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yysyntax_error: fix for consistent error with lookahead.

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* NEWS (2.5): Document.
* data/yacc.c (yysyntax_error): In a verbose syntax error
message while in a consistent state with a default action (which
must be an error action given that yysyntax_error is being
invoked), continue to drop the expected token list, but don't
drop the unexpected token unless there actually is no lookahead.
Moreover, handle that internally instead of returning 1 to tell
the caller to do it.  With that meaning of 1 gone, renumber
return codes more usefully.
(yyparse, yypush_parse): Update yysyntax_error usage.  Most
importantly, set yytoken to YYEMPTY when there's no lookahead.
* data/glr.c (yyreportSyntaxError): As in yacc.c, don't drop the
unexpected token unless there actually is no lookahead.
* data/lalr1.cc (yy::parser::parse): If there's no lookahead,
pass yyempty_ not yyla.type to yysyntax_error_.
(yy::parser::yysyntax_error_): Again, don't drop the unexpected
token unless there actually is no lookahead.
* data/lalr1.java (YYParser::parse): If there's no lookahead,
set yytoken to yyempty_ before invoking yysyntax_error.
(YYParser::yysyntax_error): Again, don't drop the unexpected
token unless there actually is no lookahead.
* tests/conflicts.at (parse.error=verbose and consistent
errors): Extend test group to further reveal how the previous
use of the simple "syntax error" message was too general.  Test
yacc.c, glr.c, lalr1.cc, and lalr1.java.  No longer an expected
failure.
* tests/java.at (AT_JAVA_COMPILE, AT_JAVA_PARSER_CHECK): Move
to...
* tests/local.at: ... here.
(_AT_BISON_OPTION_PUSHDEFS): Push AT_SKEL_JAVA_IF definition.
(AT_BISON_OPTION_POPDEFS): Pop it.
(AT_FULL_COMPILE): Extend to handle Java.
This commit is contained in:
Joel E. Denny
2010-11-07 16:01:56 -05:00
parent 25a648d8a6
commit d2060f0634
11 changed files with 802 additions and 466 deletions
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200
tests/conflicts.at
View File

@@ -147,15 +147,30 @@ AT_SETUP([[parse.error=verbose and consistent errors]])
m4_pushdef([AT_CONSISTENT_ERRORS_CHECK], [
AT_DATA_GRAMMAR([input.y],
[[%code {
AT_BISON_OPTION_PUSHDEFS([$1])
m4_pushdef([AT_YYLEX_PROTOTYPE],
[AT_SKEL_CC_IF([[int yylex (yy::parser::semantic_type *lvalp)]],
[[int yylex (YYSTYPE *lvalp)]])])
AT_SKEL_JAVA_IF([AT_DATA], [AT_DATA_GRAMMAR])([input.y],
[AT_SKEL_JAVA_IF([[
%code imports {
import java.io.IOException;
}]], [[
%code {]AT_SKEL_CC_IF([[
#include <string>]], [[
#include <assert.h>
#include <stdio.h>
int yylex (void);
void yyerror (char const *);
void yyerror (char const *msg);]])[
]AT_YYLEX_PROTOTYPE[;
#define USE(Var)
}
]AT_SKEL_CC_IF([[%defines]], [[%define api.pure]])])[
]$1[
%define parse.error verbose
@@ -164,63 +179,193 @@ AT_DATA_GRAMMAR([input.y],
]$2[
%%
]AT_SKEL_JAVA_IF([[%code lexer {]], [[%%]])[
int
yylex (void)
/*--------.
| yylex. |
`--------*/]AT_SKEL_JAVA_IF([[
public String input = "]$3[";
public int index = 0;
public int yylex ()
{
if (index < input.length ())
return input.charAt (index++);
else
return 0;
}
public Object getLVal ()
{
return new Integer(1);
}]], [[
]AT_YYLEX_PROTOTYPE[
{
static char const *input = "]$3[";
yylval = 1;
*lvalp = 1;
return *input++;
}]])[
/*----------.
| yyerror. |
`----------*/]AT_SKEL_JAVA_IF([[
public void yyerror (String msg)
{
System.err.println (msg);
}
};
%%]], [AT_SKEL_CC_IF([[
void
yy::parser::error (std::string const &msg)
{
std::cerr << msg << std::endl;
}]], [[
void
yyerror (char const *msg)
{
fprintf (stderr, "%s\n", msg);
}
}]])])[
/*-------.
