintptr_t)(ADDR2UINT(area2) % (BLOCKSIZE))) >> heapinfo2->type;
@@ -967,9 +929,8 @@ static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* ar
     }
     // Type inference from the block type.
     else if (state.types_<1>(block1, frag1) != nullptr || state.types_<2>(block2, frag2) != nullptr) {
-
-      offset1 = (char*)area1 - (char*)real_addr_frag1;
-      offset2 = (char*)area2 - (char*)real_addr_frag2;
+      offset1 = (const char*)area1 - (const char*)real_addr_frag1;
+      offset2 = (const char*)area2 - (const char*)real_addr_frag2;
 
       if (state.types_<1>(block1, frag1) != nullptr && state.types_<2>(block2, frag2) != nullptr) {
         new_type1 = get_offset_type(real_addr_frag1, state.types_<1>(block1, frag1), offset1, size, snapshot1);
@@ -987,7 +948,6 @@ static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* ar
       }
 
       if (new_type1 != nullptr && new_type2 != nullptr && new_type1 != new_type2) {
-
         type = new_type1;
         while (type->byte_size == 0 && type->subtype != nullptr)
           type = type->subtype;
@@ -1026,7 +986,6 @@ static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* ar
     if ((heapinfo1->busy_frag.ignore[frag1] > 0) &&
         (heapinfo2->busy_frag.ignore[frag2] == heapinfo1->busy_frag.ignore[frag1]))
       check_ignore = heapinfo1->busy_frag.ignore[frag1];
-
   } else
     return true;
 
@@ -1042,9 +1001,8 @@ static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* ar
     state.match_equals(previous);
   return false;
 }
-
-}
-}
+} // namespace mc
+} // namespace simgrid
 
 /************************** Snapshot comparison *******************************/
 /******************************************************************************/
@@ -1052,10 +1010,10 @@ static bool heap_area_differ(simgrid::mc::StateComparator& state, const void* ar
 static bool areas_differ_with_type(simgrid::mc::StateComparator& state, const void* real_area1,
                                    const simgrid::mc::Snapshot& snapshot1, simgrid::mc::Region* region1,
                                    const void* real_area2, const simgrid::mc::Snapshot& snapshot2,
-                                   simgrid::mc::Region* region2, simgrid::mc::Type* type, int pointer_level)
+                                   simgrid::mc::Region* region2, const simgrid::mc::Type* type, int pointer_level)
 {
-  simgrid::mc::Type* subtype;
-  simgrid::mc::Type* subsubtype;
+  const simgrid::mc::Type* subtype;
+  const simgrid::mc::Type* subsubtype;
   int elm_size;
   int i;
 
@@ -1104,8 +1062,8 @@ static bool areas_differ_with_type(simgrid::mc::StateComparator& state, const vo
       }
       for (i = 0; i < type->element_count; i++) {
         size_t off = i * elm_size;
-        if (areas_differ_with_type(state, (char*)real_area1 + off, snapshot1, region1, (char*)real_area2 + off,
-                                   snapshot2, region2, type->subtype, pointer_level))
+        if (areas_differ_with_type(state, (const char*)real_area1 + off, snapshot1, region1,
+                                   (const char*)real_area2 + off, snapshot2, region2, type->subtype, pointer_level))
           return true;
       }
       break;
@@ -1131,8 +1089,8 @@ static bool areas_differ_with_type(simgrid::mc::StateComparator& state, const vo
       // * a pointer leads to the read-only segment of the current object
       // * a pointer lead to a different ELF object
 
-      if (is_on_heap(addr_pointed1)) {
-        if (not is_on_heap(addr_pointed2))
+      if (snapshot1.on_heap(addr_pointed1)) {
+        if (not snapshot2.on_heap(addr_pointed2))
           return true;
         // The pointers are both in the heap:
         return simgrid::mc::heap_area_differ(state, addr_pointed1, addr_pointed2, snapshot1, snapshot2, nullptr,
@@ -1148,7 +1106,6 @@ static bool areas_differ_with_type(simgrid::mc::StateComparator& state, const vo
           return areas_differ_with_type(state, addr_pointed1, snapshot1, region1, addr_pointed2, snapshot2, region2,
                                         type->subtype, pointer_level);
       } else {
-
         // TODO, We do not handle very well the case where
         // it belongs to a different (non-heap) region from the current one.
 
