/* Bison Grammar Scanner -*- C -*-
- Copyright (C) 2002 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003 Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
02111-1307 USA
*/
-%option debug nodefault noyywrap never-interactive
+%option debug nodefault nounput noyywrap never-interactive
%option prefix="gram_" outfile="lex.yy.c"
%{
scanner_cursor.file = current_file; \
scanner_cursor.line = 1; \
scanner_cursor.column = 1; \
+ code_start = scanner_cursor; \
} \
while (0)
static void handle_at (int token_type, char *cp, location loc);
static void handle_syncline (char *args);
static int convert_ucn_to_byte (char const *hex_text);
-static void unexpected_end_of_file (boundary, char const *);
+static void unexpected_eof (boundary, char const *);
%}
%x SC_COMMENT SC_LINE_COMMENT SC_YACC_COMMENT
int token_type IF_LINT (= 0);
/* Location of most recent identifier, when applicable. */
- location id_loc IF_LINT (= *loc);
+ location id_loc IF_LINT (= empty_location);
- /* Where containing code started, when applicable. */
- boundary code_start IF_LINT (= loc->start);
+ /* Where containing code started, when applicable. Its initial
+ value is relevant only when yylex is invoked in the SC_EPILOGUE
+ start condition. */
+ boundary code_start = scanner_cursor;
/* Where containing comment or string or character literal started,
when applicable. */
- boundary token_start IF_LINT (= loc->start);
+ boundary token_start IF_LINT (= scanner_cursor);
%}
<INITIAL,SC_AFTER_IDENTIFIER,SC_PRE_CODE>
{
[ \f\n\t\v] ;
+ "," warn_at (*loc, _("stray `,' treated as white space"));
/* Comments. */
- "/*" token_start = loc->start; context_state = YY_START; BEGIN SC_YACC_COMMENT;
"//".* ;
+ "/*" {
+ token_start = loc->start;
+ context_state = YY_START;
+ BEGIN SC_YACC_COMMENT;
+ }
/* #line directives are not documented, and may be withdrawn or
modified in future versions of Bison. */
"%name"[-_]"prefix" return PERCENT_NAME_PREFIX;
"%no"[-_]"lines" return PERCENT_NO_LINES;
"%nonassoc" return PERCENT_NONASSOC;
+ "%nondeterministic-parser" return PERCENT_NONDETERMINISTIC_PARSER;
"%nterm" return PERCENT_NTERM;
"%output" return PERCENT_OUTPUT;
"%parse-param" token_type = PERCENT_PARSE_PARAM; BEGIN SC_PRE_CODE;
"|" rule_length = 0; return PIPE;
";" return SEMICOLON;
- "," {
- warn_at (*loc, _("stray `,' treated as white space"));
- }
-
{id} {
val->symbol = symbol_get (yytext, *loc);
id_loc = *loc;
"%%" {
static int percent_percent_count;
if (++percent_percent_count == 2)
- {
- code_start = loc->start;
- BEGIN SC_EPILOGUE;
- }
+ BEGIN SC_EPILOGUE;
return PERCENT_PERCENT;
}
. {
complain_at (*loc, _("invalid character: %s"), quote (yytext));
}
+
+ <<EOF>> {
+ loc->start = loc->end = scanner_cursor;
+ yyterminate ();
+ }
}
{
"*/" BEGIN context_state;
.|\n ;
- <<EOF>> unexpected_end_of_file (token_start, "*/");
+ <<EOF>> unexpected_eof (token_start, "*/"); BEGIN context_state;
}
<SC_COMMENT>
{
"*"{splice}"/" STRING_GROW; BEGIN context_state;
- <<EOF>> unexpected_end_of_file (token_start, "*/");
+ <<EOF>> unexpected_eof (token_start, "*/"); BEGIN context_state;
}
}
.|\n STRING_GROW;
- <<EOF>> unexpected_end_of_file (token_start, "\"");
+ <<EOF>> unexpected_eof (token_start, "\""); BEGIN INITIAL;
}
/*---------------------------------------------------------------.
