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examples: don't use yysyntax_error_arguments

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Suggested by Adrian Vogelsgesang.
https://lists.gnu.org/archive/html/bison-patches/2020-02/msg00069.html

* data/skeletons/lalr1.java (Context.EMPTY, Context.getToken): New.
(Context.yyntokens): Rename as...
(Context.NTOKENS): this.
Because (i) all the Java coding styles recommend upper case for
constants, and (ii) the Java Skeleton exposes Lexer.EOF, not
Lexer.YYEOF.
* data/skeletons/yacc.c (yyparse_context_token): New.
* examples/c/bistromathic/parse.y (yyreport_syntax_error): Don't use
yysyntax_error_arguments.
* examples/java/calc/Calc.y (yyreportSyntaxError): Likewise.
This commit is contained in:
Akim Demaille
2020-03-21 08:04:01 +01:00
parent ef8965b5f5
commit 1045c8d0ef
6 changed files with 67 additions and 26 deletions
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1
THANKS
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@@ -4,6 +4,7 @@ it is today without the invaluable help of these people:
Aaro Koskinen aaro.koskinen@iki.fi
Аскар Сафин safinaskar@mail.ru
Adam Sampson ats@offog.org
Adrian Vogelsgesang avogelsgesang@tableau.com
Ahcheong Lee dkcjd2000@gmail.com
Airy Andre Airy.Andre@edf.fr
Akim Demaille akim@gnu.org

22
data/skeletons/lalr1.java
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@@ -867,19 +867,37 @@ b4_dollar_popdef[]dnl
yytoken = token;]b4_locations_if([[
yylocation = loc;]])[
}
private YYStack yystack;
public int getToken ()
{
return yytoken;
}
/**
* Value returned by getToken when there is no token.
*/
public static final int EMPTY = ]b4_parser_class[.yyempty_;
private int yytoken;]b4_locations_if([[
public ]b4_location_type[ getLocation ()
{
return yylocation;
}
private ]b4_location_type[ yylocation;]])[
static final int yyntokens = ]b4_parser_class[.yyntokens_;
static final int NTOKENS = ]b4_parser_class[.yyntokens_;
/* Put in YYARG at most YYARGN of the expected tokens given the
current YYCTX, and return the number of tokens stored in YYARG. If
YYARG is null, return the number of expected tokens (guaranteed to
be less than YYNTOKENS). */
int yyexpectedTokens (int yyarg[], int yyargn)
{
return yyexpectedTokens (yyarg, 0, yyargn);
}
int yyexpectedTokens (int yyarg[], int yyoffset, int yyargn)
{
int yycount = yyoffset;
@@ -893,7 +911,7 @@ b4_dollar_popdef[]dnl
int yyxbegin = yyn < 0 ? -yyn : 0;
/* Stay within bounds of both yycheck and yytname. */
int yychecklim = yylast_ - yyn + 1;
int yyxend = yychecklim < yyntokens ? yychecklim : yyntokens;
int yyxend = yychecklim < NTOKENS ? yychecklim : NTOKENS;
for (int x = yyxbegin; x < yyxend; ++x)
if (yycheck_[x + yyn] == x && x != yy_error_token_
&& !yyTableValueIsError (yytable_[x + yyn]))

16
data/skeletons/yacc.c
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@@ -1198,6 +1198,10 @@ yyexpected_tokens (const yyparse_context_t *yyctx,
return yypstate_expected_tokens (yyctx->yyps, yyarg, yyargn);
}]])[
static int
yysyntax_error_arguments (const yyparse_context_t *yyctx,
int yyarg[], int yyargn) YY_ATTRIBUTE_UNUSED;
static int
yysyntax_error_arguments (const yyparse_context_t *yyctx,
int yyarg[], int yyargn)
@@ -1251,7 +1255,17 @@ yysyntax_error_arguments (const yyparse_context_t *yyctx,
]b4_parse_error_case(
[custom],
[b4_locations_if([[/* The location of this context. */
[[/* The token type of the lookahead of this context. */
static int
yyparse_context_token (const yyparse_context_t *yyctx) YY_ATTRIBUTE_UNUSED;
static int
yyparse_context_token (const yyparse_context_t *yyctx)
{
return yyctx->yytoken;
}
]b4_locations_if([[/* The location of the lookahead of this context. */
static YYLTYPE *
yyparse_context_location (const yyparse_context_t *yyctx) YY_ATTRIBUTE_UNUSED;