| main. |
`-------*/]AT_SKEL_JAVA_IF([[
class input
{
public static void main (String args[]) throws IOException
{
YYParser p = new YYParser ();
p.parse ();
}
}]], [AT_SKEL_CC_IF([[
int
main (void)
{
yy::parser parser;
return parser.parse ();
}]], [[
int
main (void)
{
return yyparse ();
}
}]])])[
]])
AT_BISON_CHECK([[-o input.c input.y]])
AT_COMPILE([[input]])
AT_FULL_COMPILE([[input]])
m4_pushdef([AT_EXPECTING], [m4_if($5, [ab], [[, expecting 'a' or 'b']],
$5, [a], [[, expecting 'a']],
$5, [b], [[, expecting 'b']])])
AT_PARSER_CHECK([[./input]], [[1]], [[]],
AT_SKEL_JAVA_IF([AT_JAVA_PARSER_CHECK([[input]], [[0]]],
[AT_PARSER_CHECK([[./input]], [[1]]]),
[[]],
[[syntax error, unexpected ]$4[]AT_EXPECTING[
]])
m4_popdef([AT_EXPECTING])
m4_popdef([AT_YYLEX_PROTOTYPE])
AT_BISON_OPTION_POPDEFS
])
m4_pushdef([AT_PREVIOUS_STATE_GRAMMAR],
[[%nonassoc 'a';
start: consistent-error-on-a-a 'a' ;
consistent-error-on-a-a:
'a' default-reduction
| 'a' default-reduction 'a'
| 'a' shift
;
default-reduction: /*empty*/ ;
shift: 'b' ;
// Provide another context in which all rules are useful so that this
// test case looks a little more realistic.
start: 'b' consistent-error-on-a-a 'c' ;
]])
m4_pushdef([AT_PREVIOUS_STATE_INPUT], [[a]])
# Unfortunately, no expected tokens are reported even though 'b' can be
# accepted. Nevertheless, the main point of this test is to make sure
# that at least the unexpected token is reported. In a previous version
# of Bison, it wasn't reported because the error is detected in a
# consistent state with an error action, and that case always triggered
# the simple "syntax error" message.
#
# The point isn't to test IELR here, but state merging happens to
# complicate this example.
AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr]],
[AT_PREVIOUS_STATE_GRAMMAR],
[AT_PREVIOUS_STATE_INPUT],
[[$end]], [[none]])
AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
%glr-parser]],
[AT_PREVIOUS_STATE_GRAMMAR],
[AT_PREVIOUS_STATE_INPUT],
[[$end]], [[none]])
AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
%language "c++"]],
[AT_PREVIOUS_STATE_GRAMMAR],
[AT_PREVIOUS_STATE_INPUT],
[[$end]], [[none]])
AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
%language "java"]],
[AT_PREVIOUS_STATE_GRAMMAR],
[AT_PREVIOUS_STATE_INPUT],
[[end of input]], [[none]])
# Even canonical LR doesn't foresee the error for 'a'!
AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
%define lr.default-reductions consistent]],
[AT_PREVIOUS_STATE_GRAMMAR],
[AT_PREVIOUS_STATE_INPUT],
[[$end]], [[ab]])
AT_CONSISTENT_ERRORS_CHECK([[%define lr.type ielr
%define lr.default-reductions accepting]],
[AT_PREVIOUS_STATE_GRAMMAR],
[AT_PREVIOUS_STATE_INPUT],
[[$end]], [[ab]])
AT_CONSISTENT_ERRORS_CHECK([[%define lr.type canonical-lr]],
[AT_PREVIOUS_STATE_GRAMMAR],
[AT_PREVIOUS_STATE_INPUT],
[[$end]], [[ab]])
m4_popdef([AT_PREVIOUS_STATE_GRAMMAR])
m4_popdef([AT_PREVIOUS_STATE_INPUT])
m4_pushdef([AT_USER_ACTION_GRAMMAR],
[[%nonassoc 'a';
// If yylval=0 here, then we know that the 'a' destructor is being
// invoked incorrectly for the 'b' set in the semantic action below.
