This is a partial solution to the ~and problem, only for side clauses.
In (~and p1 p2 p3), one often wants errors in p2 to take precedence over
errors in p1, and likewise for p3 over p2. One solution is ~commit, but
that prevents backtracking. Another is ~post, but then two ~post wrappers
are needed around p3. Also, it doesn't make sense to compare progress of
the third #:with clause from stxclass A to the second #:with clause of
stxclass B and say third beats second.
So, generalize 'post to (post group index); post frames are comparable to
each other only if group is the same, then compared by index. (Post still
beats CAR and CDR.) Each set of side clauses shares a group.
For simplicity of code generation for now, use gensyms to identify groups.
A `#:name` identifier picks the name that is bound to static
information about a structure type. An `#:extra-name` identifier
specifies an additional name to be bound to the information.
This pair of options is analogous to `#:constructor-name`
and `#:extra-constructor-name`.
Based on Jen Axel's suggestion and implementation.
Closes#1309
Provide a cleaned-up set up path-extension functions. In contrast
to `path-{add,replace}-suffix` and `filename-extension`, a dot
at the beginning of a path element is not treated as an extension
separator. Also, `path-extension` returns an extension including
its separator, which is more consistent with other extension
functions.
The new `path-has-extension?` function replaces many uses of
regexp matching in the base collections.
Closes#1307
Adjusts the docs, but a future replacement (possibly with a new name
to avoid compatibility issues) should behave like the old docs,
instead.
Closes#1292
restricted through `get-info`, which prunes the environment
variable set before it loads the "info.rkt" file. All
environment variables are pruned except those listed in
`PLT_INFO_ALLOW_VARS` (separated by semicolons).
Related to emina/rosette#17.
Add a hook to `raco setup` to make copies of installed executables,
where the copies start with the configuration or addon directory
of creation time, instead of the default installation or user-specific
path.
Although the same effect can be achived by setting environment
variables such as PLTADDONDIR, tethered executables can be easier
to work with and compose better with other programs.
See also #1206 for some discussion, although this change does
not exactly address the original idea there.
Reduce (unbox (box x)) => x
Extend the reductions for cXr to the unsafe versions, for
example reduce (unsafe-car (cons x y)) => x
Check and save types in unsafe operations
Pass a string to the handler to describe the problem.
Also, fix minor issues (GC registration, contracts and `history`
in docs) and make `pregexp`, etc., report compilation errors as
`pregexp`, etc.
Allow `system-type` on non-Windows platforms to run `uname` to get
machine information, even in a sandbox or other contexts with a
limiting secutiry guard.
Check that it works to apply a continuation that shares with
an enclosing continuation, where a runstack overflow happens
between the continuations.
Closes PR 15281
While expanding a module, the root of module-relative references is a
fresh notion of "this module".
After expansion, "this module" is shifted to "an expanded module",
which is a global constant (for top-level modules). When an expanded
module is re-expanded, "an expanded module" is shifted to a fresh
"this module" during re-expansion, and so on.
One problem with this approach is that the shift from "this module" to
"an expanded module" isn't applied to syntax properties --- but
there's some extra trickery to make it work out by mutating "this
module" to make it look like "an expanded module".
Submodule expansion introduces an intermediate "parent of this module"
that wasn't currently covered by the extra trickery, so fix that.
`->i` already supports method contracts (for use wihin `object-contract`,
whose `->i` support is tested, but undocumented), which would make `->im`
possible.
Unfortunately, that support is very incomplete, missing support for using
`this` in contracts, making this `->im` (or the undocumented `->i` +
`object-contract` combo) basically useless.
Once/if that is added, then this commit would enable `->im`. Until then,
it's mostly useful for future reference (hence will be reverted).
In the meantime, it's possible to use `->i` within class/object contracts
with an explicit `this` argument, so nothing critical is lost, just a tiny
shortcut.
Previously, on the example, the function was not anonymous, so no
`tempN' would appear on the error message.
The fixed example makes use of `flat-named-contract' on an anonymous
function, which resembles the snippet above it and demonstrates the
purpose of `flat-named-contract' better.
