Commit Graph

43 Commits

Author SHA1 Message Date
Marijn Haverbeke
61fc12d0d0 Partial implementation of resources
Non-copyability is not enforced yet, and something is still flaky with
dropping of the internal value, so don't actually use them yet. I'm
merging this in so that I don't have to keep merging against new
patches.
2011-06-25 21:15:11 +02:00
Tim Chevalier
582e1f13f0 Invalidate constraints correctly after an assignment expression
Modified typestate to throw away any constraints mentioning a
variable on the LHS of an assignment, recv, assign_op, or on
either side of a swap.

Some code cleanup as well.
2011-06-24 22:36:53 -07:00
Michael Sullivan
f3717da1b1 Modify the fn vistors in walk so that they can handle functions without names. Update the typestate code to understand this. 2011-06-24 15:46:20 -07:00
Marijn Haverbeke
9643aedb04 Remove uses of variable name 'res' from rustc
This in preparation of making 'res' a keyword for defining resources.
Please don't introduce too many new ones in the meantime...
2011-06-24 21:22:23 +02:00
Brian Anderson
05c0216654 rustc: Add ternary operator. Closes #565
The implementation is so simple it might be considered cheating: at almost
every step the expr_ternary is just converted to expr_if.
2011-06-23 22:16:11 -07:00
Tim Chevalier
9a48bd2f21 Compute typestate properly for move
typestate now drops constraints correctly in the post-state of
a move expression or a declaration whose op is a move. It doesn't
yet drop constraints mentioning variables that get updated.

To do this, I had to change typestate to use trit-vectors instead
of bit-vectors, because for every constraint, there are three
possible values: known-to-be-false (e.g. after x <- y, init(y) is
known-to-be-false), known-to-be-true, and unknown. Before, we
conflated known-to-be-false with unknown. But move requires them
to be treated differently. Consider:

(program a)
(a1) x = 1;
(a2) y <- x;
(a3) log x;

(program b)
(b1) x = 1;
(b2) y <- z;
(b3) log x;

With only two values, the postcondition of statement a2 for
constraint init(x) is the same as that of b2: 0. But in (a2)'s
postcondition, init(x) *must* be false, but in (b2)'s condition,
it's just whatever it was in the postcondition of the preceding statement.
2011-06-22 22:13:42 -07:00
Marijn Haverbeke
c34e9b33d9 Move expr ids into the expr record type
This simplifies the tag variants a bit and makes expr_node_id
obsolete.
2011-06-21 22:25:32 +02:00
Marijn Haverbeke
75681f9ad7 Get rid of def_ids and anns in AST nodes, use single node_id
This reduces some redundancy in the AST data structures and cruft in
the code that works with them. To get a def_id from a node_id, apply
ast::local_def, which adds the local crate_num to the given node_id.
Most code only deals with crate-local node_ids, and won't have to
create def_ids at all.
2011-06-20 23:53:28 +02:00
Brian Anderson
514813148b rustc: Store the lhs and rhs of receive exprs in left to right order
With the changing of receive semantics the parser has been putting the rhs
expression in the first argument of expr_recv and the lhs in the second, and
all subsequent passes have been referring to them backwords (but still doing
the right thing because they were assuming that lhs was the port and rhs was
the receiver).

This makes all code agree on what lhs and rhs mean for receive expressions.
2011-06-18 20:23:05 -07:00
Tim Chevalier
7fc89f573d Restructure the "checking" pass in typestate
I noticed that typestate was being lazier than it should be,
because it was only checking typestate for statements and
top-level expression (that is, the expression in a stmt_expr, but
not any subexpressions). So I rewrote the checks in tstate/ck.rs
to use walk, which exposed a few bugs in typestate that I fixed.

Also added some more test cases for if-check.
2011-06-17 19:09:18 -07:00
Paul Stansifer
391348ec86 Consistify ast::local. 2011-06-16 17:56:24 -07:00
Graydon Hoare
b84fffaa4e Reformat a bunch of recent churn. 2011-06-16 16:55:46 -07:00
Tim Chevalier
219924e669 Bring back if-check
Add "if check" (expr_if_check), a variation on check that executes
an "else" clause rather than failing if the check doesn't hold.
2011-06-16 12:13:20 -07:00
Michael Sullivan
cfd1f74ebb Bring swap through typechecking and typestate. 2011-06-16 11:47:54 -07:00
Marijn Haverbeke
15f71b3600 Refactor ast::item representation
Most of the fields in an AST item were present in all variants. Things
could be simplified considerably by putting them in the rec rather
than in the variant tags.
2011-06-16 13:32:35 +02:00
Tim Chevalier
a5bca7df88 Refactor data structures representing constraints (again...)
I added a "resolved" version of the ast::constr type -- ty::constr_def
-- that has a def_id field instead of an ann_field. This is more
consistent with other types and eliminates some checking.

