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22 #define LOG(message, irep) \
24 debug().source_location = irep.source_location(); \
25 debug() << message << ": " << format(irep) << eom; \
40 symbol_table(symbol_table)
55 const exprt &base_expression,
71 const exprt &expression)
const
73 if(expression.
id()==ID_symbol)
79 if(symbol.
type.
id()!=ID_code)
96 exprt const_symbol_cleared_expr=expression;
97 const_symbol_cleared_expr.
operands().clear();
101 const_symbol_cleared_expr.
operands().push_back(const_symbol_cleared_op);
104 return const_symbol_cleared_expr;
133 if(simplified_expr.
id()==ID_index)
138 else if(simplified_expr.
id()==ID_member)
143 else if(simplified_expr.
id()==ID_address_of)
147 address_expr, resolved_functions);
149 else if(simplified_expr.
id()==ID_dereference)
154 else if(simplified_expr.
id()==ID_typecast)
160 else if(simplified_expr.
id()==ID_symbol)
162 if(simplified_expr.
type().
id()==ID_code)
169 LOG(
"Non const symbol wasn't squashed", simplified_expr);
173 else if(simplified_expr.
id()==ID_constant)
183 LOG(
"Non-zero constant value found", simplified_expr);
189 LOG(
"Unrecognised expression", simplified_expr);
195 out_functions.insert(resolved_functions.begin(), resolved_functions.end());
213 for(
const exprt &value : exprs)
221 out_functions.insert(
222 potential_out_functions.begin(),
223 potential_out_functions.end());
227 LOG(
"Could not resolve expression in array", value);
255 LOG(
"Could not resolve array", index_expr);
261 LOG(
"Array not const", index_expr);
287 LOG(
"Could not resolve struct", member_expr);
293 LOG(
"Struct was not const so can't resolve values on it", member_expr);
315 LOG(
"Failed to resolve address of", address_expr);
339 LOG(
"Failed to squash dereference", deref_expr);
345 LOG(
"Dereferenced value was not const so can't dereference", deref_expr);
374 out_functions.insert(typecast_values.begin(), typecast_values.end());
379 LOG(
"Failed to squash typecast", typecast_expr);
404 bool is_resolved_expression_const =
false;
405 if(simplified_expr.
id()==ID_index)
410 index_expr, resolved_expressions, is_resolved_expression_const);
412 else if(simplified_expr.
id()==ID_member)
416 member_expr, resolved_expressions, is_resolved_expression_const);
418 else if(simplified_expr.
id()==ID_dereference)
423 deref, resolved_expressions, is_resolved_expression_const);
425 else if(simplified_expr.
id()==ID_typecast)
430 typecast_expr, resolved_expressions, is_resolved_expression_const);
432 else if(simplified_expr.
id()==ID_symbol)
434 LOG(
"Non const symbol will not be squashed", simplified_expr);
439 resolved_expressions.push_back(simplified_expr);
446 out_resolved_expression.insert(
447 out_resolved_expression.end(),
448 resolved_expressions.begin(),
449 resolved_expressions.end());
450 out_is_const=is_resolved_expression_const;
475 if(index_value_expressions.size()==1 &&
476 index_value_expressions.front().id()==ID_constant)
481 bool errors=
to_integer(constant_expr, array_index);
484 out_array_index=array_index;
516 bool array_const=
false;
520 potential_array_exprs,
525 bool all_possible_const=
true;
526 for(
const exprt &potential_array_expr : potential_array_exprs)
529 all_possible_const &&
532 if(potential_array_expr.id()==ID_array)
539 const exprt &func_expr =
540 potential_array_expr.
operands()[numeric_cast_v<std::size_t>(value)];
541 bool value_const=
false;
547 out_expressions.insert(
548 out_expressions.end(),
549 array_out_functions.begin(),
550 array_out_functions.end());
554 LOG(
"Failed to resolve array value", func_expr);
562 for(
const exprt &array_entry : potential_array_expr.
operands())
568 array_entry, array_contents, is_entry_const);
572 LOG(
"Failed to resolve array value", array_entry);
576 for(
const exprt &resolved_array_entry : array_contents)
578 out_expressions.push_back(resolved_array_entry);
586 "Squashing index of did not result in an array",
587 potential_array_expr);
592 out_is_const=all_possible_const || array_const;
597 LOG(
"Failed to squash index of to array expression", index_expr);
616 bool is_struct_const;
619 bool resolved_struct=
621 member_expr.
compound(), potential_structs, is_struct_const);
624 for(
const exprt &potential_struct : potential_structs)
626 if(potential_struct.id()==ID_struct)
629 const exprt &component_value=
632 bool component_const=
false;
635 component_value, resolved_expressions, component_const);
638 out_expressions.insert(
639 out_expressions.end(),
640 resolved_expressions.begin(),
641 resolved_expressions.end());
645 LOG(
"Could not resolve component value", component_value);
652 "Squashing member access did not resolve in a struct",
657 out_is_const=is_struct_const;
662 LOG(
"Failed to squash struct access", member_expr);
689 if(resolved && pointer_const)
691 bool all_objects_const=
true;
692 for(
const exprt &pointer_val : pointer_values)
694 if(pointer_val.id()==ID_address_of)
697 bool object_const=
false;
700 address_expr.
object(), out_object_values, object_const);
704 out_expressions.insert(
705 out_expressions.end(),
706 out_object_values.begin(),
707 out_object_values.end());
709 all_objects_const&=object_const;
713 LOG(
"Failed to resolve value of a dereference", address_expr);
719 "Squashing dereference did not result in an address", pointer_val);
723 out_is_const=all_objects_const;
730 LOG(
"Failed to resolve pointer of dereference", deref_expr);
732 else if(!pointer_const)
734 LOG(
"Pointer value not const so can't squash", deref_expr);
756 typecast_expr.
