use these prefixed token names, although the grammar itself still
uses the short names (as in the sample rule given above).
+** Variable api.value.type
+
+ This new %define variable supersedes the #define macro YYSTYPE. The use
+ of YYSTYPE is discouraged. In particular, #defining YYSTYPE *and* either
+ using %union or %defining api.value.type results in undefined behavior.
+
+ Either define api.value.type, or use "%union":
+
+ %union
+ {
+ int ival;
+ char *sval;
+ }
+ %token <ival> INT "integer"
+ %token <sval> STRING "string"
+ %printer { fprintf (yyo, "%d", $$); } <ival>
+ %destructor { free ($$); } <sval>
+
+ /* In yylex(). */
+ yylval.ival = 42; return INT;
+ yylval.sval = "42"; return STRING;
+
+ The %define variable api.value.type supports several special values. The
+ value "union" means that the user provides genuine types, not union member
+ names such as "ival" and "sval" above.
+
+ %define api.value.type "union"
+ %token <int> INT "integer"
+ %token <char *> STRING "string"
+ %printer { fprintf (yyo, "%d", $$); } <int>
+ %destructor { free ($$); } <char *>
+
+ /* In yylex(). */
+ yylval.INT = 42; return INT;
+ yylval.STRING = "42"; return STRING;
+
+ The value "variant" is somewhat equivalent, but for C++ special provision
+ is made to allow classes to be used (more about this below).
+
+ %define api.value.type "variant"
+ %token <int> INT "integer"
+ %token <std::string> STRING "string"
+
+ Any other name is a user type to use. This is where YYSTYPE used to be
+ used.
+
+ %code requires
+ {
+ struct my_value
+ {
+ enum
+ {
+ is_int, is_string
+ } kind;
+ union
+ {
+ int ival;
+ char *sval;
+ } u;
+ };
+ }
+ %define api.value.type "struct my_value"
+ %token <u.ival> INT "integer"
+ %token <u.sval> STRING "string"
+ %printer { fprintf (yyo, "%d", $$); } <u.ival>
+ %destructor { free ($$); } <u.sval>
+
+ /* In yylex(). */
+ yylval.u.ival = 42; return INT;
+ yylval.u.sval = "42"; return STRING;
+
** Variable parse.error
This variable controls the verbosity of error messages. The use of the
LocalWords: Wprecedence Rassoul Wempty Paolo Bonzini parser's Michiel loc
LocalWords: redeclaration sval fcaret reentrant XSLT xsl Wmaybe yyvsp Tedi
LocalWords: pragmas noreturn untyped Rozenman unexpanded Wojciech Polak
- LocalWords: Alexandre MERCHANTABILITY
+ LocalWords: Alexandre MERCHANTABILITY yytype
Local Variables:
mode: outline
# Whether the symbol has an id.
# - id: string
# If has_id, the id. Guaranteed to be usable as a C identifier.
+# Prefixed by api.token.prefix if defined.
# - tag: string.
# A representat of the symbol. Can be 'foo', 'foo.id', '"foo"' etc.
# - user_number: integer
# The internalized number (used after yytranslate).
# - has_type: 0, 1
# Whether has a semantic value.
+# - type_tag: string
+# When api.value.type=union, the generated name for the union member.
+# yytype_INT etc. for symbols that has_id, otherwise yytype_1 etc.
# - type
# If it has a semantic value, its type tag, or, if variant are used,
# its type.
+# In the case of api.value.type=union, type is the real type (e.g. int).
# - has_printer: 0, 1
# - printer: string
# - printer_file: string
[['%s' and '%s' cannot be used together]],
[%name-prefix],
[%define api.prefix])])])
+
+b4_percent_define_ifdef([api.value.type],
+[m4_ifdef([b4_union_members],
+[b4_complain_at(b4_percent_define_get_loc([api.value.type]),
+ [['%s' and '%s' cannot be used together]],
+ [%union],
+ [%define api.value.type])])])
# ---------------------
# Declare semantic_type.
m4_define([b4_value_type_declare],
+[b4_value_type_setup[]dnl
[ /// Symbol semantic values.
-m4_ifdef([b4_union_members],
-[ union semantic_type
+]m4_bmatch(b4_percent_define_get([api.value.type]),
+[^%union\|union$],
+[[ union semantic_type
{
-b4_user_union_members
- };],
-[m4_if(b4_tag_seen_flag, 0,
-[[ typedef int semantic_type;]],
-[[ typedef ]b4_api_PREFIX[STYPE semantic_type;]])])])
+]b4_user_union_members[
+ };]],
+[^$], [],
+[[ typedef ]b4_percent_define_get([api.value.type])[ semantic_type;]])])
# b4_public_types_declare
}]dnl
])
+
+## ---------------- ##
+## api.value.type. ##
+## ---------------- ##
+
+
+# ---------------------- #
+# api.value.type=union. #
+# ---------------------- #
+
+# b4_symbol_type_register(SYMBOL-NUM)
+# -----------------------------------
+# Symbol SYMBOL-NUM has a type (for variant) instead of a type-tag.
+# Extend the definition of %union's body with a field of that type,
+# and extend the symbol's "type" field to point to the field name,
+# instead of the type name.
+m4_define([b4_symbol_type_register],
+[m4_define([b4_symbol($1, type_tag)],
+ [b4_symbol_if([$1], [has_id],
+ [b4_symbol([$1], [id])],
+ [yytype_[]b4_symbol([$1], [number])])])dnl
+m4_append([b4_user_union_members],
+m4_expand([
+ b4_symbol_tag_comment([$1])dnl
+ b4_symbol([$1], [type]) b4_symbol([$1], [type_tag]);]))
+])
+
+
+# b4_type_define_tag(SYMBOL1-NUM, ...)
+# ------------------------------------
+# For the batch of symbols SYMBOL1-NUM... (which all have the same
+# type), enhance the %union definition for each of them, and set
+# there "type" field to the field tag name, instead of the type name.
+m4_define([b4_type_define_tag],
+[b4_symbol_if([$1], [has_type],
+ [m4_map([b4_symbol_type_register], [$@])])
+])
+
+
+# b4_symbol_value_union(VAL, [TYPE])
+# ----------------------------------
+# Same of b4_symbol_value, but when api.value.type=union.
+m4_define([b4_symbol_value_union],
+[m4_ifval([$2],
+ [(*($2*)(&$1))],
+ [$1])])
+])
+
+
+# b4_value_type_setup_union
+# -------------------------
+# Setup support for api.value.type=union. Symbols are defined with a
+# type instead of a union member name: build the corresponding union,
+# and give the symbols their tag.
+m4_define([b4_value_type_setup_union],
+[m4_define([b4_union_members])
+b4_type_foreach([b4_type_define_tag])
+m4_copy_force([b4_symbol_value_union], [b4_symbol_value])
+])
+
+
+# ---------------- #
+# api.value.type. #
+# ---------------- #
+
+
+# b4_value_type_setup_variant
+# ---------------------------
+# Setup support for api.value.type=variant. By default, fail, specialized
+# by other skeletons.
+m4_define([b4_value_type_setup_variant],
+[b4_complain_at(b4_percent_define_get_loc([api.value.type]),
+ [['%s' does not support '%s']],
+ [b4_skeleton],
+ [%define api.value.type variant])])
+
+
+# b4_value_type_setup
+# -------------------
+# Check if api.value.type is properly defined, and possibly prepare
+# its use.
+m4_define([b4_value_type_setup],
+[b4_percent_define_default([[api.value.type]],
+[m4_ifdef([b4_union_members], [%union],
+ [m4_if(b4_tag_seen_flag, 0, [int],
+ [])])])dnl
+m4_case(b4_percent_define_get([api.value.type]),
+ [union], [b4_value_type_setup_union],
+ [variant], [b4_value_type_setup_variant])])
+
+
+
## -------------- ##
## Declarations. ##
## -------------- ##
+
# b4_value_type_define
# --------------------
m4_define([b4_value_type_define],
-[[/* Value type. */
-#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
-]m4_ifdef([b4_union_members],
-[[typedef union ]b4_union_name[ ]b4_api_PREFIX[STYPE;
+[b4_value_type_setup[]dnl
+/* Value type. */
+m4_bmatch(b4_percent_define_get([api.value.type]),
+[^%?union$],
+[[#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
+typedef union ]b4_union_name[ ]b4_api_PREFIX[STYPE;
union ]b4_union_name[
{
]b4_user_union_members[
};
-# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1]],
-[m4_if(b4_tag_seen_flag, 0,
-[[typedef int ]b4_api_PREFIX[STYPE;
-# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1]])])[
+# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1
# define ]b4_api_PREFIX[STYPE_IS_DECLARED 1
#endif
-]])
+]],
+[^$], [],
+[[#if ! defined ]b4_api_PREFIX[STYPE && ! defined ]b4_api_PREFIX[STYPE_IS_DECLARED
+typedef ]b4_percent_define_get([api.value.type])[ ]b4_api_PREFIX[STYPE;
+# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1
+# define ]b4_api_PREFIX[STYPE_IS_DECLARED 1
+#endif
+]])])
# b4_location_type_define
m4_include(b4_pkgdatadir/[c++.m4])
+# api.value.type=variant is valid.
+m4_define([b4_value_type_setup_variant])
# b4_integral_parser_table_declare(TABLE-NAME, CONTENT, COMMENT)
# --------------------------------------------------------------
# b4_symbol_value_template(VAL, [TYPE])
# -------------------------------------
# Same as b4_symbol_value, but used in a template method. It makes
-# a difference when using variants.
+# a difference when using variants. Note that b4_value_type_setup_union
+# overrides b4_symbol_value, so we must override it again.
m4_copy([b4_symbol_value], [b4_symbol_value_template])
-
+m4_append([b4_value_type_setup_union],
+ [m4_copy_force([b4_symbol_value_union], [b4_symbol_value_template])])
# b4_lhs_value([TYPE])
# --------------------
Unaccepted @var{variable}s produce an error.
Some of the accepted @var{variable}s are described below.
+@c ================================================== api.namespace
@deffn Directive {%define api.namespace} @{@var{namespace}@}
@itemize
@item Languages(s): C++
@deffn Directive {%define api.value.type} @var{type}
@itemize @bullet
@item Language(s):
-C++
+all
@item Purpose:
-Request variant-based semantic values.
+The type for semantic values.
+
+@item Accepted Values:
+@table @asis
+@item @code{""}
+This grammar has no semantic value at all. This is not properly supported
+yet.
+@item @code{%union} (C, C++)
+The type is defined thanks to the @code{%union} directive. You don't have
+to define @code{api.value.type} in that case, using @code{%union} suffices.
+@xref{Union Decl, ,The Collection of Value Types}.
+For instance:
+@example
+%define api.value.type "%union"
+%union
+@{
+ int ival;
+ char *sval;
+@}
+%token <ival> INT "integer"
+%token <sval> STR "string"
+@end example
+
+@item @code{union} (C, C++)
+The symbols are defined with type names, from which Bison will generate a
+@code{union}. For instance:
+@example
+%define api.value.type "union"
+%token <int> INT "integer"
+%token <char *> STR "string"
+@end example
+This feature needs user feedback to stabilize. Note that most C++ objects
+cannot be stored in a @code{union}.
+
+@item @code{variant} (C++)
+This is similar to @code{union}, but special storage techniques are used to
+allow any kind of C++ object to be used. For instance:
+@example
+%define api.value.type "variant"
+%token <int> INT "integer"
+%token <std::string> STR "string"
+@end example
+This feature needs user feedback to stabilize.
@xref{C++ Variants}.
+@item any other identifier
+Use this name as semantic value.
+@example
+%code requires
+@{
+ struct my_value
+ @{
+ enum
+ @{
+ is_int, is_str
+ @} kind;
+ union
+ @{
+ int ival;
+ char *sval;
+ @} u;
+ @};
+@}
+%define api.value.type "struct my_value"
+%token <u.ival> INT "integer"
+%token <u.sval> STR "string"
+@end example
+@end table
+
@item Default Value:
-FIXME:
+@itemize @minus
+@item
+@code{%union} if @code{%union} is used, otherwise @dots{}
+@item
+@code{int} if type tags are used (i.e., @samp{%token <@var{type}>@dots{}} or
+@samp{%token <@var{type}>@dots{}} is used), otherwise @dots{}
+@item
+@code{""}
+@end itemize
+
@item History:
introduced in Bison 2.8. Was introduced for Java only in 2.3b as
@code{stype}.
tests/sets.at \
tests/skeletons.at \
tests/synclines.at \
- tests/torture.at
+ tests/torture.at \
+ tests/types.at
TESTSUITE = $(top_srcdir)/tests/testsuite
# Testing grammar reduction.
m4_include([reduce.at])
+# Testing conflicts detection and resolution.
+m4_include([conflicts.at])
+
# Testing that #lines are correct.
m4_include([synclines.at])
# Testing that user actions are properly performed.
m4_include([actions.at])
-# Testing conflicts detection and resolution.
-m4_include([conflicts.at])
+# Testing semantic types support.
+m4_include([types.at])
# Fulling testing (compilation and execution of the parser) on calc.
m4_include([calc.at])
--- /dev/null
+# Value type. -*- Autotest -*-
+
+# Copyright (C) 2013 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+AT_BANNER([[Value type tests.]])
+
+
+## ----------------------------------- ##
+## %union vs. %define api.value.type. ##
+## ----------------------------------- ##
+
+AT_SETUP([[%union vs. %define api.value.type]])
+
+AT_DATA([[input.y]],
+[[%union { int ival; }
+%define api.value.type "%union"
+%%
+exp: %empty;
+]])
+
+AT_BISON_CHECK([[input.y]], [[1]], [[]],
+[[input.y:2.9-22: error: '%union' and '%define api.value.type' cannot be used together
+]])
+
+AT_CLEANUP
+
+## ---------------- ##
+## api.value.type. ##
+## ---------------- ##
+
+# AT_TEST($1: BISON-DIRECTIVES,
+# $2: MORE-BISON-DIRECTIVES,
+# $3: PARSER-ACTION,
+# $4: INPUT, $5: SCANNER-ACTION,
+# $6: RESULT)
+# --------------------------------------
+# Compile the grammar and check the expected result.
+# BISON-DIRECTIVES are passed to AT_SETUP, contrary to MORE-BISON-DIRECTIVES.
+m4_pushdef([AT_TEST],
+[
+AT_SETUP([$1])
+AT_KEYWORDS([api.value.type])
+AT_BISON_OPTION_PUSHDEFS([$1 $2])
+AT_DATA_GRAMMAR([test.y],
+[[%debug
+
+%code
+{
+# include <stdio.h>
+# include <stdlib.h>
+]AT_YYERROR_DECLARE[
+]AT_YYLEX_DECLARE[
+}
+
+]$1[
+]$2[
+
+%%
+
+start: $3;
+
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE([$4], [$5])[
+]AT_MAIN_DEFINE[
+]])
+
+AT_FULL_COMPILE([[test]])
+AT_PARSER_CHECK([./test], 0, [$6
+], [stderr])
+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP
+])
+
+m4_foreach([b4_skel], [[yacc.c], [glr.c], [lalr1.cc], [glr.cc]],
+ [# A built-in type.
+ AT_TEST([%skeleton "]b4_skel["
+ %define api.value.type double],
+ [],
+ ['1' '2' { printf ("%2.1f\n", $1 + $2); }],
+ ["12"],
+ [AT_VAL = (res - '0') / 10.0],
+ [0.3])
+
+ # A user defined struct.
+ AT_TEST([%skeleton "]b4_skel["
+ %define api.value.type "struct foo"],
+ [%code requires { struct foo { float fval; int ival; }; }],
+ ['1' '2'
+ { printf ("%d %2.1f\n", $1.ival + $2.ival, $1.fval + $2.fval); }],
+ ["12"],
+ [AT_VAL.ival = (res - '0') * 10;
+ AT_VAL.fval = (res - '0') / 10.f],
+ [30 0.3])
+
+ # A user defined union.
+ AT_TEST([%skeleton "]b4_skel["
+ %define api.value.type "union foo"],
+ [%code requires { union foo { float fval; int ival; }; }],
+ ['1' '2' { printf ("%d %2.1f\n", $1.ival, $2.fval); }],
+ ["12"],
+ [if (res == '1')
+ AT_VAL.ival = 10;
+ else
+ AT_VAL.fval = .2f],
+ [10 0.2])
+
+ # A %union.
+ AT_TEST([%skeleton "]b4_skel["
+ %union { float fval; int ival; };],
+ [%token <ival> '1';
+ %token <fval> '2';],
+ ['1' '2' { printf ("%d %2.1f\n", $1, $2); }],
+ ["12"],
+ [if (res == '1')
+ AT_VAL.ival = 10;
+ else
+ AT_VAL.fval = 0.2f],
+ [10 0.2])
+
+ # A Bison-defined union.
+ # The tokens names are not available directly in C++, we use their
+ # user number to keep it simple between C and C++.
+ AT_TEST([%skeleton "]b4_skel["
+ %define api.value.type union],
+ [%token <int> ONE 101;
+ %token <float> TWO 102 THREE 103;
+ %printer { ]AT_SKEL_CC_IF([[yyoutput << $$]],
+ [[fprintf (yyo, "%d", $$)]])[; } <int>
+ %printer { ]AT_SKEL_CC_IF([[yyoutput << $$]],
+ [[fprintf (yyo, "%f", $$)]])[; } <float>
+ ],
+ [ONE TWO THREE { printf ("%d %2.1f %2.1f\n", $1, $2, $3); }],
+ [{ 101, 102, 103, EOF }],
+ [if (res == 101)
+ AT_VAL.ONE = 10;
+ else if (res == 102)
+ AT_VAL.TWO = .2f;
+ else if (res == 103)
+ AT_VAL.THREE = 3.3f],
+ [10 0.2 3.3])
+
+ # A Bison-defined variant, for lalr1.cc only.
+ m4_if(b4_skel, [lalr1.cc], [
+ AT_TEST([%skeleton "]b4_skel["
+ %define api.value.type variant],
+ [%token <int> '1';
+ %token <std::string> '2';],
+ ['1' '2' { std::cout << $1 << ", " << $2 << std::endl; }],
+ ["12"],
+ [if (res == '1')
+ AT_VAL.build(10);
+ else
+ AT_VAL.build<std::string>("two");],
+ [10, two])])
+])
+
+m4_popdef([AT_TEST])
projects / bison.git / commitdiff
