Summary:
Now that array types record only static - and therefore constant -
lengths, Sil typ and exp no longer need to be mutually recursive.
This diff:
- splits the recursion in the type definitions of typ and exp,
- splits the recursion in the comparison and pretty-printing
functions,
- and then refactors typ into a separate module.
Reviewed By: cristianoc
Differential Revision: D3423575
fbshipit-source-id: 6130630
Summary:
This diff refactors Sil.Int, which represents integer literals, into a
separate module IntLit. There are no dependencies forcing Sil.Int to
be a submodule of Sil, and it is also no simpler as a submodule.
Reviewed By: cristianoc
Differential Revision: D3422910
fbshipit-source-id: 63013f2
Summary:
Array types where the length is not statically known were represented
using fresh variables. This diff:
- Makes array type length optional, reducing the amount of work needed
for renaming, substitution, and normalization.
- Revises uses of array length so that the length component of a
Tarray type represents only the statically determined constant
length of an array type, and the length component of a Sizeof
expression represents the dynamically determined length of an array
value.
- Restricts the type of static lengths from a general expression
(Sil.exp) to an integer (Sil.Int.t), enforcing that static types are
constant. This in particular ensures that types contain no
variables, and so are invariant under operations such as renaming
and substitution.
- Removes the type substitution and renaming functions typ_sub,
typ_normalize, and typ_captured_ren. Now that array type lengths
are constant integers, all of these functions are the identity.
Reviewed By: cristianoc
Differential Revision: D3387343
fbshipit-source-id: b5db768
Summary:
This diff extends Sizeof expressions with an optional expression for the
length of the final extensible array, if any. For example, sizeof a
simple array `sizeof(t[n])` is represented by (modulo subtyping info)
`Sizeof t (Some n)`, and sizeof a struct whose final member is an array
`sizeof(struct s {... t[n] f})` is represented by `Sizeof (struct s
{... t[n] f}) (Some n)`.
This is an intermediate step toward eliminating expressions from types,
the redundancy between the length in the types and in the sizeof
expressions will be eliminated later.
Reviewed By: cristianoc
Differential Revision: D3358763
fbshipit-source-id: 2239bca
Summary:
The typ_iter_types, exp_iter_types, and instr_iter_types functions of
Sil are unused.
Reviewed By: cristianoc
Differential Revision: D3332878
fbshipit-source-id: e8d8f71