cprover
goto_symex_state.h
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1/*******************************************************************\
2
3Module: Symbolic Execution
4
5Author: Daniel Kroening, kroening@kroening.com
6
7\*******************************************************************/
8
11
12#ifndef CPROVER_GOTO_SYMEX_GOTO_SYMEX_STATE_H
13#define CPROVER_GOTO_SYMEX_GOTO_SYMEX_STATE_H
14
15#include <functional>
16#include <memory>
17
18#include <analyses/guard.h>
19
20#include <util/invariant.h>
21#include <util/nodiscard.h>
22#include <util/ssa_expr.h>
23#include <util/std_expr.h>
24
25#include "call_stack.h"
26#include "field_sensitivity.h"
27#include "goto_state.h"
28#include "renaming_level.h"
30
32
41class goto_symex_statet final : public goto_statet
42{
43public:
46 std::size_t max_field_sensitive_array_size,
47 guard_managert &manager,
48 std::function<std::size_t(const irep_idt &)> fresh_l2_name_provider);
50
53 const goto_symex_statet &other,
54 symex_target_equationt *const target)
55 : goto_symex_statet(other) // NOLINT
56 {
57 symex_target = target;
58 }
59
61
66
67 // Manager is required to be able to resize the thread vector
70
72
97 template <levelt level = L2>
99
102 template <levelt level>
105
106 template <levelt level = L2>
107 void rename(typet &type, const irep_idt &l1_identifier, const namespacet &ns);
108
110
113 ssa_exprt lhs, // L0/L1
114 const exprt &rhs, // L2
115 const namespacet &ns,
116 bool rhs_is_simplified,
117 bool record_value,
118 bool allow_pointer_unsoundness = false);
119
121
122protected:
123 template <levelt>
124 void rename_address(exprt &expr, const namespacet &ns);
125
127 template <levelt level>
130
131 // this maps L1 names to (L2) types
132 typedef std::unordered_map<irep_idt, typet> l1_typest;
134
135public:
136 // guards
138 {
139 static irep_idt id = "goto_symex::\\guard";
140 return id;
141 }
142
144 {
146 return threads[source.thread_nr].call_stack;
147 }
148
149 const call_stackt &call_stack() const
150 {
152 return threads[source.thread_nr].call_stack;
153 }
154
162 const symbol_exprt &expr,
163 std::function<std::size_t(const irep_idt &)> index_generator,
164 const namespacet &ns);
165
170 ssa_exprt declare(ssa_exprt ssa, const namespacet &ns);
171
172 void print_backtrace(std::ostream &) const;
173
174 // threads
175 typedef std::pair<unsigned, std::list<guardt> > a_s_r_entryt;
176 typedef std::list<guardt> a_s_w_entryt;
177 std::unordered_map<ssa_exprt, a_s_r_entryt, irep_hash> read_in_atomic_section;
178 std::unordered_map<ssa_exprt, a_s_w_entryt, irep_hash>
180
181 struct threadt
182 {
186 std::map<irep_idt, unsigned> function_frame;
187 unsigned atomic_section_id = 0;
190 {
191 }
192 };
193
194 std::vector<threadt> threads;
195
197 {
198 NOT_SHARED,
199 IN_ATOMIC_SECTION,
200 SHARED
201 };
202
203 bool l2_thread_read_encoding(ssa_exprt &expr, const namespacet &ns);
204 bool l2_thread_write_encoding(const ssa_exprt &expr, const namespacet &ns);
206 write_is_shared(const ssa_exprt &expr, const namespacet &ns) const;
207
208 std::stack<bool> record_events;
209
210 const incremental_dirtyt *dirty = nullptr;
211
213
216
220
223
224 unsigned total_vccs = 0;
225 unsigned remaining_vccs = 0;
226
228 void drop_existing_l1_name(const irep_idt &l1_identifier)
229 {
230 level2.current_names.erase(l1_identifier);
231 }
232
234 void drop_l1_name(const irep_idt &l1_identifier)
235 {
236 level2.current_names.erase_if_exists(l1_identifier);
237 }
238
239 std::function<std::size_t(const irep_idt &)> get_l2_name_provider() const
240 {
242 }
243
245 static bool is_read_only_object(const exprt &lvalue)
246 {
247 // Note ID_constant can occur due to a partial write to a string constant,
248 // (i.e. something like byte_extract int from "hello" offset 2), which
249 // simplifies to a plain constant.
250 return lvalue.id() == ID_string_constant || lvalue.id() == ID_null_object ||
251 lvalue.id() == "zero_string" || lvalue.id() == "is_zero_string" ||
252 lvalue.id() == "zero_string_length" || lvalue.id() == ID_constant;
253 }
254
255private:
256 std::function<std::size_t(const irep_idt &)> fresh_l2_name_provider;
257
268 goto_symex_statet(const goto_symex_statet &other) = default;
269};
270
271#endif // CPROVER_GOTO_SYMEX_GOTO_SYMEX_STATE_H
dstringt has one field, an unsigned integer no which is an index into a static table of strings.
Definition: dstring.h:37
Base class for all expressions.
Definition: expr.h:54
Control granularity of object accesses.
instructionst::const_iterator const_targett
Definition: goto_program.h:593
Container for data that varies per program point, e.g.
