extern void perror (const char *s);
%}
+/* Also exercise %union. */
+%union
+{
+ int ival; /* A comment to exercise an old bug. */
+};
+
/* Bison Declarations */
-%token CALC_EOF 0
-%token NUM
+%token CALC_EOF 0 "end of file"
+%token <ival> NUM "number"
+%type <ival> exp
%nonassoc '=' /* comparison */
%left '-' '+'
/* Grammar follows */
%%
input:
- /* empty string */
+ line
| input line
;
line:
'\n'
-| exp '\n'
+| exp '\n' {}
;
exp:
| exp '=' exp
{
if ($1 != $3)
- printf ("calc: error: %d != %d\n", $1, $3);
+ fprintf (stderr, "calc: error: %d != %d\n", $1, $3);
$$ = $1 == $3;
}
| exp '+' exp { $$ = $1 + $3; }
| '-' exp %prec NEG { $$ = -$2; }
| exp '^' exp { $$ = power ($1, $3); }
| '(' exp ')' { $$ = $2; }
+| '(' error ')' { $$ = 0; }
;
%%
/* The input. */
yyerror (const char *s)
{
#if YYLSP_NEEDED
- fprintf (stderr, "%d.%d:%d.%d: ",
+ fprintf (stderr, "%d.%d-%d.%d: ",
yylloc.first_line, yylloc.first_column,
yylloc.last_line, yylloc.last_column);
#endif
fprintf (stderr, "%s\n", s);
}
+
+#if YYLSP_NEEDED
+static YYLTYPE last_yylloc;
+#endif
static int
yygetc (void)
{
int res = getc (yyin);
#if YYLSP_NEEDED
+ last_yylloc = yylloc;
if (res == '\n')
{
yylloc.last_line++;
- yylloc.last_column = 0;
+ yylloc.last_column = 1;
}
else
yylloc.last_column++;
{
#if YYLSP_NEEDED
/* Wrong when C == `\n'. */
- yylloc.last_column--;
+ yylloc = last_yylloc;
#endif
ungetc (c, yyin);
}
if (c == '.' || isdigit (c))
{
yyungetc (c);
- yylval = read_signed_integer ();
+ yylval.ival = read_signed_integer ();
return NUM;
}
yydebug = 1;
#endif
#if YYLSP_NEEDED
- yylloc.last_column = 0;
+ yylloc.last_column = 1;
yylloc.last_line = 1;
#endif
yyparse ();
[AT_DATA([[input]],
[[$2
]])
-AT_CHECK([calc input], 0, [], [stderr])dnl
+AT_CHECK([./calc input], 0, [], [stderr])dnl
AT_CHECK([wc -l <stderr | sed 's/[[^0-9]]//g'], 0,
[m4_bmatch([$1], [--debug],
[$3], [0])
# ------------------------------------------------------------
# Run `calc' on INPUT, and expect a `parse error' message.
#
+# If INPUT starts with a slash, it is used as absolute input file name,
+# otherwise as contents.
+#
# If BISON-OPTIONS contains `--location', then make sure the ERROR-LOCATION
# is correctly output on stderr.
#
# If BISON-OPTIONS contains `--debug', then NUM-STDERR-LINES is the number
# of expected lines on stderr.
m4_define([_AT_CHECK_CALC_ERROR],
-[AT_DATA([[input]],
+[m4_bmatch([$2], [^/],
+ [AT_CHECK([./calc $2], 0, [], [stderr])],
+ [AT_DATA([[input]],
[[$2
]])
+AT_CHECK([./calc input], 0, [], [stderr])])
-AT_CHECK([calc input], 0, [], [stderr])
-
+m4_bmatch([$1], [--debug],
+[AT_CHECK([wc -l <stderr | sed 's/[[^0-9]]//g'], 0, [$3
+])])
-AT_CHECK([wc -l <stderr | sed 's/[[^0-9]]//g'], 0,
- [m4_bmatch([$1], [--debug],
- [$3], [1])
-])
-
-egrep -v '^((Start|Enter|Read|Reduc|Shift)ing|state|Error:) ' stderr >at-stderr
+# Normalize the observed and expected error messages, depending upon the
+# options.
+# 1. Remove the traces from observed.
