cprover
java_object_factoryt Class Reference
+ Collaboration diagram for java_object_factoryt:

Public Member Functions

 java_object_factoryt (std::vector< const symbolt * > &_symbols_created, const source_locationt &loc, const java_object_factory_parameterst _object_factory_parameters, symbol_table_baset &_symbol_table, const select_pointer_typet &pointer_type_selector)
 
exprt allocate_object (code_blockt &assignments, const exprt &, const typet &, allocation_typet alloc_type)
 Installs a new symbol in the symbol table, pushing the corresponding symbolt object to the field symbols_created and emits to assignments a new assignment of the form <target_expr> := address-of(new_object). More...
 
void gen_nondet_array_init (code_blockt &assignments, const exprt &expr, size_t depth, update_in_placet, const source_locationt &location)
 Create code to initialize a Java array whose size will be at most max_nondet_array_length. More...
 
void gen_nondet_enum_init (code_blockt &assignments, const exprt &expr, const java_class_typet &java_class_type, const source_locationt &location)
 We nondet-initialize enums to be equal to one of the constants defined for their type: int i = nondet(int); assume(0 < = i < $VALUES.length); expr = $VALUES[i]; where $VALUES is a variable generated by the Java compiler that stores the array that is returned by Enum.values(). More...
 
void gen_nondet_init (code_blockt &assignments, const exprt &expr, bool is_sub, irep_idt class_identifier, bool skip_classid, allocation_typet alloc_type, bool override_, const typet &override_type, size_t depth, update_in_placet, const source_locationt &location)
 Initializes a primitive-typed or reference-typed object tree rooted at expr, allocating child objects as necessary and nondet-initializing their members, or if MUST_UPDATE_IN_PLACE is set, re-initializing already-allocated objects. More...
 

Private Member Functions

code_assignt get_null_assignment (const exprt &expr, const pointer_typet &ptr_type)
 Returns a codet that assigns expr, of type ptr_type, a NULL value. More...
 
void gen_pointer_target_init (code_blockt &assignments, const exprt &expr, const typet &target_type, allocation_typet alloc_type, size_t depth, update_in_placet update_in_place, const source_locationt &location)
 Initializes the pointer-typed lvalue expression expr to point to an object of type target_type, recursively nondet-initializing the members of that object. More...
 
void allocate_nondet_length_array (code_blockt &assignments, const exprt &lhs, const exprt &max_length_expr, const typet &element_type, const source_locationt &location)
 Allocates a fresh array and emits an assignment writing to lhs the address of the new array. More...
 
void gen_nondet_pointer_init (code_blockt &assignments, const exprt &expr, allocation_typet alloc_type, const pointer_typet &pointer_type, size_t depth, const update_in_placet &update_in_place, const source_locationt &location)
 Initializes a pointer expr of type pointer_type to a primitive-typed value or an object tree. More...
 
void gen_nondet_struct_init (code_blockt &assignments, const exprt &expr, bool is_sub, irep_idt class_identifier, bool skip_classid, allocation_typet alloc_type, const struct_typet &struct_type, size_t depth, const update_in_placet &update_in_place, const source_locationt &location)
 Initializes an object tree rooted at expr, allocating child objects as necessary and nondet-initializes their members, or if MUST_UPDATE_IN_PLACE is set, re-initializes already-allocated objects. More...
 
symbol_exprt gen_nondet_subtype_pointer_init (code_blockt &assignments, allocation_typet alloc_type, const pointer_typet &substitute_pointer_type, size_t depth, const source_locationt &location)
 Generate codet assignments to initalize the selected concrete type. More...
 
const symbol_exprt gen_nondet_int_init (code_blockt &assignments, const std::string &basename_prefix, const exprt &min_length_expr, const exprt &max_length_expr, const source_locationt &location)
 Nondeterministically initializes an int i in the range min <= i <= max, where min is the integer represented by min_value_expr and max is the integer represented by max_value_expr. More...
 
void gen_method_call_if_present (code_blockt &assignments, const exprt &instance_expr, const irep_idt &method_name)
 Adds a call for the given method to the end of assignments if the method exists in the symbol table. More...
 

Private Attributes

std::vector< const symbolt * > & symbols_created
 Every new variable initialized by the code emitted by the methods of this class gets a symbol in the symbol table, and such symbols are also added to this vector. More...
 
const source_locationtloc
 The source location for new statements emitted during the operation of the methods in this class. More...
 
const java_object_factory_parameterst object_factory_parameters
 
std::unordered_set< irep_idtrecursion_set
 This is employed in conjunction with the depth above. More...
 
generic_parameter_specialization_mapt generic_parameter_specialization_map
 Every time the non-det generator visits a type and the type is generic (either a struct or a pointer), the following map is used to store and look up the concrete types of the generic parameters in the current scope. More...
 
symbol_table_basetsymbol_table
 The symbol table. More...
 
namespacet ns
 A namespace built from exclusively one symbol table - the one above. More...
 
const select_pointer_typetpointer_type_selector
 Resolves pointer types potentially using some heuristics, for example to replace pointers to interface types with pointers to concrete implementations. More...
 