Incidentally, I removed the def_map argument to the top-level function
in middle::alias, since the ty::ctxt already has a def_map field.
2011-06-15 15:38:12 -07:00
Graydon Hoare
ce72993488 Reformat source tree (minus a couple tests that are still grumpy). 2011-06-15 11:19:50 -07:00
Brian Anderson
1c9277e0d3 rustc: Make room in remaining AST item nodes for attributes
Issue #487
2011-06-15 09:48:55 -07:00
Brian Anderson
31116dcdd5 rustc: Make room in item_mod for metadata
Issue #487
2011-06-15 09:46:37 -07:00
Marijn Haverbeke
471436a299 Implement function expressions/anonymous functions
Looks like 'fn(..arg..) -> ret {body;}. They don't support type
parameters or upvars yet.
2011-06-14 18:22:46 +02:00
Tim Chevalier
a1bb4a4ded Refactor some typestate-related data structures 2011-06-13 18:21:22 -07:00
Tim Chevalier
d65ad8c31c Change decl to local in expr_for and expr_for_each
Since the decl in a for or for-each loop must always be a local
decl, I changed the AST to express this. Fewer potential match
failures and "the impossible happened" error messages = yay!
2011-06-13 17:33:04 -07:00
Tim Chevalier
698c6406ba Reject programs with unsatisfied predicate constraints
Generate appropriate constraints for calls to functions with
preconditions, and reject calls where those constraints don't
hold true in the prestate.

...by which I mean that it works for one test case :-)
2011-06-10 19:17:15 -07:00
Patrick Walton
5318248f24 rustc: Annotate vector and string literals in the AST with their uniqueness or lack thereof 2011-06-09 17:11:21 -07:00
Tim Chevalier
b34a97de39 Start to check expr_check and expr_call constraints in typestate
Start writing the cases for expr_check and expr_call to take
predicates into account, but this isn't working yet.
2011-06-09 11:37:52 -07:00
Josh Matthews
2235fb73ef Add optional message to fail. 2011-06-08 04:02:55 -04:00
Tim Chevalier
1402cd101b Redo typestate-related data structures to support predicate constraints. No actual support yet, just infrastructure. 2011-06-01 18:14:48 -07:00
Paul Stansifer
9f5dddf08c Now imports are not re-exported unless 'export' is explicitly used. 2011-05-31 18:43:26 -07:00
Michael Sullivan
5e7bba3d23 Insert plumbing for move that behaves just like assign. 2011-05-31 17:39:14 -07:00
Brian Anderson
9daa00bf83 rustc: Teach rustc to use block results as fn return values. Closes #372 2011-05-31 19:18:55 -04:00
Brian Anderson
81fc2d8728 rustc: Remove unneeded type params from alt patterns 2011-05-31 01:23:53 -04:00
Tim Chevalier
18883fea3a In pre/postcondition computation, failing calls should set the postcondition
A non-returning call should have a postcondition in which all predicates
are true -- not just a poststate. Otherwise, alt expressions where
one or more branches terminate in a non-returning call and others
initialize a variable get rejected.

Includes a test case.
2011-05-27 20:43:51 -07:00
Tim Chevalier
4f792f2dbb Track spans for each local variable in typestate
This lets us print better messages in situations with name
shadowing.
2011-05-26 18:14:32 -07:00
Lindsey Kuper
c3410bf927 More work on anonymous objects. 2011-05-20 17:59:56 -07:00
Tim Chevalier
7e82f23bc0 rm unused import 2011-05-20 16:57:37 -07:00
Tim Chevalier
e1844d2719 Add ann as an argument to visit_fn 2011-05-19 11:40:16 -07:00
Tim Chevalier
c0f728712b Rewrite pre_postconditions to use walk instead of fold 2011-05-19 11:40:16 -07:00
Tim Chevalier
e16b097599 Rewrite tstate.annotate to use walk instead of fold
and various other tidying in typestate
2011-05-19 11:40:16 -07:00
Marijn Haverbeke
28c4a5586e Start checking name collisions in modules
(And remove a boatload of duplicate imports from the typestate files.)

Name collision checking in local scopes will follow soon.
2011-05-18 22:24:20 +02:00
Patrick Walton
5047ab0b0c rustc: Flatten annotations 2011-05-17 13:55:32 -07:00
Marijn Haverbeke
09d8ef8d51 Finally rename std::_xxx to std::xxx
Except for _task, which is still a keyword.
2011-05-17 20:41:41 +02:00
Graydon Hoare
a2e2e78103 Merge remote branch 'origin/master' into HEAD
Conflicts:
	src/comp/middle/trans.rs
2011-05-16 19:04:45 -07:00
Tim Chevalier
971b5d5151 Started adding support for return checking and non-returning function annotations
* Reorganized typestate into several modules.

* Made typestate check that any function with a non-nil return type
  returns a value. For now, the check is a warning and not an error
  (see next item).

* Added a "bot" type (prettyprinted as _|_), for constructs like be, ret, break, cont, and
  fail that don't locally return a value that can be inspected. "bot"
  is distinct from "nil". There is no concrete syntax for _|_, while
  the concrete syntax for the nil type is ().

* Added support to the parser for a ! annotation on functions whose
  result type is _|_. Such a function is required to have either a
  fail or a call to another ! function that is reached in all control
  flow paths. The point of this annotation is to mark functions like
  unimpl() and span_err(), so that an alt with a call to err() in one
  case isn't a false positive for the return-value checker. I haven't
  actually annotated anything with it yet.

* Random bugfixes:

* * Fixed bug in trans::trans_binary that was throwing away the
    cleanups for nested subexpressions of an and or or
    (tests: box-inside-if and box-inside-if2).

** In typeck, unify the expected type arguments of a tag with the
   actual specified arguments.
2011-05-16 16:59:25 -07:00