/* 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)
Outside of well-formed rules, RULE_LENGTH has an undefined value. */
static int rule_length;
-static void handle_dollar (braced_code code_kind, char *cp, location loc);
-static void handle_at (braced_code code_kind, char *cp, location loc);
+static void handle_dollar (int token_type, char *cp, location loc);
+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
%x SC_STRING SC_CHARACTER
%x SC_AFTER_IDENTIFIER
%x SC_ESCAPED_STRING SC_ESCAPED_CHARACTER
-%x SC_BRACED_CODE SC_PROLOGUE SC_EPILOGUE
+%x SC_PRE_CODE SC_BRACED_CODE SC_PROLOGUE SC_EPILOGUE
letter [.abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_]
id {letter}({letter}|[0-9])*
directive %{letter}({letter}|[0-9]|-)*
-int [0-9]+
+int [0-9]+
/* POSIX says that a tag must be both an id and a C union member, but
historically almost any character is allowed in a tag. We disallow
/* Parent context state, when applicable. */
int context_state IF_LINT (= 0);
+ /* Token type to return, when applicable. */
+ 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);
%}
| Scanning white space. |
`-----------------------*/
-<INITIAL,SC_AFTER_IDENTIFIER>
+<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. */
{
"%binary" return PERCENT_NONASSOC;
"%debug" return PERCENT_DEBUG;
+ "%default"[-_]"prec" return PERCENT_DEFAULT_PREC;
"%define" return PERCENT_DEFINE;
"%defines" return PERCENT_DEFINES;
- "%destructor" return PERCENT_DESTRUCTOR;
+ "%destructor" token_type = PERCENT_DESTRUCTOR; BEGIN SC_PRE_CODE;
"%dprec" return PERCENT_DPREC;
"%error"[-_]"verbose" return PERCENT_ERROR_VERBOSE;
"%expect" return PERCENT_EXPECT;
"%file-prefix" return PERCENT_FILE_PREFIX;
"%fixed"[-_]"output"[-_]"files" return PERCENT_YACC;
+ "%initial-action" token_type = PERCENT_INITIAL_ACTION; BEGIN SC_PRE_CODE;
"%glr-parser" return PERCENT_GLR_PARSER;
"%left" return PERCENT_LEFT;
+ "%lex-param" token_type = PERCENT_LEX_PARAM; BEGIN SC_PRE_CODE;
"%locations" return PERCENT_LOCATIONS;
"%merge" return PERCENT_MERGE;
"%name"[-_]"prefix" return PERCENT_NAME_PREFIX;
+ "%no"[-_]"default"[-_]"prec" return PERCENT_NO_DEFAULT_PREC;
"%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" return PERCENT_PARSE_PARAM;
+ "%parse-param" token_type = PERCENT_PARSE_PARAM; BEGIN SC_PRE_CODE;
"%prec" rule_length--; return PERCENT_PREC;
- "%printer" return PERCENT_PRINTER;
+ "%printer" token_type = PERCENT_PRINTER; BEGIN SC_PRE_CODE;
"%pure"[-_]"parser" return PERCENT_PURE_PARSER;
"%right" return PERCENT_RIGHT;
- "%lex-param" return PERCENT_LEX_PARAM;
"%skeleton" return PERCENT_SKELETON;
"%start" return PERCENT_START;
"%term" return PERCENT_TOKEN;
"%token" return PERCENT_TOKEN;
"%token"[-_]"table" return PERCENT_TOKEN_TABLE;
"%type" return PERCENT_TYPE;
- "%union" return PERCENT_UNION;
+ "%union" token_type = PERCENT_UNION; BEGIN SC_PRE_CODE;
"%verbose" return PERCENT_VERBOSE;
"%yacc" return PERCENT_YACC;
"|" 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;
/* Code in between braces. */
"{" {
STRING_GROW;
+ token_type = BRACED_CODE;
braces_level = 0;
code_start = loc->start;
BEGIN SC_BRACED_CODE;
"%%" {
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;
}
return STRING;
}
+ \0 complain_at (*loc, _("invalid null character"));
.|\n STRING_GROW;
- <<EOF>> unexpected_end_of_file (token_start, "\"");
+ <<EOF>> unexpected_eof (token_start, "\""); BEGIN INITIAL;
}
/*---------------------------------------------------------------.
