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 valid_path_to_next_field_condition(
message: model.Message, field: model.Field, prefix: str
) -> Sequence[Expr]:
return [
If(
[
(
l.condition.substituted(substitution(message, public=True, prefix=prefix))
.simplified()
.ada_expr(),
And(
Equal(
Call(
"Predecessor",
[Variable("Ctx"), Variable(l.target.affixed_name)],
),
Variable(field.affixed_name),
),
Call(
"Valid_Next",
[Variable("Ctx"), Variable(l.target.affixed_name)],
)
if l.target != model.FINAL
else TRUE,
),
)
]
)
for l in message.outgoing(field)
if l.target != model.FINAL
]
def public_context_predicate() -> Expr:
return And(
GreaterEqual(Call(const.TYPES_TO_INDEX, [Variable("First")]), Variable("Buffer_First")),
LessEqual(Call(const.TYPES_TO_INDEX, [Variable("Last")]), Variable("Buffer_Last")),
Less(Variable("Buffer_Last"), Last(const.TYPES_INDEX)),
LessEqual(Variable("First"), Add(Variable("Last"), Number(1))),
Less(Variable("Last"), Last(const.TYPES_BIT_INDEX)),
Equal(Rem(Variable("First"), Size(const.TYPES_BYTE)), Number(1)),
Equal(Rem(Variable("Last"), Size(const.TYPES_BYTE)), Number(0)),
)
def create_valid_function() -> UnitPart:
specification = FunctionSpecification(
"Valid", "Boolean",
[Parameter(["Ctx"], "Context"),
Parameter(["Fld"], "Field")])
return UnitPart(
[
SubprogramDeclaration(
specification,
[
Postcondition(
If([(
Result("Valid"),
And(
Call(
"Structural_Valid",
[Variable("Ctx"),
Variable("Fld")],
),
Call("Present",
[Variable("Ctx"),
Variable("Fld")]),
),
)])),
],
)
],
private=[
ExpressionFunctionDeclaration(
specification,
AndThen(
Equal(
Selected(
Indexed(Variable("Ctx.Cursors"),
Variable("Fld")), "State"),
Variable("S_Valid"),
),
Less(
Selected(
Indexed(Variable("Ctx.Cursors"),
Variable("Fld")), "First"),
Add(
Selected(
Indexed(Variable("Ctx.Cursors"),
Variable("Fld")), "Last"),
Number(1),
),
),
),
)
],
)
def _create_init_pred(self, slots: Sequence[NumberedSlotInfo]) -> UnitPart:
return UnitPart([
ExpressionFunctionDeclaration(
FunctionSpecification("Initialized", "Boolean",
[Parameter(["S"], "Slots")]),
And(*[
NotEqual(
Variable("S" * self._slot_name(slot.slot_id)),
Variable("null"),
) for slot in slots
]),
)
])
def cursors_invariant() -> Expr:
return ForAllIn(
"F",
Variable("Field"),
If(
[
(
Call(
"Structural_Valid",
[Indexed(Variable("Cursors"), Variable("F"))],
),
And(
GreaterEqual(
Selected(Indexed(Variable("Cursors"), Variable("F")), "First"),
Variable("First"),
),
LessEqual(
Selected(Indexed(Variable("Cursors"), Variable("F")), "Last"),
Variable("Verified_Last"),
),
LessEqual(
Selected(Indexed(Variable("Cursors"), Variable("F")), "First"),
Add(
Selected(
Indexed(Variable("Cursors"), Variable("F")),
"Last",
),
Number(1),
),
),
Call(
"Valid_Value",
[
Variable("F"),
Selected(
Indexed(Variable("Cursors"), Variable("F")),
"Value",
),
],
),
),
)
]
),
)
def _create_global_allocated_pred(
self, slots: Sequence[NumberedSlotInfo]) -> UnitPart:
return UnitPart([
ExpressionFunctionDeclaration(
FunctionSpecification("Global_Allocated", "Boolean",
[Parameter(["S"], "Slots")]),
And(
*[
Equal(
Variable("S" * self._slot_name(slot.slot_id)),
Variable("null"),
) for slot in slots if slot.global_
],
*[
NotEqual(
Variable("S" * self._slot_name(slot.slot_id)),
Variable("null"),
) for slot in slots if not slot.global_
],
),
)
])
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),
),
),
)
],
)
],
)], )
],
)
],
)
def create_generic_opaque_getter_procedures(
self, message: Message,
opaque_fields: Sequence[Field]) -> UnitPart:
def specification(field: Field) -> ProcedureSpecification:
return ProcedureSpecification(f"Generic_Get_{field.name}",
[Parameter(["Ctx"], "Context")])
return UnitPart(
[
SubprogramDeclaration(
specification(f),
[
Precondition(
