def create_verify_message_procedure(
message: Message, context_invariant: Sequence[Expr]) -> UnitPart:
specification = ProcedureSpecification(
"Verify_Message", [InOutParameter(["Ctx"], "Context")])
return UnitPart(
[
SubprogramDeclaration(
specification,
[
Postcondition(
And(
Equal(
Call("Has_Buffer", [Variable("Ctx")]),
Old(Call("Has_Buffer", [Variable("Ctx")])),
),
*context_invariant,
)),
],
)
],
[
SubprogramBody(
specification,
[],
[
CallStatement(
"Verify",
[Variable("Ctx"),
Variable(f.affixed_name)]) for f in message.fields
],
)
],
)
def specification_bounded(field: Field) -> ProcedureSpecification:
return ProcedureSpecification(
f"Initialize_Bounded_{field.name}",
[
InOutParameter(["Ctx"], "Context"),
Parameter(["Length"], const.TYPES_BIT_LENGTH)
],
)
def insert_function(self, type_name: str) -> Subprogram:
return GenericProcedureInstantiation(
"Insert",
ProcedureSpecification(
f"{self.types.types}.Insert",
[
Parameter(["Val"], type_name),
InOutParameter(["Buffer"], self.types.bytes),
Parameter(["Offset"], self.types.offset),
],
),
[self.types.index, self.types.byte, self.types.bytes, self.types.offset, type_name],
)
def specification(field: Field, field_type: Type) -> ProcedureSpecification:
type_name = (
field_type.enum_name
if isinstance(field_type, Enumeration) and field_type.always_valid
else field_type.name
)
return ProcedureSpecification(
f"Set_{field.name}",
[
InOutParameter(["Ctx"], "Context"),
Parameter(["Val"], f"{message.package}.{type_name}"),
],
)
def insert_function(self, type_name: ID) -> Subprogram:
return GenericProcedureInstantiation(
"Insert",
ProcedureSpecification(
const.TYPES * "Insert",
[
Parameter(["Val"], type_name),
InOutParameter(["Buffer"], const.TYPES_BYTES),
Parameter(["Offset"], const.TYPES_OFFSET),
],
),
[common.prefixed_type_name(type_name, self.prefix)],
)
def create_verify_message_procedure(self, message: Message) -> UnitPart:
specification = ProcedureSpecification(
"Verify_Message", [InOutParameter(["Ctx"], "Context")])
loop_invariant = And(
Call("Has_Buffer", [Variable("Ctx")]),
*common.context_invariant(message, loop_entry=True),
)
return UnitPart(
[
SubprogramDeclaration(
specification,
[
Precondition(
Call(
self.prefix * message.identifier *
"Has_Buffer",
[Variable("Ctx")],
)),
Postcondition(
And(
Call("Has_Buffer", [Variable("Ctx")]),
*common.context_invariant(message),
)),
],
)
],
[
SubprogramBody(
specification,
[],
[
ForIn(
"F",
Variable("Field"),
[
PragmaStatement("Loop_Invariant",
[loop_invariant]),
CallStatement("Verify",
[Variable("Ctx"),
Variable("F")]),
],
)
],
)
],
)
def specification(field: Field,
field_type: Type) -> ProcedureSpecification:
if field_type.package == BUILTINS_PACKAGE:
type_name = ID(field_type.name)
elif isinstance(field_type,
Enumeration) and field_type.always_valid:
type_name = common.prefixed_type_name(
common.full_enum_name(field_type), self.prefix)
else:
type_name = common.prefixed_type_name(field_type.identifier,
self.prefix)
return ProcedureSpecification(
f"Set_{field.name}",
[
InOutParameter(["Ctx"], "Context"),