<SC_ESCAPED_CHARACTER>
{
"'" {
+ unsigned char last_string_1;
STRING_GROW;
STRING_FINISH;
loc->start = token_start;
val->symbol = symbol_get (last_string, *loc);
symbol_class_set (val->symbol, token_sym, *loc);
- symbol_user_token_number_set (val->symbol,
- (unsigned char) last_string[1], *loc);
+ last_string_1 = last_string[1];
+ symbol_user_token_number_set (val->symbol, last_string_1, *loc);
STRING_FREE;
rule_length++;
BEGIN INITIAL;
return ID;
}
+ \0 complain_at (*loc, _("invalid null character"));
.|\n STRING_GROW;
- <<EOF>> unexpected_end_of_file (token_start, "'");
+ <<EOF>> unexpected_eof (token_start, "'"); BEGIN INITIAL;
}
unsigned long c = strtoul (yytext + 1, 0, 8);
if (UCHAR_MAX < c)
complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
+ else if (! c)
+ complain_at (*loc, _("invalid null character: %s"), quote (yytext));
else
obstack_1grow (&obstack_for_string, c);
}
c = strtoul (yytext + 2, 0, 16);
if (UCHAR_MAX < c || get_errno ())
complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
+ else if (! c)
+ complain_at (*loc, _("invalid null character: %s"), quote (yytext));
else
obstack_1grow (&obstack_for_string, c);
}
int c = convert_ucn_to_byte (yytext);
if (c < 0)
complain_at (*loc, _("invalid escape sequence: %s"), quote (yytext));
+ else if (! c)
+ complain_at (*loc, _("invalid null character: %s"), quote (yytext));
else
obstack_1grow (&obstack_for_string, c);
}
{
"'" 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;
+ }
}
}
+ /*---------------------------------------------------------------.
+ | Scanning after %union etc., possibly followed by white space. |
+ | For %union only, allow arbitrary C code to appear before the |
+ | following brace, as an extension to POSIX. |
+ `---------------------------------------------------------------*/
+
+<SC_PRE_CODE>
+{
+ . {
+ bool valid = yytext[0] == '{' || token_type == PERCENT_UNION;
+ scanner_cursor.column -= mbsnwidth (yytext, yyleng, 0);
+ yyless (0);
+
+ if (valid)
+ {
+ braces_level = -1;
+ code_start = loc->start;
+ BEGIN SC_BRACED_CODE;
+ }
+ else
+ {
+ complain_at (*loc, _("missing `{' in `%s'"),
+ token_name (token_type));
+ obstack_sgrow (&obstack_for_string, "{}");
+ STRING_FINISH;
+ val->chars = last_string;
+ BEGIN INITIAL;
+ return token_type;
+ }
+ }
+
+ <<EOF>> unexpected_eof (scanner_cursor, "{}"); BEGIN INITIAL;
+}
+
+
/*---------------------------------------------------------------.
| Scanning some code in braces (%union and actions). The initial |
| "{" is already eaten. |
"{"|"<"{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++;
loc->start = code_start;
val->chars = last_string;
- rule_length++;
BEGIN INITIAL;
- return BRACED_CODE;
+ return token_type;
}
}
(as `<' `<%'). */
"<"{splice}"<" STRING_GROW;
- "$"("<"{tag}">")?(-?[0-9]+|"$") { handle_dollar (current_braced_code,
- yytext, *loc); }
- "@"(-?[0-9]+|"$") { handle_at (current_braced_code,
- yytext, *loc); }
+ "$"("<"{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;
}
| Output to OBSTACK_FOR_STRING a reference to this semantic value. |
`------------------------------------------------------------------*/
-static inline void
+static inline bool
handle_action_dollar (char *text, location loc)
{
const char *type_name = NULL;
char *cp = text + 1;
+ if (! current_rule)
+ return false;
+
/* Get the type name if explicit. */
if (*cp == '<')
{
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)
else
complain_at (loc, _("integer out of range: %s"), quote (text));
}
-}
-
-/*---------------------------------------------------------------.
