Java lambda code synthesis. More...

#include "lambda_synthesis.h"
#include <util/message.h>
#include <util/namespace.h>
#include <util/symbol_table_base.h>
#include "java_bytecode_convert_method.h"
#include "java_bytecode_parse_tree.h"
#include "java_static_initializers.h"
#include "java_types.h"
#include "java_utils.h"
#include "synthetic_methods_map.h"
#include <string.h>

Include dependency graph for lambda_synthesis.cpp:

Go to the source code of this file.

Classes
class	no_unique_unimplemented_method_exceptiont

struct	compare_base_name_and_descriptort

Typedefs
typedef std::map< const java_class_typet::methodt *, bool, compare_base_name_and_descriptort >	methods_by_name_and_descriptort
	Map from method, indexed by name and descriptor but not defining class, onto defined-ness (i.e. More...

Functions
static std::string	escape_symbol_special_chars (std::string input)

irep_idt	lambda_synthetic_class_name (const irep_idt &method_identifier, std::size_t instruction_address)

static std::optional< java_class_typet::java_lambda_method_handlet >	get_lambda_method_handle (const symbol_table_baset &symbol_table, const java_class_typet::java_lambda_method_handlest &lambda_method_handles, const size_t index)
	Retrieves the symbol of the lambda method associated with the given lambda method handle (bootstrap method). More...

static std::optional< java_class_typet::java_lambda_method_handlet >	lambda_method_handle (const symbol_table_baset &symbol_table, const irep_idt &method_identifier, const java_method_typet &dynamic_method_type)

static const methods_by_name_and_descriptort	get_interface_methods (const irep_idt &interface_id, const namespacet &ns)
	Find all methods defined by this method and its parent types, returned as a map from const java_class_typet::methodt * onto a boolean value which is true if the method is defined (i.e. More...

static const java_class_typet::methodt *	try_get_unique_unimplemented_method (const symbol_table_baset &symbol_table, const struct_tag_typet &functional_interface_tag, const irep_idt &method_identifier, const int instruction_address, const messaget &log)

symbolt	synthetic_class_symbol (const irep_idt &synthetic_class_name, const java_class_typet::java_lambda_method_handlet &lambda_method_handle, const struct_tag_typet &functional_interface_tag, const java_method_typet &dynamic_method_type)

static symbolt	constructor_symbol (synthetic_methods_mapt &synthetic_methods, const irep_idt &synthetic_class_name, java_method_typet constructor_type)

static symbolt	implemented_method_symbol (synthetic_methods_mapt &synthetic_methods, const java_class_typet::methodt &method_to_implement, const irep_idt &synthetic_class_name)

void	create_invokedynamic_synthetic_classes (const irep_idt &method_identifier, const java_bytecode_parse_treet::methodt::instructionst &instructions, symbol_table_baset &symbol_table, synthetic_methods_mapt &synthetic_methods, message_handlert &message_handler)

static const symbolt &	get_or_create_method_symbol (const irep_idt &identifier, const irep_idt &base_name, const irep_idt &pretty_name, const typet &type, const irep_idt &declaring_class, symbol_table_baset &symbol_table, message_handlert &log)

codet	invokedynamic_synthetic_constructor (const irep_idt &function_id, symbol_table_baset &symbol_table, message_handlert &message_handler)
	Create invokedynamic synthetic constructor. More...

static symbol_exprt	create_and_declare_local (const irep_idt &function_id, const irep_idt &basename, const typet &type, symbol_table_baset &symbol_table, code_blockt &method)

static symbol_exprt	instantiate_new_object (const irep_idt &function_id, const symbolt &lambda_method_symbol, symbol_table_baset &symbol_table, code_blockt &result)
	Instantiates an object suitable for calling a given constructor (but does not actually call it). More...

static std::optional< irep_idt >	get_unboxing_method (const pointer_typet &maybe_boxed_type)
	If `maybe_boxed_type` is a boxed primitive return its unboxing method; otherwise return empty. More...

