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c44a782a4e
Currently it is the front end that passes the symbol types to the
backend. For instance:
%token <ival> NUM
%type <ival> exp1 exp2
exp1: NUM { $$ = $1; }
exp2: NUM { $<ival>$ = $<ival>1; }
In both cases, $$ and $1 are passed to the backend as having type
'ival' resulting in code like `val.ival`. This is troublesome in the
case of api.value.type=union, since in that the case the code this:
%define api.value.type union
%token <int> NUM
%type <int> exp1 exp2
exp1: NUM { $$ = $1; }
exp2: NUM { $<int>$ = $<int>1; }
because in this case, since the backend does not know the symbol being
processed, it is forced to generate casts in both cases: *(int*)(&val)`.
This is unfortunate in the first case (exp1) where there is no reason
at all to use a cast instead of `val.NUM` and `val.exp1`.
So instead delegate the computation of the actual value type to the
backend: pass $<ival>$ as `symbol-number, ival` and $$ as
`symbol-number, MULL`, instead of passing `ival` before.
* src/scan-code.l (handle_action_dollar): Find the symbol the action
is about, not just its tyye. Pass both symbol-number, and explicit
type tag ($<tag>n when there is one) to b4_lhs_value and b4_rhs_value.
* data/bison.m4 (b4_symbol_action): adjust to the new signature to
b4_dollar_pushdef.
* data/c-like.m4 (_b4_dollar_dollar, b4_dollar_pushdef): Accept the
symbol-number as new argument.
* data/c.m4 (b4_symbol_value): Accept the symbol-number as new
argument, and use it.
(b4_symbol_value_union): Accept the symbol-number as new
argument, and use it to prefer ready a union member rather than
casting the union.
* data/yacc.c (b4_lhs_value, b4_rhs_value): Accept the new
symbol-number argument.
Adjust uses of b4_dollar_pushdef.
* data/glr.c (b4_lhs_value, b4_rhs_value): Adjust.
* data/lalr1.cc (b4_symbol_value_template, b4_lhs_value): Adjust
to the new symbol-number argument.
* data/variant.hh (b4_symbol_value, b4_symbol_value_template): Accept
the new symbol-number argument.
* data/java.m4 (b4_symbol_value, b4_rhs_data): New.
(b4_rhs_value): Use them.
* data/lalr1.java: Adjust to b4_dollar_pushdef, and use b4_rhs_data.
67 lines
2.3 KiB
Plaintext
67 lines
2.3 KiB
Plaintext
-*- Autoconf -*-
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# Common code for C-like languages (C, C++, Java, etc.)
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# Copyright (C) 2012-2015, 2018 Free Software Foundation, Inc.
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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# _b4_comment(TEXT, OPEN, CONTINUE, END)
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# --------------------------------------
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# Put TEXT in comment. Avoid trailing spaces: don't indent empty lines.
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# Avoid adding indentation to the first line, as the indentation comes
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# from OPEN. That's why we don't patsubst([$1], [^\(.\)], [ \1]).
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#
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# Prefix all the output lines with PREFIX.
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m4_define([_b4_comment],
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[$2[]m4_bpatsubst(m4_expand([[$1]]), [
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\(.\)], [
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$3\1])$4])
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# b4_comment(TEXT, [PREFIX])
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# --------------------------
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# Put TEXT in comment. Prefix all the output lines with PREFIX.
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m4_define([b4_comment],
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[_b4_comment([$1], [$2/* ], [$2 ], [ */])])
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# _b4_dollar_dollar(VALUE, SYMBOL-NUM, FIELD, DEFAULT-FIELD)
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# ----------------------------------------------------------
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# If FIELD (or DEFAULT-FIELD) is non-null, return "VALUE.FIELD",
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# otherwise just VALUE. Be sure to pass "(VALUE)" if VALUE is a
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# pointer.
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m4_define([_b4_dollar_dollar],
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[b4_symbol_value([$1],
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[$2],
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m4_if([$3], [[]],
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[[$4]], [[$3]]))])
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# b4_dollar_pushdef(VALUE-POINTER, SYMBOL-NUM, [TYPE_TAG], LOCATION)
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# b4_dollar_popdef
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# ------------------------------------------------------------------
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# Define b4_dollar_dollar for VALUE-POINTER and DEFAULT-FIELD,
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# and b4_at_dollar for LOCATION.
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m4_define([b4_dollar_pushdef],
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[m4_pushdef([b4_dollar_dollar],
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[_b4_dollar_dollar([$1], [$2], m4_dquote($][1), [$3])])dnl
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m4_pushdef([b4_at_dollar], [$4])dnl
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])
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m4_define([b4_dollar_popdef],
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[m4_popdef([b4_at_dollar])dnl
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m4_popdef([b4_dollar_dollar])dnl
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])
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