On OS X, it seems that access() can sometimes fail with EPERM
when checking for execute permission on a file without it.
I've previously seen this result when running as the superuser,
but that's apparently not the only possibility; a long path
may also be relevant.
Re-linking in a new namespace doesn't need the namespace of
compilation.
A "namespac.rktl" test exposed this problem, where the "transfer a
definition of a macro-introduced variable" test could fail if a GC
occurred between compilation in one namespace and evaluation in
another.
When a module is currently installed as bytecode, but without
corresponding source and without a "info.rkt" specification that
bytecode should be preserved without source, then `raco pkg` should
not count that module bytecode as a conflict (since `raco setup`
will remove it).
In case a collection "a" is composed from two places, and in
case the first place has a bytecode file for "x.rkt" while
only the second place has the source of "x.rkt" (probably it
was recently moved), then `raco setup` should delete the
sourceless bytecode so that any dependency on "x.rkt" will
reference the right version.
Nested splicing forms would lead to an "ambigious binding" error
when the nested forms bind the same name, such as in
(splicing-let ([a 1])
(splicing-let ([a 2])
(define x a)))
The problem is that splicing is implemented by adding a scope to
everything in the form's body, but removing it back off the
identifiers of a definition (so the `x` above ends up with no new
scopes). Meanwhile, a splicing form expands to a set of definitions,
where the locally bound identifier keeps the extra scope (unlike
definitions from the body). A local identifier for a nested splicing
form would then keep the inner scope but lose the outer scope, while
a local identifier from the outer splicing form would keep the outer
scope but no have the inner one --- leading to ambiguity.
The solution in this commit is to annotate a local identifier for a
splicing form with a property that says "intended to be local", so the
nested definition will keep the scope for the outer splicing form as
well as the inner one. It's not clear that this is the right approach,
but it's the best idea I have for now.
Although `eval-syntax` is not supposed to add the current namespace's
"outer edge" scope, it must add the "inner edge" scope to be consistent
with adding the inner edge to every intermediate expansion (as in
other definition contexts).
In addition, `eval`, `eval-syntax`, `expand`, and `expand-syntax`
did not cooperate properly with `local-expand` on the inner edge.
Some failure paths were missing an update before calling failure
code, and the new failure paths need to unconditionally update the
runstack pointer (because the common stub doesn't know whether the
calling context needs an update).
Genereating a use-site scope, instead of a macro-introduction scope,
prevents the scope's presense from triggering a #f result from
`syntax-original?`.
This change mostly reverts 1465ff25fc, which turned out to be a hassle
because it created more cyclic structure.
A simpler strategy is to allow a phase-specific scope to be detached
(perhaps temporarily, due to on-demand loading of bytecode) from its
group; when that's possible, the scope is not reachable from a place
where it can be moved to other syntax objects, so it's ok to be
detached. Debugging output needs to handle that gracefully, though.
Also, in case of broken bytecode, fix up a detached scope if it
does end up in an unexpected place.
Formerly, compiling a definition in one namespace and evaluating it in
another would cause the definition to take place in the original
namespace --- unless the compiled code is marshaled to a byte string
and back. Adjust the "linking" process to redirect the variable
definition and any references to the new namespace. (This is a change
relative to the compiler with the old macro expander.)
Also, repair a compiled `require` form along similar lines. (This is
*not* a change relative to the compiler with the old macro expander;
the mismatch is part of the motivation for changing `define`
handling.)
Part of the expansion to handle contracts confused internal and
external names of signature elements. The new macro expander is less
tolerant of the mistake.
Add the current definition context's scope to any expression that is
produced by macro expansion before trying to expand again, in case the
expansion needs to refer to a definition introduced by a previous
expansion.
Previously, the scope was added before any expansion and after any
expansion, but that misses intermediate points.
The old expander had this bug, too (some of the new tests fail there),
but it showed up less often and was sometimes considered correct, for
various reasons.
The revised implementation of `define-generics` for the new macro
expander wasn't right, because the macro attached to `<gen>/c` for a
given `<gen>` used a macro-introduced reference to the generic to
match up method names with the generic's methods.
I had tried to simplify the "generation 0" allocation function to
always use `GEN0_PAGE_SIZE`, but "generation 0" is also used for place
messages, in which case a much smaller size should be used.
The "place-in-channel-fnl.rkt" test exposed this problem.
A recent GC change (included with the set-of-scopes expander)
allows the GCs marking procedure to recur directly to a limited
depth, instead of always pushing pointers onto a stack. Direct
recursion is not cmopatible with ephemeron-resolution process,
so switch to no-recur mode.
This problem was uncovered by an existing test.
The combination of splitting a `letrec` and optimizing
the resulting `(let ([x <proc>]) x)` to just `<proc>`
used a bad coordinate shift, which made property testing
incorrect, etc.
For reasons that are not clear, the new expander triggered
the problem through an existing test.
The `eval-syntax` function (which is used by other functions, such as
loading a module) should not install fallback-binding scopes from
the current namespace.
When `(let ([x ...]) (let ([y x]) ... y ... y ...))` turns into
`(let ([x ...]) ... x ... x ...)`, make sure that `x` is not
still marked as single-use. Incorrect marking as single-use could
cause the optimizer to inline too much, for example.
Thanks to Gustavo for tracking down the problem.
