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. */
7 #include "src/mc/Frame.hpp"
8 #include "src/mc/ObjectInformation.hpp"
9 #include "src/mc/Variable.hpp"
14 ObjectInformation::ObjectInformation()
17 this->start = nullptr;
19 this->start_exec = nullptr;
20 this->end_exec = nullptr;
21 this->start_rw = nullptr;
22 this->end_rw = nullptr;
23 this->start_ro = nullptr;
24 this->end_ro = nullptr;
27 /** Find the DWARF offset for this ELF object
29 * An offset is applied to address found in DWARF:
31 * * for an executable obejct, addresses are virtual address
32 * (there is no offset) i.e.
33 * \f$\text{virtual address} = \{dwarf address}\f$;
35 * * for a shared object, the addreses are offset from the begining
36 * of the shared object (the base address of the mapped shared
37 * object must be used as offset
38 * i.e. \f$\text{virtual address} = \text{shared object base address}
39 * + \text{dwarf address}\f$.
41 void *ObjectInformation::base_address() const
43 if (this->executable())
46 void *result = this->start_exec;
47 if (this->start_rw != NULL && result > (void *) this->start_rw)
48 result = this->start_rw;
49 if (this->start_ro != NULL && result > (void *) this->start_ro)
50 result = this->start_ro;
54 /* Find a function by instruction pointer */
55 simgrid::mc::Frame* ObjectInformation::find_function(const void *ip) const
57 /* This is implemented by binary search on a sorted array.
59 * We do quite a lot ot those so we want this to be cache efficient.
60 * We pack the only information we need in the index entries in order
61 * to successfully do the binary search. We do not need the high_pc
62 * during the binary search (only at the end) so it is not included
63 * in the index entry. We could use parallel arrays as well.
65 * We cannot really use the std:: alogrithm for this.
66 * We could use std::binary_search by including the high_pc inside
67 * the FunctionIndexEntry.
69 const simgrid::mc::FunctionIndexEntry* base =
70 this->functions_index.data();
72 int j = this->functions_index.size() - 1;
74 int k = i + ((j - i) / 2);
76 /* In most of the search, we do not dereference the base[k].function.
77 * This way the memory accesses are located in the base[k] array. */
78 if (ip < base[k].low_pc)
80 else if (k < j && ip >= base[k + 1].low_pc)
83 /* At this point, the search is over.
84 * Either we have found the correct function or we do not know
85 * any function corresponding to this instruction address.
86 * Only at the point do we derefernce the function pointer. */
87 else if (ip < base[k].function->high_pc)
88 return base[k].function;
95 simgrid::mc::Variable* ObjectInformation::find_variable(const char* name) const
97 for (simgrid::mc::Variable& variable : this->global_variables)
98 if(variable.name == name)
103 void ObjectInformation::remove_global_variable(const char* name)
105 typedef std::vector<Variable>::size_type size_type;
107 if (this->global_variables.empty())
112 size_type last = this->global_variables.size() - 1;
114 while (first <= last) {
115 size_type cursor = first + (last - first) / 2;
116 simgrid::mc::Variable& current_var = this->global_variables[cursor];
117 int cmp = current_var.name.compare(name);
121 // Find the whole range:
122 size_type first = cursor;
123 while (first != 0 && this->global_variables[first - 1].name == name)
125 size_type size = this->global_variables.size();
126 size_type last = cursor;
127 while (last != size - 1 && this->global_variables[last + 1].name == name)
130 // Remove the whole range:
131 this->global_variables.erase(
132 this->global_variables.begin() + first,
133 this->global_variables.begin() + last + 1);
138 else if (cursor != 0)
145 /** \brief Ignore a local variable in a scope
147 * Ignore all instances of variables with a given name in
148 * any (possibly inlined) subprogram with a given namespaced
151 * \param var_name Name of the local variable (or parameter to ignore)
152 * \param subprogram_name Name of the subprogram fo ignore (NULL for any)
153 * \param subprogram (possibly inlined) Subprogram of the scope
154 * \param scope Current scope
156 static void remove_local_variable(simgrid::mc::Frame& scope,
157 const char *var_name,
158 const char *subprogram_name,
159 simgrid::mc::Frame const& subprogram)
161 typedef std::vector<Variable>::size_type size_type;
163 // If the current subprogram matches the given name:
164 if ((subprogram_name == nullptr ||
165 (!subprogram.name.empty()
166 && subprogram.name == subprogram_name))
167 && !scope.variables.empty()) {
169 // Try to find the variable and remove it:
171 size_type end = scope.variables.size() - 1;
174 while (start <= end) {
175 size_type cursor = start + (end - start) / 2;
176 simgrid::mc::Variable& current_var = scope.variables[cursor];
177 int compare = current_var.name.compare(var_name);
179 // Variable found, remove it:
180 scope.variables.erase(scope.variables.begin() + cursor);
182 } else if (compare < 0)
184 else if (cursor != 0)
191 // And recursive processing in nested scopes:
192 for (simgrid::mc::Frame& nested_scope : scope.scopes) {
193 // The new scope may be an inlined subroutine, in this case we want to use its
194 // namespaced name in recursive calls:
195 simgrid::mc::Frame const& nested_subprogram =
197 DW_TAG_inlined_subroutine ? nested_scope : subprogram;
198 remove_local_variable(nested_scope, var_name, subprogram_name,
203 void ObjectInformation::remove_local_variable(
204 const char* var_name, const char* subprogram_name)
206 for (auto& entry : this->subprograms)
207 simgrid::mc::remove_local_variable(entry.second,
208 var_name, subprogram_name, entry.second);