Repair a mismatch between `syntax-local-lift-expression` and the
way that `compile` tries to avoid creating bindings while
compiling a top-level `define` form.
Closes#1284 and #1282
Some functions were passing when they shouldn't have, only to fail when
the function is called.
Technically not backwards compatible, but should only affect functions
that were never called.
A syntax property is added as preserved or not. For backward
compatibility, the default for a 'paren-shape key is preserved, and
any other key's default is non-preserved.
Cross-module inlining that pulls a variable reference across a
module boundary imposes a more struct requirement that run-time
"constant" detection is consistent with the optimizer's view of
"constant" within a module. So, make sure they're the same.
Sometimes the optimizer removes all the references to a variable but it
doesn't detect that the variable is unused, so it keeps the definition.
Later, the sfs detects the unused variable so it marks it, but it doesn't
remove the let form.
Using `syntax` to capture local binding information in the current
phase doesn't work with the set-of-scopes expander. Although the
example could be adjust to use `(quote-syntax car #:local)`, it
seems like too much detail at that point in the explanation.
Formerly, cross-module inlining would not work for a function like
(define (f x)
(if .... .... (slow x)))
unless `slow` was also inlined into `f`. This commit changes
cross-module inlining so that it allows a call to `f` to be replaced
with an expression that references other module-level bindings (that
are not primitives), such as `slow`.
Adjusting the inlining rules can always make some program worse. In
this case, a hueristic about whether to export an optimized or
unoptimized variant of a fnuciton for inlining tends to collide with
the adjusted inlining rule, so this commit tweaks that heuristic, too.
Enable the optimizer to figure to figure out that a loop
argument is always a real number, for example, in much the
same way that it can detect fixnums and flonums for unboxing.
Unboxing information was only needed at the resolve level,
but `real?` information is useful only to the optimizer, so
the generalization enables the optimizer to reach
approximations of type information earlier (e.g., among
a subset of a function's arguments).
Simplify `(wcm <k1> <v1> (wcm <k1> <v2> <e>))` to
`(begin <v1> (wcm <k1> <v2> <e>))` for a simple enough <k1>.
A variable simple enough, so this is useful for improving
errortrace output.
Compute an `equal?` hash code for `read`able values that
is a constant, at least for a given version of Racket. Only
(interned) symbols failed to have that property before.
An `XFORM_NONGCING_NONALIASING` function doesn't trigger a GC, and
when it is given an argument that is an address of a local variable,
it fills in that address and doesn't leak it. This annotation allows
the xform transformation (to support precise GC) avoid some work for
some hash-iteration functions.
With the old representation of local variables, optimize_info_lookup
had to search the stack for the frame with the information about the
variable. This was complicated so it has many flags to be used in
different situations and extract different kind of information.
With the new representation this process is easier, so it's possible
to split the function into a few smaller functions with an easier
control flow.
In particular, this is useful to avoid marking a variable as used
inside a lambda when the reference in immediately reduced to a
constant using the type information.
The iterator saves the return points in a list. For small immutable hashes,
encode the values in the list in the bits of a fixnum to avoid allocations.
Expose tagged allocation and a function that interprets a description
of tagged shapes. As a furst cut, the description can only specify
constant offsets for pointers within the object, but future extensions
are possible.
When a chaperone-wrapped function leads to a slow-path tail
call, the continuation-mark depth can be made too deep when
resolving the slow tail call.
Closes#1265
Reduce
(eq? v v) ==> #t
(if t v v) ==> (begin t v)
(if v v #f) ==> v
when v is a local or a top level variable.
Previously, the last two reductions were used only
with local variables.
Also, move the (if x #t #f) ==> (not x) reduction
after branch optimization.
When a key is removed at a level that other only has a collision
table, the HAMT representation was not adjusted properly by
eliminating the layer. As aresult, table comparison via
`equal?` could fail. The problem could show up with hash tables
used to represent scope sets, where an internal "subset?" test
could fail and produce an incorrect binding resolution.
The transformation from
(begin (let <bindings> (begin <e1> ...)) <e2> ...)
to
(let <bindings> (begin <e1> ... <e2> ...))
makes things look simpler and might help the optimizer a little. But
it also tends to make the run-time stack deeper, and that slows some
programs a small but measurable amount.
