+
+
+## ------------------------------------------ ##
+## Diagnostic that expects two alternatives. ##
+## ------------------------------------------ ##
+
+
+# _AT_DATA_EXPECT2_Y(BISON-OPTIONS)
+# --------------------------------
+m4_define([_AT_DATA_EXPECT2_Y],
+[AT_DATA_GRAMMAR([expect2.y],
+[%{
+static int yylex (AT_LALR1_CC_IF([int *], [void]));
+AT_LALR1_CC_IF([],
+[#include <stdio.h>
+#include <stdlib.h>
+static void yyerror (const char *);])
+%}
+$1
+%defines
+%error-verbose
+%token A 1000
+%token B
+
+%%
+program: /* empty */
+ | program e ';'
+ | program error ';';
+
+e: e '+' t | t;
+t: A | B;
+
+%%
+AT_LALR1_CC_IF(
+[/* A C++ error reporting function. */
+void
+yy::parser::error (const location&, const std::string& m)
+{
+ std::cerr << m << std::endl;
+}
+
+int
+yyparse ()
+{
+ yy::parser parser;
+ return parser.parse ();
+}
+],
+[static void
+yyerror (const char *s)
+{
+ fprintf (stderr, "%s\n", s);
+}])
+
+static int
+yylex (AT_LALR1_CC_IF([int *lval], [void]))
+[{
+ static int const tokens[] =
+ {
+ 1000, '+', '+', -1
+ };
+ static size_t toknum;
+ ]AT_LALR1_CC_IF([*lval = 0; /* Pacify GCC. */])[
+ if (! (toknum < sizeof tokens / sizeof *tokens))
+ abort ();
+ return tokens[toknum++];
+}]
+
+int
+main (void)
+{
+ return yyparse ();
+}
+])
+])# _AT_DATA_EXPECT2_Y
+
+
+# AT_CHECK_EXPECT2(BISON-OPTIONS)
+# ------------------------------
+# Generate the grammar, compile it, run it.
+m4_define([AT_CHECK_EXPECT2],
+[AT_SETUP([Expecting two tokens $1])
+AT_BISON_OPTION_PUSHDEFS([$1])
+_AT_DATA_EXPECT2_Y([$1])
+AT_BISON_CHECK([-o expect2.c expect2.y])
+AT_LALR1_CC_IF(
+ [AT_BISON_CHECK([-o expect2.cc expect2.y])
+ AT_COMPILE_CXX([expect2])],
+ [AT_BISON_CHECK([-o expect2.c expect2.y])
+ AT_COMPILE([expect2])])
+AT_PARSER_CHECK([./expect2], 1, [],
+[syntax error, unexpected '+', expecting A or B
+])
+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP
+])
+
+AT_CHECK_EXPECT2()
+AT_CHECK_EXPECT2([%glr-parser])
+AT_CHECK_EXPECT2([%skeleton "lalr1.cc"])
+
+
+
+## --------------------------------------------- ##
+## Braced code in declaration in rules section. ##
+## --------------------------------------------- ##
+
+AT_SETUP([Braced code in declaration in rules section])
+
+# Bison once mistook braced code in a declaration in the rules section to be a
+# rule action.
+
+AT_DATA_GRAMMAR([input.y],
+[[%{
+#include <stdio.h>
+static void yyerror (char const *msg);
+static int yylex (void);
+%}
+
+%error-verbose
+
+%%
+
+start:
+ {
+ printf ("Bison would once convert this action to a midrule because of the"
+ " subsequent braced code.\n");
+ }
+ ;
+
+%destructor { fprintf (stderr, "DESTRUCTOR\n"); } 'a';
+%printer { fprintf (yyoutput, "PRINTER"); } 'a';
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ return 'a';
+}
+
+int
+main (void)
+{
+ yydebug = 1;
+ return !yyparse ();
+}
+]])
+
+AT_BISON_CHECK([-t -o input.c input.y])
+AT_COMPILE([input])
+AT_PARSER_CHECK([./input], 0,
+[[Bison would once convert this action to a midrule because of the subsequent braced code.
+]],
+[[Starting parse
+Entering state 0
+Reducing stack by rule 1 (line 20):
+-> $$ = nterm start ()
+Stack now 0
+Entering state 1
+Reading a token: Next token is token 'a' (PRINTER)
+syntax error, unexpected 'a', expecting $end
+Error: popping nterm start ()
+Stack now 0
+Cleanup: discarding lookahead token 'a' (PRINTER)
+DESTRUCTOR
+Stack now 0
+]])
+
+AT_CLEANUP
+
+
+
+## --------------------------------- ##
+## String alias declared after use. ##
+## --------------------------------- ##
+
+AT_SETUP([String alias declared after use])
+
+# Bison once incorrectly asserted that the symbol number for either a token or
+# its alias was the highest symbol number so far at the point of the alias
+# declaration. That was true unless the declaration appeared after their first
+# uses and other tokens appeared in between.
+
+AT_DATA([input.y],
+[[%%
+start: 'a' "A" 'b';
+%token 'a' "A";
+]])
+
+AT_BISON_CHECK([-t -o input.c input.y])
+
+AT_CLEANUP
+
+
+
+## -------------------------------- ##
+## Extra lookahead sets in report. ##
+## -------------------------------- ##
+
+AT_SETUP([[Extra lookahead sets in report]])
+
+# Bison prints each reduction's lookahead set only next to the associated
+# state's one item that (1) is associated with the same rule as the reduction
+# and (2) has its dot at the end of its RHS. Previously, Bison also
+# erroneously printed the lookahead set next to all of the state's other items
+# associated with the same rule. This bug affected only the `.output' file and
+# not the generated parser source code.
+
+AT_DATA([[input.y]],
+[[%%
+start: a | 'a' a 'a' ;
+a: 'a' ;
+]])
+
+AT_BISON_CHECK([[--report=all input.y]])
+AT_CHECK([[sed -n '/^state 1$/,/^state 2$/p' input.output]], [[0]],
+[[state 1
+
+ 2 start: 'a' . a 'a'
+ 3 a: . 'a'
+ 3 | 'a' . [$end]
+
+ 'a' shift, and go to state 4
+
+ $default reduce using rule 3 (a)
+
+ a go to state 5
+
+
+state 2
+]])
+
+AT_CLEANUP
+
+
+
+## ---------------------------------------- ##
+## Token number in precedence declaration. ##
+## ---------------------------------------- ##
+
+AT_SETUP([[Token number in precedence declaration.]])
+
+# POSIX says token numbers can be declared in %left, %right, and %nonassoc, but
+# we lost this in Bison 1.50.
+
+AT_DATA_GRAMMAR([input.y],
+[[%{
+ #include <stdio.h>
+ void yyerror (char const *);
+ int yylex (void);
+%}
+
+%error-verbose
+%left TK1 1 TK2 2 "tok alias" 3
+
+%%
+
+start: TK1 sr_conflict "tok alias" ;
+
+sr_conflict:
+ TK2
+ | TK2 "tok alias"
+ ;
+
+%%
+
+void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+yylex (void)
+{
+ static int const input[] = { 1, 2, 3, 0 };
+ static int const *inputp = input;
+ return *inputp++;
+}
+
+int
+main (void)
+{
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o input.c input.y]], [[0]],,
+[[input.y:24.5-19: warning: rule useless in parser due to conflicts: sr_conflict: TK2 "tok alias"
+]])
+AT_COMPILE([[input]])
+AT_PARSER_CHECK([[./input]])
+
+AT_CLEANUP
projects / bison.git / blobdiff