+ case 0: printf ("Successful parse.\n"); break;
+ case 1: printf ("Parsing FAILED.\n"); break;
+ default: printf ("Parsing FAILED (status %d).\n", status); break;
+ }
+ return status;
+}
+]])
+
+AT_FULL_COMPILE([input])
+
+
+# Check the location of "empty"
+# -----------------------------
+# I.e., epsilon-reductions, as in "(x)" which ends by reducing
+# an empty "line" nterm.
+# FIXME: This location is not satisfying. Depend on the lookahead?
+AT_PARSER_CHECK([./input '(x)'], 0,
+[[sending: '(' (0@0-9)
+sending: 'x' (1@10-19)
+thing (1@10-19): 'x' (1@10-19)
+sending: ')' (2@20-29)
+line (0@0-29): '(' (0@0-9) thing (1@10-19) ')' (2@20-29)
+sending: END (3@30-39)
+input (0@29-29): /* Nothing */
+input (2@0-29): line (0@0-29) input (0@29-29)
+Freeing token END (3@30-39)
+Freeing nterm input (2@0-29)
+Successful parse.
+]])
+
+
+# Check locations in error recovery
+# ---------------------------------
+# '(y)' is an error, but can be recovered from. But what's the location
+# of the error itself ('y'), and of the resulting reduction ('(error)').
+AT_PARSER_CHECK([./input '(y)'], 0,
+[[sending: '(' (0@0-9)
+sending: 'y' (1@10-19)
+10-19: syntax error, unexpected 'y', expecting 'x'
+Freeing token 'y' (1@10-19)
+sending: ')' (2@20-29)
+line (-1@0-29): '(' (0@0-9) error (@10-19) ')' (2@20-29)
+sending: END (3@30-39)
+input (0@29-29): /* Nothing */
+input (2@0-29): line (-1@0-29) input (0@29-29)
+Freeing token END (3@30-39)
+Freeing nterm input (2@0-29)
+Successful parse.
+]])
+
+
+# Syntax errors caught by the parser
+# ----------------------------------
+# Exercise the discarding of stack top and input until `error'
+# can be reduced.
+#
+# '(', 'x', 'x', 'x', 'x', 'x', ')',
+#
+# Load the stack and provoke an error that cannot be caught by the
+# grammar, to check that the stack is cleared. And make sure the
+# lookahead is freed.
+#
+# '(', 'x', ')',
+# '(', 'x', ')',
+# 'y'
+AT_PARSER_CHECK([./input '(xxxxx)(x)(x)y'], 1,
+[[sending: '(' (0@0-9)
+sending: 'x' (1@10-19)
+thing (1@10-19): 'x' (1@10-19)
+sending: 'x' (2@20-29)
+thing (2@20-29): 'x' (2@20-29)
+sending: 'x' (3@30-39)
+30-39: syntax error, unexpected 'x', expecting ')'
+Freeing nterm thing (2@20-29)
+Freeing nterm thing (1@10-19)
+Freeing token 'x' (3@30-39)
+sending: 'x' (4@40-49)
+Freeing token 'x' (4@40-49)
+sending: 'x' (5@50-59)
+Freeing token 'x' (5@50-59)
+sending: ')' (6@60-69)
+line (-1@0-69): '(' (0@0-9) error (@10-59) ')' (6@60-69)
+sending: '(' (7@70-79)
+sending: 'x' (8@80-89)
+thing (8@80-89): 'x' (8@80-89)
+sending: ')' (9@90-99)
+line (7@70-99): '(' (7@70-79) thing (8@80-89) ')' (9@90-99)
+sending: '(' (10@100-109)
+sending: 'x' (11@110-119)
+thing (11@110-119): 'x' (11@110-119)
+sending: ')' (12@120-129)
+line (10@100-129): '(' (10@100-109) thing (11@110-119) ')' (12@120-129)
+sending: 'y' (13@130-139)
+input (0@129-129): /* Nothing */
+input (2@100-129): line (10@100-129) input (0@129-129)
+input (2@70-129): line (7@70-99) input (2@100-129)
+input (2@0-129): line (-1@0-69) input (2@70-129)
+130-139: syntax error, unexpected 'y', expecting END
+Freeing nterm input (2@0-129)
+Freeing token 'y' (13@130-139)
+Parsing FAILED.
+]])
+
+
+# Syntax error caught by the parser where lookahead = END
+# --------------------------------------------------------
+# Load the stack and provoke an error that cannot be caught by the
+# grammar, to check that the stack is cleared. And make sure the
+# lookahead is freed.