A better solution would be to keep the transformation but add another
pass that moves expressions out of a `let`.
Since this operation only moves the code and doesn't make the final
bytecode bigger, it's not necessary to decrease the fuel and then it
is available for further inlining.
The calculation of used variables in a possibly unused function did
not work right when the function is referenced by a more deeply
nested function that itself is unused. The extra uses triggered by
more nested uses need to be registered as tentative in the more nested
frame, not in the outer frame.
Closes#1247
On Unix and OS X, the check to avoid replacing an existing
file or directory is made by Racket, rather than the OS,
so don't claim a system error if the operation fails for
that reason.
Also, update the docs to clarify that the check is not
atomic with the move.
Closes issue #1158
Correct the second-biggest design flaw in the bytecode optimizer:
instead of using a de Bruijn-like representation of variable
references in the optimizer pass, use variable objects.
This change is intended to address limitations on programs like the
one in
http://bugs.racket-lang.org/query/?cmd=view&pr=15244
where the optimizer could not perform a straightforward-seeming
transformation due to the constraints of its representation.
Besides handling the bug-report example better, there are other minor
optimization improvements as a side effect of refactoring the code. To
simplify the optimizer's implementation (e.g., eliminate code that I
didn't want to convert) and also preserve success for optimizer tests,
the optimizer ended up getting a little better at flattening and
eliminating `let` forms and `begin`--`let` combinations.
Overall, the optimizer tests in "optimize.rktl" pass, which helps
ensure that no optimizations were lost. I had to modify just a few
tests:
* The test at line 2139 didn't actually check against reordering as
intended, but was instead checking that the bug-report limitation
was intact (and now it's not).
* The tests around 3095 got extra `p` references, because the
optimizer is now able to eliminate an unused `let` around the
second case, but it still doesn't discover the unusedness of `p` in
the first case soon enough to eliminate the `let`. The extra
references prevent eliminating the `let` in both case, since that's
not the point of the tests.
Thanks to Gustavo for taking a close look at the changes.
LocalWords: pkgs rkt
Found with `-fsanitize=undefined`. The only changes that are potentially
bug repairs involve some abuses of pointers that can end up misaligned
(which is not an x86 issue, but might be on other platforms). Most of
the changes involve casting a signed integer to unsigned, which
effectively requests the usual two's complement behavior.
Some undefined behavior still present:
* floating-point operations that can divide by zero or coercions
from `double` to `float` that can fail;
* offset calculations such as `&SCHEME_CDR((Scheme_Object *)0x0)`,
which are supposed to be written with `offsetof`, but using
a NULL address composes better with macros.
* unaligned operations in the JIT for x86 (which are ok, because
they're platform-specific).
Hints for using `-fsanitize=undefined`:
* Add `-fsanitize=undefined` to both CPPFLAGS and LDFLAGS
* Add `-fno-sanitize=alignment -fno-sanitize=null` to CPPFLAGS to
disable those checks.
* Add `-DSTACK_SAFETY_MARGIN=200000` to CPPFLAGS to avoid stack
overflow due to large frames.
* Use `--enable-noopt` so that the JIT compiles.
The `alarm-evt` tests are inherently racy, since they depend on
the scheduler polling quickly enough. The old time values were
close enough that a test failure is particularly likely on
Windows, where the clock resolution is around 16ms. To reduce
failures, make the time differents much bigger.
Closes issue #1232
A reference to a local may be reduced in a branch to a constant, while it's unchanged in the
other because the optimizer has different type information for each branch. Try to use the
type information of the other branch to see if both branches are actually equivalent.
For example, (if (null? x) x x) is first reduced to (if (null? x) null x) using the type
information of the #t branch. But both branches are equivalent so they can be
reduced to (begin (null? x) x) and then to just x.
The functions expr_implies_predicate was very similar to
expr_produces_local_type, and slighty more general.
Merging them, is possible to use the type information
is expressions where the optimizer used only the
local types that were visible at the definition.
