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c, c++: also define YYEMPTY in yytoken_kind_t

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I have been hesitating a lot before doing it ---after all the user
must not use this kind, so what's the point of showing it in
yytoken_kind_t.  And eventually I chose to play it safe with the
typing system and make it possible to use yytoken_kind_t for all the
tokens, even the "empty token".

* data/skeletons/c.m4: Give an id and a tag to YYEMPTY.
(b4_token_enums): Define YYEMPTY.
* data/skeletons/c++.m4 (b4_token_enums): Define YYEMPTY.
* data/skeletons/glr.c, data/skeletons/glr.cc, data/skeletons/yacc.c:
(YYEMPTY): Remove.
Use b4_symbol(-2, id) instead.
This commit is contained in:
Akim Demaille
2020-04-13 08:05:09 +02:00
parent 5e2e9af56d
commit 64aec0a8d8
5 changed files with 34 additions and 30 deletions
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24
data/skeletons/yacc.c
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@@ -714,8 +714,7 @@ static const ]b4_int_type_for([b4_toknum])[ yytoknum[] =
enum { YYENOMEM = -2 };
#define yyerrok (yyerrstatus = 0)
#define yyclearin (yychar = YYEMPTY)
#define YYEMPTY (-2)
#define yyclearin (yychar = ]b4_symbol(-2, id)[)
#define YYACCEPT goto yyacceptlab
#define YYABORT goto yyabortlab
@@ -726,7 +725,7 @@ enum { YYENOMEM = -2 };
#define YYBACKUP(Token, Value) \
do \
if (yychar == YYEMPTY) \
if (yychar == ]b4_symbol(-2, id)[) \
{ \
yychar = (Token); \
yylval = (Value); \
@@ -1613,7 +1612,7 @@ b4_initialize_parser_state_variables])[
YYDPRINTF ((stderr, "Starting parse\n"));
yychar = YYEMPTY; /* Cause a token to be read. */
yychar = ]b4_symbol(-2, id)[; /* Cause a token to be read. */
]m4_ifdef([b4_initial_action], [
b4_dollar_pushdef([m4_define([b4_dollar_dollar_used])yylval], [], [],
[b4_push_if([b4_pure_if([*])yypushed_loc], [yylloc])])dnl
@@ -1735,7 +1734,7 @@ yybackup:
/* Not known => get a lookahead token if don't already have one. */
/* YYCHAR is either empty, or end-of-input, or a valid lookahead. */
if (yychar == YYEMPTY)
if (yychar == ]b4_symbol(-2, id)[)
{]b4_push_if([[
if (!yyps->yynew)
{]b4_use_push_for_pull_if([], [[
@@ -1763,7 +1762,7 @@ yyread_pushed_token:]])[
if (yychar <= ]b4_symbol(0, [id])[)
{
yychar = ]b4_symbol(0, [id])[;
yytoken = ]b4_symbol_prefix[YYEOF;
yytoken = ]b4_symbol(0, [kind])[;
YYDPRINTF ((stderr, "Now at end of input.\n"));
}
else
@@ -1805,7 +1804,7 @@ yyread_pushed_token:]])[
*++yylsp = yylloc;])[
/* Discard the shifted token. */
yychar = YYEMPTY;]b4_lac_if([[
yychar = ]b4_symbol(-2, id)[;]b4_lac_if([[
YY_LAC_DISCARD ("shift");]])[
goto yynewstate;
@@ -1896,8 +1895,7 @@ yyreduce:
yyerrlab:
/* Make sure we have latest lookahead translation. See comments at
user semantic actions for why this is necessary. */
yytoken = yychar == YYEMPTY ? ]b4_symbol_prefix[YYEMPTY : YYTRANSLATE (yychar);
yytoken = yychar == ]b4_symbol(-2, id)[ ? ]b4_symbol_prefix[YYEMPTY : YYTRANSLATE (yychar);
/* If not already recovering from an error, report this error. */
if (!yyerrstatus)
{
@@ -1907,7 +1905,7 @@ yyerrlab:
[[ {
yypcontext_t yyctx
= {]b4_push_if([[yyps]], [[yyssp]b4_lac_if([[, yyesa, &yyes, &yyes_capacity]])])[, yytoken]b4_locations_if([[, &yylloc]])[};]b4_lac_if([[
if (yychar != YYEMPTY)
if (yychar != ]b4_symbol(-2, id)[)
YY_LAC_ESTABLISH;]])[
if (yyreport_syntax_error (&yyctx]m4_ifset([b4_parse_param],
[[, ]b4_args(b4_parse_param)])[) == 2)
@@ -1920,7 +1918,7 @@ yyerrlab:
= {]b4_push_if([[yyps]], [[yyssp]b4_lac_if([[, yyesa, &yyes, &yyes_capacity]])])[, yytoken]b4_locations_if([[, &yylloc]])[};
char const *yymsgp = YY_("syntax error");
int yysyntax_error_status;]b4_lac_if([[
if (yychar != YYEMPTY)
if (yychar != ]b4_symbol(-2, id)[)
YY_LAC_ESTABLISH;]])[
yysyntax_error_status = yysyntax_error (&yymsg_alloc, &yymsg, &yyctx);
if (yysyntax_error_status == 0)
@@ -1967,7 +1965,7 @@ yyerrlab:
{
yydestruct ("Error: discarding",
yytoken, &yylval]b4_locations_if([, &yylloc])[]b4_user_args[);
yychar = YYEMPTY;
yychar = ]b4_symbol(-2, id)[;
}
}
@@ -2078,7 +2076,7 @@ yyexhaustedlab:
| yyreturn -- parsing is finished, return the result. |
`-----------------------------------------------------*/
yyreturn:
if (yychar != YYEMPTY)
if (yychar != ]b4_symbol(-2, id)[)
{
/* Make sure we have latest lookahead translation. See comments at
user semantic actions for why this is necessary. */