Checking that an item index is > 1 means ruling out `$accept: • input
$end` and `$accept: input • $end`. But actually only the latter is
possible there, i.e., we're checking whether this item is about a
successor of a (kernel) item of the initial state ($accept: input •
$end).
* src/ielr.c (is_successor_of_initial_item): Use a variable to name
this condition.
* src/gram.h (rule_is_initial): New.
* src/graphviz.c, src/print-xml.c, src/print.c, src/lalr.c: Use it.
Some of these occurrences were incorrect (checking whether this is
rule 0), and not behaving properly in the case of multistart.
* src/lalr.c: Remove incorrect comment (subsumed anyway by the
(correct) one in the header.
(set_goto_map): More debug traces.
(map_goto): Add an assertion.
This should have been part of commit "symbols: stop dealing with YYEMPTY
as b4_symbol(-2, ...)" (cd40ec9526).
Give names to all the special symbols: "eof", "error" and "undef".
* data/skeletons/bison.m4 (b4_symbol): Let `b4_symbol(eof, ...)` mean
`b4_symbol(0, ...)`, `b4_symbol(error, ...)` mean `b4_symbol(1, ...)`,
and , `b4_symbol(undef, ...)` mean `b4_symbol(2, ...)`..
* data/skeletons/c.m4, data/skeletons/glr.c, data/skeletons/glr.cc,
* data/skeletons/glr2.cc, data/skeletons/lalr1.cc,
* data/skeletons/lalr1.d, data/skeletons/lalr1.java,
* data/skeletons/yacc.c:
Prefer symbols to numbers.
examples/java/calc/Calc.java:1531: warning: [deprecation] Integer(String) in Integer has been deprecated
yylval = new Integer(st.sval);
^
* examples/java/calc/Calc.y, examples/java/simple/Calc.y,
* tests/calc.at, tests/scanner.at: Use Integer.parseInt.
Vector is synchronized, which is completely useless in our case (and
not even relevant when concurrency matters). No seasoned Java
programmer would use it.
Reported by Uxio Prego.
* data/skeletons/lalr1.java: Replace Vector with ArrayList.
Unfortunately its API is not as rich, and lacks lastElement and
setSize.
* tests/calc.at: Add tests for LAC in pull and push parsers.
Skip LAC: line from the logs.
* tests/local.at (reportSyntaxError): Output the error message in a
single call, to avoid having the error message on stderr be
interrupted by the debug traces of LAC in getExpectedTokens.
Shamelessly stolen from Adrian Vogelsgesang's implementation in
lalr1.cc.
* data/skeletons/lalr1.java (yycdebugNnl, yyLacCheck, yyLacEstablish)
(yyLacDiscard, yylacStack, yylacEstablished): New.
(Context): Use it.
* examples/java/calc/Calc.y: Enable LAC.
* upstream/maint:
doc: fix typo
maint: post-release administrivia
version 3.7.3
build: don't link bison against libreadline
gnulib: update
glr.cc: fix: use symbol_name
build: fix a concurrent build issue in examples
When printing items, it is clearer to put the dot after %emtpy rather
than before:
0 $accept: . unit "end of file"
1 unit: . assignments exp
- 2 assignments: . %empty
+ 2 assignments: %empty .
3 | . assignments assignment
Also, use the Unicode characters if they are supported.
* src/gram.c (item_print): Put the dot after %emtpy.
* tests/conflicts.at, tests/reduce.at, tests/report.at: Adjust.
Currently `b4_percent_define_ifdef([foo])` assigns a default value to
`foo` when invoked. As a consequence, skeletons such as lalr1.d
cannot specify their specific default values: `foo` was defined in
bison.m4.
Instead, provide `foo` with a default value when `b4_foo_if` is
invoked.
I could not measure a runtime difference between both cases.
* data/skeletons/bison.m4 (_b4_percent_define_define): New.
Helps getting rid of spurious indentation that resulted in spurious
white space in the output.
(b4_percent_define_if_define): Move the definition to...
(_b4_percent_define_if_define): when the defined macros is called.
* tests/local.at (AT_TOKEN_TRANSLATE_IF): New, moved from...
* tests/calc.at: here.
Instead of sorting per feature (main, yylex, calc.y) and then by
language, do the converse, so that C bits are together, etc.
This is something that has always bothered me: with pure parsers (and
they all should be) the user does not have an (easy) access to yynerrs
at the end of the parse. In the case of error recovery, that's the
only direct means to know if there were errors. The usual approach
being having the user maintain a counter incremented each time yyerror
is called.
So here, also capture yynerrs in the return value of the start-symbol
parsing functions.
* data/skeletons/yacc.c (yy_parse_impl_t): New.
(yy_parse_impl): Use it.
(b4_accept): Fill it.
