+
+
+
+## --------------------------------- ##
+## Default %printer and %destructor. ##
+## --------------------------------- ##
+
+# Check that the right %printer and %destructor are called, that they're not
+# called for $end, and that $$ and @$ work correctly.
+
+AT_SETUP([Default %printer and %destructor])
+
+AT_DATA_GRAMMAR([[input.y]],
+[[%error-verbose
+%debug
+%locations
+%initial-action {
+ @$.first_line = @$.last_line = 1;
+ @$.first_column = @$.last_column = 1;
+}
+
+%{
+# include <stdio.h>
+# include <stdlib.h>
+ static void yyerror (const char *msg);
+ static int yylex (void);
+# define USE(SYM)
+%}
+
+%printer {
+ fprintf (yyoutput, "Default printer for '%c' @ %d", $$, @$.first_column);
+} %symbol-default
+%destructor {
+ fprintf (stdout, "Default destructor for '%c' @ %d.\n", $$, @$.first_column);
+} %symbol-default
+
+%printer {
+ fprintf (yyoutput, "'b'/'c' printer for '%c' @ %d", $$, @$.first_column);
+} 'b' 'c'
+%destructor {
+ fprintf (stdout, "'b'/'c' destructor for '%c' @ %d.\n", $$, @$.first_column);
+} 'b' 'c'
+
+%%
+
+start: 'a' 'b' 'c' 'd' 'e' { $$ = 'S'; USE(($1, $2, $3, $4, $5)); } ;
+
+%%
+
+static int
+yylex (void)
+{
+ static const char *input = "abcd";
+ static int column = 1;
+ yylval = *input++;
+ yylloc.first_line = yylloc.last_line = 1;
+ yylloc.first_column = yylloc.last_column = column++;
+ return yylval;
+}
+
+static void
+yyerror (const char *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ yydebug = 1;
+ return yyparse ();
+}
+]])
+
+AT_CHECK([bison -o input.c input.y])
+AT_COMPILE([input])
+AT_PARSER_CHECK([./input], 1,
+[[Default destructor for 'd' @ 4.
+'b'/'c' destructor for 'c' @ 3.
+'b'/'c' destructor for 'b' @ 2.
+Default destructor for 'a' @ 1.
+]],
+[[Starting parse
+Entering state 0
+Reading a token: Next token is token 'a' (1.1-1.1: Default printer for 'a' @ 1)
+Shifting token 'a' (1.1-1.1: Default printer for 'a' @ 1)
+Entering state 1
+Reading a token: Next token is token 'b' (1.2-1.2: 'b'/'c' printer for 'b' @ 2)
+Shifting token 'b' (1.2-1.2: 'b'/'c' printer for 'b' @ 2)
+Entering state 3
+Reading a token: Next token is token 'c' (1.3-1.3: 'b'/'c' printer for 'c' @ 3)
+Shifting token 'c' (1.3-1.3: 'b'/'c' printer for 'c' @ 3)
+Entering state 5
+Reading a token: Next token is token 'd' (1.4-1.4: Default printer for 'd' @ 4)
+Shifting token 'd' (1.4-1.4: Default printer for 'd' @ 4)
+Entering state 6
+Reading a token: Now at end of input.
+syntax error, unexpected $end, expecting 'e'
+Error: popping token 'd' (1.4-1.4: Default printer for 'd' @ 4)
+Stack now 0 1 3 5
+Error: popping token 'c' (1.3-1.3: 'b'/'c' printer for 'c' @ 3)
+Stack now 0 1 3
+Error: popping token 'b' (1.2-1.2: 'b'/'c' printer for 'b' @ 2)
+Stack now 0 1
+Error: popping token 'a' (1.1-1.1: Default printer for 'a' @ 1)
+Stack now 0
+Cleanup: discarding lookahead token $end (1.5-1.5: )
+Stack now 0
+]])
+
+AT_CLEANUP
+
+
+
+## ------------------------------------------------------------- ##
+## Default %printer and %destructor for user-defined end token. ##
+## ------------------------------------------------------------- ##
+
+AT_SETUP([Default %printer and %destructor for user-defined end token])
+
+AT_DATA_GRAMMAR([[input.y]],
+[[%error-verbose
+%debug
+%locations
+%initial-action {
+ @$.first_line = @$.last_line = 1;
+ @$.first_column = @$.last_column = 1;
+}
+
+%{
+# include <stdio.h>
+# include <stdlib.h>
+ static void yyerror (const char *msg);
+ static int yylex (void);
+# define USE(SYM)
+%}
+
+%token END 0
+%printer {
+ fprintf (yyoutput, "Default printer for '%c' @ %d", $$, @$.first_column);
+} %symbol-default
+%destructor {
+ fprintf (stdout, "Default destructor for '%c' @ %d.\n", $$, @$.first_column);
+} %symbol-default
+
+%%
+
+start: { $$ = 'S'; } ;
+
+%%
+
+static int
+yylex (void)
+{
+ yylval = 'E';
+ yylloc.first_line = yylloc.last_line = 1;
+ yylloc.first_column = yylloc.last_column = 1;
+ return 0;
+}
+
+static void
+yyerror (const char *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ yydebug = 1;
+ return yyparse ();
+}
+]])
+
+AT_CHECK([bison -o input.c input.y])
+AT_COMPILE([input])
+AT_PARSER_CHECK([./input], 0,
+[[Default destructor for 'E' @ 1.
+Default destructor for 'S' @ 1.
+]],
+[[Starting parse
+Entering state 0
+Reducing stack by rule 1 (line 37):
+-> $$ = nterm start (1.1-1.1: Default printer for 'S' @ 1)
+Stack now 0
+Entering state 1
+Reading a token: Now at end of input.
+Shifting token END (1.1-1.1: Default printer for 'E' @ 1)
+Entering state 2
+Stack now 0 1 2
+Cleanup: popping token END (1.1-1.1: Default printer for 'E' @ 1)
+Cleanup: popping nterm start (1.1-1.1: Default printer for 'S' @ 1)
+]])
+
+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_DATA_GRAMMAR([[input.y]],
+[[%debug
+
+%{
+# include <stdio.h>
+ static void yyerror (const char *msg);
+ static int yylex (void);
+# define USE(SYM)
+%}
+
+%printer {
+ fprintf (yyoutput, "'%c'", $$);
+} %symbol-default
+%destructor {
+ fprintf (stderr, "DESTROY '%c'\n", $$);
+} %symbol-default
+
+%%
+
+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'; }
+ ;
+
+%%
+
+static int
+yylex (void)
+{
+ static const char *input = "abd";
+ yylval = *input++;
+ return yylval;
+}
+
+static void
+yyerror (const char *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ yydebug = 1;
+ return yyparse ();
+}
+]])
+
+AT_CHECK([bison -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_DATA_GRAMMAR([[input.y]],
+[[%debug /* So that %printer is actually compiled. */
+
+%{
+# include <stdio.h>
+ static void yyerror (const char *msg);
+ static int yylex (void);
+# define USE(SYM)
+%}
+
+%printer {
+ char chr = $$;
+ fprintf (yyoutput, "'%c'", chr);
+} %symbol-default
+%destructor {
+ char chr = $$;
+ fprintf (stderr, "DESTROY '%c'\n", chr);
+} %symbol-default
+
+%union { char chr; }
+%type <chr> start
+
+%%
+
+start: { USE($$); } ;
+
+%%
+
+static int
+yylex (void)
+{
+ return 0;
+}
+
+static void
+yyerror (const char *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ return yyparse ();
+}
+]])
+
+AT_CHECK([bison -o input.c input.y])
+AT_COMPILE([input])
+
+AT_CLEANUP
projects / bison.git / blobdiff