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abstract_object.h
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1/*******************************************************************\
2
3 Module: analyses variable-sensitivity
4
5 Author: Thomas Kiley, thomas.kiley@diffblue.com
6
7\*******************************************************************/
8
25
26#ifndef CPROVER_ANALYSES_VARIABLE_SENSITIVITY_ABSTRACT_OBJECT_H
27#define CPROVER_ANALYSES_VARIABLE_SENSITIVITY_ABSTRACT_OBJECT_H
28
29#include <memory>
30#include <set>
31#include <stack>
32
34#include <util/sharing_map.h>
35
37class namespacet;
39enum class widen_modet;
40
41#define CLONE \
42 internal_abstract_object_pointert mutable_clone() const override \
43 { \
44 typedef std::remove_const< \
45 std::remove_reference<decltype(*this)>::type>::type current_typet; \
46 return internal_abstract_object_pointert(new current_typet(*this)); \
47 }
48
65
66template <class T>
67using sharing_ptrt = std::shared_ptr<const T>; // NOLINT(*)
68
70using abstract_object_visitedt = std::set<abstract_object_pointert>;
71
72class abstract_objectt : public std::enable_shared_from_this<abstract_objectt>
73{
74public:
81 abstract_objectt(const typet &type, bool top, bool bottom);
82
91 const exprt &expr,
92 const abstract_environmentt &environment,
93 const namespacet &ns);
94
96 {
97 }
98
102 virtual const typet &type() const;
103
108 virtual bool is_top() const;
109
113 virtual bool is_bottom() const;
114
118 virtual bool verify() const;
119
120 virtual void get_statistics(
121 abstract_object_statisticst &statistics,
124 const namespacet &ns) const;
125
142 const exprt &expr,
143 const std::vector<abstract_object_pointert> &operands,
144 const abstract_environmentt &environment,
145 const namespacet &ns) const;
146
156 virtual exprt to_constant() const;
157
167 exprt to_predicate(const exprt &name) const;
168
186 abstract_environmentt &environment,
187 const namespacet &ns,
188 const std::stack<exprt> &stack,
189 const exprt &specifier,
190 const abstract_object_pointert &value,
191 bool merging_write) const;
192
199 virtual void output(
200 std::ostream &out,
201 const class ai_baset &ai,
202 const namespacet &ns) const;
203
207
208 static void dump_map(std::ostream out, const shared_mapt &m);
216 static void
217 dump_map_diff(std::ostream out, const shared_mapt &m1, const shared_mapt &m2);
218
227 virtual bool has_been_modified(const abstract_object_pointert &before) const
228 {
232 return this != before.get();
233 };
234
251 static combine_result merge(
252 const abstract_object_pointert &op1,
253 const abstract_object_pointert &op2,
255 const widen_modet &widen_mode);
256 static combine_result merge(
257 const abstract_object_pointert &op1,
258 const abstract_object_pointert &op2,
259 const widen_modet &widen_mode);
260
268 static combine_result meet(
269 const abstract_object_pointert &op1,
270 const abstract_object_pointert &op2);
271
278 meet(const abstract_object_pointert &other) const;
279
289 write_location_context(const locationt &location) const;
290
300 merge_location_context(const locationt &location) const;
301
302 // Const versions must perform copy-on-write
304 {
305 if(is_top())
306 return shared_from_this();
307
309 clone->set_top();
310 return clone;
311 }
312
314 {
315 if(!is_top())
316 return shared_from_this();
317
319 clone->set_not_top();
320 return clone;
321 }
322
324
330 {
332 visit(const abstract_object_pointert &element) const = 0;
333 };
334
351
352 virtual size_t internal_hash() const
353 {
354 return std::hash<abstract_object_pointert>{}(shared_from_this());
355 }
356
357 virtual bool internal_equality(const abstract_object_pointert &other) const
358 {
359 return shared_from_this() == other;
360 }
361
365 virtual exprt to_predicate_internal(const exprt &name) const;
366
367private:
370 bool bottom;
371 bool top;
372
373 // Hooks to allow a sub-class to perform its own operations on
374 // setting/clearing top
375 virtual void set_top_internal()
376 {
377 }
378 virtual void set_not_top_internal()
379 {
380 }
381
396
403
404protected:
405 template <class T>
406 using internal_sharing_ptrt = std::shared_ptr<T>;
407
410
411 // Macro is not used as this does not override
416
425
433 bool should_use_base_merge(const abstract_object_pointert &other) const;
434
443 const abstract_object_pointert &other,
444 const widen_modet &widen_mode) const;
445
452
457 bool should_use_base_meet(const abstract_object_pointert &other) const;
458
459 // The one exception is merge in descendant classes, which needs this
460 void set_top()
461 {
462 top = true;
463 this->set_top_internal();
464 }
466 {
467 top = false;
468 this->set_not_top_internal();
469 }
471 {
472 bottom = false;
473 }
474};
475
477{
479 typedef std::size_t result_typet;
480 result_typet operator()(argument_typet const &s) const noexcept
481 {
482 return s->internal_hash();
483 }
484};
485
487{
489 typedef std::size_t result_typet;
490 bool operator()(argument_typet const &left, argument_typet const &right) const
491 noexcept
492 {
493 return left->internal_equality(right);
494 }
495};
496
497#endif // CPROVER_ANALYSES_VARIABLE_SENSITIVITY_ABSTRACT_OBJECT_H
std::shared_ptr< const T > sharing_ptrt
Merge is designed to allow different abstractions to be merged gracefully.
