Summary:
The computation of provable reachability through the heap currently
uses a set of variables whose values are either determined by the
desired roots or by the heap constraints. This requires globals to be
treated as variables. In preparation for distinguishing globals from
variables, this diff changes the reachability computation to use a set
of atomic terms instead of variables.
Reviewed By: jvillard
Differential Revision: D24886573
fbshipit-source-id: c0e6763b6
Summary:
Distinguish expressions that name globals from registers. This leads
to clearer code, and globals are semantically distinct from general
registers. In particular, they are constant, so any machinery for
handling assignment does not need to consider them. This diff only
adds the distinction to LLAIR, it is not pushed through to FOL, which
will come later.
Reviewed By: jvillard
Differential Revision: D24846676
fbshipit-source-id: 3aca025bf
Summary:
This module represents the definition of a global constant, rather
than the global itself.
Reviewed By: jvillard
Differential Revision: D24846673
fbshipit-source-id: d47e67984
Summary:
Distinguish expressions that name functions from registers. This leads
to clearer code, and function names are semantically distinct from
general registers. In particular, they are constant, so any machinery
for handling assignment does not need to consider them. Unlike general
globals, they never have initializer expressions, and in particular
not recursive initializers. This diff only adds the distinction to
LLAIR, it is not pushed through to FOL, which will come later.
Reviewed By: jvillard
Differential Revision: D24846672
fbshipit-source-id: 2101f353f
Summary:
The implementation in Context, in terms of Fol.Term and Fol.Formula,
can now be used instead of Ses.Equality, implemented using
Ses.Term. The Ses modules can now be removed.
Reviewed By: jvillard
Differential Revision: D24532362
fbshipit-source-id: cee9791b7
Summary:
Change the type of `fold` functions to enable them to compose
better. The guiding reasoning behind using types such as:
```
val fold : 'a t -> 's -> f:('a -> 's -> 's) -> 's
```
is:
1. The function argument should be labeled. This is so that it can be
reordered relative to the others, since it is often a multi-line
`fun` expression.
2. The function argument should come last. This enables its
arguments (which are often polymorphic) to benefit from type-based
disambiguation information determined by the types of the other
arguments at the call sites.
3. The function argument's type should produce an
accumulator-transformer when partially-applied. That is,
`f x : 's -> 's`. This composes well with other functions designed
to produce transformers/endofunctions when partially applied, and
in particular improves the common case of composing folds into
"state-passing style" code.
4. The fold function itself should produce an accumulator-transformer
when partially applied. So `'a t -> 's -> f:_ -> 's` rather than
`'s -> 'a t -> f:_ -> 's` or `'a t -> init:'s -> f:_ -> 's` etc.
Reviewed By: jvillard
Differential Revision: D24306063
fbshipit-source-id: 13bd8bbee
Summary:
The changes in set_intf.ml dictate the rest. The previous API
minimized changes when changing the backing implementation. But that
API is hostile toward composition, partial application, and
state-passing style code.
Reviewed By: jvillard
Differential Revision: D24306089
fbshipit-source-id: 00a09f486
Summary:
The treatment of comparison and exceptions in Core/Core_kernel/Base
makes them questionable as the default. This diff changes nonstdlib so
that Core is no longer opened in the global namespace, and makes a few
changes to handle the resulting minor API changes. This leads to a
lighter-touch nonstdlib, which makes a few definitions of its own, and
selects and extends modules from several libraries, including base,
core_kernel, containers, iter.
Reviewed By: jvillard
Differential Revision: D24306090
fbshipit-source-id: 42c91bd1b
Summary:
The translation from Llair to Fol can now be implemented using only
the external interface of Fol, so move it to a separate module. This
makes Fol not depend on Llair and vice versa, as appropriate.
Reviewed By: jvillard
Differential Revision: D24306087
fbshipit-source-id: fc68a588b
Summary:
The eventual aim is for the conversion of Llair to Fol to be external
to Fol. Fol should not need to depend on Llair, nor vice versa. This
is not yet possible, but a step forward is to move the conversion
functions into separate modules outside the core Fol modules.
Reviewed By: ngorogiannis
Differential Revision: D22170522
fbshipit-source-id: 4860b4c07
Summary:
`Domain_sh.from_call.subst` is a substitution that replaces shadowed
variables with fresh ones, which is constructed by `Domain_sh.call`
and used by `Domain_sh.retn`, after inverting it. This patch changes
the stored substitution to the inverted one, and renames it to
`unshadow` for clarity.
After this change, the stored substitutions have the property that
they map variables to program variables. This is desirable since it
avoids the question about the uninverted substitution of whether the
variables in the range of the uninverted substitution are "fresh".
Reviewed By: jvillard
Differential Revision: D21974020
fbshipit-source-id: d469c89f9
Summary:
Logically there is nothing specific to memory contents (as
byte-arrays) or aggregate (struct/array) values, the theory is for
sequences of non-fixed sized elements.
Reviewed By: jvillard
Differential Revision: D21721019
fbshipit-source-id: b2b730a50
Summary:
Multiplication by a constant is primitive in the linear arithmetic
solver, while general multiplication is not, so for clarity and
predictability, use constants where possible.
Reviewed By: jvillard
Differential Revision: D21721020
fbshipit-source-id: 3497d06c9
Summary:
Refer to Llair modules using `Llair.` qualifier, except for in
`Frontend`, which makes so much use of `Llair` that it is now opened
(`Llair` only contains types and modules, so `open` is safe).
Reviewed By: jvillard
Differential Revision: D21720979
fbshipit-source-id: dd42075d9
Summary:
Rather than compute the size of the llair type of the llair
initializer expression, compute the size of the llvm initializer
directly.
Reviewed By: ngorogiannis
Differential Revision: D21720982
fbshipit-source-id: 4364baf38
Summary:
Having `val size_of : Typ.t -> t` in the signature of `Term` and `val
size_of : t -> t` in the signature of `Exp` gives the impression that
`Term` and `Exp` know something about `Typ`. But they don't, those
functions are only trivial convenience wrappers, and only have a few
uses, so just inline them to clarify that it is `Typ` that knows about
the sizes of types.
Reviewed By: jvillard
Differential Revision: D21441535
fbshipit-source-id: 09b135a8c
Josh Berdine