For example, this is useful in this expression to
transform bitwise-xor to it's unsafe version.
(lambda (x)
(when (fixnum? x)
(bitwise-xor x #xff)))
Skip calling the domain projection in that case and, if all of the
arguments are any/c then also skip putting the contract continuation mark
This appears to give about a 20% speed up on this program:
#lang racket/base
(require racket/contract/base)
(define f
(contract
(-> any/c integer?)
(λ (x) 1)
'pos 'neg))
(time
(for ([x (in-range 4000000)])
(f 1)))
The recently added fast path for property-only chaperones did not
propagate the original object in the case that the property-only
chaperone wraps a `chaperone-procedure*` chaprerone.
Merge to v6.4
Fix `procedure-specialize` for a procedure that refers to a
syntax-object literal. A syntax-object literal becomes part of the
procedure closure, but in a special way that nomrally allows syntax
objects to be loaded on demand. For now, specialization counts as
a demand of the syntax object.
Merge to v6.4
When a procedure created by `unsafe-{chaperone,impersonate}-procedure`
is given the wrong number of arguments, the original procedure's name
should be used in the error message.
During inlining, the type information gathered in
code that was inside the lambda is copied to the outer
context. But the coordinates of the type information
were shifted in the wrong direction, so the type was
assigned to the wrong variable.
This bug is difficult to trigger, so the test is convoluted.
Merge to v6.4
Add 'module-body-inside-context, 'module-body-outside-context, and
'module-body-context-simple? properties to the expansion of a
`module` form. These properties expose scopes that are used by
`module->namespace` and taht appear in marshaled bytecode.
The expression in a `define-runtime-path` form is used in
both a run-time context and a compile-time context. The
latter is used for `raco exe`. In a cross-build context,
you might need to load OpenSSL support for Linux (say)
at build time while generating executables that refer to
Windows (say) OpenSSL support. In that case, `#:runtime?-id`
lets you choose between `(cross-system-type)` and
`(system-type)`.
Merge to v6.4
In particular, instead of going directly back to the chaperone, handle
the case where the function doesn't accept keyword arguments with a
less expensive fallback.
The less expensive fallback uses a case-lambda wrapper (wrapped inside
a make-keyword-procedure) to close over the neg-party and avoid the
chaperone creation. With this commit, the program below gets about 3x
faster, and is only about 20% slower than the version that replaces
the "(let ([f f]) ...)" with its body
#lang racket/base
(module m racket/base
(require racket/contract/base)
(provide (contract-out [f (-> integer? integer?)]))
(define (f x) x))
(require 'm)
(collect-garbage)
(time (for ([x (in-range 5000000)]) (let ([f f]) (f 1))))
Thanks, @samth!
OS X's libssl is deprecated, and it doesn't work with SSL connections
that need SNI. We'll distribute out own libssl builds for OS X via a
package, but we need a native implementation that works well enough to
get that package.
The 'secure protocol symbol is just a shorthand for
`(ssl-secure-client-context)`, but it helps highlight
that the default 'auto isn't secure, and having a plain
symbol smooths the connection to native Win32 and OS X
implementations of SSL.
The repair involves making `raco exe` detect a sub-submodule
whose name is `declare-preserve-for-embedding` as an indication
that a submodule should be carried along with its enclosing module.
Normally, `define-runtime-module-path-index` would do that, but
the submodule for `place` is created with `syntax-local-lift-module`,
and the point of `syntax-local-lift-module` is to work in a
nested experssion context where definitions cannot be lifted
to the enclosing module.
Made the hash-set chaperones essentially forward the hash chaperone
operations, but now explain them all in terms of set-based operations
in the docs.
Also adjusted value-blame and has-blame? to support late-neg projections
The issue is what happens when the actual function has other arities.
For example, if the function were (λ (x [y 1]) y) then it is not okay
to simply check if procedure-arity-includes? of 1 is true (what the
code used to do) because then when the function is applied to 2
arguments, the call won't fail like it should. It is possible to check
and reject functions that don't have exactly the right arity, but if
the contract were (-> string? any), then the function would have been
allowed and only when the extra argument is supplied would the error
occur. So, this commit makes it so that (-> any/c any) is like
(-> string? any), but with the optimization that if the procedure
accepts only one argument, then no wrapper is created.