Parameter(["Val"], type_name)
],
)
def _create_finalize_proc(self,
slots: Sequence[NumberedSlotInfo]) -> UnitPart:
proc = ProcedureSpecification("Finalize",
[InOutParameter(["S"], "Slots")])
return UnitPart(
[
SubprogramDeclaration(
proc,
[Postcondition(Call("Uninitialized", [Variable("S")]))]),
],
[
SubprogramBody(
proc,
declarations=[],
statements=([
Assignment(
"S" * self._slot_name(slot.slot_id),
Variable("null"),
) for slot in slots
] if slots else [NullStatement()]),
aspects=[SparkMode(off=True)],
)
],
)
def create_internal_functions(
self, message: Message, scalar_fields: Mapping[Field, Scalar]
) -> UnitPart:
return UnitPart(
[],
[
SubprogramBody(
ProcedureSpecification(
"Set_Field_Value",
[
InOutParameter(["Ctx"], "Context"),
Parameter(["Val"], "Field_Dependent_Value"),
OutParameter(["Fst", "Lst"], self.types.bit_index),
],
),
[
*self.common.field_bit_location_declarations(Selected("Val", "Fld")),
*self.common.field_byte_location_declarations(),
],
[
Assignment("Fst", Name("First")),
Assignment("Lst", Name("Last")),
CaseStatement(
Selected("Val", "Fld"),
[
(
Name(f.affixed_name),
[
CallStatement(
"Insert",
[
Selected("Val", f"{f.name}_Value"),
Slice(
Selected(Selected("Ctx", "Buffer"), "all"),
Name("Buffer_First"),
Name("Buffer_Last"),
),
Name("Offset"),
],
)
if f in scalar_fields
else NullStatement()
],
)
for f in message.all_fields
],
),
],
[
Precondition(
AndThen(
Not(Constrained("Ctx")),
Call("Has_Buffer", [Name("Ctx")]),
In(Selected("Val", "Fld"), Range("Field")),
Call("Valid_Next", [Name("Ctx"), Selected("Val", "Fld")]),
self.common.sufficient_space_for_field_condition(
Selected("Val", "Fld")
),
ForAllIn(
"F",
Range("Field"),
If(
[
(
Call(
"Structural_Valid",
[
Indexed(
Selected("Ctx", "Cursors"), Name("F"),
)
],
),
LessEqual(
Selected(
Indexed(
Selected("Ctx", "Cursors"), Name("F"),
),
"Last",
),
Call(
"Field_Last",
[Name("Ctx"), Selected("Val", "Fld")],
),
),
)
]
),
),
)
),
Postcondition(
And(
Call("Has_Buffer", [Name("Ctx")]),
Equal(
Name("Fst"),
Call("Field_First", [Name("Ctx"), Selected("Val", "Fld")]),
),
Equal(
Name("Lst"),
Call("Field_Last", [Name("Ctx"), Selected("Val", "Fld")]),
),
GreaterEqual(Name("Fst"), Selected("Ctx", "First")),
LessEqual(Name("Fst"), Add(Name("Lst"), Number(1))),
LessEqual(
Call(self.types.byte_index, [Name("Lst")]),
Selected("Ctx", "Buffer_Last"),
),
ForAllIn(
"F",
Range("Field"),
If(
[
(
Call(
"Structural_Valid",
[
Indexed(
Selected("Ctx", "Cursors"), Name("F"),
)
],
),
LessEqual(
Selected(
Indexed(
Selected("Ctx", "Cursors"), Name("F"),
),
"Last",
),
Name("Lst"),
),
)
]
),
),
*[
Equal(e, Old(e))
for e in [
Selected("Ctx", "Buffer_First"),
Selected("Ctx", "Buffer_Last"),
Selected("Ctx", "First"),
Selected("Ctx", "Cursors"),
]
],
)
),
],
)
],
)
def specification_bounded(field: Field) -> ProcedureSpecification:
return ProcedureSpecification(
f"Initialize_Bounded_{field.name}",
[InOutParameter(["Ctx"], "Context"), Parameter(["Length"], self.types.bit_length)],
)
def specification(field: Field) -> ProcedureSpecification:
return ProcedureSpecification(