op(), typecast_values, typecast_const);
760 out_expressions.insert(
761 out_expressions.end(),
762 typecast_values.begin(),
763 typecast_values.end());
764 out_is_const=typecast_const;
769 LOG(
"Could not resolve typecast value", typecast_expr);
778 const exprt &expression)
const
792 return type.
get_bool(ID_C_constant);
804 size_t component_number=
807 return struct_expr.
operands()[component_number];
Class that provides messages with a built-in verbosity 'level'.
bool operator()(const exprt &base_expression, functionst &out_functions)
To take a function call on a function pointer, and if possible resolve it to a small collection of po...
bool try_resolve_typecast(const typecast_exprt &typecast_expr, expressionst &out_expressions, bool &out_is_const)
To squash a typecast access.
bool try_resolve_member(const member_exprt &member_expr, expressionst &out_expressions, bool &out_is_const)
To squash an member access by first finding the struct it is accessing Then return the squashed value...
const symbolt & lookup_ref(const irep_idt &name) const
Find a symbol in the symbol table for read-only access.
bool try_resolve_dereference_function_call(const dereference_exprt &deref_expr, functionst &out_functions)
To resolve an expression to the specific function calls it can be.
const typet & subtype() const
bool is_const_expression(const exprt &expression) const
To evaluate the const-ness of the expression type.
bool try_resolve_dereference(const dereference_exprt &deref_expr, expressionst &out_expressions, bool &out_is_const)
To squash a dereference access by first finding the address_of the dereference is dereferencing.
const struct_typet & to_struct_type(const typet &type)
Cast a typet to a struct_typet.
The type of an expression, extends irept.
const index_exprt & to_index_expr(const exprt &expr)
Cast an exprt to an index_exprt.
bool try_resolve_function_calls(const expressionst &exprs, functionst &out_functions)
To resolve a collection of expressions to the specific function calls they can be.
typet type
Type of symbol.
Operator to dereference a pointer.
exprt replace_const_symbols(const exprt &expression) const
To collapse the symbols down to their values where possible This takes a very general approach,...
bool try_resolve_function_call(const exprt &expr, functionst &out_functions)
To resolve an expression to the specific function calls it can be.
bool try_resolve_expression(const exprt &expr, expressionst &out_resolved_expression, bool &out_is_const)
To squash various expr types to simplify the expression.
bool try_resolve_index_of_function_call(const index_exprt &index_expr, functionst &out_functions)
To resolve an expression to the specific function calls it can be.
Base class for all expressions.
const symbol_tablet & symbol_table
bool is_const_type(const typet &type) const
To evaluate the const-ness of the type.
Expression to hold a symbol (variable)
std::size_t component_number(const irep_idt &component_name) const
Return the sequence number of the component with given name.
std::unordered_set< symbol_exprt, irep_hash > functionst
exprt get_component_value(const struct_exprt &struct_expr, const member_exprt &member_expr)
To extract the value of the specific component within a struct.
Struct constructor from list of elements.
A namespacet is essentially one or two symbol tables bound together, to allow for symbol lookups in t...
typet & type()
Return the type of the expression.
bool get_bool(const irep_namet &name) const
const address_of_exprt & to_address_of_expr(const exprt &expr)
Cast an exprt to an address_of_exprt.
const exprt & compound() const
bool try_resolve_index_of(const index_exprt &index_expr, expressionst &out_expressions, bool &out_is_const)
To squash an index access by first finding the array it is accessing Then if the index can be resolve...
#define PRECONDITION(CONDITION)
const irep_idt & get_identifier() const
exprt simplify_expr(exprt src, const namespacet &ns)
bool try_resolve_typecast_function_call(const typecast_exprt &typecast_expr, functionst &out_functions)
To resolve an expression to the specific function calls it can be.
const symbol_exprt & to_symbol_expr(const exprt &expr)
Cast an exprt to a symbol_exprt.
const irep_idt & id() const
bool try_resolve_index_value(const exprt &index_value_expr, mp_integer &out_array_index)
Given an index into an array, resolve, if possible, the index that is being accessed.
std::list< exprt > expressionst
bool try_resolve_member_function_call(const member_exprt &member_expr, functionst &out_functions)
To resolve an expression to the specific function calls it can be.
bool is_zero() const
Return whether the expression is a constant representing 0.
Extract member of struct or union.
const dereference_exprt & to_dereference_expr(const exprt &expr)
Cast an exprt to a dereference_exprt.
exprt value
Initial value of symbol.
Structure type, corresponds to C style structs.
const typet & follow(const typet &) const
Resolve type symbol to the type it points to.
const typecast_exprt & to_typecast_expr(const exprt &expr)
Cast an exprt to a typecast_exprt.
Goto Programs with Functions.
const member_exprt & to_member_expr(const exprt &expr)
Cast an exprt to a member_exprt.
irep_idt get_component_name() const
exprt resolve_symbol(const symbol_exprt &symbol_expr) const
Look up a symbol in the symbol table and return its value.
remove_const_function_pointerst(message_handlert &message_handler, const namespacet &ns, const symbol_tablet &symbol_table)
To take a function call on a function pointer, and if possible resolve it to a small collection of po...
Operator to return the address of an object.
Semantic type conversion.
A constant literal expression.
API to expression classes.
bool try_resolve_address_of_function_call(const address_of_exprt &address_expr, functionst &out_functions)
To resolve an expression to the specific function calls it can be.
#define LOG(message, irep)
const struct_exprt & to_struct_expr(const exprt &expr)
Cast an exprt to a struct_exprt.
const constant_exprt & to_constant_expr(const exprt &expr)
Cast an exprt to a constant_exprt.