In 3.0.7 (after 0cc7991855 "Ensure
that (syntax ()) results in ("), the use of #nil in syntax-rules
expansions like this:
(define-syntax foo
(syntax-rules ()
((_ x) (eq? #nil x))))
(foo #t)
could cause a crash that looks like this:
ice-9/psyntax.scm:2795:12: In procedure syntax-violation:
Syntax error:
unknown location: unexpected syntax in form ()
To fix it, add another special case (the commit mentioned above
special-cased the empty list) to preserve #nil
* module/ice-9/psyntax.scm (gen-syntax): Preserve #nil.
* test-suite/tests/syntax.test: Test #nil in syntax expansions.
Closes: 49305
Hi!
In 3.0.6, a slight incompatibility crept in: ‘syntax-error’ exceptions
include vectors like #("example.scm" 1 2) instead of good’ol source
property alists.
Here is a test case that reproduces the problem:
This change to the expander allows mixed local definitions and
expressions. The expansion turns:
(let () (a) (define (b) 42) (b) (b))
into:
(let ()
(letrec* ((t0 (begin (a) (if #f #f)))
(b (lambda () 42)))
(b)))
Which is to say, expressions that precede definitions are expanded as
definitions of a temporary via (begin EXP (if #f #f)).
* module/ice-9/psyntax.scm (expand-body): Allow mixed definitions and
expressions.
* module/ice-9/psyntax-pp.scm: Regenerate.
* test-suite/tests/syntax.test: Add a couple tests and update for new
error messages.
* libguile/eq.c (scm_equal_p, scm_raw_ihash): Add cases for syntax
objects, which should be comparable with equal?.
* test-suite/tests/syntax.test ("syntax objects"): Add tests.
* module/ice-9/boot-9.scm (%cond-expand-features): Add srfi-46.
* doc/ref/srfi-modules.texi (SRFI-0): Add srfi-46 to the list of core
features.
(SRFI-46): New node.
* doc/ref/api-macros.texi (Syntax Rules): Mention that the custom
ellipsis identifier support is specified by SRFI-46.
* test-suite/tests/syntax.test ("syntax-rules"): Add ellipsis hygiene
test from SRFI-46.
* module/ice-9/psyntax.scm (binding-type): Update the header comment
to mention the new 'ellipsis' binding type.
(macros-only-env): Preserve ellipsis bindings.
(ellipsis?): Add 'r' and 'mod' as arguments. Search the lexical
environment for an ellipsis binding, and use it.
(gen-syntax): Adapt to the additional arguments of 'ellipsis?'.
(with-ellipsis): New core syntax.
(convert-pattern): Add unary 'ellipsis?' procedure as an argument.
(gen-clause): Adapt to the additional arguments of 'ellipsis?'.
Pass unary 'ellipsis?' procedure to 'convert-pattern'.
(syntax-case): Adapt to the additional arguments of 'ellipsis?'.
(syntax-local-binding): Support new 'ellipsis' binding type.
(syntax-rules): Add support for a custom ellipsis identifier as
the first operand, as per R7RS. Collect common code within new
local procedure 'expand-syntax-rules'.
* module/ice-9/psyntax-pp.scm: Regenerate.
* module/ice-9/local-eval.scm (analyze-identifiers): Add support for
'ellipsis' binding type.
* doc/ref/api-macros.texi (Syntax Rules): Add docs for R7RS custom
ellipsis syntax. Use @dots{}.
(Syntax Case): Add docs for 'with-ellipsis'. Use @dots{}.
(Syntax Transformer Helpers): Update to include new 'ellipsis'
binding type.
* test-suite/tests/syntax.test: Add tests.
Reported by taylanbayirli@gmail.com (Taylan Ulrich B.).
* module/ice-9/psyntax.scm (cvt*): Use 'syntax-case' to destructure
the pattern tail, instead of 'pair?', 'car', and 'cdr'.
(gen-clause): When checking for errors, check for misplaced ellipsis
before duplicate pattern variables, to improve the error message in
case of multiple misplaced ellipses.
* module/ice-9/psyntax-pp.scm: Regenerate.
* test-suite/tests/syntax.test: Add tests.
* module/ice-9/boot-9.scm (cond, case): Reimplement using syntax-case,
with improved error messages and support for '=>' within 'case' as
mandated by the R7RS. Add warnings for duplicate case datums and
case datums that cannot be meaningfully compared using 'eqv?'.
* module/system/base/message.scm (%warning-types): Add 'bad-case-datum'
and 'duplicate-case-datum' warning types.
