+AT_CLEANUP
+
+
+
+## ------------------------------------------------------------------ ##
+## Default %printer and %destructor are not for error or $undefined. ##
+## ------------------------------------------------------------------ ##
+
+AT_SETUP([Default %printer and %destructor are not for error or $undefined])
+
+# If Bison were to apply the default %printer and %destructor to the error
+# token or to $undefined:
+# - For the error token:
+# - It would generate warnings for unused $n.
+# - It would invoke the %printer and %destructor on the error token's
+# semantic value, which would be initialized from the lookahead, which
+# would be destroyed separately.
+# - For $undefined, who knows what the semantic value would be.
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([[input.y]],
+[[%debug
+
+%{
+# include <stdio.h>
+# include <stdlib.h>
+]AT_YYERROR_DECLARE[
+]AT_YYLEX_DECLARE[
+# define USE(SYM)
+%}
+
+%printer {
+ fprintf (yyoutput, "'%c'", $$);
+} <> <*>
+%destructor {
+ fprintf (stderr, "DESTROY '%c'\n", $$);
+} <> <*>
+
+%%
+
+start:
+ { $$ = 'S'; }
+ /* In order to reveal the problems that this bug caused during parsing, add
+ * $2 to USE. */
+ | 'a' error 'b' 'c' { USE(($1, $3, $4)); $$ = 'S'; }
+ ;
+
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE(["abd"], [yylval = res])[
+int
+main (void)
+{
+ yydebug = 1;
+ return yyparse ();
+}
+]])
+AT_BISON_OPTION_POPDEFS
+
+AT_BISON_CHECK([-o input.c input.y])
+AT_COMPILE([input])
+AT_PARSER_CHECK([./input], [1], [],
+[[Starting parse
+Entering state 0
+Reading a token: Next token is token 'a' ('a')
+Shifting token 'a' ('a')
+Entering state 1
+Reading a token: Next token is token 'b' ('b')
+syntax error
+Shifting token error ()
+Entering state 3
+Next token is token 'b' ('b')
+Shifting token 'b' ('b')
+Entering state 5
+Reading a token: Next token is token $undefined ()
+Error: popping token 'b' ('b')
+DESTROY 'b'
+Stack now 0 1 3
+Error: popping token error ()
+Stack now 0 1
+Shifting token error ()
+Entering state 3
+Next token is token $undefined ()
+Error: discarding token $undefined ()
+Error: popping token error ()
+Stack now 0 1
+Shifting token error ()
+Entering state 3
+Reading a token: Now at end of input.
+Cleanup: discarding lookahead token $end ()
+Stack now 0 1 3
+Cleanup: popping token error ()
+Cleanup: popping token 'a' ('a')
+DESTROY 'a'
+]])
+
+AT_CLEANUP
+
+
+
+## ------------------------------------------------------ ##
+## Default %printer and %destructor are not for $accept. ##
+## ------------------------------------------------------ ##
+
+AT_SETUP([Default %printer and %destructor are not for $accept])
+
+# If YYSTYPE is a union and Bison were to apply the default %printer and
+# %destructor to $accept:
+# - The %printer and %destructor code generated for $accept would always be
+# dead code because $accept is currently never shifted onto the stack.
+# - $$ for $accept would always be of type YYSTYPE because it's not possible
+# to declare `%type <field> $accept'. (Also true for $undefined.)
+# - Thus, the compiler might complain that the user code assumes the wrong
+# type for $$ since the code might assume the type associated with a
+# specific union field, which is especially reasonable in C++ since that
+# type may be a base type. This test case checks for this problem. (Also
+# true for $undefined and the error token, so there are three warnings for
+# %printer and three for %destructor.)