// All 'a' tokens are returned by yylex, which sets yylval=1.
// If $$ = 0 here, then we know that the 'a' destructor is being invoked
// incorrectly for the 'b' set in the semantic action below. All 'a'
// tokens are returned by yylex, which sets $$ = 1.
%destructor {
if (!$$)
fprintf (stderr, "Wrong destructor.\n");
} 'a';
// The lookahead assigned by the semantic action isn't needed before
// either error action is encountered. In a previous version of Bison,
// this was a problem as it meant yychar was not translated into yytoken
// before either error action. The second error action thus invoked a
// Rather than depend on an inconsistent state to induce reading a
// lookahead as in the previous grammar, just assign the lookahead in a
// semantic action. That lookahead isn't needed before either error
// action is encountered. In a previous version of Bison, this was a
// problem as it meant yychar was not translated into yytoken before
// either error action. The second error action thus invoked a
// destructor that it selected according to the incorrect yytoken. The
// first error action would have reported an incorrect unexpected token
// except that, due to another bug, the unexpected token is not reported
// at all because the error action is the default action in a consistent
// state. That bug still needs to be fixed.
// except that, due to the bug described in the previous grammar, the
// unexpected token was not reported at all.
start: error-reduce consistent-error 'a' { USE ($][3); } ;
error-reduce:
@@ -247,13 +392,16 @@ start: 'b' consistent-error 'b' ;
]])
m4_pushdef([AT_USER_ACTION_INPUT], [[aa]])
# See comments in grammar for why this test doesn't succeed.
AT_XFAIL_IF([[:]])
AT_CONSISTENT_ERRORS_CHECK([[]],
[AT_USER_ACTION_GRAMMAR],
[AT_USER_ACTION_INPUT],
[['b']], [[none]])
AT_CONSISTENT_ERRORS_CHECK([[%glr-parser]],
[AT_USER_ACTION_GRAMMAR],
[AT_USER_ACTION_INPUT],
[['b']], [[none]])
# No C++ or Java test because yychar cannot be manipulated by users.
AT_CONSISTENT_ERRORS_CHECK([[%define lr.default-reductions consistent]],
[AT_USER_ACTION_GRAMMAR],
[AT_USER_ACTION_INPUT],

19
tests/java.at
View File

@@ -219,25 +219,6 @@ m4_define([AT_DATA_JAVA_CALC_Y],
])
# AT_JAVA_COMPILE(SOURCE)
# -----------------------
# Compile SOURCES into Java class files. Skip the test if java or javac is
# not installed.
m4_define([AT_JAVA_COMPILE],
[AT_KEYWORDS(java)
AT_CHECK([test -n "$CONF_JAVA" || exit 77
test -n "$CONF_JAVAC" || exit 77])
AT_CHECK([$SHELL ../../../javacomp.sh $1],
0, [ignore], [ignore])])
# AT_JAVA_PARSER_CHECK(COMMAND, EXIT-STATUS, EXPOUT, EXPERR, [PRE])
# -----------------------------------------------------------------
m4_define([AT_JAVA_PARSER_CHECK],
[AT_CHECK([$5 $SHELL ../../../javaexec.sh $1], [$2], [$3], [$4])])
# _AT_CHECK_JAVA_CALC_ERROR(BISON-OPTIONS, INPUT,
# [VERBOSE-AND-LOCATED-ERROR-MESSAGE])
# ---------------------------------------------------------

47
tests/local.at
View File

@@ -80,6 +80,8 @@ m4_pushdef([AT_DEFINES_IF],
[m4_bmatch([$3], [%defines], [$1], [$2])])
m4_pushdef([AT_SKEL_CC_IF],
[m4_bmatch([$3], [%language "[Cc]\+\+"\|%skeleton "[a-z0-9]+\.cc"], [$1], [$2])])
m4_pushdef([AT_SKEL_JAVA_IF],
[m4_bmatch([$3], [%language "[Jj][Aa][Vv][Aa]"\|%skeleton "[a-z0-9]+\.java"], [$1], [$2])])
m4_pushdef([AT_GLR_IF],
[m4_bmatch([$3], [%glr-parser\|%skeleton "glr\.], [$1], [$2])])
m4_pushdef([AT_LALR1_CC_IF],
@@ -189,6 +191,7 @@ m4_popdef([AT_LEXPARAM_IF])
m4_popdef([AT_YACC_IF])
m4_popdef([AT_GLR_IF])
m4_popdef([AT_SKEL_CC_IF])
m4_popdef([AT_SKEL_JAVA_IF])
m4_popdef([AT_GLR_CC_IF])
m4_popdef([AT_LALR1_CC_IF])
m4_popdef([AT_DEFINES_IF])
@@ -404,19 +407,38 @@ AT_CHECK([$BISON_CXX_WORKS], 0, ignore, ignore)
AT_CHECK([$CXX $CXXFLAGS $CPPFLAGS m4_bmatch([$1], [[.]], [], [$LDFLAGS ])-o $1 m4_default([$2], [$1.cc])[]m4_bmatch([$1], [[.]], [], [ $LIBS])],
0, [ignore], [ignore])])