* test-suite/tests/syntax.test (cond, case): Update tests to reflect
improved error reporting. Add tests for '=>' within 'case'.
* test-suite/tests/tree-il.test (partial evaluation): Update tests to
reflect changes in how 'case' is expanded.
* doc/ref/api-control.texi (Conditionals): Document '=>' within 'case'.
* module/ice-9/psyntax.scm (define-expansion-constructors)[begin-form]:
Emit a syntax-violation error for empty sequences when
--disable-deprecated.
* test-suite/tests/syntax.test (pass-if-syntax-error): Fix typo in error
message.
* doc/ref/api-control.texi (begin): Update to distinguish between
splicing begin and sequencing begin.
* module/ice-9/psyntax.scm (expand-expr): Add a back-compatibility shim
for `(begin)'.
* module/ice-9/psyntax-pp.scm: Regenerate.
* test-suite/tests/syntax.test: Update to run illegal (begin) test only
if we are not including deprecated features.
* module/ice-9/boot-9.scm (while): Specify the return value as #f under
normal conditions, #t under (break), and arg... under (break arg...).
* test-suite/tests/syntax.test ("while"): Test.
* doc/ref/api-control.texi (while do): Document.
* test-suite/tests/syntax.test (pass-if-syntax-error): Fix up for new
form of syntax errors. Adapt all tests.
* test-suite/tests/srfi-17.test: Likewise.
* test-suite/tests/syntax.test (matches?): Unfortunately this relatively
recent macro fails due to the underscore-in-literals-list prohibition.
But, it seems I was in the minority wanting _ for a literal.
* module/ice-9/psyntax.scm (chi-body): Whoops, actually render internal
definitions into a letrec* in the right order.
* module/ice-9/psyntax-pp.scm: Regenerate.
* test-suite/tests/syntax.test: Add some letrec* tests.
* libguile/eval.c (scm_primitive_eval, scm_c_primitive_eval):
(scm_init_eval): Rework so that scm_primitive_eval always calls out to
the primitive-eval variable. The previous definition is the default
value, which is probably overridden by scm_init_eval_in_scheme.
* libguile/init.c (scm_i_init_guile): Move ports and load-path up, so we
can debug when initing eval. Call scm_init_eval_in_scheme. Awesome.
* libguile/load.h:
* libguile/load.c (scm_init_eval_in_scheme): New procedure, loads up
ice-9/eval.scm to replace the primitive-eval definition, if everything
is there and up-to-date.
* libguile/modules.c (scm_module_transformer): Export to Scheme, so it's
there for eval.go.
* module/ice-9/boot-9.scm: No need to define module-transformer.
* module/ice-9/eval.scm (capture-env): Only reference the-root-module if
modules are booted.
(primitive-eval): Inline a definition for identity. Throw a more
standard error for "wrong number of arguments".
* module/ice-9/psyntax.scm (chi-install-global): The macro binding for a
syncase macro is now a pair: the transformer, and the module that was
current when the transformer was installed. The latter is used for
hygiene purposes, replacing the use of procedure-module, which didn't
work with the interpreter's shared-code closures.
(chi-macro): Adapt for the binding being a pair, and get the hygiene
from the cdr.
(eval-local-transformer): Adapt to new form of macro bindings.
* module/ice-9/psyntax-pp.scm: Regenerated.
* .gitignore: Ignore eval.go.stamp.
* module/Makefile.am: Reorder for fastest serial compilation, now that
there are no ordering constraints. I did a number of experiments here
and this seems to be the best; but the bulk of the time is compiling
psyntax-pp.scm with eval.scm. Not so great.
* libguile/vm-engine.c (vm-engine): Throw a more standard error for
"wrong type to apply".
* test-suite/tests/gc.test ("gc"): Remove a hack that shouldn't affect
the new evaluator, and throw in another (gc) for good measure.
* test-suite/tests/goops.test ("defining classes"):
* test-suite/tests/hooks.test (proc1): We can't currently check what the
arity is of a closure made by eval.scm -- or more accurately all
closures have 0 required args and no rest args. So punt for now.
* test-suite/tests/syntax.test ("letrec"): The scheme evaluator can't
check that a variable is unbound, currently; perhaps the full "fixing
letrec" expansion could fix this. But barring that, punt.
