That's one nice benefit from using enums.
* data/skeletons/lalr1.java (YYSYMBOL_YYEMPTY): No longer define it.
Use 'null' instead.
* examples/java/calc/Calc.y, tests/local.at: Adjust.
* data/skeletons/bison.m4, data/skeletons/c++.m4, data/skeletons/c.m4,
* data/skeletons/glr.cc, data/skeletons/lalr1.cc,
* data/skeletons/lalr1.d, data/skeletons/lalr1.java:
Refer to the "kind" of a symbol, not its "type", where appropriate.
* maint:
maint: post-release administrivia
version 3.5.4
examples: reccalc: really compile cleanly in C99
news: announce that Bison 3.6 drops YYERROR_VERBOSE
news: update for 3.5.4
style: fix spellos
typo: succesful -> successful
package: improve the readme
java: check and fix support for api.token.raw
java: style: prefer 'int[] foo' to 'int foo[]'
build: fix syntax-check issues
tests: recheck: work properly when the test suite was interrupted
doc: c++: promote api.token.raw
build: fix compatibility with old compilers
examples: reccalc: compile cleanly in C99
The first name is too long. We already have `yypstate`, so
`yypcontext` is ok. We are also migrating to using `*_t` for our
types.
* NEWS, data/skeletons/glr.c, data/skeletons/yacc.c, doc/bison.texi,
* examples/c/bistromathic/parse.y, src/parse-gram.y, tests/local.at:
(yyparse_context_t, yyparse_context_location, yyparse_context_token):
Rename as...
(yypcontext_t, yypcontext_location, yypcontext_token): these.
The Java enums are very different from the C model. As a consequence,
one cannot "build" an enum directly from an integer, we must retrieve
it. That's the purpose of the SymbolType.get class method.
* data/skeletons/java.m4 (b4_symbol_enum, b4_case_code_symbol)
(b4_declare_symbol_enum): New.
* data/skeletons/lalr1.java: Use SymbolType,
SymbolType.YYSYMBOL_YYEMPTY, etc.
* examples/java/calc/Calc.y, tests/local.at: Adjust.
* tests/local.at (AT_LANG_MATCH, AT_YYERROR_DECLARE(java))
(AT_YYERROR_DECLARE_EXTERN(java), AT_PARSER_CLASS): New.
(AT_MAIN_DEFINE(java)): Use AT_PARSER_CLASS.
* tests/scanner.at: Add a test for Java.
* data/skeletons/lalr1.java (yytranslate_): Cast the result.
* data/skeletons/d.m4 (b4_symbol_enum, b4_declare_symbol_enum): New.
* data/skeletons/lalr1.d: Use them.
Use SymbolType, SymbolType.YYSYMBOL_YYEMPTY etc. where appropriate.
(undef_token_, token_number_type, yy_error_token_): Remove.
Because of the insane current implementation of glr.cc, things are a
bit nasty. We will rename symbol_number_type as symbol_type_type
later, to keep this commit small.
* data/skeletons/c++.m4 (b4_declare_symbol_enum): New.
Also define YYNTOKENS to avoid type clashes when yyntokens_ was
actually defined in another enum.
Use it.
(symbol_number_type): Be an alias of symbol_type_type.
Use YYSYMBOL_YYEMPTY and the like.
Use symbol_number_type where appropriate.
(empty_symbol): Remove.
(yytranslate_): Use symbol_number_type, not token_number_type.
* data/skeletons/lalr1.cc: Use symbol_number_type where appropriate.
Adjust to the replacement of empty_symbol by YYSYMBOL_YYEMPTY.
(yy_error_token_, yy_undef_token_, yyeof_, yyntokens_): Remove.
Adjust dependencies.
* data/skeletons/glr.cc: Use symbol_number_type where appropriate.
Forward definitions of YYSYMBOL_YYEMPTY, etc. to glr.c.
* tests/headers.at: Accept YYNTOKENS and other YYSYMBOL_*.
* tests/local.at (AT_YYERROR_DEFINE(c++)): Use symbol_number_type.
Now that yacc.c and glr.c both know yysymbol_type_t, convert the
common routines.
* data/skeletons/c.m4 (yydestruct, yy_symbol_value_print)
(yy_symbol_print): Use yysymbol_type_t instead of int.
* data/skeletons/glr.c: Use yySymbol where appropriate.
* data/skeletons/yacc.c (YY_ACCESSING_SYMBOL): New wrapper around
yystos.
Use it.
* tests/local.at (yyreport_syntax_error): Use yysymbol_type_t where
appropriate.
Apply the same changes as in yacc.c. Now yySymbol and yysymbol_type_t
are aliases. We will remove the former later, to avoid cluttering
this commit.
* data/skeletons/glr.c: Use b4_declare_symbol_enum.
Use YYSYMBOL_YYEOF etc. where appropriate.
(YYUNDEFTOK, YYTERROR): Remove.
(YYTRANSLATE, yySymbol, yyexpected_tokens, yysyntax_error_arguments):
Adjust.
(yy_accessing_symbol): New.