+#
+# '(', 'x', ')',
+# '(', 'x', ')',
+# 'x'
+AT_PARSER_CHECK([./input '(x)(x)x'], 1,
+[[sending: '(' (0@0-9)
+sending: 'x' (1@10-19)
+thing (1@10-19): 'x' (1@10-19)
+sending: ')' (2@20-29)
+line (0@0-29): '(' (0@0-9) thing (1@10-19) ')' (2@20-29)
+sending: '(' (3@30-39)
+sending: 'x' (4@40-49)
+thing (4@40-49): 'x' (4@40-49)
+sending: ')' (5@50-59)
+line (3@30-59): '(' (3@30-39) thing (4@40-49) ')' (5@50-59)
+sending: 'x' (6@60-69)
+thing (6@60-69): 'x' (6@60-69)
+sending: END (7@70-79)
+70-79: syntax error, unexpected END, expecting 'x'
+Freeing nterm thing (6@60-69)
+Freeing nterm line (3@30-59)
+Freeing nterm line (0@0-29)
+Freeing token END (7@70-79)
+Parsing FAILED.
+]])
+
+
+# Check destruction upon stack overflow
+# -------------------------------------
+# Upon stack overflow, all symbols on the stack should be destroyed.
+# Only check for yacc.c.
+AT_YACC_IF([
+AT_PARSER_CHECK([./input '(x)(x)(x)(x)(x)(x)(x)'], 2,
+[[sending: '(' (0@0-9)
+sending: 'x' (1@10-19)
+thing (1@10-19): 'x' (1@10-19)
+sending: ')' (2@20-29)
+line (0@0-29): '(' (0@0-9) thing (1@10-19) ')' (2@20-29)
+sending: '(' (3@30-39)
+sending: 'x' (4@40-49)
+thing (4@40-49): 'x' (4@40-49)
+sending: ')' (5@50-59)
+line (3@30-59): '(' (3@30-39) thing (4@40-49) ')' (5@50-59)
+sending: '(' (6@60-69)
+sending: 'x' (7@70-79)
+thing (7@70-79): 'x' (7@70-79)
+sending: ')' (8@80-89)
+line (6@60-89): '(' (6@60-69) thing (7@70-79) ')' (8@80-89)
+sending: '(' (9@90-99)
+sending: 'x' (10@100-109)
+thing (10@100-109): 'x' (10@100-109)
+sending: ')' (11@110-119)
+line (9@90-119): '(' (9@90-99) thing (10@100-109) ')' (11@110-119)
+sending: '(' (12@120-129)
+sending: 'x' (13@130-139)
+thing (13@130-139): 'x' (13@130-139)
+sending: ')' (14@140-149)
+line (12@120-149): '(' (12@120-129) thing (13@130-139) ')' (14@140-149)
+sending: '(' (15@150-159)
+sending: 'x' (16@160-169)
+thing (16@160-169): 'x' (16@160-169)
+sending: ')' (17@170-179)
+line (15@150-179): '(' (15@150-159) thing (16@160-169) ')' (17@170-179)
+sending: '(' (18@180-189)
+sending: 'x' (19@190-199)
+thing (19@190-199): 'x' (19@190-199)
+sending: ')' (20@200-209)
+200-209: memory exhausted
+Freeing nterm thing (19@190-199)
+Freeing nterm line (15@150-179)
+Freeing nterm line (12@120-149)
+Freeing nterm line (9@90-119)
+Freeing nterm line (6@60-89)
+Freeing nterm line (3@30-59)
+Freeing nterm line (0@0-29)
+Parsing FAILED (status 2).
+]])
+])
+
+])
+
+
+# AT_CHECK_PRINTER_AND_DESTRUCTOR([BISON-OPTIONS], [UNION-FLAG], [SKIP_FLAG])
+# ---------------------------------------------------------------------------
+m4_define([AT_CHECK_PRINTER_AND_DESTRUCTOR],
+[AT_SETUP([Printers and Destructors $2: $1])
+
+$3
+_AT_CHECK_PRINTER_AND_DESTRUCTOR($[1], $[2], $[3], $[4],
+[%error-verbose
+%debug
+%verbose
+%locations
+$1], [$2])
+
+AT_CLEANUP
+])
+
+
+AT_CHECK_PRINTER_AND_DESTRUCTOR([])
+AT_CHECK_PRINTER_AND_DESTRUCTOR([], [with union])
+
+AT_CHECK_PRINTER_AND_DESTRUCTOR([%defines %skeleton "lalr1.cc"])
+AT_CHECK_PRINTER_AND_DESTRUCTOR([%defines %skeleton "lalr1.cc"], [with union])
+
+AT_CHECK_PRINTER_AND_DESTRUCTOR([%glr-parser])
+AT_CHECK_PRINTER_AND_DESTRUCTOR([%glr-parser], [with union])
+
+
+
+## ----------------------------------------- ##
+## Default tagless %printer and %destructor. ##
+## ----------------------------------------- ##
+
+# Check that the right %printer and %destructor are called, that they're not
+# called for $end, and that $$ and @$ work correctly.
+
+AT_SETUP([Default tagless %printer and %destructor])
+
+AT_DATA_GRAMMAR([[input.y]],
+[[%error-verbose
+%debug
+%locations
+%initial-action {
+ @$.first_line = @$.last_line = 1;
+ @$.first_column = @$.last_column = 1;
+}
+
+%{
+# include <stdio.h>
+# include <stdlib.h>
+ static void yyerror (const char *msg);
+ static int yylex (void);
+# define USE(SYM)
+%}
+
+%printer {
+ fprintf (yyoutput, "<*> printer should not be called.\n");
+} <*>
+
+%printer {
+ fprintf (yyoutput, "<> printer for '%c' @ %d", $$, @$.first_column);
+} <>
+%destructor {
+ fprintf (stdout, "<> destructor for '%c' @ %d.\n", $$, @$.first_column);
+} <>
+
+%printer {
+ fprintf (yyoutput, "'b'/'c' printer for '%c' @ %d", $$, @$.first_column);
+} 'b' 'c'
+%destructor {
+ fprintf (stdout, "'b'/'c' destructor for '%c' @ %d.\n", $$, @$.first_column);
+} 'b' 'c'
+
+%destructor {
+ fprintf (yyoutput, "<*> destructor should not be called.\n");
+} <*>
+
+%%
+
+start: 'a' 'b' 'c' 'd' 'e' { $$ = 'S'; USE(($1, $2, $3, $4, $5)); } ;
+
+%%
+
+static int
+yylex (void)
+{
+ static char const input[] = "abcd";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ yylval = input[toknum++];
+ yylloc.first_line = yylloc.last_line = 1;
+ yylloc.first_column = yylloc.last_column = toknum;
+ return yylval;
+}
+
+static void
+yyerror (const char *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ yydebug = 1;
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([-o input.c input.y])
+AT_COMPILE([input])
+AT_PARSER_CHECK([./input], 1,
+[[<> destructor for 'd' @ 4.
+'b'/'c' destructor for 'c' @ 3.
+'b'/'c' destructor for 'b' @ 2.
+<> destructor for 'a' @ 1.
+]],
+[[Starting parse
+Entering state 0
+Reading a token: Next token is token 'a' (1.1-1.1: <> printer for 'a' @ 1)
+Shifting token 'a' (1.1-1.1: <> 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: <> printer for 'd' @ 4)
+Shifting token 'd' (1.4-1.4: <> 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: <> 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: <> printer for 'a' @ 1)
+Stack now 0
+Cleanup: discarding lookahead token $end (1.5-1.5: )
+Stack now 0
+]])
+
+AT_CLEANUP
+
+
+
+## ------------------------------------------------------ ##
+## Default tagged and per-type %printer and %destructor. ##
+## ------------------------------------------------------ ##
+
+AT_SETUP([Default tagged and per-type %printer and %destructor])
+
+AT_DATA_GRAMMAR([[input.y]],
+[[%error-verbose
+%debug
+
+%{
+# include <stdio.h>
+# include <stdlib.h>
+ static void yyerror (const char *msg);
+ static int yylex (void);
+# define USE(SYM)
+%}
+
+%printer {
+ fprintf (yyoutput, "<> printer should not be called.\n");
+} <>
+
+%union { int field0; int field1; int field2; }
+%type <field0> start 'a' 'g'
+%type <field1> 'e'
+%type <field2> 'f'
+%printer {
+ fprintf (yyoutput, "<*>/<field2>/e printer");
+} <*> 'e' <field2>
+%destructor {
+ fprintf (stdout, "<*>/<field2>/e destructor.\n");
+} <*> 'e' <field2>
+
+%type <field1> 'b'
+%printer { fprintf (yyoutput, "<field1> printer"); } <field1>
+%destructor { fprintf (stdout, "<field1> destructor.\n"); } <field1>
+
+%type <field0> 'c'
+%printer { fprintf (yyoutput, "'c' printer"); } 'c'
+%destructor { fprintf (stdout, "'c' destructor.\n"); } 'c'
+
+%type <field1> 'd'
+%printer { fprintf (yyoutput, "'d' printer"); } 'd'
+%destructor { fprintf (stdout, "'d' destructor.\n"); } 'd'
+
+%destructor {
+ fprintf (yyoutput, "<> destructor should not be called.\n");
+} <>
+
+%%
+
+start:
+ 'a' 'b' 'c' 'd' 'e' 'f' 'g'