exprt	make_function_expr (const symbolt &function_symbol, const symbol_table_baset &symbol_table)
	Produce a class_method_descriptor_exprt or symbol_exprt for `function_symbol` depending on whether virtual dispatch could be required (i.e., if it is non-static and its 'this' parameter is a non-final type) More...

exprt	box_or_unbox_type_if_necessary (exprt expr, const typet &required_type, code_blockt &code_block, symbol_table_baset &symbol_table, const irep_idt &function_id, const std::string &role)
	If `expr` needs (un)boxing to satisfy `required_type`, add the required symbols to `symbol_table` and code to `code_block`, then return an expression giving the adjusted expression. More...

exprt	adjust_type_if_necessary (exprt expr, const typet &required_type, code_blockt &code_block, symbol_table_baset &symbol_table, const irep_idt &function_id, const std::string &role)
	Box or unbox expr as per box_or_unbox_type_if_necessary, then cast the result to `required_type`. More...

codet	invokedynamic_synthetic_method (const irep_idt &function_id, symbol_table_baset &symbol_table, message_handlert &message_handler)
	Create the body for the synthetic method implementing an invokedynamic method. More...

Detailed Description

Java lambda code synthesis.

Definition in file lambda_synthesis.cpp.

Typedef Documentation

◆ methods_by_name_and_descriptort

typedef std::map< const java_class_typet::methodt *, bool, compare_base_name_and_descriptort> methods_by_name_and_descriptort

Map from method, indexed by name and descriptor but not defining class, onto defined-ness (i.e.

true if defined with a default method, false if abstract)

Definition at line 125 of file lambda_synthesis.cpp.

Function Documentation

◆ adjust_type_if_necessary()

exprt adjust_type_if_necessary	(	exprt	expr,
		const typet &	required_type,
		code_blockt &	code_block,
		symbol_table_baset &	symbol_table,
		const irep_idt &	function_id,
		const std::string &	role
	)

Box or unbox expr as per box_or_unbox_type_if_necessary, then cast the result to required_type.

If the source is legal Java that should mean a pointer upcast or primitive widening conversion, but this is not checked.

Definition at line 739 of file lambda_synthesis.cpp.

◆ box_or_unbox_type_if_necessary()

exprt box_or_unbox_type_if_necessary	(	exprt	expr,
		const typet &	required_type,
		code_blockt &	code_block,
		symbol_table_baset &	symbol_table,
		const irep_idt &	function_id,
		const std::string &	role
	)

If expr needs (un)boxing to satisfy required_type, add the required symbols to symbol_table and code to code_block, then return an expression giving the adjusted expression.

Otherwise return expr unchanged. role is a suggested name prefix for any temporary variable needed; function_id is the id of the function any created code it added to.

Regarding the apparent behaviour of the Java compiler / runtime with regard to adapting generic methods to/from primtitive types:

When unboxing, it appears to permit widening numeric conversions at the same time. For example, implementing Consumer<Short> by a function of type long -> void is possible, as the generated function will look like impl(Object o) { realfunc(((Number)o).longValue()); }

On the other hand when boxing to satisfy a generic interface type this is not permitted: in theory we should be able to implement Producer<Long> by a function of type () -> int, generating boxing code like impl() { return Long.valueOf(realfunc()); }

However it appears there is no way to convey to the lambda metafactory that a Long is really required rather than an Integer (the obvious conversion from int), so the compiler forbids this and requires that only simple boxing is performed.

Therefore when unboxing we cast to Number first, while when boxing and the target type is not a specific boxed type (i.e. the target is Object or Number etc) then we use the primitive type as our cue regarding the boxed type to produce.

Definition at line 680 of file lambda_synthesis.cpp.

◆ constructor_symbol()

static symbolt constructor_symbol	(	synthetic_methods_mapt &	synthetic_methods,
		const irep_idt &	synthetic_class_name,
		java_method_typet	constructor_type
	)

static

Definition at line 298 of file lambda_synthesis.cpp.

