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.
These macros have been extremely useful when we had to support K&R C,
which we dropped long ago. Now, they merely make the code uselessly
hard to read.
* data/skeletons/c.m4, data/skeletons/glr.c, data/skeletons/glr.cc,
* data/skeletons/yacc.c:
Stop using b4_function_define.
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.
The current implementation of parser::context keeps a copy of the
lookahead. This is troublesome since we support move-only types.
Besides, while GCC is happy with the current implementation, Clang
complains that the ctor it needs to build the copy of the lookahead is
not yet available.
461. calc.at:1120: testing Calculator C++ %defines %locations parse.error=verbose %name-prefix "calc" %verbose ...
calc.at:1120: COLUMNS=1000; export COLUMNS; bison --color=no -fno-caret -Wno-deprecated -o calc.cc calc.y
calc.at:1120: $CXX $CXXFLAGS $CPPFLAGS $LDFLAGS -o calc calc.cc calc-lex.cc calc-main.cc $LIBS
stderr:
In file included from calc-lex.cc:7:
calc.hh:351:12: error: instantiation of function 'calc::parser::basic_symbol<calc::parser::by_type>::basic_symbol' required here, but no definition is available [-Werror,-Wundefined-func-template]
struct symbol_type : basic_symbol<by_type>
^
calc.hh:273:7: note: forward declaration of template entity is here
basic_symbol (const basic_symbol& that);
^
calc.hh:351:12: note: add an explicit instantiation declaration to suppress this warning if 'calc::parser::basic_symbol<calc::parser::by_type>::basic_symbol' is explicitly instantiated in another translation unit
struct symbol_type : basic_symbol<by_type>
^
1 error generated.
In file included from calc-main.cc:7:
calc.hh:351:12: error: instantiation of function 'calc::parser::basic_symbol<calc::parser::by_type>::basic_symbol' required here, but no definition is available [-Werror,-Wundefined-func-template]
struct symbol_type : basic_symbol<by_type>
^
calc.hh:273:7: note: forward declaration of template entity is here
basic_symbol (const basic_symbol& that);
^
calc.hh:351:12: note: add an explicit instantiation declaration to suppress this warning if 'calc::parser::basic_symbol<calc::parser::by_type>::basic_symbol' is explicitly instantiated in another translation unit
struct symbol_type : basic_symbol<by_type>
^
1 error generated.
stdout:
calc.at:1120: exit code was 1, expected 0
461. calc.at:1120: 461. Calculator C++ %defines %locations parse.error=verbose %name-prefix "calc" %verbose (calc.at:1120): FAILED (calc.at:1120)
* data/skeletons/lalr1.cc (context::yyla_): Make it a const-ref.
Move the implementation out of the declaration.
Address compiler warnings such as
warning: declaration of 'yyla' shadows a member of 'yy::parser::context' [-Wshadow]
* data/skeletons/lalr1.cc (context): Don't use the same names for
variables and members.
Use foo_ for private members, as in parser.
Also, use the + trick in array accesses to please ICC and provide it
with an int.
* data/skeletons/lalr1.cc: added support here
* tests/calc.at: added test cases
* tests/local.at: added yyreport_syntax_error implementation
for C++ test cases
Prefer b4_parse_error_case over the adhoc solution
`m4_case + b4_percent_define_get`. Same for b4_parse_error_bmatch.
* data/skeletons/glr.c: here
* data/skeletons/yacc.c: here
* etc/bench.pl.in: Adjust to the current use of %define's values.
Don't use %error-verbose.
Prefer Bison to CPP (e.g., api.value.type).
Avoid returning characters directly, so that %define api.token.raw works.
* doc/bison.texi (Parser Internationalization): Move most of its
content into...
(Enabling I18n): this new node.
(Token I18n): New.
(Token Decl): Refer to token internationalization.
(Error Reporting Function): Promote parse.error detailed.
Since Bison 2.7, output was indented four spaces for explanatory
statements. For example:
input.y:2.7-13: error: %type redeclaration for exp
input.y:1.7-11: previous declaration
Since the introduction of caret-diagnostics, it became less clear.
Remove the indentation and display submessages as in GCC:
input.y:2.7-13: error: %type redeclaration for exp
2 | %type <float> exp
| ^~~~~~~
input.y:1.7-11: note: previous declaration
1 | %type <int> exp
| ^~~~~
* src/complain.h (SUB_INDENT): Remove.
(warnings): Add "note" to the enum.
* src/complain.h, src/complain.c (complain_indent): Replace by...
(subcomplain): this.
Adjust all dependencies.
* tests/actions.at, tests/diagnostics.at, tests/glr-regression.at,
* tests/input.at, tests/named-refs.at, tests/regression.at:
Adjust expectations.
bison 3.5.2
* tag 'v3.5.2':
version 3.5.2
news: 3.5.2
gnulib: update
doc: update Doxygen template
java: avoid trailing white spaces
m4: fix b4_token_format
doc: clearly state that %yacc only makes sense with yacc.c
doc: spell check
examples: be more robust to spaces in paths
larlr1.cc: Reject unsupported values for parse.lac
