X-Git-Url: http://nitlanguage.org diff --git a/src/contracts.nit b/src/contracts.nit index 156bb53..78803a2 100644 --- a/src/contracts.nit +++ b/src/contracts.nit @@ -50,7 +50,7 @@ redef class AModule # The implementation of the contracts is done in two visits. # # - First step, the visitor analyzes and constructs the contracts - # for each class (invariant) and method (expects, ensures). + # for each class (invariant) and method (expect, ensure). # # - Second step the visitor analyzes each `ASendExpr` to see # if the callsite calls a method with a contract. If this is @@ -65,10 +65,11 @@ redef class AModule end end -# This visitor checks the `AMethPropdef` and the `AClassDef` to check if they have a contract annotation or it's a redefinition with a inheritance contract +# Visitor to build all contracts. private class ContractsVisitor super Visitor + # Instance of the toolcontext var toolcontext: ToolContext # The main module @@ -90,6 +91,8 @@ private class ContractsVisitor var current_location: Location is noinit # Is the contrat is an introduction or not? + # This attribute has the same value as the `is_intro` of the propdef attached to the contract. + # Note : For MClassDef `is_intro_contract == false`. This is due to the fact that a method for checking invariants is systematically added to the root object class. var is_intro_contract: Bool is noinit # Actual visited class @@ -132,12 +135,44 @@ private class ContractsVisitor assert contract_propdef != null return contract_propdef end + + # Verification if the construction of the contract is necessary. + # Three cases are checked for `expect`: + # + # - Was the `--full-contract` option passed? + # - Is the method is in the main package? + # - Is the method is in a direct imported package? + # + fun check_usage_expect(actual_mmodule: MModule): Bool + do + var main_package = mainmodule.mpackage + var actual_package = actual_mmodule.mpackage + if main_package != null and actual_package != null then + var condition_direct_arc = toolcontext.modelbuilder.model.mpackage_importation_graph.has_arc(main_package, actual_package) + return toolcontext.opt_full_contract.value or condition_direct_arc or main_package == actual_package + end + return false + end + + # Verification if the construction of the contract is necessary. + # Two cases are checked for `ensure`: + # + # - Was the `--full-contract` option passed? + # - Is the method is in the main package? + # + fun check_usage_ensure(actual_mmodule: MModule): Bool + do + return toolcontext.opt_full_contract.value or mainmodule.mpackage == actual_mmodule.mpackage + end + end # This visitor checks the `callsite` to see if the target `mpropdef` has a contract. private class CallSiteVisitor super Visitor + + # Instance of the toolcontext var toolcontext: ToolContext # Actual visited method @@ -153,21 +188,16 @@ private class CallSiteVisitor # If it's the case the callsite is replaced by another callsite to the contract method. private fun drive_method_contract(callsite: CallSite): CallSite do - if callsite.mpropdef.has_contract then + if callsite.mproperty.mcontract_facet != null then var contract_facet = callsite.mproperty.mcontract_facet var visited_mpropdef = visited_method.mpropdef assert contract_facet != null and visited_mpropdef != null - var unsafe_mtype = callsite.recv.resolve_for(callsite.recv, callsite.anchor, visited_mpropdef.mclassdef.mmodule, false) - - # This check is needed because the contract can appear after the introduction. - if unsafe_mtype.has_mproperty(visited_method.mpropdef.mclassdef.mmodule, contract_facet) then - var type_visitor = new TypeVisitor(toolcontext.modelbuilder, visited_mpropdef) - var drived_callsite = type_visitor.build_callsite_by_property(visited_method, callsite.recv, contract_facet, callsite.recv_is_self) - # This never happen this check is here for debug - assert drived_callsite != null - return drived_callsite - end + var type_visitor = new TypeVisitor(toolcontext.modelbuilder, visited_mpropdef) + var drived_callsite = type_visitor.build_callsite_by_property(visited_method, callsite.recv, contract_facet, callsite.recv_is_self) + # This never happen this check is here for debug + assert drived_callsite != null + return drived_callsite end return callsite end @@ -180,10 +210,10 @@ end redef class AAnnotation - # Returns the conditions of annotation parameters in the form of and expr - # exemple: - # the contract ensures(true, i == 10, f >= 1.0) - # return this condition (true and i == 10 and f >= 1.0) + # Returns the conditions of annotation parameters. If there are several parameters, the result is an `AAndExpr` + # Example: + # the contract `ensure(true, i == 10, f >= 1.0)` + # return this condition `(true and i == 10 and f >= 1.0)` private fun construct_condition(v : ContractsVisitor): AExpr do var n_condition = n_args.first @@ -203,9 +233,6 @@ abstract class MContract # Define the name of the contract fun contract_name: String is abstract - # Checking if the use of the contract is necessary - private fun check_usage(v: ContractsVisitor, actual_mmodule: MModule): Bool is abstract - # Method use to diplay warning when the contract is not present at the introduction private fun no_intro_contract(v: ContractsVisitor, a: AAnnotation)do end @@ -216,10 +243,10 @@ abstract class MContract private fun adapt_block_to_contract(v: ContractsVisitor, n_mpropdef: AMethPropdef) is abstract # Adapt the msignature specifically for the contract method - private fun adapt_specific_msignature(m_signature: MSignature): MSignature do return m_signature.adapt_to_condition + private fun adapt_specific_msignature(m_signature: MSignature): MSignature do return m_signature.adapt_to_contract # Adapt the nsignature specifically for the contract method - private fun adapt_specific_nsignature(n_signature: ASignature): ASignature do return n_signature.adapt_to_condition(null) + private fun adapt_specific_nsignature(n_signature: ASignature): ASignature do return n_signature.adapt_to_contract # Adapt the `m_signature` to the contract # If it is not null call the specific adapt `m_signature` for the contract @@ -247,10 +274,13 @@ abstract class MContract # Create the initial contract (intro) # All contracts have the same implementation for the introduction. # + # Example: + # ~~~nitish # fun contrat([...]) # do # assert contract_condition # end + # ~~~ # private fun create_intro_contract(v: ContractsVisitor, n_condition: nullable AExpr, mclassdef: MClassDef): AMethPropdef do @@ -291,45 +321,28 @@ class MExpect super MContract # Define the name of the contract - redef fun contract_name: String do return "expects" - - # Verification if the construction of the contract is necessary. - # Three cases are checked for `expects`: - # - # - Is the `--full-contract` option it's use? - # - Is the method is in the main package - # - Is the method is in a direct imported package. - # - redef fun check_usage(v: ContractsVisitor, actual_mmodule: MModule): Bool - do - var main_package = v.mainmodule.mpackage - var actual_package = actual_mmodule.mpackage - if main_package != null and actual_package != null then - var condition_direct_arc = v.toolcontext.modelbuilder.model.mpackage_importation_graph.has_arc(main_package, actual_package) - return v.toolcontext.opt_full_contract.value or condition_direct_arc or main_package == actual_package - end - return false - end + redef fun contract_name: String do return "expect" # Display warning if no contract is defined at introduction `expect`, # because if no contract is defined at the introduction the added # contracts will not cause any error even if they are not satisfied. # - # exemple + # Example: # ~~~nitish # class A # fun bar [...] - # fun _bar_expects([...]) + # fun _bar_expect([...]) # do # [empty contract] # end # end # # redef class A - # redef fun bar is expects(contract_condition) - # redef fun _bar_expects([...]) + # redef fun bar is expect(contract_condition) + # redef fun _bar_expect([...]) # do - # if not (contract_condition) then super + # if (contract_condition) then return + # super # end # end # ~~~~ @@ -371,21 +384,10 @@ class MExpect end end -# The root of all contracts where the call is after the execution of the original method (`invariants` and `ensures`). +# The root of all contracts where the call is after the execution of the original method (`invariant` and `ensure`). abstract class BottomMContract super MContract - # Verification if the construction of the contract is necessary. - # Two cases are checked for `expects`: - # - # - Is the `--full-contract` option it's use? - # - Is the method is in the main package - # - redef fun check_usage(v: ContractsVisitor, actual_mmodule: MModule): Bool - do - return v.toolcontext.opt_full_contract.value or v.mainmodule.mpackage == actual_mmodule.mpackage - end - redef fun create_nblock(v: ContractsVisitor, n_condition: AExpr, args: Array[AExpr]): ABlockExpr do var tid = new TId.init_tk(v.current_location) @@ -402,7 +404,9 @@ abstract class BottomMContract return n_block end - # Inject the result variable in the `n_block` of the given `n_mpropdef`. + # Inject the `result` variable into the `n_block` of the given n_mpropdef`. + # + # The purpose of the variable is to capture return values to use it in