◆ create_and_declare_local()

static symbol_exprt create_and_declare_local	(	const irep_idt &	function_id,
		const irep_idt &	basename,
		const typet &	type,
		symbol_table_baset &	symbol_table,
		code_blockt &	method
	)

static

Definition at line 537 of file lambda_synthesis.cpp.

◆ create_invokedynamic_synthetic_classes()

void create_invokedynamic_synthetic_classes	(	const irep_idt &	method_identifier,
		const java_bytecode_parse_treet::methodt::instructionst &	instructions,
		symbol_table_baset &	symbol_table,
		synthetic_methods_mapt &	synthetic_methods,
		message_handlert &	message_handler
	)

Definition at line 395 of file lambda_synthesis.cpp.

◆ escape_symbol_special_chars()

static std::string escape_symbol_special_chars ( std::string input )

static

Definition at line 27 of file lambda_synthesis.cpp.

◆ get_interface_methods()

static const methods_by_name_and_descriptort get_interface_methods	(	const irep_idt &	interface_id,
		const namespacet &	ns
	)

static

Find all methods defined by this method and its parent types, returned as a map from const java_class_typet::methodt * onto a boolean value which is true if the method is defined (i.e.

has a default definition) as of this node in the class graph. If there are multiple name-and-descriptor-compatible methods, for example because both If1.f(int) and If2.f(int) are inherited here, only one is stored in the map, chosen arbitrarily.

Definition at line 135 of file lambda_synthesis.cpp.

◆ get_lambda_method_handle()

static std::optional<java_class_typet::java_lambda_method_handlet> get_lambda_method_handle	(	const symbol_table_baset &	symbol_table,
		const java_class_typet::java_lambda_method_handlest &	lambda_method_handles,
		const size_t	index
	)

static

Retrieves the symbol of the lambda method associated with the given lambda method handle (bootstrap method).

Parameters

symbol_table	global symbol table
lambda_method_handles	Vector of lambda method handles (bootstrap methods) of the class where the lambda is called
index	Index of the lambda method handle in the vector

Returns: Symbol of the lambda method if the method handle has a known type

Definition at line 55 of file lambda_synthesis.cpp.

◆ get_or_create_method_symbol()

static const symbolt& get_or_create_method_symbol	(	const irep_idt &	identifier,
		const irep_idt &	base_name,
		const irep_idt &	pretty_name,
		const typet &	type,
		const irep_idt &	declaring_class,
		symbol_table_baset &	symbol_table,
		message_handlert &	log
	)

static

Definition at line 447 of file lambda_synthesis.cpp.

◆ get_unboxing_method()

static std::optional<irep_idt> get_unboxing_method ( const pointer_typet & maybe_boxed_type )

static

If maybe_boxed_type is a boxed primitive return its unboxing method; otherwise return empty.

Definition at line 609 of file lambda_synthesis.cpp.

◆ implemented_method_symbol()

static symbolt implemented_method_symbol	(	synthetic_methods_mapt &	synthetic_methods,
		const java_class_typet::methodt &	method_to_implement,
		const irep_idt &	synthetic_class_name
	)

static

Definition at line 337 of file lambda_synthesis.cpp.

◆ instantiate_new_object()

static symbol_exprt instantiate_new_object	(	const irep_idt &	function_id,
		const symbolt &	lambda_method_symbol,
		symbol_table_baset &	symbol_table,
		code_blockt &	result
	)

static

Instantiates an object suitable for calling a given constructor (but does not actually call it).

Adds a local to symbol_table, and code implementing the required operation to result; returns a symbol carrying a reference to the newly instantiated object.

Parameters

function_id	ID of the function that `result` falls within
lambda_method_symbol	the constructor that will be called, and so whose `this` parameter we should instantiate.
symbol_table	symbol table, will gain a local variable
result	will gain instructions instantiating the required type

Returns: the newly instantiated symbol

Definition at line 568 of file lambda_synthesis.cpp.

