Fixes <http://bugs.gnu.org/14864>.
Reported by Göran Weinholt <goran@weinholt.se>.
* module/rnrs/arithmetic/bitwise.scm (bitwise-bit-count): If the
argument is negative, return the 'bitwise-not' of the result of
'logcount', as per R6RS. Previously, 'bitwise-bit-count' was
identical to 'logcount'.
* module/language/tree-il.scm (<prompt>): Change to have the body and
handler be lambdas, and add an "escape-only?" field. This will make
generic prompts work better in CPS or ANF with the RTL VM, as it
doesn't make sense in that context to capture only part of a frame.
Escape-only prompts can still be fully inlined.
(parse-tree-il, unparse-tree-il): Add escape-only? to the
serialization.
(make-tree-il-folder, pre-post-order): Deal with escape-only?.
* module/language/tree-il/analyze.scm (analyze-lexicals): Handle
escape-only?, and the new expectations for the body and handler.
* module/language/tree-il/canonicalize.scm (canonicalize): Ensure that
the body of an escape-only continuation is a thunk, and that the
handler is always a lambda.
* module/language/tree-il/debug.scm (verify-tree-il): Assert that
escape-only? is a boolean.
* module/language/tree-il/cse.scm (cse):
* module/language/tree-il/effects.scm (make-effects-analyzer):
* module/language/tree-il/peval.scm (peval):
* module/language/tree-il/primitives.scm (*primitive-expand-table*):
* test-suite/tests/peval.test ("partial evaluation"):
* module/language/tree-il/compile-glil.scm (flatten-lambda-case): Adapt
to <prompt> change.
* libguile/vm-i-system.c (push-fluid, pop-fluid):
* doc/ref/vm.texi (Dynamic Environment Instructions): Rename wind-fluids
to push-fluid, and unwind-fluids to pop-fluid. They now only work on
one fluid binding at a time.
* module/ice-9/boot-9.scm (with-fluid*): Implement in Scheme in terms of
primcalls to push-fluid and pop-fluid.
(custom-throw-handler, catch, with-throw-handler): Use with-fluid*
instead of with-fluids, as with-fluids is no longer available before
psyntax is loaded.
(with-fluids): Define in Scheme in terms of with-fluid*.
* libguile/fluids.c (scm_with_fluid): Rename from scm_with_fluids, and
don't expose to Scheme.
* libguile/eval.c (eval): Remove SCM_M_WITH_FLUIDS case.
* libguile/expand.c (expand_with_fluids): Remove with-fluids syntax.
(DYNLET): Remove, no longer defining dynlet in the %expanded-vtables.
* libguile/expand.h: Remove dynlet definitions.
* module/ice-9/eval.scm (primitive-eval): Remove with-fluids case.
* libguile/memoize.c (do_push_fluid, do_pop_fluid): New primitive
helpers, like wind and unwind.
(memoize): Memoize wind and unwind primcalls. Don't memoize dynlet to
with-fluids.
(scm_init_memoize): Initialize push_fluid and pop_fluid here.
* libguile/memoize.h (SCM_M_WITH_FLUIDS): Remove definition.
* module/ice-9/psyntax.scm (build-dynlet): Remove; this just supported
with-fluids, which is now defined in boot-9.
* module/ice-9/psyntax-pp.scm: Regenerate.
* doc/ref/compiler.texi (Tree-IL):
* module/language/tree-il.scm:
* module/language/tree-il/analyze.scm:
* module/language/tree-il/canonicalize.scm:
* module/language/tree-il/compile-glil.scm:
* module/language/tree-il/cse.scm:
* module/language/tree-il/debug.scm:
* module/language/tree-il/effects.scm: Remove <dynlet>. Add cases for
primcalls to push-fluid and pop-fluid in compile-glil.scm and
effects.scm.
* module/language/tree-il/peval.scm (peval): Factor out
with-temporaries; probably a bad idea, but works for now. Factor out
make-begin0 (a better idea). Inline primcalls to with-fluid*, and
remove dynlet cases.
* module/language/tree-il/primitives.scm (*interesting-primitive-names*):
Add with-fluid*.
* doc/ref/compiler.texi: Remove mention of <dynwind>.
* libguile/eval.c (eval): Remove SCM_M_DYNWIND case.
* libguile/expand.c: Remove scm_sym_at_dynamic_wind.