Definition: goto_state.h:32
symex_level2t level2
Definition: goto_state.h:38
Central data structure: state.
ssa_exprt declare(ssa_exprt ssa, const namespacet &ns)
Add invalid (or a failed symbol) to the value_set if ssa is a pointer, ensure that level2 index of sy...
const call_stackt & call_stack() const
goto_programt::const_targett saved_target
ssa_exprt add_object(const symbol_exprt &expr, std::function< std::size_t(const irep_idt &)> index_generator, const namespacet &ns)
Instantiate the object expr.
call_stackt & call_stack()
NODISCARD renamedt< ssa_exprt, level > set_indices(ssa_exprt expr, const namespacet &ns)
Update values up to level.
std::pair< unsigned, std::list< guardt > > a_s_r_entryt
NODISCARD renamedt< exprt, level > rename(exprt expr, const namespacet &ns)
Rewrites symbol expressions in exprt, applying a suffix to each symbol reflecting its most recent ver...
std::stack< bool > record_events
bool l2_thread_write_encoding(const ssa_exprt &expr, const namespacet &ns)
thread encoding
goto_symex_statet(const goto_symex_statet &other, symex_target_equationt *const target)
Fake "copy constructor" that initializes the symex_target member.
std::function< std::size_t(const irep_idt &)> get_l2_name_provider() const
NODISCARD exprt l2_rename_rvalues(exprt lvalue, const namespacet &ns)
static irep_idt guard_identifier()
const incremental_dirtyt * dirty
goto_symex_statet(const symex_targett::sourcet &, std::size_t max_field_sensitive_array_size, guard_managert &manager, std::function< std::size_t(const irep_idt &)> fresh_l2_name_provider)
std::unordered_map< ssa_exprt, a_s_r_entryt, irep_hash > read_in_atomic_section
std::unordered_map< ssa_exprt, a_s_w_entryt, irep_hash > written_in_atomic_section
symex_level1t level1
void rename_address(exprt &expr, const namespacet &ns)
NODISCARD renamedt< ssa_exprt, L2 > assignment(ssa_exprt lhs, const exprt &rhs, const namespacet &ns, bool rhs_is_simplified, bool record_value, bool allow_pointer_unsoundness=false)
guard_managert & guard_manager
bool l2_thread_read_encoding(ssa_exprt &expr, const namespacet &ns)
thread encoding
void print_backtrace(std::ostream &) const
Dumps the current state of symex, printing the function name and location number for each stack frame...
symex_target_equationt * symex_target
std::unordered_map< irep_idt, typet > l1_typest
symbol_tablet symbol_table
contains symbols that are minted during symbolic execution, such as dynamically created objects etc.
std::list< guardt > a_s_w_entryt
void drop_l1_name(const irep_idt &l1_identifier)
Drops an L1 name from the local L2 map.
static bool is_read_only_object(const exprt &lvalue)
Returns true if lvalue is a read-only object, such as the null object.
field_sensitivityt field_sensitivity
write_is_shared_resultt write_is_shared(const ssa_exprt &expr, const namespacet &ns) const
symex_targett::sourcet source
bool has_saved_jump_target
This state is saved, with the PC pointing to the target of a GOTO.
goto_symex_statet(const goto_symex_statet &other)=default
Dangerous, do not use.
bool run_validation_checks
Should the additional validation checks be run?
std::vector< threadt > threads
std::function< std::size_t(const irep_idt &)> fresh_l2_name_provider
bool has_saved_next_instruction
This state is saved, with the PC pointing to the next instruction of a GOTO.
void drop_existing_l1_name(const irep_idt &l1_identifier)
Drops an L1 name from the local L2 map.
NODISCARD renamedt< ssa_exprt, level > rename_ssa(ssa_exprt ssa, const namespacet &ns)
Version of rename which is specialized for SSA exprt.
Wrapper for dirtyt that permits incremental population, ensuring each function is analysed exactly on...
Definition: dirty.h:119
const irep_idt & id() const
Definition: irep.h:396
A namespacet is essentially one or two symbol tables bound together, to allow for symbol lookups in t...
Definition: namespace.h:91
Wrapper for expressions or types which have been renamed up to a given level.
Definition: renamed.h:33
void erase_if_exists(const key_type &k)
Erase element if it exists.
Definition: sharing_map.h:274
void erase(const key_type &k)
Erase element, element must exist in map.
Definition: sharing_map.h:1203
Expression providing an SSA-renamed symbol of expressions.
Definition: ssa_expr.h:17
Expression to hold a symbol (variable)
Definition: std_expr.h:80
The symbol table.
Definition: symbol_table.h:14
Inheriting the interface of symex_targett this class represents the SSA form of the input program as ...
The Boolean constant true.
Definition: std_expr.h:2856
The type of an expression, extends irept.
Definition: type.h:29
goto_statet class definition
Guard Data Structure.
#define NODISCARD
Definition: nodiscard.h:22
Renaming levels.
#define PRECONDITION(CONDITION)
Definition: invariant.h:463
API to expression classes.
threadt(guard_managert &guard_manager)
std::map< irep_idt, unsigned > function_frame
goto_programt::const_targett pc
This is unused by this implementation of guards, but can be used by other implementations of the same...
Definition: guard_expr.h:20
Functor to set the level 1 renaming of SSA expressions.
symex_renaming_levelt current_names
Identifies source in the context of symbolic execution.
Definition: symex_target.h:37
Generate Equation using Symbolic Execution.