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 "src/mc/Frame.hpp"
12 #include "src/mc/ObjectInformation.hpp"
13 #include "src/mc/Variable.hpp"
18 ObjectInformation::ObjectInformation()
21 this->start = nullptr;
23 this->start_exec = nullptr;
24 this->end_exec = nullptr;
25 this->start_rw = nullptr;
26 this->end_rw = nullptr;
27 this->start_ro = nullptr;
28 this->end_ro = nullptr;
31 /** Find the DWARF offset for this ELF object
33 * An offset is applied to address found in DWARF:
35 * * for an executable obejct, addresses are virtual address
36 * (there is no offset) i.e.
37 * \f$\text{virtual address} = \{dwarf address}\f$;
39 * * for a shared object, the addreses are offset from the begining
40 * of the shared object (the base address of the mapped shared
41 * object must be used as offset
42 * i.e. \f$\text{virtual address} = \text{shared object base address}
43 * + \text{dwarf address}\f$.
45 void *ObjectInformation::base_address() const
47 if (this->executable())
50 void *result = this->start_exec;
51 if (this->start_rw != nullptr && result > (void *) this->start_rw)
52 result = this->start_rw;
53 if (this->start_ro != nullptr && result > (void *) this->start_ro)
54 result = this->start_ro;
58 /* Find a function by instruction pointer */
59 simgrid::mc::Frame* ObjectInformation::find_function(const void *ip) const
61 /* This is implemented by binary search on a sorted array.
63 * We do quite a lot ot those so we want this to be cache efficient.
64 * We pack the only information we need in the index entries in order
65 * to successfully do the binary search. We do not need the high_pc
66 * during the binary search (only at the end) so it is not included
67 * in the index entry. We could use parallel arrays as well.
69 * We cannot really use the std:: alogrithm for this.
70 * We could use std::binary_search by including the high_pc inside
71 * the FunctionIndexEntry.
73 const simgrid::mc::FunctionIndexEntry* base =
74 this->functions_index.data();
76 int j = this->functions_index.size() - 1;
78 int k = i + ((j - i) / 2);
80 /* In most of the search, we do not dereference the base[k].function.
81 * This way the memory accesses are located in the base[k] array. */
82 if (ip < base[k].low_pc)
84 else if (k < j && ip >= base[k + 1].low_pc)
87 /* At this point, the search is over.
88 * Either we have found the correct function or we do not know
89 * any function corresponding to this instruction address.
90 * Only at the point do we derefernce the function pointer. */
91 else if ((std::uint64_t) ip < base[k].function->range.end())
92 return base[k].function;
99 simgrid::mc::Variable* ObjectInformation::find_variable(const char* name) const
101 for (simgrid::mc::Variable& variable : this->global_variables)
102 if(variable.name == name)
107 void ObjectInformation::remove_global_variable(const char* name)
109 typedef std::vector<Variable>::size_type size_type;
111 if (this->global_variables.empty())
116 size_type last = this->global_variables.size() - 1;
118 while (first <= last) {
119 size_type cursor = first + (last - first) / 2;
120 simgrid::mc::Variable& current_var = this->global_variables[cursor];
121 int cmp = current_var.name.compare(name);
125 // Find the whole range:
126 size_type first = cursor;
127 while (first != 0 && this->global_variables[first - 1].name == name)
129 size_type size = this->global_variables.size();
130 size_type last = cursor;
131 while (last != size - 1 && this->global_variables[last + 1].name == name)
134 // Remove the whole range:
135 this->global_variables.erase(
136 this->global_variables.begin() + first,
137 this->global_variables.begin() + last + 1);
142 else if (cursor != 0)
149 /** \brief Ignore a local variable in a scope
151 * Ignore all instances of variables with a given name in
152 * any (possibly inlined) subprogram with a given namespaced
155 * \param var_name Name of the local variable (or parameter to ignore)
156 * \param subprogram_name Name of the subprogram fo ignore (nullptr for any)
157 * \param subprogram (possibly inlined) Subprogram of the scope
158 * \param scope Current scope
160 static void remove_local_variable(simgrid::mc::Frame& scope,
161 const char *var_name,
162 const char *subprogram_name,
163 simgrid::mc::Frame const& subprogram)
165 typedef std::vector<Variable>::size_type size_type;
167 // If the current subprogram matches the given name:
168 if ((subprogram_name == nullptr ||
169 (!subprogram.name.empty()
170 && subprogram.name == subprogram_name))
171 && !scope.variables.empty()) {
173 // Try to find the variable and remove it:
175 size_type end = scope.variables.size() - 1;
178 while (start <= end) {
179 size_type cursor = start + (end - start) / 2;
180 simgrid::mc::Variable& current_var = scope.variables[cursor];
181 int compare = current_var.name.compare(var_name);
183 // Variable found, remove it:
184 scope.variables.erase(scope.variables.begin() + cursor);
186 } else if (compare < 0)
188 else if (cursor != 0)
195 // And recursive processing in nested scopes:
196 for (simgrid::mc::Frame& nested_scope : scope.scopes) {
197 // The new scope may be an inlined subroutine, in this case we want to use its
198 // namespaced name in recursive calls:
199 simgrid::mc::Frame const& nested_subprogram =
201 DW_TAG_inlined_subroutine ? nested_scope : subprogram;
202 remove_local_variable(nested_scope, var_name, subprogram_name,
207 void ObjectInformation::remove_local_variable(
208 const char* var_name, const char* subprogram_name)
210 for (auto& entry : this->subprograms)
211 simgrid::mc::remove_local_variable(entry.second,
212 var_name, subprogram_name, entry.second);