* libguile/memoize.c (do_wind, do_unwind): A couple of hacky subrs. If
we see a wind or unwind primcall, we expand to a call of a quoted subr
value. It works and removes a kind of memoized value from the
interpreter. For the compiler,primcalls to wind and unwind are
handled specially.
(MAKMEMO_DYNWIND): Remove.
(scm_tc16_memoizer): Remove. Yay!
(memoize): Remove speculative lookup for toplevels to see if they are
memoizers: there are no more memoizers. Memoize calls to the wind and
unwind primitives.
(m_dynamic_wind): Remove.
(unmemoize): Remove dynwind case.
(scm_init_memoize): Add wind and unwind local definitions.
* module/ice-9/boot-9.scm (dynamic-wind): Reimplement in terms of "wind"
and "unwind" primitives. These primitives are not exposed to other
modules.
* module/ice-9/eval.scm (primitive-eval): Remove dynwind case.
* module/language/scheme/decompile-tree-il.scm (do-decompile):
(choose-output-names): Remove dynwind cases.
* module/language/tree-il.scm: Remove <dynwind>. Yaaay!
* module/language/tree-il/analyze.scm (analyze-lexicals): Remove dynwind
cases.
* module/language/tree-il/compile-glil.scm (*primcall-ops*): Add wind
and unwind.
(flatten-lambda-case): Remove dynwind case. Yay!
* module/language/tree-il/cse.scm (cse):
* module/language/tree-il/debug.scm (verify-tree-il):
* module/language/tree-il/effects.scm (make-effects-analyzer):
* module/language/tree-il/peval.scm (singly-valued-expression?, peval):
Remove <dywind> cases. Inline primcalls to dynamic-wind. Add
constant folding for thunk?.
* module/language/tree-il/primitives.scm (*interesting-primitive-names*):
Remove @dynamic-wind, and add procedure? and thunk?.
(*effect+exception-free-primitives*): Add procedure? and thunk?.
(*multiply-valued-primitives*): Remove @dynamic-wind.
Remove @dynamic-wind expander.
* test-suite/tests/peval.test ("partial evaluation"): Update tests for
dynwind desugaring.
* libguile/memoize.h:
* libguile/expand.c (scm_sym_at_call_with_values): Remove.
* libguile/memoize.c (memoize, m_call_values, unmemoize): Adapt to
memoize call-with-values primcalls.
* module/ice-9/boot-9.scm (call-with-values): Expand to a
call-with-values primcall.
* module/language/tree-il/compile-glil.scm (flatten-lambda-case): Expect
call-with-values primcall, without the @, and fall back to a normal
call.
* module/language/tree-il/peval.scm (peval): Match bare
call-with-values.
* module/language/tree-il/primitives.scm (*interesting-primitive-names*):
(*multiply-valued-primitives*): Remove @call-with-values.
* libguile/memoize.c (memoize): Recognize a primcall to 'apply as
SCM_M_APPLY.
(@apply): Remove @apply memoizer.
(unmemoize): Unmemoize using "apply", not "@apply".
* libguile/memoize.h:
* libguile/expand.c (scm_sym_atapply): Remove.
* module/ice-9/boot-9.scm (apply): Re-implement using apply primcall.
Use case-lambda, so as to give an appropriate minimum arity.
* module/language/tree-il/compile-glil.scm (flatten-lambda-case):
Compile a primcall of "apply" specially, not "@apply".
* module/language/tree-il/peval.scm (peval): Match primcalls to "apply",
not "@apply". Residualize "apply" primcalls.
* module/language/tree-il/primitives.scm (*interesting-primitive-names*):
(*multiply-valued-primitives*): Remove @apply, and apply primitive
expander.
* test-suite/tests/peval.test:
* test-suite/tests/tree-il.test: Update tests to expect residualized
"apply".
* test-suite/tests/procprop.test ("procedure-arity"): Update test for
better apply arity.
* test-suite/tests/strings.test ("string"): Update expected error.
* libguile/memoize.h:
* libguile/memoize.c (MAKMEMO_CALL_WITH_PROMPT, memoize, unmemoize):
Remove the @prompt memoizer in favor of recognizing call-with-prompt
primcalls. Rename SCM_M_PROMPT to SCM_M_CALL_WITH_PROMPT, and pass a
thunk instead of an expression so that it has normal applicative
order.
* libguile/expand.c (PRIMITIVE_REF, PRIMCALL, expand): Produce primcalls
from forms whose car is a primitive.
(expand_atat): Recognize (@@ primitive FOO) as being a primitive-ref.
