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.
All methods are now declared as const. Method getExpectedTokens() has now the
functionality of reporting only the number of expected tokens.
* data/skeletons/lalr1.d: Fix Context class.
In D's case, yyerrok() is a private method of the Parser class.
It can be called directly as `yyerrok()` from the grammar rules section.
* data/skeletons/lalr1.d: Add yyerrok().
* examples/d/calc/calc.y, examples/d/simple/calc.y: Demonstrate yyerrok().
* tests/calc.at: Update D tests to use yyerrok().
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.
This will provide the user an interface for creating custom error messages.
* data/skeletons/lalr1.d: Add the Context class.
* doc/bison.texi: Document it.
* 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.