contracts. private fun inject_result(v: ContractsVisitor, n_mpropdef: AMethPropdef, ret_type: MType): Variable do var actual_block = n_mpropdef.n_block @@ -448,7 +452,7 @@ class MEnsure super BottomMContract # Define the name of the contract - redef fun contract_name: String do return "ensures" + redef fun contract_name: String do return "ensure" redef fun adapt_specific_msignature(m_signature: MSignature): MSignature do @@ -542,7 +546,7 @@ redef class MMethod do if self.mensure != null then return true # build a new `MEnsure` contract - self.mensure = new MEnsure(intro_mclassdef, "_ensures_{name}", intro_mclassdef.location, public_visibility) + self.mensure = new MEnsure(intro_mclassdef, "_ensure_{name}", intro_mclassdef.location, public_visibility) return false end @@ -553,7 +557,7 @@ redef class MMethod do if self.mexpect != null then return true # build a new `MExpect` contract - self.mexpect = new MExpect(intro_mclassdef, "_expects_{name}", intro_mclassdef.location, public_visibility) + self.mexpect = new MExpect(intro_mclassdef, "_expect_{name}", intro_mclassdef.location, public_visibility) return false end @@ -563,7 +567,7 @@ redef class MMethod do if self.mcontract_facet != null then return true # build a new `MMethod` contract - self.mcontract_facet = new MMethod(mpropdef.mclassdef, "_contract_{name}", mpropdef.mclassdef.location, public_visibility) + self.mcontract_facet = new MMethod(intro_mclassdef, "_contract_{name}", intro_mclassdef.location, public_visibility) return false end end @@ -572,23 +576,25 @@ redef class MMethodDef # Verification of the contract facet # Check if a contract facet already exists to use it again or if it is necessary to create it. - private fun check_contract_facet(v: ContractsVisitor, n_signature: ASignature, mcontract: MContract, exist_contract: Bool) + private fun check_contract_facet(v: ContractsVisitor, n_signature: ASignature, classdef: MClassDef, mcontract: MContract, exist_contract: Bool) do var exist_contract_facet = mproperty.check_exist_contract_facet(self) if exist_contract_facet and exist_contract then return var contract_facet: AMethPropdef if not exist_contract_facet then + # If has no contract facet in intro just create it + if classdef != mproperty.intro_mclassdef then create_contract_facet(v, mproperty.intro_mclassdef, n_signature) # If has no contract facet just create it - contract_facet = create_contract_facet(v, n_signature) + contract_facet = create_contract_facet(v, classdef, n_signature) else - # Check if the contract facet already exist in this context (in this mclassdef) - if mclassdef.mpropdefs_by_property.has_key(mproperty.mcontract_facet) then + # Check if the contract facet already exist in this context (in this classdef) + if classdef.mpropdefs_by_property.has_key(mproperty.mcontract_facet) then # get the define - contract_facet = v.toolcontext.modelbuilder.mpropdef2node(mclassdef.mpropdefs_by_property[mproperty.mcontract_facet]).as(AMethPropdef) + contract_facet = v.toolcontext.modelbuilder.mpropdef2node(classdef.mpropdefs_by_property[mproperty.mcontract_facet]).as(AMethPropdef) else # create a new contract facet definition - contract_facet = create_contract_facet(v, n_signature) + contract_facet = create_contract_facet(v, classdef, n_signature) var block = v.ast_builder.make_block # super call to the contract facet var n_super_call = v.ast_builder.make_super_call(n_signature.make_parameter_read(v.ast_builder), null) @@ -607,7 +613,7 @@ redef class MMethodDef end # Method to create a contract facet of the method - private fun create_contract_facet(v: ContractsVisitor, n_signature: ASignature): AMethPropdef + private fun create_contract_facet(v: ContractsVisitor, classdef: MClassDef, n_signature: ASignature): AMethPropdef do var contract_facet = mproperty.mcontract_facet assert contract_facet != null @@ -619,7 +625,7 @@ redef class MMethodDef var m_signature: nullable MSignature = null if mproperty.intro.msignature != null then m_signature = mproperty.intro.msignature.clone - var n_contractdef = mclassdef.mclass.create_empty_method(v, contract_facet, mclassdef, m_signature, n_signature) + var n_contractdef = classdef.mclass.create_empty_method(v, contract_facet, classdef, m_signature, n_signature) # FIXME set the location because the callsite creation need the node location n_contractdef.location = v.current_location n_contractdef.validate @@ -645,13 +651,11 @@ redef class MMethodDef private fun construct_contract(v: ContractsVisitor, n_signature: ASignature, n_annotation: AAnnotation, mcontract: MContract, exist_contract: Bool) do if check_same_contract(v, n_annotation, mcontract) then return - # Check if the contract is necessary - if not mcontract.check_usage(v, mclassdef.mmodule) then return if not exist_contract and not is_intro then no_intro_contract(v, n_signature, mcontract, n_annotation) v.define_signature(mcontract, n_signature, mproperty.intro.msignature) var conditiondef = v.build_contract(n_annotation, mcontract, mclassdef) - check_contract_facet(v, n_signature.clone, mcontract, exist_contract) + check_contract_facet(v, n_signature.clone, mclassdef, mcontract, exist_contract) has_contract = true end @@ -667,9 +671,9 @@ redef class MMethodDef # Is the contract already defined in the context # # Exemple : - # fun foo is expects([...]), expects([...]) + # fun foo is expect([...]), expect([...]) # - # Here `check_same_contract` display an error when the second expects is processed + # Here `check_same_contract` display an error when the second expect is processed private fun check_same_contract(v: ContractsVisitor, n_annotation: AAnnotation ,mcontract: MContract): Bool do if self.mclassdef.mpropdefs_by_property.has_key(mcontract) then @@ -731,10 +735,12 @@ redef class AMethPropdef # If this is the case, we built the appropriate contract. private fun check_annotation(v: ContractsVisitor, n_annotation: AAnnotation) do - if n_annotation.name == "expects" then + if n_annotation.name == "expect" then + if not v.check_usage_expect(mpropdef.mclassdef.mmodule) then return var exist_contract = mpropdef.mproperty.check_exist_expect mpropdef.construct_contract(v, self.n_signature.as(not null), n_annotation, mpropdef.mproperty.mexpect.as(not null), exist_contract) - else if n_annotation.name == "ensures" then + else if n_annotation.name == "ensure" then + if not v.check_usage_ensure(mpropdef.mclassdef.mmodule) then return var exist_contract = mpropdef.mproperty.check_exist_ensure mpropdef.construct_contract(v, self.n_signature.as(not null), n_annotation, mpropdef.mproperty.mensure.as(not null), exist_contract) else if n_annotation.name == "no_contract" then @@ -765,25 +771,26 @@ end redef class MSignature - # Adapt signature for a expect condition - # Removed the return type is it not necessary - private fun adapt_to_condition: MSignature do return new MSignature(mparameters.to_a, null) + # Adapt signature for an contract + # + # The returned `MSignature` is the copy of `self` without return type. + private fun adapt_to_contract: MSignature do return new MSignature(mparameters.to_a, null) - # Adapt signature for a ensure condition + # Adapt signature for a ensure contract # - # Create new parameter with the return type + # The returned `MSignature` is the copy of `self` without return type. + # The return type is replaced by a new parameter `result` private fun adapt_to_ensurecondition: MSignature do var rtype = return_mtype - var msignature = adapt_to_condition + var msignature = adapt_to_contract if rtype != null then msignature.mparameters.add(new MParameter("result", rtype, false)) end return msignature end - # Adapt signature for a expect condition - # Removed the return type is it not necessary + # The returned `MSignature` is the exact copy of `self`. private fun clone: MSignature do return new MSignature(mparameters.to_a, return_mtype) end @@ -803,26 +810,26 @@ redef class ASignature return args end - # Return a copy of self adapted for the expect condition - # npropdef it is use to define the parent of the parameters - private fun adapt_to_condition(return_type: nullable AType): ASignature + # Create a new ASignature adapted for contract + # + # The returned `ASignature` is the copy of `self` without return type. + private fun adapt_to_contract: ASignature do var adapt_nsignature = self.clone - adapt_nsignature.n_type = return_type + if adapt_nsignature.n_type != null then adapt_nsignature.n_type.detach return adapt_nsignature end - # Return a copy of self adapted for postcondition on npropdef + # Create a new ASignature adapted for ensure + # + # The returned `ASignature` is the copy of `self` without return type. + # The return type is replaced by a new parameter `result` private fun adapt_to_ensurecondition: ASignature do - var nsignature = adapt_to_condition(null) + var nsignature = adapt_to_contract if ret_type != null then - var n_id = new TId - n_id.text = "result" - var new_param = new AParam - new_param.n_id = n_id - new_param.variable = new Variable(n_id.text) - new_param.variable.declared_type = ret_type - nsignature.n_params.add new_param + var variable = new Variable("result") + variable.declared_type = ret_type + nsignature.n_params.add new AParam.make(variable, ret_type.create_ast_representation) end return nsignature end