Bison used to feature %raw, documented as follows:
@item %raw
The output file @file{@var{name}.h} normally defines the tokens with
Yacc-compatible token numbers. If this option is specified, the
internal Bison numbers are used instead. (Yacc-compatible numbers start
at 257 except for single character tokens; Bison assigns token numbers
sequentially for all tokens starting at 3.)
Unfortunately, as far as I can tell, it never worked: token numbers
are indeed changed in the generated tables (from external token number
to internal), yet the code was still applying the mapping from
external token numbers to internal token numbers.
This commit reintroduces the feature as it was expected to be.
* data/skeletons/bison.m4 (b4_token_format): When api.token.raw is
enabled, use the internal token number.
* data/skeletons/yacc.c (yytranslate): Don't emit if api.token.raw is
enabled.
(YYTRANSLATE): Adjust.
* data/skeletons/yacc.c (yysyntax_error): Change the nesting of `m4`
conditions slightly to make it more readable.
The generated C code stays unchanged.
Currently, with --no-lines, instead of "#line file line\n", we emit
"\n". Let's emit nothing.
* data/skeletons/bison.m4 (b4_syncline): Emit at end-of-line when enabled.
* data/skeletons/bison.m4, data/skeletons/c.m4, data/skeletons/glr.cc,
* data/skeletons/lalr1.cc, src/output.c: Use dnl after b4_syncline to
avoid spurious empty lines.
* tests/synclines.at (Sync Lines): Make sure that --no-lines is like
grep -v #line.
* tests/calc.at: Make sure that a rich grammar file behaves properly
with %no-lines.
The variable spec_defines_file denotes the name of the generated
header. Its name is derived from --defines/%defines, whose name in
turn is derived from the fact that the header, in Yacc, contained the
Not only does the header now contain a lot more than just the token
definitions, but we no longer even generate macros, but an enum...
Let's modernize our vocabulary.
* src/files.h, src/files.c (spec_defines_file): Rename as...
(spec_header_file): this.
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.
* data/skeletons/yacc.c: here.
This is more logical for the time stamps, but it's also required by
following patches: the shared declarations are also in charge of
handling api.value.type=union. So far, they are run in the
implementation file in both cases (with or without header). But if we
run them only in the header, then the implementation file is emited
with incorrect support for api.value.type=union.
Arguably we should not have such dependencies. This is because we
have side-effects in our backend (redefining the symbols' type and
type_tag). In the future we should find a better solution for this,
without sacrificing the independence of the backend from bison
itself (i.e., I don't think we should handle api.value.type=union in
bison, leave it to m4).
While hacking on the computation of the automaton, I had yystate being
equal to -1, and the parser loops. Let's catch this when
parser.assert is enabled.
* data/skeletons/yacc.c (YY_ASSERT): New.
Use it.
Not using the name YYASSERT, to make it clear that this is private.
glr.c should probably move to YY_ASSERT too.
Also, while at it, report 'Entering state...' even before growing the
stacks.
Reported by Derek Clegg.
http://lists.gnu.org/archive/html/bug-bison/2019-01/msg00004.html
* configure.ac (warn_common): Add -Wimplicit-fallthrough.
This does trigger failures in the test suite.
* data/skeletons/glr.c, data/skeletons/lalr1.cc,
* data/skeletons/yacc.c, tests/c++.at:
Make fall-throws explicit.
