string_refinement.h File Reference

String support via creating string constraints and progressively instantiating the universal constraints as needed. More...

#include <util/union_find_replace.h>
#include <solvers/refinement/bv_refinement.h>
#include "string_constraint_generator.h"
#include "string_dependencies.h"
#include "string_refinement_util.h"

Include dependency graph for string_refinement.h:

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Classes
class	string_refinementt
struct	string_refinementt::configt
struct	string_refinementt::infot
	string_refinementt constructor arguments More...

Macros
#define	OPT_STRING_REFINEMENT
#define	HELP_STRING_REFINEMENT
#define	OPT_STRING_REFINEMENT_CBMC
#define	HELP_STRING_REFINEMENT_CBMC
#define	DEFAULT_MAX_NB_REFINEMENT   std::numeric_limits<size_t>::max()

Functions
exprt	substitute_array_lists (exprt expr, std::size_t string_max_length)
union_find_replacet	string_identifiers_resolution_from_equations (const std::vector< equal_exprt > &equations, const namespacet &ns, messaget::mstreamt &stream)
	Symbol resolution for expressions of type string typet. More...
exprt	substitute_array_access (exprt expr, symbol_generatort &symbol_generator, const bool left_propagate)
	Create an equivalent expression where array accesses and 'with' expressions are replaced by 'if' expressions, in particular: More...

Detailed Description

String support via creating string constraints and progressively instantiating the universal constraints as needed.

The procedure is described in the PASS paper at HVC'13: "PASS: String Solving with Parameterized Array and Interval Automaton" by Guodong Li and Indradeep Ghosh

Definition in file string_refinement.h.

Macro Definition Documentation

DEFAULT_MAX_NB_REFINEMENT

#define DEFAULT_MAX_NB_REFINEMENT   std::numeric_limits<size_t>::max()

Definition at line 61 of file string_refinement.h.

HELP_STRING_REFINEMENT

#define HELP_STRING_REFINEMENT

Value:

  " {y--no-refine-strings} \t turn off string refinement\n"                    \
  " {y--string-printable} \t restrict to printable strings and characters\n"   \
  " {y--string-non-empty} \t restrict to non-empty strings (experimental)\n"   \
  " {y--string-input-value} {ust} \t "                                         \
  "restrict non-null strings to a fixed value {ust}; the switch can be used "  \
  "multiple times to give several strings\n"                                   \
  " {y--max-nondet-string-length} {un} \t "                                    \
  "bound the length of nondet (e.g. input) strings. Default is " +             \
    std::to_string(MAX_CONCRETE_STRING_SIZE - 1) +                             \
    "; note that setting the value higher than this does not work "            \
    "with {y--trace} or {y--validate-trace}.\n"

Definition at line 38 of file string_refinement.h.

HELP_STRING_REFINEMENT_CBMC

#define HELP_STRING_REFINEMENT_CBMC

Value:

  " {y--refine-strings} \t use string refinement (experimental)\n"             \
  " {y--string-printable} \t restrict to printable strings (experimental)\n"

Definition at line 57 of file string_refinement.h.

OPT_STRING_REFINEMENT

#define OPT_STRING_REFINEMENT

Value:

  "(no-refine-strings)" \
  "(string-printable)" \
  "(string-input-value):" \
  "(string-non-empty)" \
  "(max-nondet-string-length):"

Definition at line 31 of file string_refinement.h.

OPT_STRING_REFINEMENT_CBMC

#define OPT_STRING_REFINEMENT_CBMC

Value:

  "(refine-strings)" \
  "(string-printable)"

Definition at line 53 of file string_refinement.h.

Function Documentation

string_identifiers_resolution_from_equations()

union_find_replacet string_identifiers_resolution_from_equations	(	const std::vector< equal_exprt > &	equations,
		const namespacet &	ns,
		messaget::mstreamt &	stream
	)

Symbol resolution for expressions of type string typet.

We record equality between these expressions in the output if one of the function calls depends on them.

Parameters

equations	list of equations
ns	namespace
stream	output stream

Returns

union_find_replacet structure containing the correspondences.

Definition at line 470 of file string_refinement.cpp.

substitute_array_access()

exprt substitute_array_access	(	exprt	expr,
		symbol_generatort &	symbol_generator,
		const bool	left_propagate
	)

Create an equivalent expression where array accesses and 'with' expressions are replaced by 'if' expressions, in particular:

• for an array access arr[index], where: arr := {12, 24, 48} the constructed expression will be: index==0 ? 12 : index==1 ? 24 : 48
• for an array access arr[index], where: arr := array_of(12) with {0:=24} with {2:=42} the constructed expression will be: index==0 ? 24 : index==2 ? 42 : 12
• for an array access (g1?arr1:arr2)[x] where arr1 := {12} and arr2 := {34}, the constructed expression will be: g1 ? 12 : 34
• for an access in an empty array { }[x] returns a fresh symbol, this corresponds to a non-deterministic result Note that if left_propagate is set to true, the with case will result in something like: index <= 0 ? 24 : index <= 2 ? 42 : 12

  Parameters

  expr	an expression containing array accesses
  symbol_generator	a symbol generator
  left_propagate	should values be propagated to the left in with expressions

  Returns

  an expression containing no array access

Definition at line 1281 of file string_refinement.cpp.

substitute_array_lists()

exprt substitute_array_lists	(	exprt	expr,
		std::size_t	string_max_length
	)