+egrep -v '^((Start|Enter|Read|Reduc|Shift)ing|state|Error:|Next|Discarding) ' stderr >at-stderr
mv at-stderr stderr
-
-AT_CHECK([cat stderr], 0,
-[m4_bmatch([$1], [--location], [$4: ])[]dnl
-parse error[]dnl
-m4_bmatch([$1], [--yyerror-verbose], [, $5])[]dnl
-
+# 2. Create the reference error message.
+AT_DATA([[expout]],
+[$4
])
-
+# 3. If locations are not used, remove them.
+m4_bmatch([$1], [--location], [],
+[[sed 's/^[-0-9.]*: //' expout >at-expout
+mv at-expout expout]])
+# 4. If error-verbose is not used, strip the`, unexpected....' part.
+m4_bmatch([$1], [--yyerror-verbose], [],
+[[sed 's/parse error, .*$/parse error/' expout >at-expout
+mv at-expout expout]])
+# 5. Check
+AT_CHECK([cat stderr], 0, [expout])
])
AT_CHECK([bison calc.y -o calc.c m4_bpatsubst([$1], [--yyerror-verbose])],
[0], [], [])
-# Some compilers issue warnings we don't want to hear about.
-# Maybe some day we will have proper Autoconf macros to disable these
-# warnings, but this place is not the right one for that.
-# So let's keep only GCC warnings, which we know are sane.
-# Well, that's only part of the story: some assemblers issue warnings
-# which can be totally useless, and actually polluting. It seems that
-# the best bet be to completely ignore stderr, but to pass -Werror
-# to GCC.
-if test "$GCC" = yes; then
- CFLAGS="$CFLAGS -Werror"
-fi
AT_CHECK([$CC $CFLAGS $CPPFLAGS calc.c -o calc], 0, [], [ignore])
# Test the priorities.
1 - (2 - 3) = 2
2^2^3 = 256
-(2^2)^3 = 64], [491])
+(2^2)^3 = 64], [486])
# Some parse errors.
-_AT_CHECK_CALC_ERROR([$1], [+1], [8],
- [1.0:1.1],
- [unexpected '+'])
-_AT_CHECK_CALC_ERROR([$1], [1//2], [17],
- [1.2:1.3],
- [unexpected '/', expecting NUM or '-' or '('])
-_AT_CHECK_CALC_ERROR([$1], [error], [8],
- [1.0:1.1],
- [unexpected $undefined.])
-_AT_CHECK_CALC_ERROR([$1], [1 = 2 = 3], [23],
- [1.6:1.7],
- [unexpected '='])
+_AT_CHECK_CALC_ERROR([$1], [0 0], [10],
+ [1.3-1.4: parse error, unexpected "number"])
+_AT_CHECK_CALC_ERROR([$1], [1//2], [13],
+ [1.3-1.4: parse error, unexpected '/', expecting "number" or '-' or '('])
+_AT_CHECK_CALC_ERROR([$1], [error], [4],
+ [1.1-1.2: parse error, unexpected $undefined., expecting "number" or '-' or '\n' or '('])
+_AT_CHECK_CALC_ERROR([$1], [1 = 2 = 3], [19],
+ [1.7-1.8: parse error, unexpected '='])
_AT_CHECK_CALC_ERROR([$1],
[
+1],
- [16],
- [2.0:2.1],
- [unexpected '+'])
+ [13],
+ [2.1-2.2: parse error, unexpected '+'])
+# Exercise error messages with EOF: work on an empty file.
+_AT_CHECK_CALC_ERROR([$1],
+ [/dev/null],
+ [4],
+ [1.1-1.2: parse error, unexpected "end of file", expecting "number" or '-' or '\n' or '('])
+
+# Exercise the error token: without it, we die at the first error,
+# hence be sure i. to have several errors, ii. to test the action
+# associated to `error'.
+_AT_CHECK_CALC_ERROR([$1],
+ [(1 ++ 2) + (0 0) = 1],
+ [76],
+[1.5-1.6: parse error, unexpected '+', expecting "number" or '-' or '('
+1.15-1.16: parse error, unexpected "number"
+calc: error: 0 != 1])
+
+# Add a studid example demonstrating that Bison can further improve the
+# error message. FIXME: Fix this ridiculous message.
+_AT_CHECK_CALC_ERROR([$1],
+ [()],
+ [21],
+[1.2-1.3: parse error, unexpected ')', expecting error or "number" or '-' or '('])
AT_CLEANUP
])# AT_CHECK_CALC