f"Initialize_{field.name}", [InOutParameter(["Ctx"], "Context")]
)
def create_verify_procedure(self, message: Message,
context_invariant: Sequence[Expr]) -> UnitPart:
specification = ProcedureSpecification(
"Verify",
[InOutParameter(["Ctx"], "Context"),
Parameter(["Fld"], "Field")])
valid_field_condition = And(
Call(
"Valid_Value",
[Variable("Value")],
),
Call(
"Field_Condition",
[
Variable("Ctx"),
Variable("Value"),
*([
Call(
"Field_Length",
[Variable("Ctx"), Variable("Fld")])
] if common.length_dependent_condition(message) else []),
],
),
)
set_cursors_statements = [
IfStatement(
[(
Call("Composite_Field", [Variable("Fld")]),
[
Assignment(
Indexed(Variable("Ctx.Cursors"), Variable("Fld")),
NamedAggregate(
("State", Variable("S_Structural_Valid")),
(
"First",
Call("Field_First",
[Variable("Ctx"),
Variable("Fld")]),
),
(
"Last",
Call("Field_Last",
[Variable("Ctx"),
Variable("Fld")]),
),
("Value", Variable("Value")),
(
"Predecessor",
Selected(
Indexed(Variable("Ctx.Cursors"),
Variable("Fld")),
"Predecessor",
),
),
),
)
],
)],
[
Assignment(
Indexed(Variable("Ctx.Cursors"), Variable("Fld")),
NamedAggregate(
("State", Variable("S_Valid")),
("First",
Call("Field_First",
[Variable("Ctx"),
Variable("Fld")])),
("Last",
Call("Field_Last",
[Variable("Ctx"),
Variable("Fld")])),
("Value", Variable("Value")),
(
"Predecessor",
Selected(
Indexed(Variable("Ctx.Cursors"),
Variable("Fld")), "Predecessor"),
),
),
)
],
),
# WORKAROUND:
# Limitation of GNAT Community 2019 / SPARK Pro 20.0
# Provability of predicate is increased by adding part of
# predicate as assert
PragmaStatement("Assert", [
str(common.message_structure_invariant(message, self.prefix))
]),
# WORKAROUND:
# Limitation of GNAT Community 2019 / SPARK Pro 20.0
# Provability of predicate is increased by splitting
# assignment in multiple statements
IfStatement([(
Equal(Variable("Fld"), Variable(f.affixed_name)),
[
Assignment(
Indexed(
Variable("Ctx.Cursors"),
Call("Successor",
[Variable("Ctx"),
Variable("Fld")]),
),
NamedAggregate(
("State", Variable("S_Invalid")),
("Predecessor", Variable("Fld")),
),
)
],
) for f in message.fields]),
]
return UnitPart(
[
SubprogramDeclaration(
specification,
[
Postcondition(
And(
Equal(
Call("Has_Buffer", [Variable("Ctx")]),
Old(Call("Has_Buffer", [Variable("Ctx")])),
),
*context_invariant,
)),
],
)
],
[
SubprogramBody(
specification,
[ObjectDeclaration(["Value"], "Field_Dependent_Value")],
[
IfStatement([(
AndThen(
Call("Has_Buffer", [Variable("Ctx")]),
Call(
"Invalid",
[
Indexed(Variable("Ctx.Cursors"),
Variable("Fld"))
],
),
Call("Valid_Predecessor",
[Variable("Ctx"),
Variable("Fld")]),
Call("Path_Condition",
[Variable("Ctx"),
Variable("Fld")]),
),
[
IfStatement(
[(
Call(
"Sufficient_Buffer_Length",
[Variable("Ctx"),
Variable("Fld")],
),
[
Assignment(
"Value",
Call(
"Get_Field_Value",
[
Variable("Ctx"),
Variable("Fld")
],
),
),
IfStatement(
[(
valid_field_condition,
set_cursors_statements,
)],
[
Assignment(
Indexed(
Variable(
"Ctx.Cursors"),
Variable("Fld"),
),
NamedAggregate(
(
"State",
Variable(
"S_Invalid"
),
),
(
"Predecessor",
Variable(
FINAL.
