X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/03e3767659028e0c414e9e60c2cbc1430fd31010..c73bbc06caa1eb2ca3965708222a1655c4c14644:/src/mc/compare.cpp diff --git a/src/mc/compare.cpp b/src/mc/compare.cpp index a477e83ad8..cdf9d1b6c8 100644 --- a/src/mc/compare.cpp +++ b/src/mc/compare.cpp @@ -41,8 +41,7 @@ #include "src/mc/mc_dwarf.hpp" #include "src/mc/Type.hpp" -XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_compare, xbt, - "Logging specific to mc_compare in mc"); +XBT_LOG_NEW_DEFAULT_SUBCATEGORY(mc_compare, xbt, "Logging specific to mc_compare in mc"); namespace simgrid { namespace mc { @@ -272,15 +271,11 @@ void StateComparator::match_equals(HeapLocationPairs* list) { for (auto const& pair : *list) { if (pair[0].fragment != -1) { - this->equals_to1_(pair[0].block, pair[0].fragment) = - simgrid::mc::HeapArea(pair[1].block, pair[1].fragment); - this->equals_to2_(pair[1].block, pair[1].fragment) = - simgrid::mc::HeapArea(pair[0].block, pair[0].fragment); + this->equals_to1_(pair[0].block, pair[0].fragment) = simgrid::mc::HeapArea(pair[1].block, pair[1].fragment); + this->equals_to2_(pair[1].block, pair[1].fragment) = simgrid::mc::HeapArea(pair[0].block, pair[0].fragment); } else { - this->equals_to1_(pair[0].block, 0) = - simgrid::mc::HeapArea(pair[1].block, pair[1].fragment); - this->equals_to2_(pair[1].block, 0) = - simgrid::mc::HeapArea(pair[0].block, pair[0].fragment); + this->equals_to1_(pair[0].block, 0) = simgrid::mc::HeapArea(pair[1].block, pair[1].fragment); + this->equals_to2_(pair[1].block, 0) = simgrid::mc::HeapArea(pair[0].block, pair[0].fragment); } } } @@ -325,16 +320,20 @@ int mmalloc_compare_heap( simgrid::mc::Process* process = &mc_model_checker->process(); /* Start comparison */ - size_t i1, i2, j1, j2, k; - void *addr_block1, *addr_block2, *addr_frag1, *addr_frag2; - int nb_diff1 = 0, nb_diff2 = 0; - - int equal, res_compare = 0; + size_t j1; + size_t j2; + size_t k; + void* addr_block2; + void* addr_frag1; + void* addr_frag2; + int nb_diff1 = 0; + int nb_diff2 = 0; /* Check busy blocks */ - i1 = 1; + size_t i1 = 1; - malloc_info heapinfo_temp1, heapinfo_temp2; + malloc_info heapinfo_temp1; + malloc_info heapinfo_temp2; malloc_info heapinfo_temp2b; mc_mem_region_t heap_region1 = MC_get_heap_region(snapshot1); @@ -364,9 +363,7 @@ int mmalloc_compare_heap( abort(); } - addr_block1 = - ((void *) (((ADDR2UINT(i1)) - 1) * BLOCKSIZE + - (char *) state.std_heap_copy.heapbase)); + void* addr_block1 = ((void*)(((ADDR2UINT(i1)) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase)); if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED) { /* Large block */ @@ -384,18 +381,16 @@ int mmalloc_compare_heap( continue; } - i2 = 1; - equal = 0; - res_compare = 0; + size_t i2 = 1; + int equal = 0; + int res_compare = 0; /* Try first to associate to same block in the other heap */ if (heapinfo2->type == heapinfo1->type && state.equals_to2_(i1, 0).valid == 0) { - addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + - (char *) state.std_heap_copy.heapbase; - res_compare = compare_heap_area(state, simgrid::mc::ProcessIndexMissing, - addr_block1, addr_block2, snapshot1, snapshot2, - nullptr, nullptr, 0); + addr_block2 = (ADDR2UINT(i1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase; + res_compare = compare_heap_area(state, simgrid::mc::ProcessIndexMissing, addr_block1, addr_block2, snapshot1, + snapshot2, nullptr, nullptr, 0); if (res_compare != 1) { for (k = 1; k < heapinfo2->busy_block.size; k++) state.equals_to2_(i1 + k, 0) = HeapArea(i1, -1); @@ -408,8 +403,7 @@ int mmalloc_compare_heap( while (i2 < state.heaplimit && !equal) { - addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + - (char *) state.std_heap_copy.heapbase; + addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase; if (i2 == i1) { i2++; @@ -445,8 +439,7 @@ int mmalloc_compare_heap( } if (!equal) { - XBT_DEBUG("Block %zu not found (size_used = %zu, addr = %p)", i1, - heapinfo1->busy_block.busy_size, addr_block1); + XBT_DEBUG("Block %zu not found (size_used = %zu, addr = %p)", i1, heapinfo1->busy_block.busy_size, addr_block1); i1 = state.heaplimit + 1; nb_diff1++; //i1++; @@ -462,8 +455,7 @@ int mmalloc_compare_heap( if (state.equals_to1_(i1, j1).valid) continue; - addr_frag1 = - (void *) ((char *) addr_block1 + (j1 << heapinfo1->type)); + addr_frag1 = (void*)((char*)addr_block1 + (j1 << heapinfo1->type)); i2 = 1; equal = 0; @@ -476,15 +468,12 @@ int mmalloc_compare_heap( addr_frag2 = (void *) ((char *) addr_block2 + (j1 << heapinfo2->type)); - res_compare = compare_heap_area(state, simgrid::mc::ProcessIndexMissing, - addr_frag1, addr_frag2, snapshot1, snapshot2, - nullptr, nullptr, 0); + res_compare = compare_heap_area(state, simgrid::mc::ProcessIndexMissing, addr_frag1, addr_frag2, snapshot1, + snapshot2, nullptr, nullptr, 0); if (res_compare != 1) equal = 1; } - - while (i2 < state.heaplimit && !equal) { const malloc_info* heapinfo2b = (const malloc_info*) MC_region_read( @@ -516,16 +505,11 @@ int mmalloc_compare_heap( if (state.equals_to2_(i2, j2).valid) continue; - addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + - (char *) state.std_heap_copy.heapbase; - addr_frag2 = - (void *) ((char *) addr_block2 + - (j2 << heapinfo2b->type)); + addr_block2 = (ADDR2UINT(i2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase; + addr_frag2 = (void*)((char*)addr_block2 + (j2 << heapinfo2b->type)); - res_compare = compare_heap_area( - state, simgrid::mc::ProcessIndexMissing, - addr_frag1, addr_frag2, snapshot2, snapshot2, - nullptr, nullptr, 0); + res_compare = compare_heap_area(state, simgrid::mc::ProcessIndexMissing, addr_frag1, addr_frag2, snapshot2, + snapshot2, nullptr, nullptr, 0); if (res_compare != 1) { equal = 1; break; @@ -536,10 +520,8 @@ int mmalloc_compare_heap( } if (!equal) { - XBT_DEBUG - ("Block %zu, fragment %zu not found (size_used = %zd, address = %p)\n", - i1, j1, heapinfo1->busy_frag.frag_size[j1], - addr_frag1); + XBT_DEBUG("Block %zu, fragment %zu not found (size_used = %zd, address = %p)\n", i1, j1, + heapinfo1->busy_frag.frag_size[j1], addr_frag1); i2 = state.heaplimit + 1; i1 = state.heaplimit + 1; nb_diff1++; @@ -552,29 +534,24 @@ int mmalloc_compare_heap( } /* All blocks/fragments are equal to another block/fragment ? */ - size_t i = 1, j = 0; + size_t i = 1; + size_t j = 0; for(i = 1; i < state.heaplimit; i++) { const malloc_info* heapinfo1 = (const malloc_info*) MC_region_read( heap_region1, &heapinfo_temp1, &heapinfos1[i], sizeof(malloc_info)); - if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED - && i1 == state.heaplimit - && heapinfo1->busy_block.busy_size > 0 - && !state.equals_to1_(i, 0).valid) { - XBT_DEBUG("Block %zu not found (size used = %zu)", i, - heapinfo1->busy_block.busy_size); + if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && i1 == state.heaplimit && heapinfo1->busy_block.busy_size > 0 && + !state.equals_to1_(i, 0).valid) { + XBT_DEBUG("Block %zu not found (size used = %zu)", i, heapinfo1->busy_block.busy_size); nb_diff1++; } if (heapinfo1->type <= 0) continue; for (j = 0; j < (size_t) (BLOCKSIZE >> heapinfo1->type); j++) - if (i1 == state.heaplimit - && heapinfo1->busy_frag.frag_size[j] > 0 - && !state.equals_to1_(i, j).valid) { - XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)", - i, j, heapinfo1->busy_frag.frag_size[j]); + if (i1 == state.heaplimit && heapinfo1->busy_frag.frag_size[j] > 0 && !state.equals_to1_(i, j).valid) { + XBT_DEBUG("Block %zu, Fragment %zu not found (size used = %zd)", i, j, heapinfo1->busy_frag.frag_size[j]); nb_diff1++; } } @@ -741,9 +718,12 @@ top: return 0; } - simgrid::mc::Type *subtype, *subsubtype; - int res, elm_size; - const void *addr_pointed1, *addr_pointed2; + simgrid::mc::Type* subtype; + simgrid::mc::Type* subsubtype; + int res; + int elm_size; + const void* addr_pointed1; + const