+
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([[input.y]],
+[[%debug /* So that %printer is actually compiled. */
+
+%{
+# include <stdio.h>
+# include <stdlib.h>
+]AT_YYERROR_DECLARE[
+]AT_YYLEX_DECLARE[
+# define USE(SYM)
+%}
+
+%printer {
+ char chr = $$;
+ fprintf (yyoutput, "'%c'", chr);
+} <> <*>
+%destructor {
+ char chr = $$;
+ fprintf (stderr, "DESTROY '%c'\n", chr);
+} <> <*>
+
+%union { char chr; }
+%type <chr> start
+
+%%
+
+start: { USE($$); } ;
+
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE[
+int
+main (void)
+{
+ return yyparse ();
+}
+]])
+AT_BISON_OPTION_POPDEFS
+
+AT_BISON_CHECK([-o input.c input.y])
+AT_COMPILE([input])
+
+AT_CLEANUP
+
+
+
+## ------------------------------------------------------ ##
+## Default %printer and %destructor for mid-rule values. ##
+## ------------------------------------------------------ ##
+
+AT_SETUP([Default %printer and %destructor for mid-rule values])
+
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([[input.y]],
+[[%debug /* So that %printer is actually compiled. */
+
+%{
+# include <stdio.h>
+# include <stdlib.h>
+]AT_YYERROR_DECLARE[
+]AT_YYLEX_DECLARE[
+# define USE(SYM)
+# define YYLTYPE int
+# define YYLLOC_DEFAULT(Current, Rhs, N) (void)(Rhs)
+# define YY_LOCATION_PRINT(File, Loc)
+%}
+
+%printer { fprintf (yyoutput, "%d", @$); } <>
+%destructor { fprintf (stderr, "DESTROY %d\n", @$); } <>
+%printer { fprintf (yyoutput, "<*> printer should not be called"); } <*>
+%destructor { fprintf (yyoutput, "<*> destructor should not be called"); } <*>
+
+%%
+
+start:
+ { @$ = 1; } // Not set or used.
+ { USE ($$); @$ = 2; } // Both set and used.
+ { USE ($$); @$ = 3; } // Only set.
+ { @$ = 4; } // Only used.
+ 'c'
+ { USE (($$, $2, $4, $5)); @$ = 0; }
+ ;
+
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE[
+int
+main (void)
+{
+ yydebug = 1;
+ return yyparse ();
+}
+]])
+AT_BISON_OPTION_POPDEFS
+
+AT_BISON_CHECK([-o input.c input.y], 0,,
+[[input.y:33.3-23: warning: unset value: $$
+input.y:30.3-35.37: warning: unused value: $3
+]])
+
+AT_COMPILE([input])
+AT_PARSER_CHECK([./input], 1,,
+[[Starting parse
+Entering state 0
+Reducing stack by rule 1 (line 30):
+-> $$ = nterm $@1 (: )
+Stack now 0
+Entering state 2
+Reducing stack by rule 2 (line 31):
+-> $$ = nterm @2 (: 2)
+Stack now 0 2
+Entering state 4
+Reducing stack by rule 3 (line 32):
+-> $$ = nterm @3 (: 3)
+Stack now 0 2 4
+Entering state 5
+Reducing stack by rule 4 (line 33):
+-> $$ = nterm @4 (: 4)
+Stack now 0 2 4 5
+Entering state 6
+Reading a token: Now at end of input.
+syntax error
+Error: popping nterm @4 (: 4)
+DESTROY 4
+Stack now 0 2 4 5
+Error: popping nterm @3 (: 3)
+DESTROY 3
+Stack now 0 2 4
+Error: popping nterm @2 (: 2)
+DESTROY 2
+Stack now 0 2
+Error: popping nterm $@1 (: )
+Stack now 0
+Cleanup: discarding lookahead token $end (: )
+Stack now 0
+]])
+
+AT_CLEANUP
+
+
+## ----------------------- ##
+## @$ implies %locations. ##
+## ----------------------- ##
+
+# Bison once forgot to check for @$ in actions other than semantic actions.
+
+# AT_CHECK_ACTION_LOCATIONS(ACTION-DIRECTIVE)
+# -------------------------------------------
+m4_define([AT_CHECK_ACTION_LOCATIONS],
+[AT_SETUP([[@$ in ]$1[ implies %locations]])
+AT_BISON_OPTION_PUSHDEFS
+AT_DATA_GRAMMAR([[input.y]],
+[[%code {
+ #include <stdio.h>
+]AT_YYERROR_DECLARE[
+]AT_YYLEX_DECLARE[
+}
+
+%debug
+
+]$1[ {
+ fprintf (stderr, "%d\n", @$.first_line);
+} ]m4_if($1, [%initial-action], [], [[start]])[
+
+%%
+
+start: ;
+
+%%
+
+static int
+yylex (void)
+{
+ return 0;
+}
+
+]AT_YYERROR_DEFINE[
+int
+main (void)
+{
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o input.c input.y]])
+AT_COMPILE([[input]])
+AT_BISON_OPTION_POPDEFS
+AT_CLEANUP])
+
+AT_CHECK_ACTION_LOCATIONS([[%initial-action]])
+AT_CHECK_ACTION_LOCATIONS([[%destructor]])
+AT_CHECK_ACTION_LOCATIONS([[%printer]])
+
+
+## ------------------------- ##
+## Qualified $$ in actions. ##
+## ------------------------- ##
+
+# Check that we can used qualified $$ (v.g., $<type>$) not only in
+# rule actions, but also where $$ is valid: %printer and %destructor.