* examples/c/lexcalc/parse.y, examples/c/lexcalc/scan.l: No longer
pass nerrs as lex- and parse-param, just use the resulting yynerrs.
bistromathic and reccalc both demonstrate %param.
After all, why not?
* src/reader.c (switching_token): Use symbol_id_get.
(check_start_symbols): Require that the start symbol is a token only
if it's the only one.
* examples/c/lexcalc/parse.y: Let NUM be a start symbol.
For each start symbol, generate a parsing function with a richer
return value than the usual of yyparse. Reserve a place for the
returned semantic value, in order to avoid having to pass a pointer as
argument to "return" that value. This also makes the call to the
parsing function independent of whether a given start-symbol is typed.
For instance, if the grammar file contains:
%type <int> expression
%start input expression
(so "input" is valueless) we get
typedef struct
{
int yystatus;
} yyparse_input_t;
yyparse_input_t yyparse_input (void);
typedef struct
{
int yyvalue;
int yystatus;
} yyparse_expression_t;
yyparse_expression_t yyparse_expression (void);
This commit also changes the implementation of the parser termination:
when there are multiple start symbols, it is the initial rules that
explicitly YYACCEPT. They do that after having exported the
start-symbol's value (if it is typed):
switch (yyn)
{
case 1: /* $accept: YY_EXPRESSION expression $end */
{ ((*yyvalue).TOK_expression) = (yyvsp[-1].TOK_expression); YYACCEPT; }
break;
case 2: /* $accept: YY_INPUT input $end */
{ YYACCEPT; }
break;
I have tried several ways to deal with termination, and this is the
one that appears the best one to me. It is also the most natural.
* src/scan-code.h, src/scan-code.l (obstack_for_actions): New.
* src/reader.c (grammar_rule_check_and_complete): Generate the actions
of the rules for each start symbol.
* data/skeletons/bison.m4 (b4_symbol_slot): New, with safer semantics
than type and type_tag.
* data/skeletons/yacc.c (b4_accept): New.
Generates the body of the action of the start rules.
(_b4_declare_sub_yyparse): For each start symbol define a dedicated
return type for its parsing function.
Adjust the declaration of its parsing function.
(_b4_define_sub_yyparse): Adjust the definition of the function.
* examples/c/lexcalc/parse.y: Check the case of valueless symbols.
* examples/c/lexcalc/lexcalc.test: Check start symbols.
So far we were not checking the generated rule 0 at all. Now there
can be several of them. Instead of not checking at all, let's be more
selective on the check to run on them.
* src/reader.c (grammar_rule_check_and_complete): Don't check for
value usage for generated rules, it is ok to have a valued start
symbol, in which case it is ok for the generated rule ("accept: start
$end {}") to not use $1.
(packgram): Call grammar_rule_check_and_complete for all the rules.
Currently the core of the initial state is limited to the single rule
on $accept.
* src/lr0.c (generate_states): There may now be several rules on
$accept.
* src/graphviz.c (conclude_red): Recognize "final" transitions by the
fact that we reduce to "$accept".
* src/print.c (print_reduction): Likewise.
* src/print-xml.c (print_reduction): Likewise.
Now that the parser can read several start symbols, let's process
them, and create the corresponding rules.
* src/parse-gram.y (grammar_declaration): Accept a list of start symbols.
* src/reader.h, src/reader.c (grammar_start_symbol_set): Rename as...
(grammar_start_symbols_set): this.
* src/reader.h, src/reader.c (start_flag): Replace with...
(start_symbols): this.
* src/reader.c (grammar_start_symbols_set): Build a list of start
symbols.
(switching_token, create_start_rules): New.
(check_and_convert_grammar): Use them to turn the list of start
symbols into a set of rules.
* src/reduce.c (nonterminals_reduce): Don't complain about $accept,
it's an internal detail.
(reduce_grammar): Complain about all the start symbols that don't
derive sentences.
* src/symtab.c (startsymbol, startsymbol_loc): Remove, replaced by
start_symbols.
symbols_pack): Move the check about the start symbols
to...
* src/symlist.c (check_start_symbols): here.
Adjust to multiple start symbols.
* tests/reduce.at (Empty Language): Generalize into...
(Bad start symbols): this.
Currently this example crashes on input such as "T (x) + y;".
The same example with glr.c works properly.
* examples/c++/glr/Makefile, examples/c++/glr/README.md,
* examples/c++/glr/c++-types.test, examples/c++/glr/c++-types.yy,
* examples/c++/glr/local.mk, examples/c++/local.mk: New.
Based on examples/c/glr/c++-types.y.
The D skeleton was not properly supporting @1 etc.
Reported by Adela Vais.
https://lists.gnu.org/r/bison-patches/2020-09/msg00049.html
* data/skeletons/d.m4 (b4_rhs_location): Fix it.