* module/ice-9/boot-9.scm (call-with-prompt): Instead of dispatching to
the wonky @prompt memoizer, residualize a primcall to
call-with-prompt. The memoizer will DTRT to allow call-with-prompt to
be interpreted correctly without needing an additional binding.
* module/ice-9/eval.scm (primitive-eval): Change the 'prompt clause to a
call to call-with-prompt.
* module/language/tree-il/primitives.scm: No more need to recognize
@prompt.
* libguile/eval.c (eval): Adapt to SCM_M_PROMPT renaming to
SCM_M_CALL_WITH_PROMPT, and apply the thunk.
* libguile/throw.c (pre_init_throw): Adapt to scm_abort_to_prompt_star
rename.
* ice-9/psyntax.scm (@@): Recognize new form, (@@ primitive NAME), which
in operator position expands to a primcall. This expansion is only
available for forms in the (guile) module. Added an argument to @@
and @ procedures, the module, for use by expanded syntax objects;
adapted callers.
(analyze-variable): Error when accessing a primitive for value.
(get-global-definition-hook): Primitives are not macros.
(syntax-type): A form with a primitive in the car is a
primitive-call.
(expand-expr): Residualize primitive calls as primcalls.
(syntax-local-binding): Return 'primitive as the type for primitives.
* module/language/tree-il.scm (<tree-il>): Remove pre and post fields
from <dynwind>. A dynwind now assumes that in normal entry and exit,
that the code runs the winders and unwinders using <seq> and
<let-values> and such things.
(parse-tree-il, unparse-tree-il, make-tree-il-folder, pre-post-order):
Adapt <dynwind> users.
* module/language/tree-il/analyze.scm (analyze-lexicals):
* module/language/tree-il/compile-glil.scm (flatten-lambda-case):
* module/language/tree-il/cse.scm (cse):
* module/language/tree-il/debug.scm (verify-tree-il):
* module/language/tree-il/effects.scm (make-effects-analyzer): Adapt.
* module/language/tree-il/peval.scm (peval):
* module/language/tree-il/primitives.scm (*primitive-expand-table*):
Produce tree-il that calls the winder and unwinder. Recognize
singly-valued dynamic-wind expressions.
* test-suite/tests/peval.test ("partial evaluation"): Add tests.
* module/language/tree-il/peval.scm (singly-valued-expression?): Add
support for conditionals. In the future we should add more
expressions here.
(peval): Don't inline values into the body of a dynwind, as that could
cause the consumer to run in the wrong dynamic context.
If the producer is singly-valued and the consumer just has a rest arg,
reduce to "let" and cons up a list in the consumer. This may reduce
further.
* test-suite/tests/peval.test ("partial evaluation"): Add a test.
* module/language/tree-il.scm (tree-il-fold): Implement using
make-tree-il-folder. This is an incompatible change: there is no more
"leaf" procedure, and tree-il-fold only works on tree-il and not
lists.
* module/language/tree-il/analyze.scm (<tree-analysis>, analyze-tree):
Adapt to tree-il-fold change, losing the "leaf" handler.
(unused-variable-analysis, unused-toplevel-analysis)
(unbound-variable-analysis, arity-analysis): Adapt to tree-analysis
change.
* module/language/tree-il/canonicalize.scm (tree-il-any)
* module/language/tree-il/cse.scm (build-assigned-var-table)
* module/language/tree-il/peval.scm (tree-il-any, build-var-table)
(peval): Adapt to tree-il-fold change.
* test-suite/tests/tree-il.test ("tree-il-fold"): Adapt tests for new
interface and expectations.
* module/language/tree-il.scm (pre-order): Re-implement in terms of
pre-post-order, and rename from pre-order!.
* module/language/tree-il/primitives.scm (expand-primitives): Adapt to
pre-order change, and rename from expand-primitives!.
* module/language/tree-il/optimize.scm (optimize): Adapt to
expand-primitives! change, and rename from optimize!.
* module/language/tree-il/compile-glil.scm:
* module/system/repl/common.scm:
* test-suite/tests/cse.test:
* test-suite/tests/peval.test:
* test-suite/tests/tree-il.test: Adapt to expand-primitives and optimize
changes.
* module/language/tree-il.scm (pre-post-order): New helper, like
pre-order! and post-order! but not destructive.
(post-order): Implement in terms of pre-post-order, and rename from
post-order!.