This is a backwards incompatible change because it used to be the
case that (flat-contract? (-> any)) returned #t and it now returns #f.
When a module defines <name-1> and doesn't export it, but when
the module imports <name-2> and re-exports that refers to another
module's definition of <name-1>, then <name-1> wasn't properly
registered as an unexported binding.
Most of the implementation change is just a clean-up of an
unnecessary traversal from before the addition of a `count`
field in each hash table.
Also, add `#:skip-filtered-directory?` to `find-files`.
Less significantly, adjust `pathlist-closure` to be consistent in the
way that it includes a separator at the end of a directory path.
Although `procedure-specialize` should be useful in places where
inlining does not apply, allowing inlining and related optimizations
through it, anyway.
- use chaperone-hash-set for set/c when the contract allows only hash-sets
- add a #:lazy flag to allow explicit choice of when to use laziness
(but have a backwards-compatible default that, roughly, eschews laziness
only when the resulting contract would be flat)
Specifically, remove reliance on procedure-closure-contents-eq? to
tell when a pending check is stronger in favor of usint
contract-stronger?
Also, tighten up the specification of contract-stronger? to require
that any contract is stronger than itself
With this commit, this program gets about 10% slower:
#lang racket/base
(require racket/contract/base)
(define f
(contract
(-> any/c integer?)
(λ (x) (if (zero? x)
0
(f (- x 1))))
'pos 'neg))
(time (f 2000000))
becuase the checking is doing work more explicitly now but because the
checking in more general, it identifies the redundant checking in this
program
#lang racket/base
(require racket/contract/base)
(define f
(contract
(-> any/c integer?)
(contract
(-> any/c integer?)
(λ (x) (if (zero? x)
0
(f (- x 1))))
'pos 'neg)
'pos 'neg))
(time (f 200000))
which makes it run about 13x faster than it did before
I'm not sure if this is a win overall, since the checking can be more
significant in the case of "near misses". For example, with this
program, where neither the new nor the old checking detects the
redundancy is about 40% slower after this commit than it was before:
#lang racket/base
(require racket/contract/base)
(define f
(contract
(-> any/c (<=/c 0))
(contract
(-> any/c (>=/c 0))
(λ (x) (if (zero? x)
0
(f (- x 1))))
'pos 'neg)
'pos 'neg))
(time (f 50000))
(The redundancy isn't detected here because the contract system only
looks at the first pending contract check.)
Overall, despite the fact that it slows down some programs and speeds
up others, my main thought is that it is worth doing because it
eliminates a (painful) reliance on procedure-closure-contents-eq? that
inhibits other approaches to optimizing these contracts we might try.
The `procedure-specialize` function is the identity function, but it
provides a hint to the JIT to compile the body of a closure
specifically for the values in the closure (as opposed to compiling
the body generically for all closure instances).
This hint is useful to the contract system, where a predicate
is coerced to a projection with
(lambda (p?)
(procedure-specialize
(lambda (v)
(if (p? v)
v
....))))
Specializing the projection to a given `p?` allows primitive
predicates to be JIT-inlined in the projection's body.
in particular, when there is a recursive contract, then we check only
some part of the first-order checks and see if that was enough to
distinguish the branches. if it was, we don't continue and otherwise we do
A value that starts "1", "y", or "Y" enabled incremental mode
permanently (any value was allowed formerly), while a value that
starts "0", "n", or "N" causes incremental-mode requests to be
ignored.
When custom categories are used in older versions, raco setup will
report a warning, but the documentation will still appear under the
Miscellaneous section. Thus, this is a backwards compatible
implementation of the idea.
Port `examples`, `interactions`, etc., to use the new `examples`
form of `scribble/examples`. The main intended effect is to ensure
that errors are produced by examples only as specifically
indicated.