* tests/calc.at: Check the support of @n for all the skeletons.
Based on the test case 668 (cxx-type.at:437) "GLR: Merge conflicting
parses, pure, locations".
* examples/c/glr/Makefile, examples/c/glr/README.md,
* examples/c/glr/c++-types.test, examples/c/glr/c++-types.y,
* examples/c/glr/local.mk: New.
This is consistent with --defines being deprecated in favor of
--header. The directive %defines is also too similar to %define.
And %header matches nicely with api.header.name.
* src/scan-gram.l (%defines): Deprecate to %header.
(%header): Scan it.
* src/parse-gram.y (PERCENT_DEFINES): Replace with...
(PERCENT_HEADER): this.
* data/skeletons/lalr1.java
* doc/bison.texi
* tests/actions.at, tests/c++.at, tests/calc.at, tests/conflicts.at,
* tests/input.at, tests/java.at, tests/local.at, tests/output.at,
* tests/synclines.at, tests/types.at:
Convert most tests to check %header instead of %defines.
The name "defines" is incorrect, the generated file contains far more
than just #defines.
* src/getargs.h, src/getargs.c (-H, --header): New option.
With optional argument, just like --defines, --xml, etc.
(defines_flag): Rename as...
(header_flag): this.
Adjust dependencies.
* data/skeletons/bison.m4, data/skeletons/c.m4, data/skeletons/glr.c,
* data/skeletons/glr.cc, data/skeletons/glr2.cc, data/skeletons/lalr1.cc,
* data/skeletons/yacc.c:
Adjust.
* examples, doc/bison.texi: Adjust.
* tests/headers.at, tests/local.at, tests/output.at: Convert most
tests from using --defines to using --header.
231. conflicts.at:1096: testing Syntax error in consistent error state: glr2.cc ...
tests/conflicts.at:1096: $CXX $CXXFLAGS $CPPFLAGS $LDFLAGS -o input input.cc $LIBS
input.cc: In member function 'YYRESULTTAG glr_stack::yyresolveValue(glr_state*)':
input.cc:2674:36: error: 'yysval' may be used uninitialized in this function [-Werror=uninitialized]
Do not initialize the variable: this way ASAN can really make sure we
do set it to a proper value.
If we initialize it, ASAN would report nothing.
* data/skeletons/c.m4 (YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN): Disable
GCC 4.6's -Wuninitialized.
* data/skeletons/glr2.cc: Disable the warning locally.
231. conflicts.at:1096: testing Syntax error in consistent error state: glr2.cc ...
tests/conflicts.at:1096: $CXX $CXXFLAGS $CPPFLAGS $LDFLAGS -o input input.cc $LIBS
input.cc: In function 'int yyparse(yy::parser&)':
input.cc:3147:41: error: 'yyarg' may be used uninitialized in this function [-Werror=maybe-uninitialized]
return yytnamerr_ (yytname_[yysymbol]);
^
input.cc:2058:34: note: 'yyarg' was declared here
yy::parser::symbol_kind_type yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM];
^
* data/skeletons/glr2.cc (yyreportSyntaxError): Initialize yyarg.
Fix a warning triggered in GCC (at least from 4.6 to 4.9):
input.cc: In constructor 'glr_stack_item::glr_stack_item(bool)':
input.cc:1371:5: error: declaration of 'is_state' shadows a member of 'this' [-Werror=shadow]
: is_state_(is_state)
^
* data/skeletons/glr2.cc (glr_stack_item): Alpha-convert.
On the CI, tests fail with GCC 4.6 to GCC 6 as follows:
tests/synclines.at:440: COLUMNS=1000; export COLUMNS; NO_TERM_HYPERLINKS=1; export NO_TERM_HYPERLINKS; bison --color=no -fno-caret -o \"\\\"\".cc \"\\\"\".y
tests/synclines.at:440: $CXX $CXXFLAGS $CPPFLAGS $LDFLAGS -o \"\\\"\" \"\\\"\".cc $LIBS
stderr:
"\"".cc: In member function 'glr_state& glr_stack_item::getState()':
"\"".cc:1404:47: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
return *reinterpret_cast<glr_state*>(&raw_);
^
"\"".cc: In member function 'const glr_state& glr_stack_item::getState() const':
"\"".cc:1408:53: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
return *reinterpret_cast<const glr_state*>(&raw_);
^
"\"".cc: In member function 'semantic_option& glr_stack_item::getOption()':
"\"".cc:1413:53: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
return *reinterpret_cast<semantic_option*>(&raw_);
^
"\"".cc: In member function 'const semantic_option& glr_stack_item::getOption() const':
"\"".cc:1417:59: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
return *reinterpret_cast<const semantic_option*>(&raw_);
^
See also be6fa942ac.
