1 /* Copyright (c) 2014-2019. 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 /* For an executable object, addresses are virtual address
19 * (there is no offset) i.e.
20 * \f$\text{virtual address} = \{dwarf address}\f$
22 * For a shared object, the addreses are offset from the begining
23 * of the shared object (the base address of the mapped shared
24 * object must be used as offset
25 * i.e. \f$\text{virtual address} = \text{shared object base address}
26 * + \text{dwarf address}\f$.
28 void* ObjectInformation::base_address() const
30 // For an executable (more precisely for a ET_EXEC) the base it 0:
31 if (this->executable())
34 // For an a shared-object (ET_DYN, including position-independant executables)
35 // the base address is its lowest address:
36 void* result = this->start_exec;
37 if (this->start_rw != nullptr && result > (void*)this->start_rw)
38 result = this->start_rw;
39 if (this->start_ro != nullptr && result > (void*)this->start_ro)
40 result = this->start_ro;
44 simgrid::mc::Frame* ObjectInformation::find_function(const void* ip) const
46 /* This is implemented by binary search on a sorted array.
48 * We do quite a lot of those so we want this to be cache efficient.
49 * We pack the only information we need in the index entries in order
50 * to successfully do the binary search. We do not need the high_pc
51 * during the binary search (only at the end) so it is not included
52 * in the index entry. We could use parallel arrays as well.
54 * We cannot really use the std:: algorithm for this.
55 * We could use std::binary_search by including the high_pc inside
56 * the FunctionIndexEntry.
58 const simgrid::mc::FunctionIndexEntry* base = this->functions_index.data();
60 int j = this->functions_index.size() - 1;
62 int k = i + ((j - i) / 2);
64 /* In most of the search, we do not dereference the base[k].function.
65 * This way the memory accesses are located in the base[k] array. */
66 if (ip < base[k].low_pc)
68 else if (k < j && ip >= base[k + 1].low_pc)
71 /* At this point, the search is over.
72 * Either we have found the correct function or we do not know
73 * any function corresponding to this instruction address.
74 * Only at the point do we dereference the function pointer. */
75 else if ((std::uint64_t)ip < base[k].function->range.end())
76 return base[k].function;
83 const simgrid::mc::Variable* ObjectInformation::find_variable(const char* name) const
85 for (simgrid::mc::Variable const& variable : this->global_variables)
86 if (variable.name == name)
91 void ObjectInformation::remove_global_variable(const char* name)
93 typedef std::vector<Variable>::size_type size_type;
95 if (this->global_variables.empty())
100 size_type last = this->global_variables.size() - 1;
102 while (first <= last) {
103 size_type cursor = first + (last - first) / 2;
104 simgrid::mc::Variable& current_var = this->global_variables[cursor];
105 int cmp = current_var.name.compare(name);
109 // Find the whole range:
111 while (first != 0 && this->global_variables[first - 1].name == name)
113 size_type size = this->global_variables.size();
115 while (last != size - 1 && this->global_variables[last + 1].name == name)
118 // Remove the whole range:
119 this->global_variables.erase(this->global_variables.begin() + first, this->global_variables.begin() + last + 1);
124 else if (cursor != 0)
131 /** Ignore a local variable in a scope
133 * Ignore all instances of variables with a given name in
134 * any (possibly inlined) subprogram with a given namespaced
137 * @param var_name Name of the local variable to ignore
138 * @param subprogram_name Name of the subprogram to ignore (nullptr for any)
139 * @param subprogram (possibly inlined) Subprogram of the scope current scope
140 * @param scope Current scope
142 static void remove_local_variable(simgrid::mc::Frame& scope, const char* var_name, const char* subprogram_name,
143 simgrid::mc::Frame const& subprogram)
145 typedef std::vector<Variable>::size_type size_type;
147 // If the current subprogram matches the given name:
148 if ((subprogram_name == nullptr || (not subprogram.name.empty() && subprogram.name == subprogram_name)) &&
149 not scope.variables.empty()) {
151 // Try to find the variable and remove it:
153 size_type end = scope.variables.size() - 1;
156 while (start <= end) {
157 size_type cursor = start + (end - start) / 2;
158 simgrid::mc::Variable& current_var = scope.variables[cursor];
159 int compare = current_var.name.compare(var_name);
161 // Variable found, remove it:
162 scope.variables.erase(scope.variables.begin() + cursor);
164 } else if (compare < 0)
166 else if (cursor != 0)
173 // And recursive processing in nested scopes:
174 for (simgrid::mc::Frame& nested_scope : scope.scopes) {
175 // The new scope may be an inlined subroutine, in this case we want to use its
176 // namespaced name in recursive calls:
177 simgrid::mc::Frame const& nested_subprogram =
178 nested_scope.tag == DW_TAG_inlined_subroutine ? nested_scope : subprogram;
179 remove_local_variable(nested_scope, var_name, subprogram_name, nested_subprogram);
183 void ObjectInformation::remove_local_variable(const char* var_name, const char* subprogram_name)
185 for (auto& entry : this->subprograms)
186 simgrid::mc::remove_local_variable(entry.second, var_name, subprogram_name, entry.second);
190 } // namespace simgrid