* module/ice-9/compile-psyntax.scm (squeeze-tree-il):
* module/language/tree-il/canonicalize.scm (canonicalize):
* module/language/tree-il/fix-letrec.scm (fix-letrec):
* module/language/tree-il/primitives.scm (resolve-primitives): Use
post-order, and rename from the destructive
variants (squeeze-tree-il!, canonicalize!, etc). Adapt callers.
* test-suite/tests/tree-il.test (strip-source): Adapt to post-order.
* test-suite/tests/cse.test:
* test-suite/tests/peval.test:
* module/language/tree-il/optimize.scm: Adapt callers.
* module/language/tree-il/peval.scm (peval): let-values with a consumer
that has only one argument is the same as let.
* test-suite/tests/peval.test ("partial evaluation"): Add test.
* module/system/vm/assembler.scm (link-procprops, link-objects): Arrange
to write procedure property links out to a separate section.
* libguile/procprop.c (scm_procedure_properties):
* libguile/programs.h:
* libguile/programs.c (scm_i_rtl_program_properties):
* module/system/vm/debug.scm (find-program-properties): Wire up
procedure-properties for RTL procedures. Yeah! Fistpumps! :)
* module/system/vm/debug.scm (find-program-debug-info): Return #f if the
string is "", as it is if we don't have a name. Perhaps
elf-symbol-name should return #f in that case...
* test-suite/tests/rtl.test: Add some tests.
* libguile/procprop.h:
* libguile/procprop.c (scm_procedure_documentation): Move here from
procs.c, and to make the logic more similar to that of procedure-name,
which allows RTL programs to dispatch to rtl-program-documentation.
* libguile/programs.c (scm_i_rtl_program_documentation):
* libguile/programs.h:
* module/system/vm/program.scm (rtl-program-documentation): New
plumbing.
* module/system/vm/debug.scm (find-program-docstring): New interface to
grovel ELF for a docstring.
* libguile/procprop.c (scm_i_procedure_arity): Allow RTL programs to
dispatch to scm_i_program_arity.
* libguile/programs.c (scm_i_program_print): Refactor reference to
write-program.
(scm_i_rtl_program_minimum_arity): New procedure, dispatches to
Scheme.
(scm_i_program_arity): Dispatch to scm_i_rtl_program_minimum_arity if
appropriate.
* module/system/vm/debug.scm (program-minimum-arity): New export.
* module/system/vm/program.scm (rtl-program-minimum-arity): New internal
function.
(program-arguments-alists): New helper, implemented also for RTL
procedures.
(write-program): Refactor a bit, and call program-arguments-alists.
* test-suite/tests/rtl.test ("simply procedure arity"): Add tests that
arities make it all the way to cold ELF and back to warm Guile.
* module/system/vm/debug.scm (<arity>): New object, for reading
arities. Unlike <arity> in the assembler, this one only holds on to a
couple of pointers, and doesn't even load in argument names. Unlike
the arity lists in (system vm program), it can load in names. Very
early days but it does seem to work.
(find-program-arities, arity-arguments-alist): New higher-level
interfaces.
* module/system/vm/assembler.scm (<meta>, <arity>): Assembler now tracks
arities of a function.
(begin-standard-arity, begin-opt-arity, begin-kw-arity, end-arity):
New macro-assemblers.
* test-suite/tests/rtl.test: Adapt all tests to use begin-standard-arity
and end-arity.
* module/system/vm/assembler.scm (pack-flags): New helper.
(standard-prelude, opt-prelude, kw-prelude): New macro-instructions.
* test-suite/tests/rtl.test: Update tests to use standard-prelude.
* module/system/vm/assembler.scm (assert-match): New helper macro to
check argument types.
(<meta>): Add properties field. Rename name field to "label" to
indicate that it should be unique.
(make-meta, meta-name): New helpers.
(begin-program): Take additional properties argument.
(emit-init-constants): Adapt to begin-program change.
(link-symtab): Allow for anonymous procedures.
* test-suite/tests/rtl.test: Adapt tests.
* libguile/print.c (iprin1): Use scm_i_program_print for RTL programs
too.
* libguile/procprop.c (scm_procedure_name): For RTL programs, call
scm_i_rtl_program_name if there is no override.
* libguile/programs.h:
* libguile/programs.c (scm_i_rtl_program_name): New helper, dispatches
to (system vm program).
(scm_i_program_print): For RTL programs, the fallback prints the code
pointer too.
* module/system/vm/program.scm (rtl-program-name): Use the debug info to
get an RTL program name.
(write-program): Work with RTL programs too.
