1 /* Copyright (c) 2014-2015. The SimGrid Team.
2 * All rights reserved. */
4 /* This program is free software; you can redistribute it and/or modify it
5 * under the terms of the license (GNU LGPL) which comes with this package. */
11 #include "mc_object_info.h"
12 #include "mc_private.h"
19 static void mc_frame_free(void* frame)
21 delete (simgrid::mc::Frame*)frame;
24 static void mc_type_free(void* t)
26 delete (simgrid::mc::Type*)t;
36 this->element_count = 0;
37 this->is_pointer_type = 0;
39 this->subtype = nullptr;
40 this->full_type = nullptr;
47 this->dwarf_offset = 0;
51 this->address = nullptr;
52 this->start_scope = 0;
53 this->object_info = nullptr;
61 this->low_pc = nullptr;
62 this->high_pc = nullptr;
64 this->abstract_origin_id = 0;
65 this->object_info = nullptr;
70 ObjectInformation::ObjectInformation()
73 this->start = nullptr;
75 this->start_exec = nullptr;
76 this->end_exec = nullptr;
77 this->start_rw = nullptr;
78 this->end_rw = nullptr;
79 this->start_ro = nullptr;
80 this->end_ro = nullptr;
83 /** Find the DWARF offset for this ELF object
85 * An offset is applied to address found in DWARF:
87 * * for an executable obejct, addresses are virtual address
88 * (there is no offset) i.e.
89 * \f$\text{virtual address} = \{dwarf address}\f$;
91 * * for a shared object, the addreses are offset from the begining
92 * of the shared object (the base address of the mapped shared
93 * object must be used as offset
94 * i.e. \f$\text{virtual address} = \text{shared object base address}
95 * + \text{dwarf address}\f$.
97 void *ObjectInformation::base_address() const
99 if (this->executable())
102 void *result = this->start_exec;
103 if (this->start_rw != NULL && result > (void *) this->start_rw)
104 result = this->start_rw;
105 if (this->start_ro != NULL && result > (void *) this->start_ro)
106 result = this->start_ro;
110 /* Find a function by instruction pointer */
111 simgrid::mc::Frame* ObjectInformation::find_function(const void *ip) const
113 /* This is implemented by binary search on a sorted array.
115 * We do quite a lot ot those so we want this to be cache efficient.
116 * We pack the only information we need in the index entries in order
117 * to successfully do the binary search. We do not need the high_pc
118 * during the binary search (only at the end) so it is not included
119 * in the index entry. We could use parallel arrays as well.
121 * We cannot really use the std:: alogrithm for this.
122 * We could use std::binary_search by including the high_pc inside
123 * the FunctionIndexEntry.
125 const simgrid::mc::FunctionIndexEntry* base =
126 this->functions_index.data();
128 int j = this->functions_index.size() - 1;
130 int k = i + ((j - i) / 2);
132 /* In most of the search, we do not dereference the base[k].function.
133 * This way the memory accesses are located in the base[k] array. */
134 if (ip < base[k].low_pc)
136 else if (k < j && ip >= base[k + 1].low_pc)
139 /* At this point, the search is over.
140 * Either we have found the correct function or we do not know
141 * any function corresponding to this instruction address.
142 * Only at the point do we derefernce the function pointer. */
143 else if (ip < base[k].function->high_pc)
144 return base[k].function;
151 simgrid::mc::Variable* ObjectInformation::find_variable(const char* name) const
153 for (simgrid::mc::Variable& variable : this->global_variables)
154 if(variable.name == name)