Detailed Description

Definition at line 24 of file java_object_factory.cpp.

Constructor & Destructor Documentation

◆ java_object_factoryt()

java_object_factoryt::java_object_factoryt ( std::vector< const symbolt * > &  _symbols_created,
const source_locationt loc,
const java_object_factory_parameterst  _object_factory_parameters,
symbol_table_baset _symbol_table,
const select_pointer_typet pointer_type_selector 
)
inline

Definition at line 85 of file java_object_factory.cpp.

Member Function Documentation

◆ allocate_nondet_length_array()

void java_object_factoryt::allocate_nondet_length_array ( code_blockt assignments,
const exprt lhs,
const exprt max_length_expr,
const typet element_type,
const source_locationt location 
)
private

Allocates a fresh array and emits an assignment writing to lhs the address of the new array.

Single-use at the moment, but useful to keep as a separate function for downstream branches.

Parameters
[out]assignmentsCode is emitted here.
lhsSymbol to assign the new array structure.
max_length_exprMaximum length of the new array (minimum is fixed at zero for now).
element_typeActual element type of the array (the array for all reference types will have void* type, but this will be annotated as the true member type).
locationSource location associated with nondet-initialization.
Returns
Appends instructions to assignments

Definition at line 1351 of file java_object_factory.cpp.

◆ allocate_object()

exprt java_object_factoryt::allocate_object ( code_blockt assignments,
const exprt target_expr,
const typet allocate_type,
allocation_typet  alloc_type 
)

Installs a new symbol in the symbol table, pushing the corresponding symbolt object to the field symbols_created and emits to assignments a new assignment of the form <target_expr> := address-of(new_object).

The allocate_type may differ from target_expr.type(), e.g. for target_expr having type int* and allocate_type being an int[10].

Parameters
assignmentsThe code block to add code to.
target_exprThe expression which we are allocating a symbol for.
allocate_type
alloc_typeAllocation type (global, local or dynamic)
Returns
An address_of_exprt of the newly allocated object.

Definition at line 297 of file java_object_factory.cpp.

◆ gen_method_call_if_present()

void java_object_factoryt::gen_method_call_if_present ( code_blockt assignments,
const exprt instance_expr,
const irep_idt method_name 
)
private

Adds a call for the given method to the end of assignments if the method exists in the symbol table.

Does nothing if the method does not exist.

Parameters
assignmentsA code block that the method call will be appended to.
instance_exprThe instance to call the method on. This argument is ignored if the method is static.
method_nameThe name of the method to be called.

Definition at line 1771 of file java_object_factory.cpp.

◆ gen_nondet_array_init()

void java_object_factoryt::gen_nondet_array_init ( code_blockt assignments,
const exprt expr,
size_t  depth,
update_in_placet  update_in_place,
const source_locationt location 
)

Create code to initialize a Java array whose size will be at most max_nondet_array_length.

The code is emitted to assignments does as follows:

  1. non-deterministically choose a length for the array
  2. assume that such length is >=0 and <= max_length
  3. loop through all elements of the array and initialize them

Definition at line 1380 of file java_object_factory.cpp.

◆ gen_nondet_enum_init()

void java_object_factoryt::gen_nondet_enum_init ( code_blockt assignments,
const exprt expr,
const java_class_typet java_class_type,
const source_locationt location 
)

We nondet-initialize enums to be equal to one of the constants defined for their type: int i = nondet(int); assume(0 < = i < $VALUES.length); expr = $VALUES[i]; where $VALUES is a variable generated by the Java compiler that stores the array that is returned by Enum.values().

Definition at line 1518 of file java_object_factory.cpp.

◆ gen_nondet_init()

void java_object_factoryt::gen_nondet_init ( code_blockt assignments,
const exprt expr,
bool  is_sub,
irep_idt  class_identifier,
bool  skip_classid,
allocation_typet  alloc_type,
bool  override_,
const typet override_type,
size_t  depth,
update_in_placet  update_in_place,
const source_locationt location 
)

Initializes a primitive-typed or reference-typed object tree rooted at expr, allocating child objects as necessary and nondet-initializing their members, or if MUST_UPDATE_IN_PLACE is set, re-initializing already-allocated objects.