+#
+# FIXME: Not actually checking %desctructor, but it's the same code as
+# %printer...
+#
+# To do that, use a semantic value that has two fields (sem_type),
+# declare symbols to have only one of these types (INT, float), and
+# use $<type>$ to get the other one. Including for symbols that are
+# not typed (UNTYPED).
+
+m4_pushdef([AT_TEST],
+[AT_SETUP([[Qualified $$ in actions: $1]])
+
+AT_BISON_OPTION_PUSHDEFS([%locations %skeleton "$1"])
+
+AT_DATA_GRAMMAR([[input.y]],
+[[%skeleton "$1"
+%defines // FIXME: Mandated by lalr1.cc in Bison 2.6.
+%locations // FIXME: Mandated by lalr1.cc in Bison 2.6.
+%debug
+%code requires
+{
+ typedef struct sem_type
+ {
+ int ival;
+ float fval;
+ } sem_type;
+
+# define YYSTYPE sem_type
+
+]AT_SKEL_CC_IF([[
+# include <iostream>
+ static void
+ report (std::ostream& yyo, int ival, float fval)
+ {
+ yyo << "ival: " << ival << ", fval: " << fval;
+ }
+]], [[
+# include <stdio.h>
+ static void
+ report (FILE* yyo, int ival, float fval)
+ {
+ fprintf (yyo, "ival: %d, fval: %1.1f", ival, fval);
+ }
+]])[
+}
+
+%code
+{
+ ]AT_YYERROR_DECLARE[
+ ]AT_YYLEX_DECLARE[
+}
+
+%token UNTYPED
+%token <ival> INT
+%type <fval> float
+%printer { report (yyo, $$, $<fval>$); } <ival>;
+%printer { report (yyo, $<ival>$, $$ ); } <fval>;
+%printer { report (yyo, $<ival>$, $<fval>$); } <>;
+
+]AT_SKEL_CC_IF([[
+/* The lalr1.cc skeleton, for backward compatibility, defines
+ a constructor for position that initializes the filename. The
+ glr.cc skeleton does not (and in fact cannot: location/position
+ are stored in a union, from which objects with constructors are
+ excluded in C++). */
+%initial-action {
+ @$.initialize ();
+}
+]])[
+
+%initial-action
+{
+ $<ival>$ = 42;
+ $<fval>$ = 4.2;
+}
+
+%%
+float: UNTYPED INT
+{
+ $$ = $<fval>1 + $<fval>2;
+ $<ival>$ = $<ival>1 + $][2;
+};
+%%
+]AT_YYERROR_DEFINE[
+]AT_YYLEX_DEFINE(AT_SKEL_CC_IF([[{yy::parser::token::UNTYPED,
+ yy::parser::token::INT,
+ EOF}]],
+ [[{UNTYPED, INT, EOF}]]),
+ [AT_VAL.ival = toknum * 10; AT_VAL.fval = toknum / 10.0;])[
+int
+main (void)
+{]AT_SKEL_CC_IF([[
+ yy::parser p;
+ p.set_debug_level(1);
+ return p.parse ();]], [[
+ yydebug = 1;
+ return yyparse ();]])[
+}
+]])
+
+AT_FULL_COMPILE([[input]])
+AT_PARSER_CHECK([./input], 0, [], [stderr])
+# Don't be too picky on the traces, GLR is not exactly the same. Keep
+# only the lines from the printer.
+#
+# Don't care about locations. FIXME: remove their removal when Bison
+# supports C++ without locations.
+AT_CHECK([[sed -ne 's/([-0-9.]*: /(/;/ival:/p' stderr]], 0,
+[[Reading a token: Next token is token UNTYPED (ival: 10, fval: 0.1)
+Shifting token UNTYPED (ival: 10, fval: 0.1)
+Reading a token: Next token is token INT (ival: 20, fval: 0.2)
+Shifting token INT (ival: 20, fval: 0.2)
+ $][1 = token UNTYPED (ival: 10, fval: 0.1)
+ $][2 = token INT (ival: 20, fval: 0.2)
+-> $$ = nterm float (ival: 30, fval: 0.3)
+Cleanup: popping nterm float (ival: 30, fval: 0.3)
+]])
+
+AT_BISON_OPTION_POPDEFS
+
+AT_CLEANUP
projects / bison.git / blobdiff