29
examples/c/bistromathic/parse.y
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@@ -284,23 +284,26 @@ yylex (const char **line, YYSTYPE *yylval, YYLTYPE *yylloc)
int
yyreport_syntax_error (const yyparse_context_t *ctx)
{
enum { ARGMAX = 10 };
int res = 0;
int arg[ARGMAX];
int n = yysyntax_error_arguments (ctx, arg, ARGMAX);
if (n < 0)
// Forward errors to yyparse.
res = n;
YY_LOCATION_PRINT (stderr, *yyparse_context_location (ctx));
fprintf (stderr, ": syntax error");
if (n >= 0)
{
for (int i = 1; i < n; ++i)
{
enum { TOKENMAX = 10 };
int expected[TOKENMAX];
int n = yyexpected_tokens (ctx, expected, TOKENMAX);
if (n < 0)
// Forward errors to yyparse.
res = n;
else
for (int i = 0; i < n; ++i)
fprintf (stderr, "%s %s",
i == 1 ? ": expected" : " or", yysymbol_name (arg[i]));
if (n)
fprintf (stderr, " before %s", yysymbol_name (arg[0]));
}
i == 0 ? ": expected" : " or", yysymbol_name (expected[i]));
}
{
int lookahead = yyparse_context_token (ctx);
if (lookahead != YYEMPTY)
fprintf (stderr, " before %s", yysymbol_name (lookahead));
}
fprintf (stderr, "\n");
return res;
}

21
examples/java/calc/Calc.y
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@@ -108,15 +108,20 @@ class CalcLexer implements Calc.Lexer {
public void yyreportSyntaxError (Calc.Context ctx)
{
final int ARGMAX = 10;
int[] arg = new int[ARGMAX];
int n = ctx.yysyntaxErrorArguments (arg, ARGMAX);
System.err.print (ctx.getLocation () + ": syntax error");
for (int i = 1; i < n; ++i)
System.err.print ((i == 1 ? ": expected " : " or ")
+ ctx.yysymbolName (arg[i]));
if (n != 0)
System.err.print (" before " + ctx.yysymbolName (arg[0]));
{
final int TOKENMAX = 10;
int[] arg = new int[TOKENMAX];
int n = ctx.yyexpectedTokens (arg, TOKENMAX);
for (int i = 0; i < n; ++i)
System.err.print ((i == 0 ? ": expected " : " or ")
+ ctx.yysymbolName (arg[i]));
}
{
int lookahead = ctx.getToken ();
if (lookahead != ctx.EMPTY)
System.err.print (" before " + ctx.yysymbolName (lookahead));
}
System.err.println ("");
}

4
tests/local.at
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@@ -964,8 +964,8 @@ m4_define([AT_YYERROR_DEFINE(java)],
]AT_ERROR_CUSTOM_IF([[
public void yyreportSyntaxError (Calc.Context ctx)
{
int[] arg = new int[ctx.yyntokens];
int n = ctx.yysyntaxErrorArguments (arg, ctx.yyntokens);
int[] arg = new int[ctx.NTOKENS];
int n = ctx.yysyntaxErrorArguments (arg, ctx.NTOKENS);
System.err.print (]AT_LOCATION_IF([[ctx.getLocation () + ": "]]
+ )["syntax error on token @<:@" + ctx.yysymbolName (arg[0]) + "@:>@");
if (1 < n)