void* addr_pointed2; mc_mem_region_t heap_region1 = MC_get_heap_region(snapshot1); mc_mem_region_t heap_region2 = MC_get_heap_region(snapshot2); @@ -953,9 +933,8 @@ static simgrid::mc::Type* get_offset_type(void *real_base_address, simgrid::mc:: if (member.offset() == offset) return member.type; } else { - void *real_member = simgrid::dwarf::resolve_member( - real_base_address, type, &member, snapshot, process_index); - if ((char*) real_member - (char *) real_base_address == offset) + void* real_member = simgrid::dwarf::resolve_member(real_base_address, type, &member, snapshot, process_index); + if ((char*)real_member - (char*)real_base_address == offset) return member.type; } } @@ -990,25 +969,33 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, simgrid::mc::Process* process = &mc_model_checker->process(); int res_compare; - ssize_t block1, frag1, block2, frag2; + ssize_t block1; + ssize_t frag1; + ssize_t block2; + ssize_t frag2; ssize_t size; int check_ignore = 0; - void *real_addr_block1, *real_addr_block2, *real_addr_frag1, *real_addr_frag2; + void* real_addr_block1; + void* real_addr_block2; + void* real_addr_frag1; + void* real_addr_frag2; int type_size = -1; - int offset1 = 0, offset2 = 0; - int new_size1 = -1, new_size2 = -1; - simgrid::mc::Type *new_type1 = nullptr, *new_type2 = nullptr; + int offset1 = 0; + int offset2 = 0; + int new_size1 = -1; + int new_size2 = -1; + + simgrid::mc::Type* new_type1 = nullptr; + simgrid::mc::Type* new_type2 = nullptr; bool match_pairs = false; // This is the address of std_heap->heapinfo in the application process: void* heapinfo_address = &((xbt_mheap_t) process->heap_address)->heapinfo; - const malloc_info* heapinfos1 = snapshot1->read( - remote((const malloc_info**)heapinfo_address), process_index); - const malloc_info* heapinfos2 = snapshot2->read( - remote((const malloc_info**)heapinfo_address), process_index); + const malloc_info* heapinfos1 = snapshot1->read(remote((const malloc_info**)heapinfo_address), process_index); + const malloc_info* heapinfos2 = snapshot2->read(remote((const malloc_info**)heapinfo_address), process_index); malloc_info heapinfo_temp1, heapinfo_temp2; @@ -1019,38 +1006,29 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, } // 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 = ((char*)area1 - (char*)state.std_heap_copy.heapbase) / BLOCKSIZE + 1; + block2 = ((char*)area2 - (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)) { - previous->insert(simgrid::mc::makeHeapLocationPair( - block1, -1, block2, -1)); + previous->insert(simgrid::mc::makeHeapLocationPair(block1, -1, block2, -1)); if (match_pairs) state.match_equals(previous); return 0; } // 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) - || (block2 > (ssize_t) state.processStates[1].heapsize) || (block2 < 1)) { + 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) || + (block2 > (ssize_t)state.processStates[1].heapsize) || (block2 < 1)) { return 1; } // Process address of the block: - real_addr_block1 = (ADDR2UINT(block1) - 1) * BLOCKSIZE + - (char *) state.std_heap_copy.heapbase; - real_addr_block2 = (ADDR2UINT(block2) - 1) * BLOCKSIZE + - (char *) state.std_heap_copy.heapbase; + real_addr_block1 = (ADDR2UINT(block1) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase; + real_addr_block2 = (ADDR2UINT(block2) - 1) * BLOCKSIZE + (char*)state.std_heap_copy.heapbase; if (type) { - if (type->full_type) type = type->full_type; @@ -1059,9 +1037,8 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, type = type->subtype; // Find type_size: - if (type->type == DW_TAG_pointer_type - || (type->type == DW_TAG_base_type && !type->name.empty() - && type->name == "char")) + if (type->type == DW_TAG_pointer_type || + (type->type == DW_TAG_base_type && !type->name.empty() && type->name == "char")) type_size = -1; else type_size = type->byte_size; @@ -1084,18 +1061,15 