Future/bison
1
0
Fork 0
mirror of https://git.savannah.gnu.org/git/bison.git synced 2026-03-09 12:23:04 +00:00
Code Issues Packages Projects Releases Wiki Activity

During deterministic GLR operation, user actions should be able to

Browse Source 
influence the parse by changing yychar.  To make this easier to fix and
to make glr.c easier to evolve in general, don't maintain yytoken in
parallel with yychar; just compute yytoken when needed.
* tests/glr-regression.at (Incorrect lookahead during deterministic
GLR): Check that setting yychar in a user action has the intended
effect.
* data/glr.c (yyGLRStack): Remove yytokenp member.
(yyclearin): Don't set *yytokenp.
(yyprocessOneStack, yyreportSyntaxError, yyrecoverSyntaxError): Examine
yychar rather than *yytokenp to determine the current lookahead.
Compute yytoken locally when needed.
(yyparse): Likewise.  Remove the local yytoken that yytokenp used to
point to.

* doc/bison.texinfo (Bison Options): Remove stray sentence fragment
after `--report' documentation.
This commit is contained in:
Joel E. Denny
2006-01-30 11:15:15 +00:00
parent e2a8c0f591
commit 3f0014152b
6 changed files with 63 additions and 39 deletions
Download Patch File Download Diff File Expand all files Collapse all files