* data/skeletons/glr2.cc (glr_stack_item): Use a temporary void*
variable to avoid type-punning issues with reinterpret_cast.
Currently the compiler attributes are defined in
b4_shared_declarations (that can in the header if it exists, otherwise
in the implementation file). This is not needed, only the
implementation file needs them.
Besides, glr2.cc was also defining these macros in the implementation
file, so we had two definitions.
* data/skeletons/glr.cc, data/skeletons/glr2.cc: Define the compiler
attribute macros only in the implementation files.
* tests/regression.at (Lex and parse params): Generate a header, to
make it easy to check that the header is self-sufficient.
input.cc: In constructor 'glr_stack_item::glr_stack_item(bool)':
input.cc:1423:5: error: declaration of 'isState' shadows a member of 'this' [-Werror=shadow]
: isState_(isState) {
^
test.cc:1165:45: error: declaration of 'begin' shadows a member of 'this' [-Werror=shadow]
test.cc:1167:45: error: declaration of 'end' shadows a member of 'this' [-Werror=shadow]
* data/skeletons/glr2.cc (isState): Rename as...
(is_state): this.
Formatting changes.
(reduceToOneStack): Rename variables to avoid name clashes.
Commit af000bab11 ("doc: work around
Texinfo 6.7 bug"), published in 3.4.91, added a dependency on the
"all" target.
This is a super bad idea, since "make all" will run this
target *before* "all", which builds bison. It turns out that this new
dependency actually needed bison to be built. So all the regular
process (i) build $(BUILT_SOURCES) and then (ii) build bison, was
wrecked since some of the $(BUILT_SOURCES) depended on bison...
It was "easy" to see in the logs of "make V=1" because we were
building bison files (such as src/files.o) *before* displaying the
banner for "all-recursive". With this fix, we finally get again the
proper sequence:
rm -f examples/c/reccalc/scan.stamp examples/c/reccalc/scan.stamp.tmp
/opt/local/libexec/gnubin/mkdir -p examples/c/reccalc
touch examples/c/reccalc/scan.stamp.tmp
flex -oexamples/c/reccalc/scan.c --header=examples/c/reccalc/scan.h ./examples/c/reccalc/scan.l
mv examples/c/reccalc/scan.stamp.tmp examples/c/reccalc/scan.stamp
rm -f lib/fcntl.h-t lib/fcntl.h && \
{ echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
...
} > lib/fcntl.h-t && \
mv lib/fcntl.h-t lib/fcntl.h
...
mv -f lib/alloca.h-t lib/alloca.h
make all-recursive
Reported by Mingli Yu <[email protected]>.
https://github.com/akimd/bison/issues/31https://lists.gnu.org/r/bison-patches/2020-05/msg00055.html
Reported by Claudio Calvelli <[email protected]>.
https://lists.gnu.org/r/bug-bison/2020-09/msg00001.htmlhttps://bugs.gentoo.org/716516
* doc/local.mk (all): Rename as...
(all-local): this.
So that we don't compete with BUILT_SOURCES.
The yyerror stand-alone function was used to bounce from glr.c's call
to yyerror to glr.cc's parser.error. Now that glr.c is out of the
way, just directly use parser.error.
* data/skeletons/glr2.cc (yyerror): Remove.
Adjust callers.
(b4_yyerror_args, b4_lyyerror_args, b4_pure_formals): Remove.
Now unused.
On a case such as
%%
exp
: empty "a"
| "a" empty
empty
: %empty
we used to display
warning: shift/reduce conflict on token "a" [-Wcounterexamples]
Example: • "a"
Shift derivation
exp
↳ 2: • "a" empty
↳ 2: ε
Example: • "a"
Reduce derivation
exp
↳ 1: empty "a"
↳ 3: •
where the shift derivation shows an item "2: empty → ε", with an
explicit "ε", but the reduce derivation shows "3: empty → •", without
"ε".
For consistency, let's always show ε/%empty in rules with an empty
rhs:
Reduce derivation
exp
↳ 1: empty "a"
↳ 3: ε •
* src/derivation.c (derivation_width, derivation_print_tree_impl):
Always show ε/%empty in counterexamples.
* tests/diagnostics.at: Check that case.
* tests/conflicts.at, tests/counterexample.at: Adjust.
* data/skeletons/glr2.cc: Fix some documentation.
Be consistent between class/struct.
(yydoAction, yyresolveAction): Avoid passing yyparser where useless.
Reported by Dennis Clarke.
https://lists.gnu.org/r/bug-bison/2020-08/msg00013.html
* examples/d/local.mk, examples/java/calc/local.mk,
* examples/java/simple/local.mk: Pass bison's options before its
argument, in case we're in POSIX mode.
Akim Demaille