@@ -1157,9 +1114,9 @@ static bool areas_differ_with_type(simgrid::mc::StateComparator& state, const vo
     }
     case DW_TAG_structure_type:
     case DW_TAG_class_type:
-      for (simgrid::mc::Member& member : type->members) {
-        void* member1                   = simgrid::dwarf::resolve_member(real_area1, type, &member, &snapshot1);
-        void* member2                   = simgrid::dwarf::resolve_member(real_area2, type, &member, &snapshot2);
+      for (const simgrid::mc::Member& member : type->members) {
+        const void* member1             = simgrid::dwarf::resolve_member(real_area1, type, &member, &snapshot1);
+        const void* member2             = simgrid::dwarf::resolve_member(real_area2, type, &member, &snapshot2);
         simgrid::mc::Region* subregion1 = snapshot1.get_region(member1, region1); // region1 is hinted
         simgrid::mc::Region* subregion2 = snapshot2.get_region(member2, region2); // region2 is hinted
         if (areas_differ_with_type(state, member1, snapshot1, subregion1, member2, snapshot2, subregion2, member.type,
@@ -1177,16 +1134,16 @@ static bool areas_differ_with_type(simgrid::mc::StateComparator& state, const vo
   return false;
 }
 
-static bool global_variables_differ(simgrid::mc::StateComparator& state, simgrid::mc::ObjectInformation* object_info,
-                                    simgrid::mc::Region* r1, simgrid::mc::Region* r2,
-                                    const simgrid::mc::Snapshot& snapshot1, const simgrid::mc::Snapshot& snapshot2)
+static bool global_variables_differ(simgrid::mc::StateComparator& state,
+                                    const simgrid::mc::ObjectInformation* object_info, simgrid::mc::Region* r1,
+                                    simgrid::mc::Region* r2, const simgrid::mc::Snapshot& snapshot1,
+                                    const simgrid::mc::Snapshot& snapshot2)
 {
   xbt_assert(r1 && r2, "Missing region.");
 
   const std::vector<simgrid::mc::Variable>& variables = object_info->global_variables;
 
   for (simgrid::mc::Variable const& current_var : variables) {
-
     // If the variable is not in this object, skip it:
     // We do not expect to find a pointer to something which is not reachable
     // by the global variables.
@@ -1194,7 +1151,7 @@ static bool global_variables_differ(simgrid::mc::StateComparator& state, simgrid
         || (char *) current_var.address > (char *) object_info->end_rw)
       continue;
 
-    simgrid::mc::Type* bvariable_type = current_var.type;
+    const simgrid::mc::Type* bvariable_type = current_var.type;
     if (areas_differ_with_type(state, current_var.address, snapshot1, r1, current_var.address, snapshot2, r2,
                                bvariable_type, 0)) {
       XBT_VERB("Global variable %s (%p) is different between snapshots", current_var.name.c_str(), current_var.address);
@@ -1272,12 +1229,10 @@ bool snapshot_equal(const Snapshot* s1, const Snapshot* s2)
   }
 
   /* Init heap information used in heap comparison algorithm */
-  xbt_mheap_t heap1 =
-      static_cast<xbt_mheap_t>(s1->read_bytes(alloca(sizeof(struct mdesc)), sizeof(struct mdesc),
-                                              remote(process.heap_address), simgrid::mc::ReadOptions::lazy()));
-  xbt_mheap_t heap2 =
-      static_cast<xbt_mheap_t>(s2->read_bytes(alloca(sizeof(struct mdesc)), sizeof(struct mdesc),
-                                              remote(process.heap_address), simgrid::mc::ReadOptions::lazy()));
+  const s_xbt_mheap_t* heap1 = static_cast<xbt_mheap_t>(s1->read_bytes(
+      alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), remote(process.heap_address), ReadOptions::lazy()));
+  const s_xbt_mheap_t* heap2 = static_cast<xbt_mheap_t>(s2->read_bytes(
+      alloca(sizeof(s_xbt_mheap_t)), sizeof(s_xbt_mheap_t), remote(process.heap_address), ReadOptions::lazy()));
   if (state_comparator.initHeapInformation(heap1, heap2, s1->to_ignore_, s2->to_ignore_) == -1) {
     XBT_VERB("(%d - %d) Different heap information", s1->num_state_, s2->num_state_);
     return false;
@@ -1328,6 +1283,5 @@ bool snapshot_equal(const Snapshot* s1, const Snapshot* s2)
 
   return true;
 }
-
-}
-}
+} // namespace mc
+} // namespace simgrid