affixed_name
),
),
),
)
],
),
],
)],
[
Assignment(
Indexed(Variable("Ctx.Cursors"),
Variable("Fld")),
NamedAggregate(
("State",
Variable("S_Incomplete")),
(
"Predecessor",
Variable(
FINAL.affixed_name),
),
),
)
],
)
],
)], )
],
)
],
)
def create_internal_functions(
self, message: Message,
scalar_fields: Mapping[Field, Scalar]) -> UnitPart:
return UnitPart(
[],
[
SubprogramBody(
ProcedureSpecification(
"Set_Field_Value",
[
InOutParameter(["Ctx"], "Context"),
Parameter(["Val"], "Field_Dependent_Value"),
OutParameter(["Fst", "Lst"],
const.TYPES_BIT_INDEX),
],
),
[
*common.field_bit_location_declarations(
Variable("Val.Fld")),
*common.field_byte_location_declarations(),
*unique(
self.insert_function(common.full_base_type_name(t))
for t in message.types.values()
if isinstance(t, Scalar)),
],
[
Assignment("Fst", Variable("First")),
Assignment("Lst", Variable("Last")),
CaseStatement(
Variable("Val.Fld"),
[(
Variable(f.affixed_name),
[
CallStatement(
"Insert",
[
Variable(f"Val.{f.name}_Value"),
Slice(
Variable("Ctx.Buffer.all"),
Variable("Buffer_First"),
Variable("Buffer_Last"),
),
Variable("Offset"),
],
)
if f in scalar_fields else NullStatement()
],
) for f in message.all_fields],
),
],
[
Precondition(
AndThen(
Not(Constrained("Ctx")),
Call("Has_Buffer", [Variable("Ctx")]),
In(Variable("Val.Fld"), Range("Field")),
Call("Valid_Next",
[Variable("Ctx"),
Variable("Val.Fld")]),
common.sufficient_space_for_field_condition(
Variable("Val.Fld")),
ForAllIn(
"F",
Range("Field"),
If([(
Call(
"Structural_Valid",
[
Indexed(
Variable("Ctx.Cursors"),
Variable("F"),
)
],
),
LessEqual(
Selected(
Indexed(
Variable("Ctx.Cursors"),
Variable("F"),
),
"Last",
),
Call(
"Field_Last",
[
Variable("Ctx"),
Variable("Val.Fld")
],
),
),
)]),
),
)),
Postcondition(
And(
Call("Has_Buffer", [Variable("Ctx")]),
Equal(
Variable("Fst"),
Call(
"Field_First",
[Variable("Ctx"),
Variable("Val.Fld")]),
),
Equal(
Variable("Lst"),
Call(
"Field_Last",
[Variable("Ctx"),
Variable("Val.Fld")]),
),
GreaterEqual(Variable("Fst"),
Variable("Ctx.First")),
LessEqual(Variable("Fst"),
Add(Variable("Lst"), Number(1))),
LessEqual(
Call(const.TYPES_BYTE_INDEX,
[Variable("Lst")]),
Variable("Ctx.Buffer_Last"),
),
ForAllIn(
"F",
Range("Field"),
If([(
Call(
"Structural_Valid",
[
Indexed(
Variable("Ctx.Cursors"),
Variable("F"),
)
],
),
LessEqual(
Selected(
Indexed(
Variable("Ctx.Cursors"),
Variable("F"),
),
"Last",
),
Variable("Lst"),
),
)]),
),
*[
Equal(e, Old(e)) for e in [
Variable("Ctx.Buffer_First"),
Variable("Ctx.Buffer_Last"),
Variable("Ctx.First"),
Variable("Ctx.Cursors"),
]
],
)),
],
)
] if scalar_fields else [],
)
def specification(field: Field) -> ProcedureSpecification:
return ProcedureSpecification(f"Set_{field.name}_Empty",
[InOutParameter(["Ctx"], "Context")])
def create_verify_procedure(
self,
message: Message,
scalar_fields: Mapping[Field, Scalar],
composite_fields: Sequence[Field],
) -> UnitPart:
specification = ProcedureSpecification(
"Verify",
[InOutParameter(["Ctx"], "Context"),
Parameter(["Fld"], "Field")])
valid_field_condition = AndThen(
Call(
"Valid_Value",
[Variable("Fld"), Variable("Value")],
),
Call(
"Field_Condition",
[
Variable("Ctx"),
Variable("Fld"),
*([Variable("Value")] if
common.has_value_dependent_condition(message) else []),
*([
Slice(
Variable("Ctx.Buffer.all"),
Call(