-| TEXT is expected to be $$ in some code associated to a symbol: |
-| destructor or printer. |
-`---------------------------------------------------------------*/
-
-static inline void
-handle_symbol_code_dollar (char *text, location loc)
-{
- char *cp = text + 1;
- if (*cp == '$')
- obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar[");
- else
- complain_at (loc, _("invalid value: %s"), quote (text));
+ return true;
}
-/*-----------------------------------------------------------------.
-| Dispatch onto handle_action_dollar, or handle_destructor_dollar, |
-| depending upon CODE_KIND. |
-`-----------------------------------------------------------------*/
+/*----------------------------------------------------------------.
+| Map `$?' onto the proper M4 symbol, depending on its TOKEN_TYPE |
+| (are we in an action?). |
+`----------------------------------------------------------------*/
static void
-handle_dollar (braced_code braced_code_kind, char *text, location loc)
+handle_dollar (int token_type, char *text, location loc)
{
- switch (braced_code_kind)
+ switch (token_type)
{
- case action_braced_code:
- handle_action_dollar (text, loc);
+ case BRACED_CODE:
+ if (handle_action_dollar (text, loc))
+ return;
break;
- case destructor_braced_code:
- case printer_braced_code:
- handle_symbol_code_dollar (text, loc);
+ case PERCENT_DESTRUCTOR:
+ case PERCENT_INITIAL_ACTION:
+ case PERCENT_PRINTER:
+ if (text[1] == '$')
+ {
+ obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar[");
+ return;
+ }
+ break;
+
+ default:
break;
}
+
+ complain_at (loc, _("invalid value: %s"), quote (text));
}
| OBSTACK_FOR_STRING a reference to this location. |
`------------------------------------------------------*/
-static inline void
+static inline bool
handle_action_at (char *text, location loc)
{
char *cp = text + 1;
- locations_flag = 1;
+ locations_flag = true;
+
+ if (! current_rule)
+ return false;
if (*cp == '$')
- {
- obstack_sgrow (&obstack_for_string, "]b4_lhs_location[");
- }
+ obstack_sgrow (&obstack_for_string, "]b4_lhs_location[");
else
{
long num;
else
complain_at (loc, _("integer out of range: %s"), quote (text));
}
-}
-
-
-/*---------------------------------------------------------------.
-| TEXT is expected to be @$ in some code associated to a symbol: |
-| destructor or printer. |
-`---------------------------------------------------------------*/
-static inline void
-handle_symbol_code_at (char *text, location loc)
-{
- char *cp = text + 1;
- if (*cp == '$')
- obstack_sgrow (&obstack_for_string, "]b4_at_dollar[");
- else
- complain_at (loc, _("invalid value: %s"), quote (text));
+ return true;
}
-/*-------------------------------------------------------------------.
-| Dispatch onto handle_action_at, or handle_destructor_at, depending |
-| upon CODE_KIND. |
-`-------------------------------------------------------------------*/
+/*----------------------------------------------------------------.
+| Map `@?' onto the proper M4 symbol, depending on its TOKEN_TYPE |
+| (are we in an action?). |
+`----------------------------------------------------------------*/
static void
-handle_at (braced_code braced_code_kind, char *text, location loc)
+handle_at (int token_type, char *text, location loc)
{
- switch (braced_code_kind)
+ switch (token_type)
{
- case action_braced_code:
+ case BRACED_CODE:
handle_action_at (text, loc);
+ return;
+
+ case PERCENT_INITIAL_ACTION:
+ case PERCENT_DESTRUCTOR:
+ case PERCENT_PRINTER:
+ if (text[1] == '$')
+ {
+ obstack_sgrow (&obstack_for_string, "]b4_at_dollar[");
+ return;
+ }
break;
- case destructor_braced_code:
- case printer_braced_code:
- handle_symbol_code_at (text, loc);
+ default:
break;
}
+
+ complain_at (loc, _("invalid value: %s"), quote (text));
}
/*------------------------------------------------------------------------.
| 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]);
}
projects / bison.git / blobdiff