Use it where appropriate.
This triggers warnings with several compilers. For instance ICC fills
the logs with pages and pages of
input.c(477): error: a value of type "int" cannot be used to initialize an entity of type "const yysymbol_type_t={yysymbol_type_t}"
0, 2, 2, 2, 2, 2, 2, 2, 2, 2,
^
input.c(477): error: a value of type "int" cannot be used to initialize an entity of type "const yysymbol_type_t={yysymbol_type_t}"
0, 2, 2, 2, 2, 2, 2, 2, 2, 2,
^
And so does G++9 when compiling yacc.c's (C) output
input.c:545:8: error: invalid conversion from 'int' to 'yysymbol_type_t' [-fpermissive]
545 | 0, 5, 9, 2, 2, 2, 2, 2, 2, 2,
| ^
| |
| int
input.c:545:15: error: invalid conversion from 'int' to 'yysymbol_type_t' [-fpermissive]
545 | 0, 5, 9, 2, 2, 2, 2, 2, 2, 2,
| ^
| |
| int
Clang++ is no exception
input.c:545:8: error: cannot initialize an array element of type 'const yysymbol_type_t' with an rvalue of type 'int'
0, 5, 9, 2, 2, 2, 2, 2, 2, 2,
^
input.c:545:15: error: cannot initialize an array element of type 'const yysymbol_type_t' with an rvalue of type 'int'
0, 5, 9, 2, 2, 2, 2, 2, 2, 2,
^
At some point we could use yysymbol_type_t's enumerators to define
yytranslate. Meanwhile...
* data/skeletons/yacc.c (yytranslate): Use the original integral type
to define it.
(YYTRANSLATE): Cast the result into yysymbol_type_t.
Currently we define enumerators only for symbols that have an
identifier. That rules out tokens such as '+', and nonterminals such
as foo-bar and foo.bar. As a consequence we are taking chances: the
compiler might compile yysymbol_type_t as too small an integral type
for some symbol codes.
* data/skeletons/bison.m4 (b4_symbol_sid): Forge a unique symbol
identifier for symbols that don't have an ID.
This is not only cleaner, it also protects us from mixing signed
values (YYEMPTY is #defined as -2) with unsigned types (the
yysymbol_type_t enum is typically compiled as a small unsigned).
For instance GCC 9:
input.c: In function 'yyparse':
input.c:1107:7: error: conversion to 'unsigned int' from 'int'
may change the sign of the result
[-Werror=sign-conversion]
1107 | yyn += yytoken;
| ^~
input.c:1107:10: error: conversion to 'int' from 'unsigned int'
may change the sign of the result
[-Werror=sign-conversion]
1107 | yyn += yytoken;
| ^~~~~~~
input.c:1108:47: error: comparison of integer expressions of
different signedness:
'yytype_int8' {aka 'const signed char'} and
'yysymbol_type_t' {aka 'enum yysymbol_type_t'}
[-Werror=sign-compare]
1108 | if (yyn < 0 || YYLAST < yyn || yycheck[yyn] != yytoken)
| ^~
input.c:702:25: error: operand of ?: changes signedness from 'int'
to 'unsigned int' due to unsignedness of
other operand [-Werror=sign-compare]
702 | #define YYEMPTY (-2)
| ^~~~
input.c:1220:33: note: in expansion of macro 'YYEMPTY'
1220 | yytoken = yychar == YYEMPTY ? YYEMPTY : YYTRANSLATE (yychar);
| ^~~~~~~
input.c:1220:41: error: unsigned conversion from 'int' to
'unsigned int' changes value
from '-2' to '4294967294'
[-Werror=sign-conversion]
1220 | yytoken = yychar == YYEMPTY ? YYEMPTY : YYTRANSLATE (yychar);
| ^
Eventually, it might be interesting to move away from -2 (which is the
only possible negative symbol number) and use the next available
number, to save bits. We could actually even simply use "0" and shift
the rest, which would allow to write "!yytoken" to mean really
"yytoken != YYEMPTY".
* data/skeletons/c.m4 (b4_declare_symbol_enum): Define YYSYMBOL_YYEMPTY.
* data/skeletons/yacc.c: Use it.
* src/parse-gram.y (yyreport_syntax_error): Use YYSYMBOL_YYEMPTY, not
YYEMPTY, when dealing with a symbol.
* tests/regression.at: Adjust.
Now that we have a proper type for internal symbol numbers, let's use
it. More code needs conversion, e.g., printers and destructors, but
they are shared with glr.c, which is not ready yet for this change.
It will also help us deal with warnings such as (GCC9 on GNU/Linux):
input.c: In function 'int yyparse()':
input.c:475:37: error: enumeral and non-enumeral type in conditional expression [-Werror=extra]
475 | (0 <= (YYX) && (YYX) <= YYMAXUTOK ? yytranslate[YYX] : YYSYMBOL_YYUNDEF)
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
input.c:1024:17: note: in expansion of macro 'YYTRANSLATE'
1024 | yytoken = YYTRANSLATE (yychar);
| ^~~~~~~~~~~
* data/skeletons/yacc.c (yytranslate, yysymbol_name)
(yyparse_context_t, yyexpected_tokens, yypstate_expected_tokens)
(yysyntax_error_arguments):
Use yysymbol_type_t instead of int.
There's a number of advantage in exposing the symbol (internal)
numbers:
- custom error messages can use them to decide how to represent a
given symbol, or a set of symbols.
- we need something similar in uses of yyexpected_tokens. For
instance, currently, bistromathic's completion() reads:
int ntokens = expected_tokens (line, tokens, YYNTOKENS);
[...]
for (int i = 0; i < ntokens; ++i)
if (tokens[i] == YYTRANSLATE (TOK_VAR))
[...]
else if (tokens[i] == YYTRANSLATE (TOK_FUN))
[...]
else
[...]
- now that it's a compile-time expression, we can easily build static
tables, switch, etc.
- some users depended on the ability to get the token number from a
symbol to write test cases for their scanners. But Bison 3.5
removed the table this feature depended upon (a reverse
yytranslate). Now they can check against the actual symbol number,
without having pay (space and time) a conversion.
See https://lists.gnu.org/r/bug-bison/2020-01/msg00001.html, and
https://lists.gnu.org/archive/html/bug-bison/2020-03/msg00015.html.
- it helps us clearly separate the internal symbol numbers from the
external token numbers, whose difference is sometimes blurred in the
code when values coincide (e.g. "yychar = yytoken = YYEOF").
- it allows us to get rid of ugly macros with inconsistent names such
as YYUNDEFTOK and YYTERROR, and to group related definitions
together.
- similarly it provides a clean access to the $accept symbol (which
proves convenient in a current experimentation of mine with several
%start symbols).
Let's declare this type as a private type (in the *.c file, not
the *.h one). So it does not need to be influenced by the api prefix.
* data/skeletons/bison.m4 (b4_symbol_sid): New.
(b4_symbol): Use it.
* data/skeletons/c.m4 (b4_symbol_enum, b4_declare_symbol_enum): New.
* data/skeletons/yacc.c: Use b4_declare_symbol_enum.
(YYUNDEFTOK, YYTERROR): Remove.
Use the corresponding symbol enum instead.
* data/skeletons/lalr1.java (yysyntaxErrorArguments): Move it from the
context, to the parser object.
Generate only for detailed and verbose error messages.
* tests/local.at (AT_YYERROR_DEFINE(java)): Use yyexpectedTokens
instead.
We could just "inline yysyntax_error_arguments back" in the routines
it was originally extracted from, but I think the code is nicer to
read this way.
* data/skeletons/glr.c (yysyntax_error_arguments): Generate only for
detailed and verbose error messages.
* data/skeletons/yacc.c: Likewise.
* data/skeletons/lalr1.cc (parser::context::yysyntax_error_arguments):
Move as...
(parser::yysyntax_error_arguments_): this.
And only for detailed and verbose error messages.
Because glr.c shares the same testing routines, we also need to
convert it.
* data/skeletons/glr.c (yyparse_context_token): New.
* tests/local.at (yyreport_syntax_error): here.
Suggested by Adrian Vogelsgesang.
https://lists.gnu.org/archive/html/bison-patches/2020-02/msg00069.html
* data/skeletons/lalr1.java (Context.EMPTY, Context.getToken): New.
(Context.yyntokens): Rename as...
(Context.NTOKENS): this.
Because (i) all the Java coding styles recommend upper case for
constants, and (ii) the Java Skeleton exposes Lexer.EOF, not
Lexer.YYEOF.
* data/skeletons/yacc.c (yyparse_context_token): New.
* examples/c/bistromathic/parse.y (yyreport_syntax_error): Don't use
yysyntax_error_arguments.
* examples/java/calc/Calc.y (yyreportSyntaxError): Likewise.
yyparse returns 0, 1, 2 since ages (accept, reject, memory exhausted).
Some of our auxiliary functions such as yy_lac and
yyreport_syntax_error also need to return error codes and also use 0,
1, 2. Because it uses yy_lac, yyexpected_tokens also needs to return
"problem", "memory exhausted", but in case of success, it needs to
return the number of tokens, so it cannot use 1 and 2 as error code.
Currently it uses -1 and -2, which is later converted into 1 and 2 as
yacc.c expects it.
Let's simplify this and use consistently -1 and -2 for auxiliary
functions that are not exposed (or not yet exposed) to the user. In
particular this will save the user from having to convert
yyexpected_tokens's -2 into yyreport_syntax_error's 2: both return -1
or -2.
* data/skeletons/yacc.c (yy_lac, yyreport_syntax_error)
(yy_lac_stack_realloc): Return -1, -2 for errors instead of 1, 2.
Adjust callers.
* examples/c/bistromathic/parse.y (yyreport_syntax_error): Do take
error codes into account.
Issue a syntax error message even if we ran out of memory.
* src/parse-gram.y, tests/local.at (yyreport_syntax_error): Adjust.