std::set< abstract_object_pointert > abstract_object_visitedt
sharing_ptrt< class abstract_objectt > abstract_object_pointert
virtual bool internal_equality(const abstract_object_pointert &other) const
virtual exprt to_constant() const
Converts to a constant expression if possible.
virtual bool is_top() const
Find out if the abstract object is top.
static void dump_map(std::ostream out, const shared_mapt &m)
virtual bool verify() const
Verify the internal structure of an abstract_object is correct.
virtual abstract_object_pointert write(abstract_environmentt &environment, const namespacet &ns, const std::stack< exprt > &stack, const exprt &specifier, const abstract_object_pointert &value, bool merging_write) const
A helper function to evaluate writing to a component of an abstract object.
virtual bool is_bottom() const
Find out if the abstract object is bottom.
virtual internal_abstract_object_pointert mutable_clone() const
virtual abstract_object_pointert write_location_context(const locationt &location) const
Update the write location context for an abstract object.
virtual abstract_object_pointert expression_transform(const exprt &expr, const std::vector< abstract_object_pointert > &operands, const abstract_environmentt &environment, const namespacet &ns) const
Interface for transforms.
virtual void set_not_top_internal()
virtual exprt to_predicate_internal(const exprt &name) const
to_predicate implementation - derived classes will override
goto_programt::const_targett locationt
bool should_use_base_meet(const abstract_object_pointert &other) const
Helper function to decide if base meet implementation should be used.
virtual void set_top_internal()
virtual abstract_object_pointert abstract_object_meet_internal(const abstract_object_pointert &other) const
Helper function for base meet, in case additional work was needed.
exprt to_predicate(const exprt &name) const
Converts to an invariant expression.
static void dump_map_diff(std::ostream out, const shared_mapt &m1, const shared_mapt &m2)
Dump all elements in m1 that are different or missing in m2.
std::shared_ptr< T > internal_sharing_ptrt
abstract_object_pointert make_top() const
virtual size_t internal_hash() const
virtual abstract_object_pointert visit_sub_elements(const abstract_object_visitort &visitor) const
Apply a visitor operation to all sub elements of this abstract_object.
abstract_object_pointert abstract_object_meet(const abstract_object_pointert &other) const
Helper function for base meet.
abstract_object_pointert clear_top() const
static combine_result merge(const abstract_object_pointert &op1, const abstract_object_pointert &op2, const locationt &merge_location, const widen_modet &widen_mode)
bool should_use_base_merge(const abstract_object_pointert &other) const
To detect the cases where the base merge is sufficient to do a merge We can't do if this->is_bottom()...
virtual void output(std::ostream &out, const class ai_baset &ai, const namespacet &ns) const
Print the value of the abstract object.
static combine_result meet(const abstract_object_pointert &op1, const abstract_object_pointert &op2)
Interface method for the meet operation.
virtual abstract_object_pointert merge_location_context(const locationt &location) const
Update the merge location context for an abstract object.
abstract_object_pointert abstract_object_merge(const abstract_object_pointert &other) const
Create a new abstract object that is the result of the merge, unless the object would be unchanged,...
virtual abstract_object_pointert abstract_object_merge_internal(const abstract_object_pointert &other) const
Helper function for abstract_objectt::abstract_object_merge to perform any additional actions after t...
internal_sharing_ptrt< class abstract_objectt > internal_abstract_object_pointert
sharing_mapt< irep_idt, abstract_object_pointert, false, irep_id_hash > shared_mapt
virtual abstract_object_pointert unwrap_context() const
typet t
To enforce copy-on-write these are private and have read-only accessors.
virtual void get_statistics(abstract_object_statisticst &statistics, abstract_object_visitedt &visited, const abstract_environmentt &env, const namespacet &ns) const
virtual ~abstract_objectt()
virtual bool has_been_modified(const abstract_object_pointert &before) const
Determine whether 'this' abstract_object has been modified in comparison to a previous 'before' state...
virtual const typet & type() const
Get the real type of the variable this abstract object is representing.
This is the basic interface of the abstract interpreter with default implementations of the core func...
Definition ai.h:117
ait supplies three of the four components needed: an abstract interpreter (in this case handling func...
Definition ai.h:562
Base class for all expressions.
Definition expr.h:56
instructionst::const_iterator const_targett
A namespacet is essentially one or two symbol tables bound together, to allow for symbol lookups in t...
Definition namespace.h:91
The type of an expression, extends irept.
Definition type.h:29
Concrete Goto Program.
Sharing map.
abstract_object_pointert argument_typet
std::size_t result_typet
bool operator()(argument_typet const &left, argument_typet const &right) const noexcept
abstract_object_pointert argument_typet
std::size_t result_typet
result_typet operator()(argument_typet const &s) const noexcept
Pure virtual interface required of a client that can apply a copy-on-write operation to a given abstr...
virtual abstract_object_pointert visit(const abstract_object_pointert &element) const =0
Clones the first parameter and merges it with the second.
abstract_object_pointert object