And(
Call(
self.prefix * message.identifier *
"Has_Buffer",
[Variable("Ctx")],
),
Call(
self.prefix * message.identifier *
"Present",
[
Variable("Ctx"),
Variable(
self.prefix * message.identifier *
f.affixed_name),
],
),
))
],
[
FormalSubprogramDeclaration(
ProcedureSpecification(
f"Process_{f.name}",
[Parameter([f.name], const.TYPES_BYTES)]))
],
) for f in opaque_fields
],
[
SubprogramBody(
specification(f),
[
ObjectDeclaration(
["First"],
const.TYPES_INDEX,
Call(
const.TYPES_TO_INDEX,
[
Selected(
Indexed(
Variable("Ctx.Cursors"),
Variable(f.affixed_name),
),
"First",
)
],
),
constant=True,
),
ObjectDeclaration(
["Last"],
const.TYPES_INDEX,
Call(
const.TYPES_TO_INDEX,
[
Selected(
Indexed(
Variable("Ctx.Cursors"),
Variable(f.affixed_name),
),
"Last",
)
],
),
constant=True,
),
],
[
CallStatement(
f"Process_{f.name}",
[
Slice(Variable("Ctx.Buffer.all"),
Variable("First"), Variable("Last"))
],
)
],
) for f in opaque_fields
],
)
def context_predicate(
message: model.Message, composite_fields: Sequence[model.Field], prefix: str
) -> Expr:
def cursors_invariant() -> Expr:
return ForAllIn(
"F",
Variable("Field"),
If(
[
(
Call(
"Structural_Valid",
[Indexed(Variable("Cursors"), Variable("F"))],
),
And(
GreaterEqual(
Selected(Indexed(Variable("Cursors"), Variable("F")), "First"),
Variable("First"),
),
LessEqual(
Selected(Indexed(Variable("Cursors"), Variable("F")), "Last"),
Variable("Verified_Last"),
),
LessEqual(
Selected(Indexed(Variable("Cursors"), Variable("F")), "First"),
Add(
Selected(
Indexed(Variable("Cursors"), Variable("F")),
"Last",
),
Number(1),
),
),
Call(
"Valid_Value",
[
Variable("F"),
Selected(
Indexed(Variable("Cursors"), Variable("F")),
"Value",
),
],
),
),
)
]
),
)
def valid_predecessors_invariant() -> Expr:
return AndThen(
*[
If(
[
(
Call(
"Structural_Valid",
[
Indexed(
Variable("Cursors"),
Variable(f.affixed_name),
)
],
),
Or(
*[
expr.AndThen(
expr.Call(
"Structural_Valid"
if l.source in composite_fields
else "Valid",
[
expr.Indexed(
expr.Variable("Cursors"),
expr.Variable(l.source.affixed_name),
)
],
),
expr.Equal(
expr.Selected(
expr.Indexed(
expr.Variable("Cursors"),
expr.Variable(f.affixed_name),
),
"Predecessor",
),
expr.Variable(l.source.affixed_name),
),
l.condition.substituted(
substitution(message, embedded=True, prefix=prefix)
),
)
.simplified()
.ada_expr()
for l in message.incoming(f)
]
),
)
]
)
for f in message.fields
if f not in message.direct_successors(model.INITIAL)
]
)
def invalid_successors_invariant() -> Expr:
return AndThen(
*[
If(
[
(
AndThen(
*[
Call(
"Invalid",
[
Indexed(
Variable("Cursors"),
Variable(p.affixed_name),
)
],
)
for p in message.direct_predecessors(f)
]
),
Call(
"Invalid",
[
Indexed(
Variable("Cursors"),
Variable(f.affixed_name),
)
],
),
)
]
)
for f in message.fields
if f not in message.direct_successors(model.INITIAL)
]
)
return AndThen(
If(
[
(
NotEqual(Variable("Buffer"), Variable("null")),
And(
Equal(First("Buffer"), Variable("Buffer_First")),
Equal(Last("Buffer"), Variable("Buffer_Last")),
),
)
]
),
public_context_predicate(),
LessEqual(Sub(Variable("First"), Number(1)), Variable("Verified_Last")),
LessEqual(Sub(Variable("First"), Number(1)), Variable("Written_Last")),
LessEqual(Variable("Verified_Last"), Variable("Written_Last")),
LessEqual(Variable("Written_Last"), Variable("Last")),
Equal(Rem(Variable("First"), Size(const.TYPES_BYTE)), Number(1)),
Equal(Rem(Variable("Last"), Size(const.TYPES_BYTE)), Number(0)),
Equal(Rem(Variable("Verified_Last"), Size(const.TYPES_BYTE)), Number(0)),
Equal(Rem(Variable("Written_Last"), Size(const.TYPES_BYTE)), Number(0)),
cursors_invariant(),
valid_predecessors_invariant(),
invalid_successors_invariant(),
message_structure_invariant(message, prefix, embedded=True),
)