* libguile/eval.c: So, ladies & gents, a new evaluator. It's similar to
the old one, in that we memoize and then evaluate, but in this
incarnation, memoization of an expression happens before evaluation,
not lazily as the expression is evaluated. This makes the evaluation
itself much cleaner, in addition to being threadsafe. In addition,
since this C evaluator will in the future just serve to bootstrap the
Scheme evaluator, we don't have to pay much concern for debugging
conveniences. So the environment is just a list of values, and the
memoizer pre-computes where it's going to find each individual value
in the environment.
Interface changes are commented below, with eval.h.
(scm_evaluator_traps): No need to reset the debug mode after rnning te
traps thing. But really, the whole traps system needs some love.
* libguile/memoize.h:
* libguile/memoize.c: New memoizer, which runs before evaluation,
checking all syntax before evaluation begins. Significantly, no
debugging information is left for lexical variables, which is not so
great for interactive debugging; perhaps we should change this to have
a var list in the future as per the classic interpreters. But it's
quite fast, and the resulting code is quite good. Also note that it
doesn't produce ilocs, memoized code is a smob whose type is in the
first word of the smob itself.
* libguile/eval.h (scm_sym_and, scm_sym_begin, scm_sym_case)
(scm_sym_cond, scm_sym_define, scm_sym_do, scm_sym_if, scm_sym_lambda)
(scm_sym_let, scm_sym_letstar, scm_sym_letrec, scm_sym_quote)
(scm_sym_quasiquote, scm_sym_unquote, scm_sym_uq_splicing, scm_sym_at)
(scm_sym_atat, scm_sym_atapply, scm_sym_atcall_cc)
(scm_sym_at_call_with_values, scm_sym_delay, scm_sym_eval_when)
(scm_sym_arrow, scm_sym_else, scm_sym_apply, scm_sym_set_x)
(scm_sym_args): Remove public declaration of these symbols.
(scm_ilookup, scm_lookupcar, scm_eval_car, scm_eval_body)
(scm_eval_args, scm_i_eval_x, scm_i_eval): Remove public declaration
of these functions.
(scm_ceval, scm_deval, scm_ceval_ptr): Remove declarations of these
deprecated functions.
(scm_i_print_iloc, scm_i_print_isym, scm_i_unmemocopy_expr)
(scm_i_unmemocopy_body): Remove declarations of these internal
functions.
(scm_primitive_eval_x, scm_eval_x): Redefine as macros for their less
destructive siblings.
* libguile/Makefile.am: Add memoize.[ch] to the build.
* libguile/debug.h (scm_debug_mode_p, scm_check_entry_p)
(scm_check_apply_p, scm_check_exit_p, scm_check_memoize_p)
(scm_debug_eframe_size): Remove these vars that were tied to the old
evaluator's execution model.
(SCM_RESET_DEBUG_MODE): Remove, no more need for this.
(SCM_MEMOIZEDP, SCM_MEMOIZED_EXP, SCM_MEMOIZED_ENV): Remove macros
referring to old memoized code representation.
(scm_local_eval, scm_procedure_environment, scm_memoized_environment)
(scm_make_memoized, scm_memoized_p): Remove functions operating on old
memoized code representation.
(scm_memcons, scm_mem_to_proc, scm_proc_to_mem): Remove debug-only
code for old evaluator.
* libguile/debug.c: Remove code to correspond with debug.h removals.
(scm_debug_options): No need to set the debug mode or frame limit
here, as we don't have C stack limits any more. Perhaps this is a bug,
but as long as we can compile eval.scm, we should be fine.
* libguile/init.c (scm_i_init_guile): Init memoize.c.
* libguile/modules.c (scm_top_level_env, scm_env_top_level)
(scm_env_module, scm_system_module_env_p): Remove these functions.
* libguile/print.c (iprin1): No more need to handle isyms. Adapt to new
form of interpreted procedures.
* libguile/procprop.c (scm_i_procedure_arity): Adapt to new form of
interpreted procedures.
* libguile/procs.c (scm_thunk_p): Adapt to new form of interpreted
procedures.
* libguile/procs.h (SCM_CLOSURE_FORMALS): Removed, this exists no more.
(SCM_CLOSURE_NUM_REQUIRED_ARGS, SCM_CLOSURE_HAS_REST_ARGS): New
accessors.
* libguile/srcprop.c (scm_source_properties, scm_source_property)
(scm_set_source_property_x): Remove special cases for memoized code.
* libguile/stacks.c (read_frame): Remove a source-property case for
interpreted code.
(NEXT_FRAME): Remove a case that I don't fully understand, that seems
to be designed to skip over apply frames. Will be obsolete in the
futures.
(read_frames): Default source value for interpreted frames to #f.
