https://lists.gnu.org/archive/html/bison-patches/2019-08/msg00007.html
When Bison is started with a flag that suppresses warning messages, the
error_message() function can produce a few gigabytes of indentation
because of a dangling pointer.
* src/complain.c (error_message): Don't reset indent_ptr here, but...
(complain_indent): here.
* tests/diagnostics.at (Indentation with message suppression): Check
this case.
It is more consistent with --color=html, --color=test, etc.
* src/getargs.h, src/getargs.c (style_debug): Rename as...
(color_debug): this.
(getargs_colors): Rename --style=debug as --color=debug.
Adjust dependencies.
* 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 we pass only the columns based on the screen-width, which is
important for the carets. But we don't pass the bytes-based columns,
which is important for the colors. Pass both.
* src/muscle-tab.c (muscle_boundary_grow): Also pass the byte-based column.
* src/location.c (location_caret): Clarify.
(boundary_set_from_string): Adjust to the new format.
* tests/diagnostics.at (Tabulations and multibyte characters from M4): New.
Locations issued from M4 need the byte-based column for the
diagnostics to work properly. Currently they were unassigned, which
typically resulted in partially non-colored diagnostics.
* src/location.c (boundary_set_from_string): Fix the parsed location.
* src/muscle-tab.c (muscle_percent_define_default): Set the byte values.
* tests/diagnostics.at (Locations from M4): New.
The "identifier and colon" of a rule is implemented as a single token,
but whose location is only that of the identifier (so that messages
about the lhs of a rule are accurate). When reducing empty rules, the
default location is the single point location on the end of the
previous symbol. As a consequence, when Bison parses a grammar, the
location of the right-hand side of an empty rule is based on the
lhs, *independently of the position of the colon*. And the colon can
be way farther, separated by comments, white spaces, including empty
lines.
As a result, some messages look really bad. For instance:
$ cat foo.y
%%
foo : /* empty */
bar
: /* empty */
gives
$ bison -Wall foo.y
foo.y:2.4: warning: empty rule without %empty [-Wempty-rule]
2 | foo : /* empty */
| ^
foo.y:3.4: warning: empty rule without %empty [-Wempty-rule]
3 | bar
| ^
The carets are not at the right column, not even the right line.
This commit passes the colon "again" after the "id colon" token, which
gives more accurate locations for these messages:
$ bison -Wall foo.y
foo.y:2.10: warning: empty rule without %empty [-Wempty-rule]
2 | foo : /* empty */
| ^
foo.y:4.2: warning: empty rule without %empty [-Wempty-rule]
4 | : /* empty */
| ^
* src/scan-gram.l (SC_AFTER_IDENTIFIER): Rollback the colon, so that
we scan it again afterwards.
(INITIAL): Scan colons.
* src/parse-gram.y (COLON): New.
(rules): Parse the colon after the rule's id_colon (and possible
named reference).
* tests/actions.at, tests/conflicts.at, tests/diagnostics.at,
* tests/existing.at: Adjust.
Currently, when we quote the source file, we indent it with one space,
and preserve tabulations, so there is a discrepancy and the visual
rendering is bad. One way out is to indent with a tab instead of a
space, but then this space can be used for more information. This is
what GCC9 does. Let's play copy cats.
See
https://lists.gnu.org/archive/html/bison-patches/2019-04/msg00025.htmlhttps://developers.redhat.com/blog/2019/03/08/usability-improvements-in-gcc-9/https://gcc.gnu.org/onlinedocs/gccint/Guidelines-for-Diagnostics.html#Guidelines-for-Diagnostics
* src/location.c (location_caret): Prefix quoted lines with the line
number and a pipe, fitting 8 columns.
* tests/actions.at, tests/c++.at, tests/conflicts.at,
* tests/diagnostics.at, tests/input.at, tests/java.at,
* tests/named-refs.at, tests/reduce.at, tests/regression.at,
* tests/sets.at: Adjust expectations.
Partly by "./build-aux/update-test tests/testsuite.dir/*/testsuite.log"
repeatedly, and partly by hand.
This is a pity: efforts were invested in computing correctly the
number of screen columns consumed by multibyte characters, but the
routines that do that were fed by single-byte inputs...
As a consequence Bison never displayed correctly locations when there
are multibyte characters.
* src/scan-gram.l (mbchar): New.
Use it instead of . in the catch-all clause.
* tests/diagnostics.at (Tabulations): Enhance into...
(Tabulations and multibyte characters): this.
Single point locations (equal boundaries) are troublesome, and we were
incorrectly ending the style in their case. Which results in an abort
in libtextstyle.
There is also a confusion between columns as displayed on the
screen (which take into account multibyte characters and tabulations),
and the number of bytes. Counting the screen-column
incrementally (character by character) is uneasy (because of multibyte
characters), and I don't want to maintain a buffer of the current line
when displaying the diagnostic. So I believe the simplest solution is
to track the byte number in addition to the screen column.
* src/location.h, src/location.c (boundary): Add the byte-column.
Adjust dependencies.
* src/getargs.c, src/scan-gram.l: Adjust.
* tests/diagnostics.at: Check zero-width locations.
Enable checking of styles even when libtextstyle is not installed.
* src/getargs.h, src/getargs.c (style_debug): New.
(getargs_colors): Set it when --style=debug.
* src/complain.c (begin_use_class, end_use_class): Use it.
* tests/diagnostics.at: New.