# AT_JAVA_COMPILE(SOURCES)
# ------------------------
# Compile SOURCES into Java class files. Skip the test if java or javac
# is not installed.
m4_define([AT_JAVA_COMPILE],
[AT_KEYWORDS(java)
AT_CHECK([[test -n "$CONF_JAVA" || exit 77
test -n "$CONF_JAVAC" || exit 77]])
AT_CHECK([[$SHELL ../../../javacomp.sh ]$1],
[[0]], [ignore], [ignore])])
# AT_FULL_COMPILE(OUTPUT, [OTHER])
# --------------------------------
# Compile OUTPUT.y to OUTPUT.c or OUTPUT.cc, and compile it to OUTPUT.
# If OTHER is specified, compile OUTPUT-OTHER.c or OUTPUT-OTHER.cc to OUTPUT
# along with it.
# Relies on AT_SKEL_CC_IF.
m4_define([AT_FULL_COMPILE],
[AT_SKEL_CC_IF(
[AT_BISON_CHECK([-o $1.cc $1.y])
AT_COMPILE_CXX([$1]m4_ifval($2, [, [$1.cc $1-$2.cc]]))],
[AT_BISON_CHECK([-o $1.c $1.y])
AT_COMPILE([$1]m4_ifval($2, [, [$1.c $1-$2.c]]))])
# Compile OUTPUT.y to OUTPUT.c, OUTPUT.cc, or OUTPUT.java, and then
# compile it to OUTPUT or OUTPUT.class. If OTHER is specified, compile
# OUTPUT-OTHER.c, OUTPUT-OTHER.cc, or OUTPUT-OTHER.java to OUTPUT or
# OUTPUT.java along with it. Relies on AT_SKEL_CC_IF and
# AT_SKEL_JAVA_IF.
m4_define([AT_FULL_COMPILE], [
AT_SKEL_JAVA_IF([
AT_BISON_CHECK([[-o ]$1[.java ]$1[.y]])
AT_JAVA_COMPILE([$1[.java]]m4_ifval($2,
[[$1[.java ]$1[-]$2[.java]]]))
], [
AT_SKEL_CC_IF([
AT_BISON_CHECK([[-o ]$1[.cc ]$1[.y]])
AT_COMPILE_CXX([$1]m4_ifval($2, [, [$1[.cc ]$1[-]$2[.cc]]]))
], [
AT_BISON_CHECK([[-o ]$1[.c ]$1[.y]])
AT_COMPILE([$1]m4_ifval($2, [, [$1[.c ]$1[-]$2[.c]]]))
])
])
])
@@ -430,6 +452,11 @@ m4_define([AT_FULL_COMPILE],
m4_define([AT_PARSER_CHECK],
[AT_CHECK([$5 $PREPARSER $1], [$2], [$3], [$4])])
# AT_JAVA_PARSER_CHECK(COMMAND, EXIT-STATUS, EXPOUT, EXPERR, [PRE])
# -----------------------------------------------------------------
m4_define([AT_JAVA_PARSER_CHECK],
[AT_CHECK([$5[ $SHELL ../../../javaexec.sh ]$1], [$2], [$3], [$4])])
# AT_TEST_TABLES_AND_PARSE(TITLE, COND-VALUE, TEST-SPEC,
# DECLS, GRAMMAR, INPUT,
# BISON-STDERR, TABLES-OR-LAST-STATE,