(narrow_stack): Don't pay attention to the system_module thing.
* libguile/tags.h: Remove isyms and ilocs. Whee!
* libguile/validate.h (SCM_VALIDATE_MEMOIZED): Fix to use the new
MEMOIZED_P formulation.
* module/ice-9/psyntax-pp.scm (do, quasiquote, case): Adapt for these no
longer being primitive macros.
* module/ice-9/boot-9.scm: Whitespace change, but just a poke to force a
rebuild due to and/or/cond/... not being primitives any more.
* module/ice-9/deprecated.scm (unmemoize-expr): Deprecate, it's
unmemoize-expression now.
* test-suite/tests/eval.test ("define set procedure-name"): XFAIL a
couple of tests here; I don't know what to do about them. I reckon the
expander should ensure that defined values are named.
* test-suite/tests/chars.test ("basic char handling"): Fix expected
exception when trying to apply a char.
* module/ice-9/psyntax.scm (lambda-formals, chi-simple-lambda)
(lambda*-formals, chi-lambda-case): Refactor the lambda
transformations with an eye to being able to do case-lambda.
* module/ice-9/psyntax-pp.scm: Regenerated.
* test-suite/tests/syntax.test: Adapted tests so that the errors we
expect match what is given by psyntax.
* module/ice-9/boot-9.scm (eval): Here at the tail of boot-9, replace
the root definition of `eval' with a procedure that will call
`compile'.
* test-suite/tests/syntax.test ("top-level define"):
("internal define"): Run unmemoization tests in the interpreter, using
primitive-eval.
* test-suite/tests/syntax.test ("top-level define"): Remove the test for
currying, as we don't do that any more by default. It should be easy
for the user to add in if she wants it, though.
("do"): Remove unmemoization tests, as sc-expand fully expands `do'.
("while"): Remove while tests in empty environments. They have been
throwing 'unresolved, and the problem they seek to test is fully
handled by hygiene anyway.
And otherwise tweak expected exception strings, and everything passes!
* module/ice-9/boot-9.scm (cond): Implement srfi-61; most of the code is
from the SRFI itself. Yuk.
(%print-module, make-modules-in, %app, (%app modules))
(module-name): Syncase needs to get at the names of modules, even at
anonymous modules. So lazily assign gensyms as module names. Name %app
as (%app), but since (%app modules) is at the top of the module
hierarchy, name it ().
* module/ice-9/psyntax.scm: When building tree-il, try to name lambdas in
definitions and in lets.
(let, letrec): Give more specific errors in a couple of cases.
* module/ice-9/psyntax-pp.scm: Regenerated.
* test-suite/tests/syntax.test: More work. Many exceptions have different
messages than they used to, many more generic; we can roll this back to
be faithful to the original strings, but it doesn't seem necessary to
me.
* module/language/tree-il.scm (tree-il->scheme):
* module/ice-9/psyntax.scm (build-conditional): Attempt to not generate
(if #f #f) as the second arm of an if, but it doesn't seem to be
successful.
* module/ice-9/psyntax-pp.scm (syntax-rules): Regenerate.
* test-suite/tests/syntax.test (exception:unexpected-syntax): Change
capitalization.
("unquote-splicing"): Update test.
("begin"): Add in second arms on these ifs, to avoid the strange though
harmless expansion of `if'.
(matches?): New helper macro.
("lambda"): Match on lexically bound symbols, as they will be
alpha-renamed.
* module/language/tree-il.scm (parse-tree-il): Fix a number of bugs.
(unparse-tree-il): Apply takes rest args now.
* module/language/tree-il/analyze.scm (analyze-lexicals)
(analyze-lexicals): Heap vars shouldn't increment the number of locals.
* module/language/tree-il/optimize.scm (resolve-primitives!): Don't
resolve public refs to primitives, not at the moment anyway.
* test-suite/Makefile.am (SCM_TESTS): Add tree-il test.
* test-suite/lib.scm (pass-if, expect-fail, pass-if-exception)
(expect-fail-exception): Rewrite as syntax-rules macros. In a very
amusing turn of events, it turns out that bindings introduced by
hygienic macros are not visible inside expansions produced by
defmacros. This seems to be expected, so go ahead and work around the
problem.
* test-suite/tests/srfi-31.test ("rec special form"): Expand in eval.
* test-suite/tests/syntax.test ("begin"): Do some more expanding in eval,
though all is not yet well.
* test-suite/tests/tree-il.test: New test suite, for tree-il->glil
compilation.