63
data/glr.c
View File

@@ -803,7 +803,6 @@ struct yyGLRStack {
YYSTYPE yyval;
YYLTYPE yyloc;
])[
yySymbol* yytokenp;
YYJMP_BUF yyexception_buffer;
yyGLRStackItem* yyitems;
yyGLRStackItem* yynextFree;
@@ -910,7 +909,7 @@ yyuserAction (yyRuleNum yyn, int yyrhslen, yyGLRStackItem* yyvsp,
# undef YYRECOVERING
# define YYRECOVERING (yystackp->yyerrState != 0)
# undef yyclearin
# define yyclearin (yychar = *(yystackp->yytokenp) = YYEMPTY)
# define yyclearin (yychar = YYEMPTY)
# undef YYFILL
# define YYFILL(N) yyfill (yyvsp, &yylow, N, yynormal)
# undef YYBACKUP
@@ -1929,7 +1928,6 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
int yyaction;
const short int* yyconflicts;
yyRuleNum yyrule;
yySymbol* const yytokenp = yystackp->yytokenp;
while (yystackp->yytops.yystates[yyk] != NULL)
{
@@ -1953,15 +1951,18 @@ yyprocessOneStack (yyGLRStack* yystackp, size_t yyk,
}
else
{
yySymbol yytoken;
yystackp->yytops.yylookaheadNeeds[yyk] = yytrue;
if (*yytokenp == YYEMPTY)
if (yychar == YYEMPTY)
{
YYDPRINTF ((stderr, "Reading a token: "));
yychar = YYLEX;
*yytokenp = YYTRANSLATE (yychar);
YY_SYMBOL_PRINT ("Next token is", *yytokenp, &yylval, &yylloc);
yytoken = YYTRANSLATE (yychar);
YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
}
yygetLRActions (yystate, *yytokenp, &yyaction, &yyconflicts);
else
yytoken = YYTRANSLATE (yychar);
yygetLRActions (yystate, yytoken, &yyaction, &yyconflicts);
while (*yyconflicts != 0)
{
@@ -1999,12 +2000,12 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
if (yystackp->yyerrState == 0)
{
#if YYERROR_VERBOSE
yySymbol* const yytokenp = yystackp->yytokenp;
int yyn;
yyn = yypact[yystackp->yytops.yystates[0]->yylrState];
if (YYPACT_NINF < yyn && yyn < YYLAST)
{
size_t yysize0 = yytnamerr (NULL, yytokenName (*yytokenp));
yySymbol yytoken = YYTRANSLATE (yychar);
size_t yysize0 = yytnamerr (NULL, yytokenName (yytoken));
size_t yysize = yysize0;
size_t yysize1;
yybool yysize_overflow = yyfalse;
@@ -2032,7 +2033,7 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
int yyxend = yychecklim < YYNTOKENS ? yychecklim : YYNTOKENS;
int yycount = 1;
yyarg[0] = yytokenName (*yytokenp);
yyarg[0] = yytokenName (yytoken);
yyfmt = yystpcpy (yyformat, yyunexpected);
for (yyx = yyxbegin; yyx < yyxend; ++yyx)
@@ -2100,7 +2101,6 @@ yyreportSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
/*ARGSUSED*/ static void
yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
{
yySymbol* const yytokenp = yystackp->yytokenp;
size_t yyk;
int yyj;
@@ -2109,9 +2109,10 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
reductions. Skip tokens until we can proceed. */
while (YYID (yytrue))
{
if (*yytokenp == YYEOF)
yySymbol yytoken;
if (yychar == YYEOF)
yyFail (yystackp][]b4_lpure_args[, NULL);
if (*yytokenp != YYEMPTY)
if (yychar != YYEMPTY)
{]b4_location_if([[
/* We throw away the lookahead, but the error range
of the shifted error token must take it into account. */
@@ -2120,18 +2121,19 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
yyerror_range[1].yystate.yyloc = yys->yyloc;
yyerror_range[2].yystate.yyloc = yylloc;
YYLLOC_DEFAULT ((yys->yyloc), yyerror_range, 2);]])[
yytoken = YYTRANSLATE (yychar);
yydestruct ("Error: discarding",
*yytokenp, &yylval]b4_location_if([, &yylloc])[]b4_user_args[);
yytoken, &yylval]b4_location_if([, &yylloc])[]b4_user_args[);
}
YYDPRINTF ((stderr, "Reading a token: "));
yychar = YYLEX;
*yytokenp = YYTRANSLATE (yychar);
YY_SYMBOL_PRINT ("Next token is", *yytokenp, &yylval, &yylloc);
yytoken = YYTRANSLATE (yychar);
YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
yyj = yypact[yystackp->yytops.yystates[0]->yylrState];
if (yyis_pact_ninf (yyj))
return;
yyj += *yytokenp;
if (yyj < 0 || YYLAST < yyj || yycheck[yyj] != *yytokenp)
yyj += yytoken;
if (yyj < 0 || YYLAST < yyj || yycheck[yyj] != yytoken)
{
if (yydefact[yystackp->yytops.yystates[0]->yylrState] != 0)
return;
@@ -2209,7 +2211,6 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
]b4_c_ansi_function_def([yyparse], [int], b4_parse_param)[
{
int yyresult;
yySymbol yytoken;
yyGLRStack yystack;
yyGLRStack* const yystackp = &yystack;
size_t yyposn;
@@ -2217,7 +2218,6 @@ yyrecoverSyntaxError (yyGLRStack* yystackp]b4_user_formals[)
YYDPRINTF ((stderr, "Starting parse\n"));
yychar = YYEMPTY;
yytoken = YYEMPTY;
yylval = yyval_default;
]b4_location_if([
#if YYLTYPE_IS_TRIVIAL
@@ -2244,7 +2244,6 @@ b4_syncline([@oline@], [@ofile@])])dnl
case 2: goto yyexhaustedlab;
default: goto yybuglab;
}
yystack.yytokenp = &yytoken;
yyglrShift (&yystack, 0, 0, 0, &yylval, &yylloc);
yyposn = 0;
@@ -2277,24 +2276,24 @@ b4_syncline([@oline@], [@ofile@])])dnl
}
else
{
if (yytoken == YYEMPTY)
yySymbol yytoken;
if (yychar == YYEMPTY)
{
YYDPRINTF ((stderr, "Reading a token: "));
yychar = YYLEX;
yytoken = YYTRANSLATE (yychar);
YY_SYMBOL_PRINT ("Next token is", yytoken, &yylval, &yylloc);
}
else
yytoken = YYTRANSLATE (yychar);
yygetLRActions (yystate, yytoken, &yyaction, &yyconflicts);
if (*yyconflicts != 0)
break;
if (yyisShiftAction (yyaction))
{
YY_SYMBOL_PRINT ("Shifting", yytoken, &yylval, &yylloc);
if (yytoken != YYEOF)
{
yychar = YYEMPTY;
yytoken = YYEMPTY;
}
if (yychar != YYEOF)
yychar = YYEMPTY;
yyposn += 1;
yyglrShift (&yystack, 0, yyaction, yyposn, &yylval, &yylloc);
if (0 < yystack.yyerrState)
@@ -2346,12 +2345,11 @@ b4_syncline([@oline@], [@ofile@])])dnl
/* If any yyglrShift call fails, it will fail after shifting. Thus,
a copy of yylval will already be on stack 0 in the event of a
failure in the following loop. Thus, yytoken is set to YYEMPTY
failure in the following loop. Thus, yychar is set to YYEMPTY
before the loop to make sure the user destructor for yylval isn't
called twice. */
yytoken_to_shift = yytoken;
yytoken_to_shift = YYTRANSLATE (yychar);
yychar = YYEMPTY;
yytoken = YYEMPTY;
yyposn += 1;
for (yys = 0; yys < yyn; yys += 1)
{
@@ -2412,9 +2410,10 @@ b4_syncline([@oline@], [@ofile@])])dnl
goto yyreturn;
yyreturn:
if (yytoken != YYEOF && yytoken != YYEMPTY)
if (yychar != YYEOF && yychar != YYEMPTY)
yydestruct ("Cleanup: discarding lookahead",
yytoken, &yylval]b4_location_if([, &yylloc])[]b4_user_args[);
YYTRANSLATE (yychar),
&yylval]b4_location_if([, &yylloc])[]b4_user_args[);
/* If the stack is well-formed, pop the stack until it is empty,
destroying its entries as we go. But free the stack regardless