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, return 0; } - if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED - && heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED) { + if (heapinfo1->type == MMALLOC_TYPE_UNFRAGMENTED && heapinfo2->type == MMALLOC_TYPE_UNFRAGMENTED) { /* Complete block */ // TODO, lookup variable type from block type as done for fragmented blocks - offset1 = (char *) area1 - (char *) real_addr_block1; - offset2 = (char *) area2 - (char *) real_addr_block2; + offset1 = (char*)area1 - (char*)real_addr_block1; + offset2 = (char*)area2 - (char*)real_addr_block2; - if (state.equals_to1_(block1, 0).valid - && state.equals_to2_(block2, 0).valid - && state.blocksEqual(block1, block2)) { + if (state.equals_to1_(block1, 0).valid && state.equals_to2_(block2, 0).valid && state.blocksEqual(block1, block2)) { if (match_pairs) state.match_equals(previous); return 0; @@ -1116,8 +1090,7 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, if (heapinfo1->busy_block.busy_size != heapinfo2->busy_block.busy_size) return 1; - if (!previous->insert(simgrid::mc::makeHeapLocationPair( - block1, -1, block2, -1)).second) { + if (!previous->insert(simgrid::mc::makeHeapLocationPair(block1, -1, block2, -1)).second) { if (match_pairs) state.match_equals(previous); return 0; @@ -1148,23 +1121,16 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, } else if ((heapinfo1->type > 0) && (heapinfo2->type > 0)) { /* Fragmented block */ // Fragment number: - frag1 = - ((uintptr_t) (ADDR2UINT(area1) % (BLOCKSIZE))) >> heapinfo1->type; - frag2 = - ((uintptr_t) (ADDR2UINT(area2) % (BLOCKSIZE))) >> heapinfo2->type; + frag1 = ((uintptr_t)(ADDR2UINT(area1) % (BLOCKSIZE))) >> heapinfo1->type; + frag2 = ((uintptr_t)(ADDR2UINT(area2) % (BLOCKSIZE))) >> heapinfo2->type; // Process address of the fragment: - real_addr_frag1 = - (void *) ((char *) real_addr_block1 + - (frag1 << heapinfo1->type)); - real_addr_frag2 = - (void *) ((char *) real_addr_block2 + - (frag2 << heapinfo2->type)); + real_addr_frag1 = (void*)((char*)real_addr_block1 + (frag1 << heapinfo1->type)); + real_addr_frag2 = (void*)((char*)real_addr_block2 + (frag2 << heapinfo2->type)); // Check the size of the fragments against the size of the type: if (type_size != -1) { - if (heapinfo1->busy_frag.frag_size[frag1] == -1 - || heapinfo2->busy_frag.frag_size[frag2] == -1) { + if (heapinfo1->busy_frag.frag_size[frag1] == -1 || heapinfo2->busy_frag.frag_size[frag2] == -1) { if (match_pairs) state.match_equals(previous); return -1; @@ -1179,8 +1145,7 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, } // Check if the blocks are already matched together: - if (state.equals_to1_(block1, frag1).valid - && state.equals_to2_(block2, frag2).valid) { + if (state.equals_to1_(block1, frag1).valid && state.equals_to2_(block2, frag2).valid) { if (offset1==offset2 && state.fragmentsEqual(block1, frag1, block2, frag2)) { if (match_pairs) state.match_equals(previous); @@ -1188,8 +1153,7 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, } } // Compare the size of both fragments: - if (heapinfo1->busy_frag.frag_size[frag1] != - heapinfo2->busy_frag.frag_size[frag2]) { + if (heapinfo1->busy_frag.frag_size[frag1] != heapinfo2->busy_frag.frag_size[frag2]) { if (type_size == -1) { if (match_pairs) state.match_equals(previous); @@ -1214,34 +1178,26 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, new_type2 = type; } // Type inference from the block type. - else if (state.types1_(block1, frag1) != nullptr - || state.types2_(block2, frag2) != nullptr) { + else if (state.types1_(block1, frag1) != nullptr || state.types2_(block2, frag2) != nullptr) { - offset1 = (char *) area1 - (char *) real_addr_frag1; - offset2 = (char *) area2 - (char *) real_addr_frag2; + offset1 = (char*)area1 - (char*)real_addr_frag1; + offset2 = (char*)area2 - (char*)real_addr_frag2; - if (state.types1_(block1, frag1) != nullptr - && state.types2_(block2, frag2) != nullptr) { + if (state.types1_(block1, frag1) != nullptr && state.types2_(block2, frag2) != nullptr) { new_type1 = - get_offset_type(real_addr_frag1, state.types1_(block1, frag1), - offset1, size, snapshot1, process_index); + get_offset_type(real_addr_frag1, state.types1_(block1, frag1), offset1, size, snapshot1, process_index); new_type2 = - get_offset_type(real_addr_frag2, state.types2_(block2, frag2), - offset1, size, snapshot2, process_index); + get_offset_type(real_addr_frag2, state.types2_(block2, frag2), offset1, size, snapshot2, process_index); } else if (state.types1_(block1, frag1) != nullptr) { new_type1 = - get_offset_type(real_addr_frag1, state.types1_(block1, frag1), - offset1, size, snapshot1, process_index); + get_offset_type(real_addr_frag1, state.types1_(block1, frag1), offset1, size, snapshot1, process_index); new_type2 = - get_offset_type(real_addr_frag2, state.types1_(block1, frag1), - offset2, size, snapshot2, process_index); + get_offset_type(real_addr_frag2, state.types1_(block1, frag1), offset2, size, snapshot2, process_index); } else if (state.types2_(block2, frag2) != nullptr) { new_type1 = - get_offset_type(real_addr_frag1, state.types2_(block2, frag2), - offset1, size, snapshot1, process_index); + get_offset_type(real_addr_frag1, state.types2_(block2, frag2), offset1, size, snapshot1, process_index); new_type2 = - get_offset_type(real_addr_frag2, state.types2_(block2, frag2), - offset2, size, snapshot2, process_index); + get_offset_type(real_addr_frag2, state.types2_(block2, frag2), offset2, size, snapshot2, process_index); } else { if (match_pairs) state.match_equals(previous); @@ -1272,13 +1228,12 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, size = new_size1; } - if (offset1 == 0 && offset2 == 0 - && !previous->insert(simgrid::mc::makeHeapLocationPair( - block1, frag1, block2, frag2)).second) { - if (match_pairs) - state.match_equals(previous); - return 0; - } + if (offset1 == 0 && offset2 == 0 && + !previous->insert(simgrid::mc::makeHeapLocationPair(block1, frag1, block2, frag2)).second) { + if (match_pairs) + state.match_equals(previous); + return 0; + } if (size <= 0) { if (match_pairs) @@ -1286,9 +1241,8 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, return 0; } - if ((heapinfo1->busy_frag.ignore[frag1] > 0) - && (heapinfo2->busy_frag.ignore[frag2] == - heapinfo1->busy_frag.ignore[frag1])) + 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 @@ -1297,14 +1251,11 @@ int compare_heap_area(simgrid::mc::StateComparator& state, int process_index, /* Start comparison */ if (type) - res_compare = - compare_heap_area_with_type(state, process_index, area1, area2, snapshot1, snapshot2, - previous, type, size, check_ignore, - pointer_level); + res_compare = compare_heap_area_with_type(state, process_index, area1, area2, snapshot1, snapshot2, previous, type, + size, check_ignore, pointer_level); else - res_compare = - compare_heap_area_without_type(state, process_index, area1, area2, snapshot1, snapshot2, - previous, size, check_ignore); + res_compare = compare_heap_area_without_type(state, process_index, area1, area2, snapshot1, snapshot2, previous, + size, check_ignore); if (res_compare == 1) return res_compare; @@ -1330,7 +1281,9 @@ static int compare_areas_with_type(simgrid::mc::StateComparator& state, simgrid::mc::Type* subtype; simgrid::mc::Type* subsubtype; - int elm_size, i, res; + int elm_size; + int i; + int res; top: switch (type->type) { @@ -1340,11 +1293,7 @@ static int compare_areas_with_type(simgrid::mc::StateComparator& state, case DW_TAG_base_type: case DW_TAG_enumeration_type: case DW_TAG_union_type: - { - return MC_snapshot_region_memcmp( - real_area1, region1, real_area2, region2, - type->byte_size) != 0; - } + return MC_snapshot_region_memcmp(real_area1, region1, real_area2, region2, type->byte_size) != 0; case DW_TAG_typedef: case DW_TAG_volatile_type: case DW_TAG_const_type: