Currently, in C, the default semantic action is implemented by being
always run before running the actual user semantic action. As a
consequence, when the user action is run, $$ is already set as $1.
In C++ with variants, we don't do that, since we cannot manipulate the
semantic value without knowing its exact type. When variants are
enabled, the only guarantee is that $$ is default contructed and ready
to the used.
Some users still would like the default action to be run with
variants. Frank Heckenbach's parser in
C++17 (http://lists.gnu.org/archive/html/bug-bison/2018-04/msg00011.html)
provides this feature, but relying on std::variant's dynamic typing,
which we forbid in lalr1.cc.
The simplest seems to be actually generating the default semantic
action (in all languages/skeletons). This makes the pre-action (that
sets $$ to $1) useless. But... maybe some users depend on this, in
spite of the comments that clearly warn againt this. So let's not
turn this off just yet.
* src/reader.c (grammar_rule_check_and_complete): Rename as...
(grammar_rule_check_and_complete): this.
Install the default semantic action when applicable.
* examples/variant-11.yy, examples/variant.yy, tests/calc.at:
Exercise the default semantic action, even with variants.
Now that distcheck no longer fails (see previous commit), let's
address the shortcomings.
* Makefile.am (CLEANDIRS, clean-local): New.
* doc/local.mk, examples/calc++/local.mk, examples/local.mk,
* examples/mfcalc/local.mk, examples/rpcalc/local.mk,
* src/local.mk
(CLEANDIRS): Get rid of Apple's *.dSYM directories.
(CLEANFILES): Get rid of *.output files.
* examples/variant-11.yy, examples/variant.yy: Don't generate
any of the auxiliary files (location.hh and the like).
In the case a user wants to create location.hh elsewhere, it can be
helpful to define api.location.file to some possibly absolute path
such as -Dapi.location.file='"$(top_srcdir)/include/ast/location.hh"'.
Currently this does not work with `-o foo/parser.cc`, as we join foo/
and $(top_srcdir) together, the latter starting with slash.
We should not try to do that in m4, manipulating file names is quite
complex when you through Windows file name in. Let m4 delegate this
to gnulib.
* src/scan-skel.l (at_output): Accept up to two arguments.
* data/bison.m4 (b4_output): Adjust.
* tests/skeletons.at (Fatal errors but M4 continues producing output):
Adjust to keep the error.
* data/location.cc, data/stack.hh: Leave the concatenation to @output.
* tests/output.at: Exercise api.location.file with an absolute path.
* src/getargs.c (getargs): Don't display any argv other that argv[0]
when reporting a missing argument.
* tests/bison.in: Neutralize path differences in stderr.
* tests/input.at (Invalid number of arguments): New.
* src/getargs.c (usage): Rely on setlocale (LC_MESSAGES, NULL)
trick only on glibc, as POSIX does not specify the output
of setlocale in this case, and the Gnulib localename module
source code indicates that the trick works only on glibc.
C11 no longer requires support for variable-length arrays, and
VS2015 does not have them. Redo UNIQSTR_CONCAT to use a method
that is simpler and better anyway.
* src/uniqstr.c (uniqstr_vsprintf): Remove; no longer needed.
* src/uniqstr.h (UNIQSTR_GEN_FORMAT, UNIQSTR_GEN_FORMAT_):
* src/uniqstr.c (uniqstr_concat): New function.
* src/uniqstr.h (UNIQSTR_CONCAT): Use it instead of using
uniqstr_vsprintf.
The code was already using midrule only, never mid_rule. This is
simpler to remember, and matches a similar change we made from
look-ahead to lookahead.
* NEWS, doc/bison.texi, src/reader.c, src/scan-code.h, src/scan-code.l
* tests/actions.at, tests/c++.at, tests/existing.at: here.
That's the version on Ubuntu Precise.
See also 1dac131ec4.
* src/flex-scanner.h: Disable -Wdocumentation.
* doc/bison.texi: Turn off a warning triggered by Flex 2.6.4.
Reported by Jannick.
http://lists.gnu.org/archive/html/bug-bison/2017-05/msg00001.html
"Amusingly" enough, we have the same problem with %defines when the
parser file name has backslashes or quotes: we generate #includes with
an incorrect C string.
* src/output.c (prepare_symbol_definitions): Escape properly the file
names before passing them to M4.
* data/bison.m4, data/lalr1.cc: Don't simply put the file name between
two quotes (that should have been strong enough a smell...), expect
the string to be properly quoted.
* tests/synclines.at: New tests to check this.
Suggested by Paul Eggert.
* src/reader.c (find_start_symbol): Don't check 'res', we know it is
not null. That suffices to avoid the GCC warnings.
* bootstrap.conf: We don't need 'assume', which doesn't exist anyway.
With GCC 7.3.0 and Flex 2.6.4, we get warnings on all the generated
scanners:
examples/calc++/calc++-scanner.cc: In function 'void yyrestart(FILE*)':
examples/calc++/calc++-scanner.cc:1611:20: error: potential null pointer dereference [-Werror=null-dereference]
/* %endif */
~~~~~~~~~~~ ^
examples/calc++/calc++-scanner.cc:1607:19: error: potential null pointer dereference [-Werror=null-dereference]
/* %if-c-only */
~~~~~~~~~~~~~~~ ^
examples/calc++/calc++-scanner.cc:1611:20: error: potential null pointer dereference [-Werror=null-dereference]
/* %endif */
~~~~~~~~~~~ ^
examples/calc++/calc++-scanner.cc:1607:19: error: potential null pointer dereference [-Werror=null-dereference]
/* %if-c-only */
~~~~~~~~~~~~~~~ ^
cc1plus: all warnings being treated as errors
Obviously the lines are incorrect, and the warnings are emitted twice.
Still, let's get rid of these warnings.
* doc/bison.texi, src/flex-scanner.h: Disable these warnings in code
generated by Flex.
Commit 3df32101e7 introduced invalid C
code. Caught by GCC 7.3.0.
* bootstrap.conf (gnulib_modules): We need assume.
* src/reader.c (find_start_symbol): Fix the signature (too much C++,
sorry...).
Prefer 'assume' to 'assert', so that we don't have these warnings even
when NDEBUG is defined.
Make sure that we cannot apply a type to the (main) action of a rule.
* src/reader.c (grammar_rule_check): Issue the warning.
* tests/input.at (Cannot type action): Check the warning.