* test-suite/tests/rtl.test ("procedure name"): Add test.
* module/Makefile.am:
* module/system/vm/debug.scm: New module.
* module/system/vm/elf.scm (elf-section-by-name): New helper.
(elf-symbol-table-len): New helper.
* test-suite/tests/rtl.test: Add test for finding debug info.
* module/Makefile.am:
* module/system/vm/assembler.scm: New module, implementing an assembler
for RTL.
* test-suite/Makefile.am:
* test-suite/tests/rtl.test: New test suite.
* module/system/vm/elf.scm (make-elf-symbol*): Add constructor; export
as make-elf-symbol.
(elf-symbol-len): New export.
(write-elf32-symbol, write-elf64-symbol): New helpers.
(write-elf-symbol): New export.
* module/system/vm/linker.scm (make-string-table): Rework to be a
stateful object instead of a function object. Works better in this
case. Adapt users.
(string-table-intern!): Rename from string-table-intern, and just
return the index of the string.
(link-string-table!): Rename from link-string-table, and set a flag to
prevent interning strings after linking, as that's not going to work
well.
* module/language/objcode/elf.scm (bytecode->elf): Adapt.
* libguile/vm.c (vm_error_kwargs_invalid_keyword,
vm_error_kwargs_unrecognized_keyword): Add parameter. Pass it
enclosed in a list as the last argument to `scm_error_scm'.
* libguile/vm-i-system.c (bind_kwargs): Adjust accordingly.
* libguile/eval.c (error_invalid_keyword, error_unrecognized_keyword):
Add parameter.
(prepare_boot_closure_env_for_apply): Adjust accordingly.
* module/ice-9/eval.scm (primitive-eval): Likewise.
* libguile/error.c (scm_error_scm): Mention `keyword-argument-error' in
docstring.
* module/ice-9/boot-9.scm (keyword-error-printer): New procedure; use it.
* test-suite/tests/optargs.test (c&e, with-test-prefix/c&e): Remove.
("define*")["unrecognized keyword"]: Test the value passed along the
`keyword-argument-error' exception.
["invalid keyword"]: New test.
* doc/ref/api-control.texi (Error Reporting): Update `scm-error'
description.
* libguile/vm-engine.c (rtl_vm_engine): Add new VM.
(vm_engine): Add support for calling RTL programs.
* libguile/tags.h (scm_tc7_rtl_program): New type for procedures that
run on the new VM.
* libguile/evalext.c (scm_self_evaluating_p):
* libguile/goops.c (scm_class_of):
* libguile/print.c (iprin1):
* libguile/procprop.c (scm_i_procedure_arity):
* libguile/procs.c (scm_procedure_p): Add hooks for the new tc7.
* libguile/programs.h:
* libguile/programs.c (scm_make_rtl_program, scm_i_rtl_program_print)
(scm_rtl_program_p, scm_rtl_program_code):
* module/system/vm/program.scm: Add constructors and accessors for the
new "RTL programs".
* libguile/vm.c (rtl_boot_continuation): Define a boot program.
(rtl_apply, rtl_values): New static RTL programs.
* libguile/frames.c (scm_frame_num_locals): Adapt for frames of RTL
programs.
* libguile/frames.h: Add description of RTL frames.
* libguile/Makefile.am: Add rules to generate vm-operations.h.
* .gitignore: Ignore vm-operations.h.
* module/system/vm/instruction.scm:
* libguile/instructions.c:
* libguile/instructions.h: Use vm-operations.h to define enumerated
values for the new RTL opcodes. Define some helper macros to pack and
unpack 32-bit instruction words.
(rtl-instruction-list): New function, exported by (system vm
instruction).
* libguile/objcodes.c: Wire up the bits needed to detect the new RTL
bytecode and load it, as appropriate.
* doc/ref/api-debug.texi (VM Hooks): Update documentation.
* libguile/vm.c (vm_dispatch_hook):
* libguile/vm-engine.c: Rework the hook machinery so that they can
receive an arbitrary number of arguments. The return and abort
hooks will pass the values that they return to their continuations.
(vm_engine): Adapt to ABORT_CONTINUATION_HOOK change.
* libguile/vm-i-system.c (return, return/values): Adapt to
POP_CONTINUATION_HOOK change.
* module/system/vm/frame.scm (frame-return-values): Remove. The
pop-continuation-hook will pass the values directly.
* module/system/vm/trace.scm (print-return):
(trace-calls-to-procedure):
(trace-calls-in-procedure): Update to receive return values
directly.
* module/system/vm/traps.scm (trap-in-procedure)
(trap-in-dynamic-extent): Ignore return values.
(trap-frame-finish, trap-calls-in-dynamic-extent)
(trap-calls-to-procedure): Pass return values to the handlers.
* libguile/objcodes.c (register_elf, scm_find_mapped_elf_image): New
interfaces that keep a list of all ELF mappings. Exported from the
(system vm objcode) module.
* module/system/vm/objcode.scm: Export find-mapped-elf-image.
* module/system/vm/linker.scm (make-linker-object):
(linker-object-section-symbol):
(linker-object-symbols*): Create a symbol to the start of a linker
object. Hide it from the external linker-object-symbols* accessor.
(segment-kind, count-segments): Sections without SHF_ALLOC don't get
segments.
(collate-objects-into-segments): Allow for #f segment types. If two
sections have the same type and flags, leave them in the same order.
(align): Allow for 0 alignment.
(add-elf-objects): New helper: puts the ELF data structures (header,
segment table, and section table) in sections of their own. This
lends a nice clarity and conceptual unity to the linker.
(relocate-section-header, allocate-segment): Lay out segments with
congruent, contiguous addresses, so that we can just mmap the file and
if debugging sections that are not in segments are present, they can
be lazily paged in if needed by the kernel's VM system.
(link-elf): Refactor to use the new interfaces.
* test-suite/tests/linker.test: Update to expect the additional sections
for the header and section table.
* module/system/vm/elf.scm: Add commentary.
(make-elf): Add a constructor similar to make-elf-segment and
make-elf-section.
(write-elf32-header, write-elf64-header, write-elf-header): Take an
<elf> instead of all the fields separately.
(<elf-segment>, <elf-section>): Add "index" property. Adapt
constructors accordingly.
* module/language/objcode/elf.scm (bytecode->elf): Arrange to set the
section indexes when creating ELF sections.
* module/system/vm/linker.scm (fold-values): New helper.
(alloc-segment, relocate-section-header): Arrange to set segment and
section indexes.
(find-shstrndx): New helper, replaces compute-sections-by-name. Now
that sections know their indexes, this is easier.
(allocate-elf, write-elf): New helpers, factored out of link-elf.
Easier now that sections have indexes.
(link-elf): Simplify. Check that the incoming objects have sensible
numbers.
* test-suite/tests/linker.test: Update to set #:index on the linker
objects.
* module/Makefile.am:
* module/system/vm/linker.scm: New file, split out of (system vm elf).
(make-string-table, string-table-intern): Export under their bare
names, instead of make-elf-string-table and elf-string-table-intern.
* module/system/vm/elf.scm: Remove linking capabilities.
(string-table-ref): Export.
* module/language/objcode/elf.scm (bytecode->elf): Adapt to use (system
vm linker).
* test-suite/tests/linker.test: New test.
* module/web/uri.scm (uri-encode): the hexadecimal percent-encoding %HH
is now uppercased as suggested by RFC3986:
"For consistency, URI producers and normalizers should use
uppercase hexadecimal digits for all percent-encodings."
* test-suite/tests/web-uri.test ("encode"): update tests.
* libguile/fports.c (scm_open_file_with_encoding): New API function,
containing the code previously found in 'scm_open_file', but modified
to accept the new 'guess_encoding' and 'encoding' arguments.
(scm_open_file): Now just a simple wrapper that calls
'scm_open_file_with_encoding'.
(scm_i_open_file): New implementation of 'open-file' that accepts
keyword arguments '#:guess-encoding' and '#:encoding', and calls
'scm_open_file_with_encoding'.
(scm_init_fports_keywords): New initialization function that gets
called after keywords are initialized.
* libguile/fports.h (scm_open_file_with_encoding,
scm_init_fports_keywords): Add prototypes.
* libguile/init.c (scm_i_init_guile): Call 'scm_init_fports_keywords'.
* module/ice-9/boot-9.scm: Add enhanced versions of 'open-input-file',
'open-output-file', 'call-with-input-file', 'call-with-output-file',
'with-input-from-file', 'with-output-to-file', and
'with-error-to-file', that accept keyword arguments '#:binary',
'#:encoding', and (for input port constructors) '#:guess-encoding'.
* doc/ref/api-io.texi (File Ports): Update documentation.
* test-suite/tests/ports.test ("keyword arguments for file openers"):
Add tests.