- uniformly remove the extra layers of calls to unknown functions for
chapereone-of? checks that make sure that chaperone contracts are
well-behaved (put those checks only in contracts that are created
outside racket/contract)
- clean up and simplify how missing projection functions are created
(val-first vs late-neg vs the regular ones)
- add some logging to more accurately tell when late-neg projections
aren't being used
- port the contract combinator that ->m uses to use late-neg
- port the </c combinator to use late-neg
Really, just improve when majors GCs are forced to trigger
further finalizations. This improvement makes `(collect-garbage)`
followed by `(collect-garbage 'incremental)` move more
reliably into incremental mode.
Although calling `(collect-garbage 'incremental)` in a program with
a periodic task is the best way to request incremental collection, it's
handy for some experiments to have an environment variable that turns
it on permanently.
This change also makes incremental-mode minor collections log as "mIn"
instead of "min", and it changes the first field of the logged
`gc-info` structure to be a mode symbol instead of a boolean.
The bug was an induced failure in the http server, to test retry
support, triggered another run of half of the synchronization
protocol, leading to a stuck state.
The strategy of converting a bignum to a flonum by converting on word
boundaries can lose one bit of precision. (If the use of a word
boundary causes a single bit to get rounded away, but the first bit of
the next word is non-zero, then the rounding might have been down when
it should have been up.)
Avoid the problem by aligning relative to the high bit, instead.
Fix even basic readind when extflonums are not supported, but
also fix reading extflonums with large exponents (related to
the other recent changes to number parsing).
Allow a more dynamic (than `impersonator-prop:application-mark`)
determination of continuation marks and associated values to wrap the
call of an impersonated procedure.
When an internal-definition context is used with `local-expand`, the
any binding added to the context affect expansion, but the binding do
not appear in the expansion. As a result, Check Syntax was unable to
draw an arrow from the `s` use to its binding in
(class object%
(define-struct s ())
s)
The general solution is to add the internal-definition context's
bindings to the expansion as a 'disappeared-bindings property. The new
`internal-definitionc-context-track` function does that using a new
`internal-definition-context-binding-identifier` primitive.
In #956, @gus-massa warned that `syntax-local-infer-name` was changed
in a breaking way, but the implications were not clear. At a minimum,
identifiers need to be treated like symbols, so that `mzlib/contract`
name inference works right. I'm erroring more generally on the side
of keeping the old behavior for anything other than pair-based
trees.
Closes#1117.
Repairs 3eb2c20ad0, which used a scope-set comparison for
a table that maps scopes to propagation actions (add, remove,
or flip).
Closes#1113
Merge to v6.3
So now (-> any/c integer?) will avoid the chaperone wrapper when the
function is a struct predicate while simultaneously supporting the
"extra argument neg party" protocol
In `syntax-local-lift-require`, avoid scope adjustments intended
to deal with `require` forms that are compiled in one namespace
and evaluated in another.
When `or` has many subexpressions, the expansion generates a
sequence of deeply nested `let`s, where original and macro-introduced
forms are interleaved in a way that defeats a minimal
child-is-same-as-parent sharing of scope sets. Add a small
cache that's good enough to capture extra sharing and
dramatically lower memory use for an `or` that has 1000
subexpressions.
When an import is shadowed by another import or by a definition, don't
include it in the set of bindings in the resut of
`syntax-local-module-required-identifiers` or in the set that can be
exported by `all-from-out`.
Merge to v6.3
To make the API consistent for MSVC versus MinGW builds, make
a functional formerly required for embedding on 32-bit Windows
always available and required for all Windows variants.
Make the old-generation marking process incremental
on request, where `(collect-garbage 'incremental)`
makes a request.
Only the marking phase of an old-generation collection
is incremental, so far. In exchange for slower
minor collections and a larger heap, you get a major
collection pause time that is roughly halved. So, this
is a step forward, but not good enough for most purposes
that need incremental collection.
An incremental-mode request sticks until the next
major GC. The idea is that any program that could
benefit from incremental collection will have
some sort of periodic task where it can naturally
request incremental mode. (In particular, that
request belongs in the program, not in some external
flag to the runtime system.) Otherwise, the
system should revert to non-incremental mode, given
that incremental mode is slower overall and can
use much more memory --- usually within a factor of
two, but the factor can be much worse due to
fragmentation.