const.TYPES_TO_INDEX,
[
Call("Field_First",
[Variable("Ctx"),
Variable("Fld")])
],
),
Call(
const.TYPES_TO_INDEX,
[
Call("Field_Last",
[Variable("Ctx"),
Variable("Fld")])
],
),
)
] if common.has_aggregate_dependent_condition(message) else
[]),
*([Call("Field_Size",
[Variable("Ctx"), Variable("Fld")])]
if common.has_size_dependent_condition(message) else []),
],
),
)
last = Mul(
Div(
Add(
Call("Field_Last",
[Variable("Ctx"), Variable("Fld")]),
Size(const.TYPES_BYTE),
-Number(1),
),
Size(const.TYPES_BYTE),
),
Size(const.TYPES_BYTE),
)
set_cursors_statements = [
*([
PragmaStatement(
"Assert",
[
If([(
Or(*[
Equal(Variable("Fld"), Variable(
f.affixed_name))
for f in message.direct_predecessors(FINAL)
]),
Equal(
Mod(
Call("Field_Last",
[Variable("Ctx"),
Variable("Fld")]),
Size(const.TYPES_BYTE),
),
Number(0),
),
)])
],
)
] if len(message.fields) > 1 else []),
# Improve provability of context predicate
PragmaStatement(
"Assert",
[Equal(Mod(last, Size(const.TYPES_BYTE)), Number(0))]),
Assignment(Variable("Ctx.Verified_Last"), last),
PragmaStatement(
"Assert",
[
LessEqual(
Call("Field_Last", [Variable("Ctx"),
Variable("Fld")]),
Variable("Ctx.Verified_Last"),
)
],
),
IfStatement(
[(
Call("Composite_Field", [Variable("Fld")]),
[set_context_cursor_composite_field("Fld")],
)],
[set_context_cursor_scalar()],
) if scalar_fields and composite_fields else
set_context_cursor_scalar()
if scalar_fields and not composite_fields else
set_context_cursor_composite_field("Fld"),
*([
# https://github.com/Componolit/RecordFlux/issues/664
# The provability of the context predicate is increased by splitting the
# assignment into multiple statements.
Assignment(
Indexed(
Variable("Ctx.Cursors"),
Call(
"Successor",
[Variable("Ctx"), Variable("Fld")],
),
),
NamedAggregate(
("State", Variable("S_Invalid")),
("Predecessor", Variable("Fld")),
),
)
] if len(message.fields) > 1 else []),
]
return UnitPart(
[
SubprogramDeclaration(
specification,
[
Precondition(
Call(
self.prefix * message.identifier *
"Has_Buffer",
[Variable("Ctx")],
)),
Postcondition(
And(
Call("Has_Buffer", [Variable("Ctx")]),
*common.context_invariant(message),
)),
],
)
],
[
SubprogramBody(
specification,
[ObjectDeclaration(["Value"], const.TYPES_BASE_INT)],
[
IfStatement([(
AndThen(
Call(
"Invalid",
[
Indexed(Variable("Ctx.Cursors"),
Variable("Fld"))
],
),
Call("Valid_Predecessor",
[Variable("Ctx"),
Variable("Fld")]),
Call("Path_Condition",
[Variable("Ctx"),
Variable("Fld")]),
),
[
IfStatement(
[(
Call(
"Sufficient_Buffer_Length",
[Variable("Ctx"),
Variable("Fld")],
),
[
Assignment(
"Value",
If(
[(
Call(
"Composite_Field",
[
Variable(
"Fld"),
],
),
Number(0),
)],
Call(
"Get",
[
Variable("Ctx"),
Variable("Fld"),
],
),
) if scalar_fields
and composite_fields else Call(
"Get",
[
Variable("Ctx"),
Variable("Fld"),
],
) if scalar_fields else
Number(0),
),
IfStatement(
[(
valid_field_condition,
set_cursors_statements,
)],
[
Assignment(
Indexed(
Variable(
"Ctx.Cursors"),
Variable("Fld"),
),
NamedAggregate(
(
"State",
Variable(
"S_Invalid"
),
),
(
"Predecessor",
Variable(
FINAL.
affixed_name,
),
),
),
)
],
),
],
)],
[
Assignment(
Indexed(Variable("Ctx.Cursors"),
Variable("Fld")),
NamedAggregate(
("State",
Variable("S_Incomplete")),
(
"Predecessor",
Variable(
FINAL.affixed_name),
),
),
)
],
)
],
)], )
],
)
],
)