◆ invokedynamic_synthetic_constructor()

codet invokedynamic_synthetic_constructor	(	const irep_idt &	function_id,
		symbol_table_baset &	symbol_table,
		message_handlert &	message_handler
	)

Create invokedynamic synthetic constructor.

Definition at line 471 of file lambda_synthesis.cpp.

◆ invokedynamic_synthetic_method()

codet invokedynamic_synthetic_method	(	const irep_idt &	function_id,
		symbol_table_baset &	symbol_table,
		message_handlert &	message_handler
	)

Create the body for the synthetic method implementing an invokedynamic method.

Create invokedynamic synthetic method.

For most lambdas this means creating a simple function body like TR new_synthetic_method(T1 param1, T2 param2, ...) { return target_method(capture1, capture2, ..., param1, param2, ...); }, where the first parameter might be a this parameter. For a constructor method, the generated code will be of the form TNew new_synthetic_method(T1 param1, T2 param2, ...) { return new TNew(capture1, capture2, ..., param1, param2, ...); } i.e. the TNew object will be both instantiated and constructed.

Parameters

function_id	synthetic method whose body should be generated; information about the lambda method to generate has already been stored in the symbol table by create_invokedynamic_synthetic_classes.
symbol_table	will gain local variable symbols
message_handler	log

Returns: the method body for function_id

Definition at line 769 of file lambda_synthesis.cpp.

◆ lambda_method_handle()

static std::optional<java_class_typet::java_lambda_method_handlet> lambda_method_handle	(	const symbol_table_baset &	symbol_table,
		const irep_idt &	method_identifier,
		const java_method_typet &	dynamic_method_type
	)

static

Definition at line 77 of file lambda_synthesis.cpp.

◆ lambda_synthetic_class_name()

irep_idt lambda_synthetic_class_name	(	const irep_idt &	method_identifier,
		std::size_t	instruction_address
	)

Definition at line 37 of file lambda_synthesis.cpp.

◆ make_function_expr()

exprt make_function_expr	(	const symbolt &	function_symbol,
		const symbol_table_baset &	symbol_table
	)

Produce a class_method_descriptor_exprt or symbol_exprt for function_symbol depending on whether virtual dispatch could be required (i.e., if it is non-static and its 'this' parameter is a non-final type)

Definition at line 622 of file lambda_synthesis.cpp.

◆ synthetic_class_symbol()

symbolt synthetic_class_symbol	(	const irep_idt &	synthetic_class_name,
		const java_class_typet::java_lambda_method_handlet &	lambda_method_handle,
		const struct_tag_typet &	functional_interface_tag,
		const java_method_typet &	dynamic_method_type
	)

Definition at line 250 of file lambda_synthesis.cpp.

◆ try_get_unique_unimplemented_method()

static const java_class_typet::methodt* try_get_unique_unimplemented_method	(	const symbol_table_baset &	symbol_table,
		const struct_tag_typet &	functional_interface_tag,
		const irep_idt &	method_identifier,
		const int	instruction_address,
		const messaget &	log
	)

static

Definition at line 204 of file lambda_synthesis.cpp.

Classes

Typedefs

Functions

Detailed Description

Typedef Documentation

◆ methods_by_name_and_descriptort

Function Documentation

◆ adjust_type_if_necessary()

◆ box_or_unbox_type_if_necessary()

◆ constructor_symbol()

◆ create_and_declare_local()

◆ create_invokedynamic_synthetic_classes()

◆ escape_symbol_special_chars()

◆ get_interface_methods()

◆ get_lambda_method_handle()

◆ get_or_create_method_symbol()

◆ get_unboxing_method()

◆ implemented_method_symbol()

◆ instantiate_new_object()

◆ invokedynamic_synthetic_constructor()

◆ invokedynamic_synthetic_method()

◆ lambda_method_handle()

◆ lambda_synthetic_class_name()

◆ make_function_expr()

◆ synthetic_class_symbol()

◆ try_get_unique_unimplemented_method()