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%union: fix the support for named %union

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Bison supports a union tag, for obscure reasons.  But it does a poor
job at it, especially since Bison 3.0.
Reported by Stephen Cameron and Tobias Frost.

It did not ensure that the name was not given several times.  An easy
way to do this is to make the %union tag be handled as a %define
variable, as they cannot be defined several times.

Since Bison 3.0, the synclines were wrongly placed, resulting in
invalid code.  Addressing this issue, because of the way the union tag
was stored (as a code muscle), would have been tedious.  Unless we
rather define the %union tag as a %percent variable, whose synclines
are easier to manipulate.

So replace the b4_union_name muscle by the api.value.union.name
%define variable, document, and check.

* data/bison.m4: Make sure that api.value.union.name has a keyword value.
* data/c++.m4: Make sure that api.value.union.name is not defined.
* data/c.m4 (b4_union_name): No longer use it, use api.value.union.name.
* doc/bison.texi (%define Summary): Document it.
* src/parse-gram.y (union_name): No longer define b4_uion_name, but
api.value.union.name.
* tests/input.at (Redefined %union name): New.
* tests/synclines.at (%union name syncline): New.
* tests/types.at: Check named %unions.
This commit is contained in:
Akim Demaille
2015-01-04 14:16:23 +01:00
parent 3209eb1c4c
commit 827bc59ca1
12 changed files with 363 additions and 212 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
NEWS
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@@ -4,6 +4,15 @@ GNU Bison NEWS
** Bug fixes
*** Named %union support
Bison 3.0 introduced a regression on named %union such as
%union foo { int ival; };
The possibility to use a name was introduced ``for Yacc compatibility''.
It is however not required by POSIX Yacc, and its usefulness is not clear.
*** %define api.value.type union with %defines
The yacc.c and glr.c parsers were broken when %defines was used

2
THANKS
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@@ -126,6 +126,7 @@ Sebastien Fricker sebastien.fricker@gmail.com
Sergei Steshenko sergstesh@yahoo.com
Shura debil_urod@ngs.ru
Stefano Lattarini stefano.lattarini@gmail.com
Stephen Cameron stephenmcameron@gmail.com
Steve Murphy murf@parsetree.com
Sum Wu sum@geekhouse.org
Théophile Ranquet theophile.ranquet@gmail.com
@@ -133,6 +134,7 @@ Thiru Ramakrishnan thiru.ramakrishnan@gmail.com
Tim Josling tej@melbpc.org.au
Tim Landscheidt tim@tim-landscheidt.de
Tim Van Holder tim.van.holder@pandora.be
Tobias Frost tobi@debian.org
Tom Lane tgl@sss.pgh.pa.us
Tom Tromey tromey@cygnus.com
Tommy Nordgren tommy.nordgren@chello.se

3
data/bison.m4
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@@ -1061,3 +1061,6 @@ b4_percent_define_ifdef([api.value.type],
[['%s' and '%s' cannot be used together]],
[%yacc],
[%define api.value.type "union"])])])])
# api.value.union.name.
b4_percent_define_check_kind([api.value.union.name], [keyword])

5
data/c++.m4
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@@ -17,6 +17,11 @@
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# Sanity checks, before defaults installed by c.m4.
b4_percent_define_ifdef([[api.value.union.name]],
[b4_complain_at(b4_percent_define_get_loc([[api.value.union.name]]),
[named %union is invalid in C++])])
m4_include(b4_pkgdatadir/[c.m4])
# b4_comment(TEXT, [PREFIX])

16
data/c.m4
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@@ -97,7 +97,8 @@ m4_define([b4_api_PREFIX],
m4_define_default([b4_prefix], [b4_api_prefix])
# If the %union is not named, its name is YYSTYPE.
m4_define_default([b4_union_name], [b4_api_PREFIX[]STYPE])
b4_percent_define_default([[api.value.union.name]],
[b4_api_PREFIX[][STYPE]])
## ------------------------ ##
@@ -608,10 +609,9 @@ m4_copy_force([b4_symbol_value_union], [b4_symbol_value])
])
# ---------------- #
# api.value.type. #
# ---------------- #
# -------------------------- #
# api.value.type = variant. #
# -------------------------- #
# b4_value_type_setup_variant
# ---------------------------
@@ -686,11 +686,13 @@ typedef ]b4_percent_define_get([[api.value.type]])[ ]b4_api_PREFIX[STYPE;
[m4_bmatch(b4_percent_define_get([[api.value.type]]),
[union\|union-directive],
[[#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_percent_define_get_syncline([[api.value.union.name]])[
union ]b4_percent_define_get([[api.value.union.name]])[
{
]b4_user_union_members[
};
]b4_percent_define_get_syncline([[api.value.union.name]])[
typedef union ]b4_percent_define_get([[api.value.union.name]])[ ]b4_api_PREFIX[STYPE;
# define ]b4_api_PREFIX[STYPE_IS_TRIVIAL 1
# define ]b4_api_PREFIX[STYPE_IS_DECLARED 1
#endif

32
doc/bison.texi
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@@ -3851,7 +3851,7 @@ example:
@noindent
specifies the union tag @code{value}, so the corresponding C type is
@code{union value}. If you do not specify a tag, it defaults to
@code{YYSTYPE}.
@code{YYSTYPE} (@pxref{%define Summary,,api.value.union.name}).
As another extension to POSIX, you may specify multiple @code{%union}
declarations; their contents are concatenated. However, only the first
@@ -6014,12 +6014,12 @@ Use this @var{type} as semantic value.
@item Default Value:
@itemize @minus
@item
@code{%union} if @code{%union} is used, otherwise @dots{}
@code{union-directive} 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{}
@samp{%type <@var{type}>@dots{}} is used), otherwise @dots{}
@item
@code{""}
undefined.
@end itemize
@item History:
@@ -6030,6 +6030,30 @@ introduced in Bison 3.0. Was introduced for Java only in 2.3b as
@c api.value.type
@c ================================================== api.value.union.name
@deffn Directive {%define api.value.union.name} @var{name}
@itemize @bullet
@item Language(s):
C
@item Purpose:
The tag of the generated @code{union} (@emph{not} the name of the
@code{typedef}). This variable is set to @code{@var{id}} when @samp{%union
@var{id}} is used. There is no clear reason to give this union a name.
@item Accepted Values:
Any valid identifier.
@item Default Value:
@code{YYSTYPE}.
@item History:
Introduced in Bison 3.0.3.
@end itemize
@end deffn
@c api.value.type
@c ================================================== location_type
@deffn Directive {%define location_type}
Obsoleted by @code{api.location.type} since Bison 2.7.

374
src/parse-gram.c
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File diff suppressed because it is too large Load Diff

8
src/parse-gram.h
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@@ -61,7 +61,7 @@ extern int gram_debug;
param_parse = 1 << 1,
param_both = param_lex | param_parse
} param_type;
#line 645 "src/parse-gram.y" /* yacc.c:1909 */
#line 647 "src/parse-gram.y" /* yacc.c:1909 */
#include "muscle-tab.h"
#line 68 "src/parse-gram.h" /* yacc.c:1909 */
@@ -132,7 +132,7 @@ extern int gram_debug;
/* Value type. */
#if ! defined GRAM_STYPE && ! defined GRAM_STYPE_IS_DECLARED
typedef union GRAM_STYPE GRAM_STYPE;
union GRAM_STYPE
{
#line 182 "src/parse-gram.y" /* yacc.c:1909 */
@@ -155,7 +155,7 @@ named_ref *named_ref;
param_type param;
#line 409 "src/parse-gram.y" /* yacc.c:1909 */
code_props_type code_type;
#line 647 "src/parse-gram.y" /* yacc.c:1909 */
#line 649 "src/parse-gram.y" /* yacc.c:1909 */
struct
{
@@ -165,6 +165,8 @@ code_props_type code_type;
#line 167 "src/parse-gram.h" /* yacc.c:1909 */
};
typedef union GRAM_STYPE GRAM_STYPE;
# define GRAM_STYPE_IS_TRIVIAL 1
# define GRAM_STYPE_IS_DECLARED 1
#endif

4
src/parse-gram.y
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@@ -421,7 +421,9 @@ code_props_type:
union_name:
%empty {}
| ID { muscle_code_grow ("union_name", $1, @1); }
| ID { muscle_percent_define_insert ("api.value.union.name",
@1, muscle_keyword, $1,
MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE); }
;
grammar_declaration:

45
tests/input.at
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@@ -1904,6 +1904,51 @@ m4_popdef([AT_TEST])
AT_CLEANUP
## ----------------------- ##
## Redefined %union name. ##
## ----------------------- ##
AT_SETUP([[Redefined %union name]])
# AT_TEST(DIRECTIVES, ERROR)
# --------------------------
m4_pushdef([AT_TEST],
[AT_DATA([[input.y]],
[$1
%%
exp: %empty;
])
AT_BISON_CHECK([[input.y]], [[1]], [[]],
[$2])
])
AT_TEST([[%union foo {};
%union {};
%union foo {};
%define api.value.union.name foo]],
[[input.y:3.8-10: error: %define variable 'api.value.union.name' redefined
input.y:1.8-10: previous definition
input.y:4.9-28: error: %define variable 'api.value.union.name' redefined
input.y:3.8-10: previous definition
]])
AT_TEST([[%define api.value.union.name {foo}]],
[[input.y:1.9-28: error: %define variable 'api.value.union.name' requires keyword values
input.y:1.9-28: error: %define variable 'api.value.union.name' is not used
]])
AT_TEST([[%define api.value.union.name "foo"]],
[[input.y:1.9-28: error: %define variable 'api.value.union.name' requires keyword values
input.y:1.9-28: error: %define variable 'api.value.union.name' is not used
]])
m4_popdef([AT_TEST])
AT_CLEANUP
## -------------- ##
## Stray $ or @. ##
## -------------- ##

29
tests/synclines.at
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@@ -182,6 +182,35 @@ exp: '0';
])
## ---------------------- ##
## %union name syncline. ##
## ---------------------- ##
# Check that invalid union names are properly reported in the
# source file.
AT_SETUP([%union name syncline])
AT_BISON_OPTION_PUSHDEFS
AT_DATA([[input.y]],
[[%union break
{
char dummy;
}
%{
]AT_YYERROR_DECLARE_EXTERN[
]AT_YYLEX_DECLARE_EXTERN[
%}
%%
exp: '0';
%%
]])
AT_BISON_CHECK([-o input.c input.y])
AT_SYNCLINES_COMPILE([input.c])
AT_CHECK([[grep '^input.y:1' stdout]], 0, [ignore])
AT_BISON_OPTION_POPDEFS
AT_CLEANUP
## ----------------------- ##
## Postprologue syncline. ##
## ----------------------- ##

32
tests/types.at
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@@ -197,9 +197,14 @@ m4_foreach([b4_skel], [[yacc.c], [glr.c], [lalr1.cc], [glr.cc]],
AT_VAL.fval = .2f],
[10 0.2])
# A %union.
AT_TEST([%skeleton "]b4_skel["
%union { float fval; int ival; };],
# A %union and a named %union. In C++ named %union is an error.
m4_foreach([b4_union],
[m4_bmatch(b4_skel, [\.cc$],
[[%union]],
[[%union], [%union foo],
[%define api.value.union.name foo; %union]])],
[AT_TEST([%skeleton "]b4_skel["
]b4_union[ { float fval; int ival; };],
[%token <ival> '1';
%token <fval> '2';],
['1' '2' { printf ("%d %2.1f\n", $1, $2); }],
@@ -208,7 +213,7 @@ m4_foreach([b4_skel], [[yacc.c], [glr.c], [lalr1.cc], [glr.cc]],
AT_VAL.ival = 10;
else
AT_VAL.fval = 0.2f],
[10 0.2])
[10 0.2])])
# A Bison-defined union.
# The tokens names are not available directly in C++, we use their
@@ -249,3 +254,22 @@ m4_foreach([b4_skel], [[yacc.c], [glr.c], [lalr1.cc], [glr.cc]],
m4_popdef([AT_TEST])
m4_popdef([_AT_TEST])
## ------------------- ##
## C++: Named %union. ##
## ------------------- ##
m4_foreach([b4_skel], [[lalr1.cc], [glr.cc]],
[AT_SETUP([b4_skel: Named %union])
AT_DATA([input.y],
[%skeleton "]b4_skel["
%union foo { float fval; int ival; };
%%
exp: %empty;
])
AT_BISON_CHECK([input.y], 1, [],
[[input.y:2.8-10: error: named %union is invalid in C++
]])
AT_CLEANUP
])