X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/84866159725a9df9febc1050643c0355eba5916c..730739e41d3b031a89ea24e267a59eec4ec4f936:/tests/actions.at?ds=sidebyside
diff --git a/tests/actions.at b/tests/actions.at
index 7a03fb00..e17f7003 100644
--- a/tests/actions.at
+++ b/tests/actions.at
@@ -1,20 +1,19 @@
# Executing Actions. -*- Autotest -*-
-# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007 Free Software
+# Foundation, Inc.
-# This program is free software; you can redistribute it and/or modify
+# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2, or (at your option)
-# any later version.
-
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
-
+#
# You should have received a copy of the GNU General Public License
-# along with this program; if not, write to the Free Software
-# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-# 02110-1301, USA.
+# along with this program. If not, see .
AT_BANNER([[User Actions.]])
@@ -55,8 +54,11 @@ exp: { putchar ('0'); }
static int
yylex (void)
{
- static const char *input = "123456789";
- return *input++;
+ static char const input[] = "123456789";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ return input[toknum++];
}
static void
@@ -131,6 +133,9 @@ sum_of_the_five_previous_values:
static int
yylex (void)
{
+ static int called;
+ if (called++)
+ abort ();
return EOF;
}
@@ -172,9 +177,10 @@ m4_if([$1$2$3], $[1]$[2]$[3], [],
# helping macros. So don't put any directly in the Bison file.
AT_BISON_OPTION_PUSHDEFS([$5])
AT_DATA_GRAMMAR([[input.y]],
-[[%{
+[[%code requires {
#include
#include
+#include
#include
#define YYINITDEPTH 10
@@ -182,24 +188,23 @@ AT_DATA_GRAMMAR([[input.y]],
]AT_LALR1_CC_IF(
[#define RANGE(Location) (Location).begin.line, (Location).end.line],
[#define RANGE(Location) (Location).first_line, (Location).last_line])
-[%}
+[}
$5]
m4_ifval([$6], [%union
{
int ival;
}])
-AT_LALR1_CC_IF([%define "global_tokens_and_yystype"])
-[
-%{
-]AT_LALR1_CC_IF([typedef yy::location YYLTYPE;
- m4_ifval([$6], , [#define YYSTYPE int])])
+AT_LALR1_CC_IF([%define global_tokens_and_yystype])
+m4_ifval([$6], [[%code provides {]], [[%code {]])
+AT_LALR1_CC_IF([typedef yy::location YYLTYPE;])
[static int yylex (]AT_LEX_FORMALS[);
]AT_LALR1_CC_IF([], [static void yyerror (const char *msg);])
-[%}
+[}
-]m4_ifval([$6], [%type '(' 'x' 'y' ')' ';' thing line input])[
+]m4_ifval([$6], [%type '(' 'x' 'y' ')' ';' thing line input END])[
+/* FIXME: This %printer isn't actually tested. */
%printer
{
]AT_LALR1_CC_IF([debug_stream () << $$;],
@@ -227,6 +232,11 @@ AT_LALR1_CC_IF([%define "global_tokens_and_yystype"])
{ printf ("Freeing token 'y' (%d@%d-%d)\n", $$, RANGE (@$)); }
'y'
+%token END 0
+%destructor
+ { printf ("Freeing token END (%d@%d-%d)\n", $$, RANGE (@$)); }
+ END
+
%%
/*
This grammar is made to exercise error recovery.
@@ -242,7 +252,7 @@ input:
printf ("input (%d@%d-%d): /* Nothing */\n", $$, RANGE (@$));
}
| line input /* Right recursive to load the stack so that popping at
- EOF can be exercised. */
+ END can be exercised. */
{
$$ = 2;
printf ("input (%d@%d-%d): line (%d@%d-%d) input (%d@%d-%d)\n",
@@ -306,10 +316,12 @@ yylex (]AT_LEX_FORMALS[)
AT_LOC.last_line = AT_LOC.last_column = AT_LOC.first_line + 9;
])[
+ if (! (0 <= c && c <= strlen (source)))
+ abort ();
if (source[c])
printf ("sending: '%c'", source[c]);
else
- printf ("sending: EOF");
+ printf ("sending: END");
printf (" (%d@%d-%d)\n", c, RANGE (]AT_LOC[));
return source[c];
}
@@ -373,9 +385,10 @@ 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: EOF (3@30-39)
+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.
]])
@@ -392,9 +405,10 @@ sending: 'y' (1@10-19)
Freeing token 'y' (1@10-19)
sending: ')' (2@20-29)
line (-1@0-29): '(' (0@0-9) error (@10-19) ')' (2@20-29)
-sending: EOF (3@30-39)
+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.
]])
@@ -446,12 +460,45 @@ 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
+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.
@@ -527,11 +574,733 @@ AT_CLEANUP
AT_CHECK_PRINTER_AND_DESTRUCTOR([])
AT_CHECK_PRINTER_AND_DESTRUCTOR([], [with union])
-# These tests currently fail on a Debian GNU/Linux 3.0r2 x86 host,
-# but the 2nd test succeeds on a Solaris 9 sparc hosts (Forte 7 cc).
-# Skip them until we figure out what the problem is.
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
+# include
+ 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_CHECK([bison -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
+# include
+ 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 start 'a' 'g'
+%type 'e'
+%type 'f'
+%printer {
+ fprintf (yyoutput, "<*>//e printer");
+} <*> 'e'
+%destructor {
+ fprintf (stdout, "<*>//e destructor.\n");
+} <*> 'e'
+
+%type 'b'
+%printer { fprintf (yyoutput, " printer"); }
+%destructor { fprintf (stdout, " destructor.\n"); }
+
+%type 'c'
+%printer { fprintf (yyoutput, "'c' printer"); } 'c'
+%destructor { fprintf (stdout, "'c' destructor.\n"); } 'c'
+
+%type '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'
+ {
+ USE(($1, $2, $3, $4, $5, $6, $7));
+ $$ = 'S';
+ }
+ ;
+
+%%
+
+static int
+yylex (void)
+{
+ static char const input[] = "abcdef";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ return input[toknum++];
+}
+
+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,
+[[<*>//e destructor.
+<*>//e destructor.
+'d' destructor.
+'c' destructor.
+ destructor.
+<*>//e destructor.
+]],
+[[Starting parse
+Entering state 0
+Reading a token: Next token is token 'a' (<*>//e printer)
+Shifting token 'a' (<*>//e printer)
+Entering state 1
+Reading a token: Next token is token 'b' ( printer)
+Shifting token 'b' ( printer)
+Entering state 3
+Reading a token: Next token is token 'c' ('c' printer)
+Shifting token 'c' ('c' printer)
+Entering state 5
+Reading a token: Next token is token 'd' ('d' printer)
+Shifting token 'd' ('d' printer)
+Entering state 6
+Reading a token: Next token is token 'e' (<*>//e printer)
+Shifting token 'e' (<*>//e printer)
+Entering state 7
+Reading a token: Next token is token 'f' (<*>//e printer)
+Shifting token 'f' (<*>//e printer)
+Entering state 8
+Reading a token: Now at end of input.
+syntax error, unexpected $end, expecting 'g'
+Error: popping token 'f' (<*>//e printer)
+Stack now 0 1 3 5 6 7
+Error: popping token 'e' (<*>//e printer)
+Stack now 0 1 3 5 6
+Error: popping token 'd' ('d' printer)
+Stack now 0 1 3 5
+Error: popping token 'c' ('c' printer)
+Stack now 0 1 3
+Error: popping token 'b' ( printer)
+Stack now 0 1
+Error: popping token 'a' (<*>//e printer)
+Stack now 0
+Cleanup: discarding lookahead token $end ()
+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_CHECK_DEFAULT_PRINTER_AND_DESTRUCTOR_FOR_END_TOKEN(TYPED)
+# -----------------------------------------------------------------------------
+m4_define([_AT_CHECK_DEFAULT_PRINTER_AND_DESTRUCTOR_FOR_END_TOKEN],
+[m4_if($1, 0,
+ [m4_pushdef([kind], []) m4_pushdef([not_kind], [*])],
+ [m4_pushdef([kind], [*]) m4_pushdef([not_kind], [])])
+
+AT_DATA_GRAMMAR([[input]]$1[[.y]],
+[[%error-verbose
+%debug
+%locations
+%initial-action {
+ @$.first_line = @$.last_line = 1;
+ @$.first_column = @$.last_column = 1;
+}
+
+%{
+# include
+# include
+ static void yyerror (const char *msg);
+ static int yylex (void);
+# define USE(SYM)
+%}
+
+%destructor {
+ fprintf (yyoutput, "<]]not_kind[[> destructor should not be called.\n");
+} <]]not_kind[[>
+
+%token END 0
+%printer {
+ fprintf (yyoutput, "<]]kind[[> for '%c' @ %d", $$, @$.first_column);
+} <]]kind[[>
+%destructor {
+ fprintf (stdout, "<]]kind[[> for '%c' @ %d.\n", $$, @$.first_column);
+} <]]kind[[>
+
+%printer {
+ fprintf (yyoutput, "<]]not_kind[[> printer should not be called.\n");
+} <]]not_kind[[>
+
+]]m4_if($1, 0, [[[
+]]],
+[[[%union { char tag; }
+%type start END]]])[[
+
+%%
+
+start: { $$ = 'S'; } ;
+
+%%
+
+static int
+yylex (void)
+{
+ static int called;
+ if (called++)
+ abort ();
+ yylval]]m4_if($1, 0,, [[[.tag]]])[[ = 'E';
+ yylloc.first_line = yylloc.last_line = 1;
+ yylloc.first_column = yylloc.last_column = 1;
+ return 0;
+}
+
+static void
+yyerror (const char *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ yydebug = 1;
+ return yyparse ();
+}
+]])
+
+AT_CHECK([bison -o input$1.c input$1.y])
+AT_COMPILE([input$1])
+AT_PARSER_CHECK([./input$1], 0,
+[[<]]kind[[> for 'E' @ 1.
+<]]kind[[> for 'S' @ 1.
+]],
+[[Starting parse
+Entering state 0
+Reducing stack by rule 1 (line 46):
+-> $$ = nterm start (1.1-1.1: <]]kind[[> for 'S' @ 1)
+Stack now 0
+Entering state 1
+Reading a token: Now at end of input.
+Shifting token END (1.1-1.1: <]]kind[[> for 'E' @ 1)
+Entering state 2
+Stack now 0 1 2
+Cleanup: popping token END (1.1-1.1: <]]kind[[> for 'E' @ 1)
+Cleanup: popping nterm start (1.1-1.1: <]]kind[[> for 'S' @ 1)
+]])
+
+m4_popdef([kind])
+m4_popdef([not_kind])
+])
+
+_AT_CHECK_DEFAULT_PRINTER_AND_DESTRUCTOR_FOR_END_TOKEN(0)
+_AT_CHECK_DEFAULT_PRINTER_AND_DESTRUCTOR_FOR_END_TOKEN(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
+# include
+ static void yyerror (const char *msg);
+ static int yylex (void);
+# 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'; }
+ ;
+
+%%
+
+static int
+yylex (void)
+{
+ static char const input[] = "abd";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ yylval = input[toknum++];
+ 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.
+# - $$ for $accept would always be of type YYSTYPE because it's not possible
+# to declare `%type $accept'. (Also true for $undefined.)
+# - Thus, the compiler might complain that the user code assumes the wrong
+# type for $$ 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
+# include
+ static void yyerror (const char *msg);
+ static int yylex (void);
+# define USE(SYM)
+%}
+
+%printer {
+ char chr = $$;
+ fprintf (yyoutput, "'%c'", chr);
+} <> <*>
+%destructor {
+ char chr = $$;
+ fprintf (stderr, "DESTROY '%c'\n", chr);
+} <> <*>
+
+%union { char chr; }
+%type start
+
+%%
+
+start: { USE($$); } ;
+
+%%
+
+static int
+yylex (void)
+{
+ static int called;
+ if (called++)
+ abort ();
+ return 0;
+}
+
+static void
+yyerror (const char *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ return yyparse ();
+}
+]])
+
+AT_CHECK([bison -o input.c input.y])
+AT_COMPILE([input])
+
+AT_CLEANUP
+
+
+
+## ------------------------------------------------------ ##
+## Default %printer and %destructor for mid-rule values. ##
+## ------------------------------------------------------ ##
+
+AT_SETUP([Default %printer and %destructor for mid-rule values])
+
+AT_DATA_GRAMMAR([[input.y]],
+[[%debug /* So that %printer is actually compiled. */
+
+%{
+# include
+# include
+ static void yyerror (const char *msg);
+ static int yylex (void);
+# define USE(SYM)
+# define YYLTYPE int
+# define YYLLOC_DEFAULT(Current, Rhs, N)
+# define YY_LOCATION_PRINT(File, Loc)
+%}
+
+%printer { fprintf (yyoutput, "%d", @$); } <>
+%destructor { fprintf (stderr, "DESTROY %d\n", @$); } <>
+%printer { fprintf (yyoutput, "<*> printer should not be called"); } <*>
+%destructor { fprintf (yyoutput, "<*> destructor should not be called"); } <*>
+
+%%
+
+start:
+ { @$ = 1; } // Not set or used.
+ { USE ($$); @$ = 2; } // Both set and used.
+ { USE ($$); @$ = 3; } // Only set.
+ { @$ = 4; } // Only used.
+ 'c'
+ { USE (($$, $2, $4, $5)); @$ = 0; }
+ ;
+
+%%
+
+static int
+yylex (void)
+{
+ static int called;
+ if (called++)
+ abort ();
+ 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], 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_DATA_GRAMMAR([[input.y]],
+[[%code {
+ #include
+ static int yylex (void);
+ static void yyerror (char const *msg);
+}
+
+%debug
+
+]$1[ {
+ printf ("%d\n", @$.first_line);
+} ]m4_if($1, [%initial-action], [], [[start]])[
+
+%%
+
+start: ;
+
+%%
+
+static int
+yylex (void)
+{
+ return 0;
+}
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+int
+main (void)
+{
+ return yyparse ();
+}
+]])
+
+AT_CHECK([[bison -o input.c input.y]])
+AT_COMPILE([[input]])
+
+AT_CLEANUP])
+
+AT_CHECK_ACTION_LOCATIONS([[%initial-action]])
+AT_CHECK_ACTION_LOCATIONS([[%destructor]])
+AT_CHECK_ACTION_LOCATIONS([[%printer]])