}
.|\n STRING_GROW;
- <<EOF>> unexpected_end_of_file (token_start, "'");
+ <<EOF>> unexpected_eof (token_start, "'"); BEGIN INITIAL;
}
{
"'" STRING_GROW; BEGIN context_state;
\\{splice}[^$@\[\]] STRING_GROW;
- <<EOF>> unexpected_end_of_file (token_start, "'");
+ <<EOF>> unexpected_eof (token_start, "'"); BEGIN context_state;
}
{
"\"" STRING_GROW; BEGIN context_state;
\\{splice}[^$@\[\]] STRING_GROW;
- <<EOF>> unexpected_end_of_file (token_start, "\"");
+ <<EOF>> {
+ unexpected_eof (token_start, "\"");
+ BEGIN context_state;
+ }
}
return token_type;
}
}
+
+ <<EOF>> unexpected_eof (scanner_cursor, "{}"); BEGIN INITIAL;
}
"{"|"<"{splice}"%" STRING_GROW; braces_level++;
"%"{splice}">" STRING_GROW; braces_level--;
"}" {
- STRING_GROW;
- braces_level--;
- if (braces_level < 0)
+ bool outer_brace = --braces_level < 0;
+
+ /* As an undocumented Bison extension, append `;' before the last
+ brace in braced code, so that the user code can omit trailing
+ `;'. But do not append `;' if emulating Yacc, since Yacc does
+ not append one.
+
+ FIXME: Bison should warn if a semicolon seems to be necessary
+ here, and should omit the semicolon if it seems unnecessary
+ (e.g., after ';', '{', or '}', each followed by comments or
+ white space). Such a warning shouldn't depend on --yacc; it
+ should depend on a new --pedantic option, which would cause
+ Bison to warn if it detects an extension to POSIX. --pedantic
+ should also diagnose other Bison extensions like %yacc.
+ Perhaps there should also be a GCC-style --pedantic-errors
+ option, so that such warnings are diagnosed as errors. */
+ if (outer_brace && token_type == BRACED_CODE && ! yacc_flag)
+ obstack_1grow (&obstack_for_string, ';');
+
+ obstack_1grow (&obstack_for_string, '}');
+
+ if (outer_brace)
{
STRING_FINISH;
rule_length++;
"$"("<"{tag}">")?(-?[0-9]+|"$") handle_dollar (token_type, yytext, *loc);
"@"(-?[0-9]+|"$") handle_at (token_type, yytext, *loc);
- <<EOF>> unexpected_end_of_file (code_start, "}");
+ <<EOF>> unexpected_eof (code_start, "}"); BEGIN INITIAL;
}
return PROLOGUE;
}
- <<EOF>> unexpected_end_of_file (code_start, "%}");
+ <<EOF>> unexpected_eof (code_start, "%}"); BEGIN INITIAL;
}
%%
+/* Keeps track of the maximum number of semantic values to the left of
+ a handle (those referenced by $0, $-1, etc.) are required by the
+ semantic actions of this grammar. */
+int max_left_semantic_context = 0;
+
/* Set *LOC and adjust scanner cursor to account for token TOKEN of
size SIZE. */
static size_t
no_cr_read (FILE *fp, char *buf, size_t size)
{
- size_t s = fread (buf, 1, size, fp);
- if (s)
+ size_t bytes_read = fread (buf, 1, size, fp);
+ if (bytes_read)
{
- char *w = memchr (buf, '\r', s);
+ char *w = memchr (buf, '\r', bytes_read);
if (w)
{
char const *r = ++w;
- char const *lim = buf + s;
+ char const *lim = buf + bytes_read;
for (;;)
{
}
}
- return s;
+ return bytes_read;
}
if (INT_MIN <= num && num <= rule_length && ! get_errno ())
{
int n = num;
+ if (1-n > max_left_semantic_context)
+ max_left_semantic_context = 1-n;
if (!type_name && n > 0)
type_name = symbol_list_n_type_name_get (current_rule, loc, n);
if (!type_name && typed)
handle_action_at (char *text, location loc)
{
char *cp = text + 1;
- locations_flag = 1;
+ locations_flag = true;
if (! current_rule)
return false;
/*------------------------------------------------------------------------.
| Report an unexpected EOF in a token or comment starting at START. |
| An end of file was encountered and the expected TOKEN_END was missing. |
-| After reporting the problem, pretend that TOKEN_END was found. |
`------------------------------------------------------------------------*/
static void
-unexpected_end_of_file (boundary start, char const *token_end)
+unexpected_eof (boundary start, char const *token_end)
{
- size_t i = strlen (token_end);
-
location loc;
loc.start = start;
loc.end = scanner_cursor;
complain_at (loc, _("missing `%s' at end of file"), token_end);
-
- /* Adjust scanner cursor so that any later message does not count
- the characters about to be inserted. */
- scanner_cursor.column -= i;
-
- while (i != 0)
- unput (token_end[--i]);
}
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