Parameters
assignmentsA code block where the initializing assignments will be appended to.
exprLvalue expression to initialize.
is_subIf true, expr is a substructure of a larger object, which in Java necessarily means a base class.
class_identifierName of the parent class. Used to initialize the @class_identifier among others.
skip_classidIf true, skip initializing @class_identifier.
alloc_typeAllocation type (global, local or dynamic)
override_If true, initialize with override_type instead of expr.type(). Used at the moment for reference arrays, which are implemented as void* arrays but should be init'd as their true type with appropriate casts.
depthNumber of times that a pointer has been dereferenced from the root of the object tree that we are initializing.
override_typeOverride type per above.
update_in_placeNO_UPDATE_IN_PLACE: initialize expr from scratch MAY_UPDATE_IN_PLACE: generate a runtime nondet branch between the NO_ and MUST_ cases. MUST_UPDATE_IN_PLACE: reinitialize an existing object
locationSource location associated with nondet-initialization.

Definition at line 1200 of file java_object_factory.cpp.

◆ gen_nondet_int_init()

const symbol_exprt java_object_factoryt::gen_nondet_int_init ( code_blockt assignments,
const std::string &  basename_prefix,
const exprt min_value_expr,
const exprt max_value_expr,
const source_locationt location 
)
private

Nondeterministically initializes an int i in the range min <= i <= max, where min is the integer represented by min_value_expr and max is the integer represented by max_value_expr.

Parameters
[out]assignmentsA code block that the initializing assignments will be appended to.
basename_prefixUsed for naming the newly created symbol.
min_value_exprRepresents the minimum value for the integer.
max_value_exprRepresents the maximum value for the integer.
locationSource location associated with nondet-initialization.
Returns
A symbol expression for the resulting integer.

Definition at line 1292 of file java_object_factory.cpp.

◆ gen_nondet_pointer_init()

void java_object_factoryt::gen_nondet_pointer_init ( code_blockt assignments,
const exprt expr,
allocation_typet  alloc_type,
const pointer_typet pointer_type,
size_t  depth,
const update_in_placet update_in_place,
const source_locationt location 
)
private

Initializes a pointer expr of type pointer_type to a primitive-typed value or an object tree.

It allocates child objects as necessary and nondet-initializes their members, or if MUST_UPDATE_IN_PLACE is set, re-initializes already-allocated objects.

Parameters
assignmentsThe code block we are building with initialization code.
exprPointer-typed lvalue expression to initialize.
alloc_typeAllocation type (global, local or dynamic)
depthNumber of times that a pointer has been dereferenced from the root of the object tree that we are initializing.
pointer_typeThe type of the pointer we are initalizing
update_in_place
  • NO_UPDATE_IN_PLACE: initialize expr from scratch
  • MAY_UPDATE_IN_PLACE: generate a runtime nondet branch between the NO_ and MUST_ cases.
  • MUST_UPDATE_IN_PLACE: reinitialize an existing object
locationSource location associated with nondet-initialization.

Definition at line 684 of file java_object_factory.cpp.

◆ gen_nondet_struct_init()

void java_object_factoryt::gen_nondet_struct_init ( code_blockt assignments,
const exprt expr,
bool  is_sub,
irep_idt  class_identifier,
bool  skip_classid,
allocation_typet  alloc_type,
const struct_typet struct_type,
size_t  depth,
const update_in_placet update_in_place,
const source_locationt location 
)
private

Initializes an object tree rooted at expr, allocating child objects as necessary and nondet-initializes their members, or if MUST_UPDATE_IN_PLACE is set, re-initializes already-allocated objects.

After initialization calls validation method expr.cproverNondetInitialize() if it was provided by the user.

Parameters
assignmentsThe code block to append the new instructions to.
exprStruct-typed lvalue expression to initialize.
is_subIf true, expr is a substructure of a larger object, which in Java necessarily means a base class.
class_identifierName of the parent class. Used to initialize the @class_identifier among others.
skip_classidIf true, skip initializing @class_identifier.
alloc_typeAllocation type (global, local or dynamic)
struct_typeThe type of the struct we are initalizing.
depthNumber of times that a pointer has been dereferenced from the root of the object tree that we are initializing.
update_in_placeNO_UPDATE_IN_PLACE: initialize expr from scratch MUST_UPDATE_IN_PLACE: reinitialize an existing object MAY_UPDATE_IN_PLACE: invalid input
locationSource location associated with nondet-initialization.

Definition at line 1000 of file java_object_factory.cpp.

◆ gen_nondet_subtype_pointer_init()

symbol_exprt java_object_factoryt::gen_nondet_subtype_pointer_init ( code_blockt assignments,
allocation_typet  alloc_type,
const pointer_typet replacement_pointer,
size_t  depth,
const source_locationt location 
)
private

Generate codet assignments to initalize the selected concrete type.

Generated code looks as follows (here A = replacement_pointer.subtype()):

// allocate memory for a new object, depends on alloc_type A { ... } tmp_object;

// non-det init all the fields of A A.x = NONDET(...) A.y = NONDET(...)