Previously all the predicates recognized only non-#f things, so ´not´ can be
added to the list of disjoint predicates. But many of the parts of the code
relied on the non-#f property and had to be modified.
In (if (eq? x <pred?-expr>) <tbranch> <fbranch>) infer that the type of
x is pred? in the tbranch.
Also, reduce (eq? x y) => #f when the types are different.
The optimizer reduces the variables with a known type to #t in a Boolean context.
But some predicates imply that the variable has a definite values, so they can be
reduced in a non-Boolean context too.
For example, in (lambda (x) (if (null? x) x 0))) reduce the last x ==> null.
This fixes the bug twice:
* Don't reduce mutable variables with a type to #t in a Boolean context.
* Don't record the type of mutable variables when a predicate is
checked in a test condition.
While reducing some ignored constructors, the optimizer may wrap the arguments
<expr> in (values <expr>) to ensure that it's a single value non-cm expression.
This avoids the unnecessary nesting of (values (values <expr>)).
Similarly, add the cases for begin and begin0 to single_valued_noncm_expression
When a package "p" is clone-linked and the repo for "p" changes to be
a multi-package repository (e.g., with "p-lib", "p-doc", and "p"), a
`raco update` would get confused. Unofrtunately, a plain `raco pkg
update p` can't work in that case, because the clone link would still
be a pathless repo URL; the repairs make `raco pkg update --lookup
--clone ..../p` work as is should.
Related: fix inference of package names in the early check for whether
a package is installed.
While `#:in-original-place? #t` provides one way to serialize
foreign calls, it acts as a single lock and requires expensive
context switches. Using an explicit lock can be more efficient
for serializing calls across different places.
For example, running "plot.scrbl" takes 70 seconds on my machine
in the original place and using `#:lock-name` in any place,
while it took 162 seconds in a non-main place with Cairo+Pango
serialization via `#:in-original-place? #t`.
Internally, the named lock combines compare-and-swap with a
place channel. That strategy gives good performance in the case
of no contention, and it cooperates properly with the Racket
scheduler where there is contention.
The optimizer was able to use the type information gained outside
the let's to reduce expressions inside the lets. For example, in
(lambda (z) (car z) (let ([o (random)]) (pair? z)))
it reduces (pair? z) ==> #t.
This enable the propagation in the other direction so in
(lambda (z) (let ([o (random)]) (car z)) (pair? z))
it reduces (pair? z) ==> #t too.
Using `(thread-resume t1 t2)` would not prevent a GC of t1, but it
would create an intermediate record to make the link from t1 to t2,
and that intermediate record would leak due to a missing level of
indirection in a table-cleanup traveral. The leak not only accumulated
memory, it also caused ever slower traversals of the table in an
attempt to clean up.
(Since the leak is small and the leaking object is not directly
accessible, I don't have a good idea on how to test this repair
automatically, but see the program in the PR.)
Closes PR 15099.
Modern OS configurations likely use an even larger buffer size, and
making it small can have substantial negative performance effects
(e.g., with PostgreSQL over TCP).
When AC_PROG_CC picks GCC, move its selection of CFLAGS
into CPPFLAGS, so that preprocessing will have the same
optimization and debugging flags as compilation.
Arguably, AC_PROG_CC plus AC_PROG_CPP should do that
soemhow, but it's understandable that the autoconf
implementers didn't cover the possibility of
preprocessing that changes with the optimization level.
Closes#945
- Coalesce repeated use of the same predicate.
- Fix scoring of Exact patterns, and scoring generally.
- Use `OrderedAnd` where needed.
- Guarantee that `and` patterns match in order.
- Thread bound variable information properly in GSeq compilation.
- Warn when variables are used non-linearly with `...`
(making this behave properly was not backwards compatible).
Closes#952, which now runs in <1ms and make it a test case.
Also add margin note about `?` patterns and multiple calls.
Before consulting a catalog, etc., check whether a given package name
is currently installed. The new check applies only if a scope is
specified, since scope inference implies the check already.
When `local-require` is used in a non-phase-0 position and it is
`expand`ed (as opposed to compiled directly), then the generated
`#%require` form had the wrong binding phase.
Merge to v6.2
In many use cases the length of the vector is fixed and know,
so we are sure that make-vector will not raise an error and
we can recognize these expressions as omittable and drop
them when the result is ignored.
The result of some procedures is a vector, but they are not omittable
because they may rise an error. With the recent changes of the
predicate reduction these cases are correctly handled.
Adds a sealing and unsealing function to attach (or detach)
seals onto a class via impersonator properties. Since these
properties override, they do not accumulate wrappers.
Calling seal multiple times will still accumulate multiple seal
values inside the property.
A sealed class cannot be instantiated and a subclass may not
add class members that match any of the sealed names in its
sealed parent.
These functions are intended for use by TR's `sealing->/c`
contract, but are parameterized over checking functions and
could be used for other purposes.
An empty string provided to `raco pkg config --set catalogs` would
trigger an error previously. Instead, turn it into a `#f` in the
configuration file, which is replaced by the default search sequence.
The optimizer checks the type of the argument of some unary procedures and
uses the gathered information to replace them by the unsafe version, reduce
predicates and detect type errors. This extends the checks to more procedures
that have no unsafe version and procedures that have more than one argument.
