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yacc: use the most appropriate integral type for state numbers

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Currently we properly use the "best" integral type for tables,
including those storing state numbers.  However the variables for
state numbers used in yyparse (and its dependencies such as
yy_stack_print) still use int16_t invariably.  As a consequence, very
large models overflow these variables.

Let's use the "best" type for these variables too.  It turns out that
we can still use 16 bits for twice larger automata: stick to unsigned
types.

However using 'unsigned' when 16 bits are not enough is troublesome
and generates tons of warnings about signedness issues.  Instead,
let's use 'int'.

Reported by Tom Kramer.
https://lists.gnu.org/archive/html/bug-bison/2019-09/msg00018.html

* data/skeletons/yacc.c (b4_state_num_type): New.
(yy_state_num): Be computed from YYNSTATES.
* tests/linear: New.
* tests/torture.at (State number type): New.
Use it.
This commit is contained in:
Akim Demaille
2019-09-28 13:48:35 +02:00
parent 871c02b327
commit 2ca6b71967
5 changed files with 160 additions and 25 deletions
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44
data/skeletons/yacc.c
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@@ -127,6 +127,18 @@ m4_define([b4_int_type],
[int])])
# b4_state_num_type(MIN, MAX)
# ---------------------------
# Likewise, but prefer 'int' to 'unsigned' for large integers.
m4_define([b4_state_num_type],
[m4_if(b4_ints_in($@, [0], [255]), [1], [yytype_uint8],
b4_ints_in($@, [-128], [127]), [1], [yytype_int8],
b4_ints_in($@, [0], [65535]), [1], [yytype_uint16],
b4_ints_in($@, [-32768], [32767]), [1], [yytype_int16],
[int])])
## ----------------- ##
## Semantic Values. ##
@@ -432,7 +444,7 @@ typedef short yytype_int16;
/* State numbers. */
typedef yytype_int16 yy_state_num;
typedef ]b4_state_num_type(0, m4_eval(b4_states_number - 1))[ yy_state_num;
#ifndef YY_
@@ -740,10 +752,7 @@ do { \
{
YYFPRINTF (stderr, "Stack now");
for (; yybottom <= yytop; yybottom++)
{
int yybot = *yybottom;
YYFPRINTF (stderr, " %d", yybot);
}
YYFPRINTF (stderr, " %u", (unsigned) *yybottom);
YYFPRINTF (stderr, "\n");
}
@@ -985,7 +994,7 @@ yy_lac (yy_state_num *yyesa, yy_state_num **yyes,
}
else
{
yyrule = yytable[yyrule];
yyrule = (int) yytable[yyrule];
if (yytable_value_is_error (yyrule))
{
YYDPRINTF ((stderr, " Err\n"));
@@ -1022,11 +1031,10 @@ yy_lac (yy_state_num *yyesa, yy_state_num **yyes,
int yystate;
{
const int yylhs = yyr1[yyrule] - YYNTOKENS;
const int yyi = yypgoto[yylhs] + *yyesp;
yystate = ((yy_state_num)
(0 <= yyi && yyi <= YYLAST && yycheck[yyi] == *yyesp
? yytable[yyi]
: yydefgoto[yylhs]));
const int yyi = yypgoto[yylhs] + (int) *yyesp;
yystate = (0 <= yyi && yyi <= YYLAST && yycheck[yyi] == *yyesp
? (int) yytable[yyi]
: yydefgoto[yylhs]);
}
if (yyesp == yyes_prev)
{
@@ -1046,7 +1054,7 @@ yy_lac (yy_state_num *yyesa, yy_state_num **yyes,
}
*++yyesp = (yy_state_num) yystate;
}
YYDPRINTF ((stderr, " G%d", (int) yystate));
YYDPRINTF ((stderr, " G%d", yystate));
}
}
}]])[
@@ -1639,7 +1647,7 @@ yyread_pushed_token:]])[
goto yydefault;
}]], [[
goto yydefault;]])[
yyn = yytable[yyn];
yyn = (int) yytable[yyn];
if (yyn <= 0)
{
if (yytable_value_is_error (yyn))
@@ -1661,7 +1669,7 @@ yyread_pushed_token:]])[
yychar = YYEMPTY;]b4_lac_if([[
YY_LAC_DISCARD ("shift");]])[
yystate = (yy_state_num) yyn;
yystate = yyn;
YY_IGNORE_MAYBE_UNINITIALIZED_BEGIN
*++yyvsp = yylval;
YY_IGNORE_MAYBE_UNINITIALIZED_END]b4_locations_if([
@@ -1741,9 +1749,9 @@ yyreduce:
number reduced by. */
{
const int yylhs = yyr1[yyn] - YYNTOKENS;
const int yyi = yypgoto[yylhs] + *yyssp;
const int yyi = yypgoto[yylhs] + (int) *yyssp;
yystate = (0 <= yyi && yyi <= YYLAST && yycheck[yyi] == *yyssp
? yytable[yyi]
? (int) yytable[yyi]
: yydefgoto[yylhs]);
}
@@ -1859,7 +1867,7 @@ yyerrlab1:
yyn += YYTERROR;
if (0 <= yyn && yyn <= YYLAST && yycheck[yyn] == YYTERROR)
{
yyn = yytable[yyn];
yyn = (int) yytable[yyn];
if (0 < yyn)
break;
}
@@ -1894,7 +1902,7 @@ yyerrlab1:
/* Shift the error token. */
YY_SYMBOL_PRINT ("Shifting", yystos[yyn], yyvsp, yylsp);
yystate = (yy_state_num) yyn;
yystate = yyn;
goto yynewstate;