// assign expr with a suitably casted pointer to new_object A * p = &tmp_object

Parameters
assignmentsA block of code where we append the generated code.
alloc_typeAllocation type (global, local or dynamic)
replacement_pointerThe type of the pointer we actually want to to create.
depthNumber of times that a pointer has been dereferenced from the root of the object tree that we are initializing.
locationSource location associated with nondet-initialization.
Returns
A symbol expression of type replacement_pointer corresponding to a pointer to object tmp_object (see above).

Definition at line 910 of file java_object_factory.cpp.

◆ gen_pointer_target_init()

void java_object_factoryt::gen_pointer_target_init ( code_blockt assignments,
const exprt expr,
const typet target_type,
allocation_typet  alloc_type,
size_t  depth,
update_in_placet  update_in_place,
const source_locationt location 
)
private

Initializes the pointer-typed lvalue expression expr to point to an object of type target_type, recursively nondet-initializing the members of that object.

Code emitted mainly depends on update_in_place:

When in NO_UPDATE_IN_PLACE mode, the code emitted looks like:

struct new_object obj; // depends on alloc_type
<expr> := &obj
// recursive initialization of obj in NO_UPDATE_IN_PLACE mode

When in MUST_UPDATE_IN_PLACE mode, all code is emitted by a recursive call to gen_nondet_init in MUST_UPDATE_IN_PLACE mode, and looks like:

(*<expr>).some_int := NONDET(int)
(*<expr>).some_char := NONDET(char)

It is illegal to call the function with MAY_UPDATE_IN_PLACE.

Parameters
[out]assignmentsA code_blockt where the initialization code will be emitted to.
exprPointer-typed lvalue expression to initialize. The pointed type equals target_type.
target_typeStructure type to initialize, which may not match *expr (for example, expr might be have type void*). It cannot be a pointer to a primitive type because Java does not allow so.
alloc_typeAllocation type (global, local or dynamic)
depthNumber of times that a pointer has been dereferenced from the root of the object tree that we are initializing.
update_in_placeNO_UPDATE_IN_PLACE: initialize expr from scratch MUST_UPDATE_IN_PLACE: reinitialize an existing object MAY_UPDATE_IN_PLACE: invalid input
locationSource location associated with nondet-initialization.

Definition at line 401 of file java_object_factory.cpp.

◆ get_null_assignment()

code_assignt java_object_factoryt::get_null_assignment ( const exprt expr,
const pointer_typet ptr_type 
)
private

Returns a codet that assigns expr, of type ptr_type, a NULL value.

Definition at line 350 of file java_object_factory.cpp.

Member Data Documentation

◆ generic_parameter_specialization_map

generic_parameter_specialization_mapt java_object_factoryt::generic_parameter_specialization_map
private

Every time the non-det generator visits a type and the type is generic (either a struct or a pointer), the following map is used to store and look up the concrete types of the generic parameters in the current scope.

Note that not all generic parameters need to have a concrete type, e.g., the method under test is generic. The types are removed from the map when the scope changes. Note that in different depths of the scope the parameters can be specialized with different types so we keep a stack of types for each parameter.

Definition at line 51 of file java_object_factory.cpp.

◆ loc

const source_locationt& java_object_factoryt::loc
private

The source location for new statements emitted during the operation of the methods in this class.

Definition at line 33 of file java_object_factory.cpp.

◆ ns

namespacet java_object_factoryt::ns
private

A namespace built from exclusively one symbol table - the one above.

Definition at line 57 of file java_object_factory.cpp.

◆ object_factory_parameters

const java_object_factory_parameterst java_object_factoryt::object_factory_parameters
private

Definition at line 35 of file java_object_factory.cpp.

◆ pointer_type_selector

const select_pointer_typet& java_object_factoryt::pointer_type_selector
private

Resolves pointer types potentially using some heuristics, for example to replace pointers to interface types with pointers to concrete implementations.

Definition at line 62 of file java_object_factory.cpp.

◆ recursion_set

std::unordered_set<irep_idt> java_object_factoryt::recursion_set
private

This is employed in conjunction with the depth above.

Every time the non-det generator visits a type, the type is added to this set. We forbid the non-det initialization when we see the type for the second time in this set AND the tree depth becomes >= than the maximum value above.

Definition at line 41 of file java_object_factory.cpp.

◆ symbol_table

symbol_table_baset& java_object_factoryt::symbol_table
private

The symbol table.

Definition at line 54 of file java_object_factory.cpp.

◆ symbols_created

std::vector<const symbolt *>& java_object_factoryt::symbols_created
private

Every new variable initialized by the code emitted by the methods of this class gets a symbol in the symbol table, and such symbols are also added to this vector.

Definition at line 29 of file java_object_factory.cpp.


The documentation for this class was generated from the following file: