* maint:
maint: post-release administrivia
version 3.5.4
examples: reccalc: really compile cleanly in C99
news: announce that Bison 3.6 drops YYERROR_VERBOSE
news: update for 3.5.4
style: fix spellos
typo: succesful -> successful
package: improve the readme
java: check and fix support for api.token.raw
java: style: prefer 'int[] foo' to 'int foo[]'
build: fix syntax-check issues
tests: recheck: work properly when the test suite was interrupted
doc: c++: promote api.token.raw
build: fix compatibility with old compilers
examples: reccalc: compile cleanly in C99
The previous fix does not suffice, and actually managed to make things
worse by defining yyscan_t twice in parse.y...
Reported by kencu.
https://trac.macports.org/ticket/59927#comment:29
* examples/c/reccalc/parse.y (yyscan_t): Define it with the same
guards as used by Flex.
The first name is too long. We already have `yypstate`, so
`yypcontext` is ok. We are also migrating to using `*_t` for our
types.
* NEWS, data/skeletons/glr.c, data/skeletons/yacc.c, doc/bison.texi,
* examples/c/bistromathic/parse.y, src/parse-gram.y, tests/local.at:
(yyparse_context_t, yyparse_context_location, yyparse_context_token):
Rename as...
(yypcontext_t, yypcontext_location, yypcontext_token): these.
Now that we have a proper type for internal symbol numbers, let's use
it. More code needs conversion, e.g., printers and destructors, but
they are shared with glr.c, which is not ready yet for this change.
It will also help us deal with warnings such as (GCC9 on GNU/Linux):
input.c: In function 'int yyparse()':
input.c:475:37: error: enumeral and non-enumeral type in conditional expression [-Werror=extra]
475 | (0 <= (YYX) && (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYSYMBOL_YYUNDEF)
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
input.c:1024:17: note: in expansion of macro 'YYTRANSLATE'
1024 | yytoken = YYTRANSLATE (yychar);
| ^~~~~~~~~~~
* data/skeletons/yacc.c (yytranslate, yysymbol_name)
(yyparse_context_t, yyexpected_tokens, yypstate_expected_tokens)
(yysyntax_error_arguments):
Use yysymbol_type_t instead of int.
Suggested by Adrian Vogelsgesang.
https://lists.gnu.org/archive/html/bison-patches/2020-02/msg00069.html
* data/skeletons/lalr1.java (Context.EMPTY, Context.getToken): New.
(Context.yyntokens): Rename as...
(Context.NTOKENS): this.
Because (i) all the Java coding styles recommend upper case for
constants, and (ii) the Java Skeleton exposes Lexer.EOF, not
Lexer.YYEOF.
* data/skeletons/yacc.c (yyparse_context_token): New.
* examples/c/bistromathic/parse.y (yyreport_syntax_error): Don't use
yysyntax_error_arguments.
* examples/java/calc/Calc.y (yyreportSyntaxError): Likewise.
yyparse returns 0, 1, 2 since ages (accept, reject, memory exhausted).
Some of our auxiliary functions such as yy_lac and
yyreport_syntax_error also need to return error codes and also use 0,
1, 2. Because it uses yy_lac, yyexpected_tokens also needs to return
"problem", "memory exhausted", but in case of success, it needs to
return the number of tokens, so it cannot use 1 and 2 as error code.
Currently it uses -1 and -2, which is later converted into 1 and 2 as
yacc.c expects it.
Let's simplify this and use consistently -1 and -2 for auxiliary
functions that are not exposed (or not yet exposed) to the user. In
particular this will save the user from having to convert
yyexpected_tokens's -2 into yyreport_syntax_error's 2: both return -1
or -2.
* data/skeletons/yacc.c (yy_lac, yyreport_syntax_error)
(yy_lac_stack_realloc): Return -1, -2 for errors instead of 1, 2.
Adjust callers.
* examples/c/bistromathic/parse.y (yyreport_syntax_error): Do take
error codes into account.
Issue a syntax error message even if we ran out of memory.
* src/parse-gram.y, tests/local.at (yyreport_syntax_error): Adjust.
In push parsers, when asking for the list of expected tokens at some
point, it makes no sense to build a yyparse_context_t: the yypstate
alone suffices (the only difference being the lookahead). Instead of
forcing the user to build a useless shell around yypstate, let's offer
yypstate_expected_tokens.
See https://lists.gnu.org/r/bison-patches/2020-03/msg00025.html.
* data/skeletons/yacc.c (yypstate): Declare earlier, so that we can
use it for...
(yypstate_expected_tokens): this new function, when in push parsers.
Adjust dependencies.
* examples/c/bistromathic/parse.y: Simplify: use
yypstate_expected_tokens.
Style fixes.
Reduce scopes (reported by Joel E. Denny).
Currently pstate_new does not set up its variables, this task is left
to yypush_parse. This was probably to share more code with usual pull
parsers, where these (local) variables are indeed initialized by
yyparse.
But as a consequence yyexpected_tokens crashes at the very beginning
of the parse, since, for instance, the stacks are not even set up.
See https://lists.gnu.org/r/bison-patches/2020-03/msg00001.html.
The fix could have very simple, but the documentation actually makes
it very clear that we can reuse a pstate for several parses:
After yypush_parse returns a status other than YYPUSH_MORE, the
parser instance yyps may be reused for a new parse.
so we need to restore the parser to its pristine state so that (i) it
is ready to run the next parse, (ii) it properly supports
yyexpected_tokens for the next run.
* data/skeletons/yacc.c (b4_initialize_parser_state_variables): New,
extracted from the top of yyparse/yypush_parse.
(yypstate_clear): New.
(yypstate_new): Use it when push parsers are enabled.
Define after the yyps macros so that we can use the same code as the
regular pull parsers.
(yyparse): Use it when push parsers are _not_ enabled.
* examples/c/bistromathic/bistromathic.test: Check the completion on
the beginning of the line.
Currently completion on "at" proposes only "atan", but does not
actually complete "at" into "atan".
* examples/c/bistromathic/parse.y (completion): Install the lcp in
matches[0].
* examples/c/bistromathic/bistromathic.test: Check that case.
Currently "(1+<TAB>" does not work as expected, because "+" is not a
word breaking character.
* examples/c/bistromathic/parse.y (init_readline): Specify our word
breaking characters.
* examples/c/bistromathic/bistromathic.test: Avoid trailing spaces.
Let's use GNU readline and its TAB autocompletion to demonstrate the
use of yyexpected_tokens.
This shows a number of weaknesses in our current approach:
- some macros (yyssp, etc.) from push parsers "leak" in user code, we
need to undefine them
- the context needed by yyexpected_tokens does not need the token,
yypstate actually suffices
- yypstate is not properly setup when first allocated, which results
in a crash of yyexpected_tokens if fired before a first token was
read. We should move initialization from yypush_parse into
yypstate_new.
* examples/c/bistromathic/parse.y (yylex): Take input as a string, not
a file.
(EXIT): New token.
(input): Adjust to work only on a line.
(line): Remove.
(symbol_count, process_line, expected_tokens, completion)
(init_readline): New.
* examples/c/bistromathic/bistromathic.test: Adjust expectations.
This example will soon use GNU readline, so its scanner should be easy
to use (concurrently) on strings, not streams. This is not a place
where Flex shines, and anyway, these are examples of Bison, not Flex.
There's already lexcalc and reccalc that demonstrate the use of Flex.
* examples/c/bistromathic/scan.l: Remove.
* examples/c/bistromathic/parse.y (yylex): New.
Adjust dependencies.
The bistromathic example should not use Flex, it makes it too complex.
But it was the only example to show location tracking with Flex.
* examples/c/lexcalc/lexcalc.test, examples/c/lexcalc/parse.y,
* examples/c/lexcalc/scan.l: Demonstrate location tracking as is done
in bistromathic.
Currently, if we have long rules and series of shift, we stack states
without showing stack. Let's be more incremental, and do how the Java
skeleton does.
* data/skeletons/lalr1.cc, data/skeletons/lalr1.d,
* data/skeletons/yacc.c:
Here.
Adjust test cases.
* tests/torture.at (AT_DATA_STACK_TORTURE): Disable stack traces: this
test produces a very large stack, and showing the stack each time we
shift a token goes quadatric.
Add an example to demonstrate the use of push parser. I'm pleasantly
surprised: parse.error=detailed works like a charm with push parsers.
* examples/c/local.mk, examples/c/pushcalc/Makefile
* examples/c/pushcalc/README.md, examples/c/pushcalc/calc.test,
* examples/c/pushcalc/calc.y, examples/c/pushcalc/local.mk:
New.
* examples/c/calc/calc.y: Restore to its original state, with
parse.error=detailed instead of parse.error=custom (this example
should be simple).
* examples/c/calc/calc.test: Check syntax errors.
* examples/c/lexcalc/parse.y: Add comments.
Provide users with a means to query for the currently allowed tokens.
Could be used for autocompletion for instance.
* data/skeletons/yacc.c (yyexpected_tokens): New, extracted from
yysyntax_error_arguments.
* examples/c/calc/calc.y (PRINT_EXPECTED_TOKENS): New.
Use it.
When parse.error is custom, let users define a yyreport_syntax_error
function, and use it.
* data/skeletons/bison.m4 (b4_error_verbose_if): Accept 'custom'.
* data/skeletons/yacc.c: Implement it.
* examples/c/calc/calc.y: Experiment with it.
Reported by Thomas Petazzoni.
https://lists.gnu.org/archive/html/bug-bison/2019-08/msg00000.html
* examples/c/reccalc/local.mk: Complete dependencies, including for
earlier versions of Automake (for sake of our CI, on top of Ubuntu
Xenial/Bionic, which feature only Automake 1.15).
(%D%/scan.c %D%/scan.h): Upgrade to the full version provided in
Automake's documentation.
It works only in implicit rules (or with GNU Make, but not with
Solaris Make).
Reported by Bruno Haible.
http://lists.gnu.org/archive/html/bug-bison/2019-05/msg00009.html
Diagnosed thanks to Kiyoshi Kanazawa.
* examples/c/reccalc/local.mk, examples/d/local.mk,
* examples/java/local.mk: Don't use $< in non implicit rules.
Because some of our examples use
%C%_reccalc_SOURCES = %D%/parse.y
Automake ships parse.y and parse.c, and possibly parse.h when it
"understands" that there is one. This is not what we want: ship only
parser.y. Yet we still want to use Automake to compile the sources
from parser.y. The easiest seems to use
nodist_%C%_reccalc_SOURCES = %D%/parse.y
together with
dist_reccalc_DATA = %D%/parse.y %D%/scan.l %D%/Makefile %D%/README.md
which guarantees that parse.y is indeed shipped.
* examples/c/calc/local.mk, examples/c/lexcalc/local.mk,
* examples/c/reccalc/local.mk: Always use nodist_*SOURCES for parsers,
let the dist_*_DATA rules do their job.
* cfg.mk: Disable checks where needed (e.g., we do want to check the
behavior with tabs).
(sc_at_parser_check): Remove. Unfortunately since
a11c144609 we no longer use the './'
prefix to run programs in the current directory. That was so that we
could run Java programs like the other, although they are no run with
the `./` prefix (see 967a59d2c0).
As a consequence this sc check no longer makes sense.
However, since now AT_PARSER_CHECK passes the `./` prefix itself, this
sc-check was superfluous.
* examples/c/reccalc/scan.l: Use memcpy, not strncpy.
* src/ielr.c, src/reader.c: Obfuscate "lr(0)" so that the sc-check for
"space before paren" does not fire.
* tests/diagnostics.at: Avoid space-tab, use tab-tab.
Currently when --defines is used, we generate a header, and paste an
exact copy of it into the generated parser implementation file. Let's
provide a means to #include it instead.
We don't do it by default because of the Autotools' ylwrap. This
program wraps invocations of yacc (that uses a fixed output name:
y.tab.c, y.tab.h, y.output) to support a more modern naming
scheme (dir/foo.y -> dir/foo.tab.c, dir/foo.tab.h, etc.). It does
that by renaming the generated files, and then by running sed to
propagate these renamings inside the files themselves.
Unfortunately Automake's Makefiles uses Bison as if it were Yacc (with
--yacc or with -o y.tab.c) and invoke bison via ylwrap. As a
consequence, as far as Bison is concerned, the output files are
y.tab.c and y.tab.h, so it emits '#include "y.tab.h"'. So far, so
good. But now ylwrap processes this '#include "y.tab.h"' into
'#include "dir/foo.tab.h"', which is not guaranteed to always work.
So, let's do the Right Thing when the output file is not y.tab.c, in
which case the user should %define api.header.include. Binding this
behavior to --yacc is tempting, but we recently told people to stop
using --yacc (as it also enables the Yacc warnings), but rather to use
-o y.tab.c.
Yacc.c is the only skeleton concerned: all the others do include their
header.
* data/skeletons/yacc.c (b4_header_include_if): New.
(api.header.include): Provide a default value when the output is not
y.tab.c.
* src/parse-gram.y (api.header.include): Define.
