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style: avoid explicit symbol numbers

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This should have been part of commit "symbols: stop dealing with YYEMPTY
as b4_symbol(-2, ...)" (cd40ec9526).
Give names to all the special symbols: "eof", "error" and "undef".

* data/skeletons/bison.m4 (b4_symbol): Let `b4_symbol(eof, ...)` mean
`b4_symbol(0, ...)`, `b4_symbol(error, ...)` mean `b4_symbol(1, ...)`,
and , `b4_symbol(undef, ...)` mean `b4_symbol(2, ...)`..

* data/skeletons/c.m4, data/skeletons/glr.c, data/skeletons/glr.cc,
* data/skeletons/glr2.cc, data/skeletons/lalr1.cc,
* data/skeletons/lalr1.d, data/skeletons/lalr1.java,
* data/skeletons/yacc.c:
Prefer symbols to numbers.
This commit is contained in:
Akim Demaille
2020-11-07 16:21:00 +01:00
parent 34e6e8815a
commit 5a31cda4c3
10 changed files with 82 additions and 75 deletions
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28
data/skeletons/yacc.c
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@@ -755,8 +755,8 @@ enum { YYENOMEM = -2 };
while (0)
/* Backward compatibility with an undocumented macro.
Use ]b4_symbol(1, id)[ or ]b4_symbol(2, id)[. */
#define YYERRCODE ]b4_symbol(2, id)[
Use ]b4_symbol(error, id)[ or ]b4_symbol(undef, id)[. */
#define YYERRCODE ]b4_symbol(undef, id)[
]b4_locations_if([[
]b4_yylloc_default_define[
#define YYRHSLOC(Rhs, K) ((Rhs)[K])
@@ -1165,7 +1165,7 @@ yypcontext_expected_tokens (const yypcontext_t *yyctx,
for (yyx = 0; yyx < YYNTOKENS; ++yyx)
{
yysymbol_kind_t yysym = YY_CAST (yysymbol_kind_t, yyx);
if (yysym != ]b4_symbol(1, kind)[ && yysym != ]b4_symbol_prefix[YYUNDEF)
if (yysym != ]b4_symbol(error, kind)[ && yysym != ]b4_symbol_prefix[YYUNDEF)
switch (yy_lac (]b4_push_if([[yyps->yyesa, &yyps->yyes, &yyps->yyes_capacity, yyps->yyssp, yysym]],
[[yyctx->yyesa, yyctx->yyes, yyctx->yyes_capacity, yyctx->yyssp, yysym]])[))
{
@@ -1194,7 +1194,7 @@ yypcontext_expected_tokens (const yypcontext_t *yyctx,
int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
int yyx;
for (yyx = yyxbegin; yyx < yyxend; ++yyx)
if (yycheck[yyx + yyn] == yyx && yyx != ]b4_symbol(1, kind)[
if (yycheck[yyx + yyn] == yyx && yyx != ]b4_symbol(error, kind)[
&& !yytable_value_is_error (yytable[yyx + yyn]))
{
if (!yyarg)
@@ -1820,20 +1820,20 @@ yyread_pushed_token:]])[
yychar = ]b4_lex[;]])[
}
if (yychar <= ]b4_symbol(0, [id])[)
if (yychar <= ]b4_symbol(eof, [id])[)
{
yychar = ]b4_symbol(0, [id])[;
yytoken = ]b4_symbol(0, [kind])[;
yychar = ]b4_symbol(eof, [id])[;
yytoken = ]b4_symbol(eof, [kind])[;
YYDPRINTF ((stderr, "Now at end of input.\n"));
}
else if (yychar == ]b4_symbol(1, [id])[)
else if (yychar == ]b4_symbol(error, [id])[)
{
/* The scanner already issued an error message, process directly
to error recovery. But do not keep the error token as
lookahead, it is too special and may lead us to an endless
loop in error recovery. */
yychar = ]b4_symbol(2, [id])[;
yytoken = ]b4_symbol(1, [kind])[;]b4_locations_if([[
yychar = ]b4_symbol(undef, [id])[;
yytoken = ]b4_symbol(error, [kind])[;]b4_locations_if([[
yyerror_range[1] = yylloc;]])[
goto yyerrlab1;
}
@@ -2026,10 +2026,10 @@ yyerrlab:
/* If just tried and failed to reuse lookahead token after an
error, discard it. */
if (yychar <= ]b4_symbol(0, [id])[)
if (yychar <= ]b4_symbol(eof, [id])[)
{
/* Return failure if at end of input. */
if (yychar == ]b4_symbol(0, [id])[)
if (yychar == ]b4_symbol(eof, [id])[)
YYABORT;
}
else
@@ -2076,8 +2076,8 @@ yyerrlab1:
yyn = yypact[yystate];
if (!yypact_value_is_default (yyn))
{
yyn += ]b4_symbol(1, kind)[;
if (0 <= yyn && yyn <= YYLAST && yycheck[yyn] == ]b4_symbol(1, kind)[)
yyn += ]b4_symbol(error, kind)[;
if (0 <= yyn && yyn <= YYLAST && yycheck[yyn] == ]b4_symbol(error, kind)[)
{
yyn = yytable[yyn];
if (0 < yyn)