/* Bison Action Scanner -*- C -*- Copyright (C) 2006 Free Software Foundation, Inc. This file is part of Bison, the GNU Compiler Compiler. 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 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 */ %option debug nodefault nounput noyywrap never-interactive %option prefix="code_" outfile="lex.yy.c" %{ /* Work around a bug in flex 2.5.31. See Debian bug 333231 . */ #undef code_wrap #define code_wrap() 1 #define FLEX_PREFIX(Id) code_ ## Id #include "complain.h" #include "flex-scanner.h" #include "reader.h" #include "getargs.h" #include #include #include #include "scan-code.h" /* The current calling start condition: SC_RULE_ACTION or SC_SYMBOL_ACTION. */ # define YY_DECL const char *code_lex (int sc_context) YY_DECL; #define YY_USER_ACTION location_compute (loc, &loc->end, yytext, yyleng); static void handle_action_dollar (char *cp, location dollar_loc); static void handle_action_at (char *cp, location at_loc); static location the_location; static location *loc = &the_location; /* The rule being processed. */ symbol_list *current_rule; %} /* C and C++ comments in code. */ %x SC_COMMENT SC_LINE_COMMENT /* Strings and characters in code. */ %x SC_STRING SC_CHARACTER /* Whether in a rule or symbol action. Specifies the translation of $ and @. */ %x SC_RULE_ACTION SC_SYMBOL_ACTION /* 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 NUL and newline, as this simplifies our implementation. */ tag [^\0\n>]+ /* Zero or more instances of backslash-newline. Following GCC, allow white space between the backslash and the newline. */ splice (\\[ \f\t\v]*\n)* %% %{ /* Nesting level of the current code in braces. */ int braces_level IF_LINT (= 0); /* This scanner is special: it is invoked only once, henceforth is expected to return only once. This initialization is therefore done once per action to translate. */ assert (sc_context == SC_SYMBOL_ACTION || sc_context == SC_RULE_ACTION || sc_context == INITIAL); BEGIN sc_context; %} /*------------------------------------------------------------. | Scanning a C comment. The initial `/ *' is already eaten. | `------------------------------------------------------------*/ { "*"{splice}"/" STRING_GROW; BEGIN sc_context; } /*--------------------------------------------------------------. | Scanning a line comment. The initial `//' is already eaten. | `--------------------------------------------------------------*/ { "\n" STRING_GROW; BEGIN sc_context; {splice} STRING_GROW; } /*--------------------------------------------. | Scanning user-code characters and strings. | `--------------------------------------------*/ { {splice}|\\{splice}. STRING_GROW; } { "'" STRING_GROW; BEGIN sc_context; } { "\"" STRING_GROW; BEGIN sc_context; } { "'" { STRING_GROW; BEGIN SC_CHARACTER; } "\"" { STRING_GROW; BEGIN SC_STRING; } "/"{splice}"*" { STRING_GROW; BEGIN SC_COMMENT; } "/"{splice}"/" { STRING_GROW; BEGIN SC_LINE_COMMENT; } } { "$"("<"{tag}">")?(-?[0-9]+|"$") handle_action_dollar (yytext, *loc); "@"(-?[0-9]+|"$") handle_action_at (yytext, *loc); "$" { warn_at (*loc, _("stray `$'")); obstack_sgrow (&obstack_for_string, "$]["); } "@" { warn_at (*loc, _("stray `@'")); obstack_sgrow (&obstack_for_string, "@@"); } "{" STRING_GROW; ++braces_level; "}" { 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 && ! yacc_flag) obstack_1grow (&obstack_for_string, ';'); STRING_GROW; } } { "$$" obstack_sgrow (&obstack_for_string, "]b4_dollar_dollar["); "@$" obstack_sgrow (&obstack_for_string, "]b4_at_dollar["); } /*-----------------------------------------. | Escape M4 quoting characters in C code. | `-----------------------------------------*/ <*> { \$ obstack_sgrow (&obstack_for_string, "$]["); \@ obstack_sgrow (&obstack_for_string, "@@"); \[ obstack_sgrow (&obstack_for_string, "@{"); \] obstack_sgrow (&obstack_for_string, "@}"); } /*-----------------------------------------------------. | By default, grow the string obstack with the input. | `-----------------------------------------------------*/ <*>.|\n STRING_GROW; /* End of processing. */ <*><> { obstack_1grow (&obstack_for_string, '\0'); return obstack_finish (&obstack_for_string); } %% /* Keeps track of the maximum number of semantic values to the left of a handle (those referenced by $0, $-1, etc.) are required by the semantic actions of this grammar. */ int max_left_semantic_context = 0; /*------------------------------------------------------------------. | TEXT is pointing to a wannabee semantic value (i.e., a `$'). | | | | Possible inputs: $[]($|integer) | | | | Output to OBSTACK_FOR_STRING a reference to this semantic value. | `------------------------------------------------------------------*/ static void handle_action_dollar (char *text, location dollar_loc) { const char *type_name = NULL; char *cp = text + 1; int rule_length = symbol_list_length (current_rule->next); /* Get the type name if explicit. */ if (*cp == '<') { type_name = ++cp; while (*cp != '>') ++cp; *cp = '\0'; ++cp; } if (*cp == '$') { if (!type_name) type_name = symbol_list_n_type_name_get (current_rule, dollar_loc, 0); if (!type_name && typed) complain_at (dollar_loc, _("$$ of `%s' has no declared type"), current_rule->sym->tag); if (!type_name) type_name = ""; obstack_fgrow1 (&obstack_for_string, "]b4_lhs_value([%s])[", type_name); current_rule->used = true; } else { long int num; set_errno (0); num = strtol (cp, 0, 10); 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, dollar_loc, n); if (!type_name && typed) complain_at (dollar_loc, _("$%d of `%s' has no declared type"), n, current_rule->sym->tag); if (!type_name) type_name = ""; obstack_fgrow3 (&obstack_for_string, "]b4_rhs_value(%d, %d, [%s])[", rule_length, n, type_name); symbol_list_n_used_set (current_rule, n, true); } else complain_at (dollar_loc, _("integer out of range: %s"), quote (text)); } } /*------------------------------------------------------. | TEXT is a location token (i.e., a `@...'). Output to | | OBSTACK_FOR_STRING a reference to this location. | `------------------------------------------------------*/ static void handle_action_at (char *text, location at_loc) { char *cp = text + 1; int rule_length = symbol_list_length (current_rule->next); locations_flag = true; if (*cp == '$') obstack_sgrow (&obstack_for_string, "]b4_lhs_location["); else { long int num; set_errno (0); num = strtol (cp, 0, 10); if (INT_MIN <= num && num <= rule_length && ! get_errno ()) { int n = num; obstack_fgrow2 (&obstack_for_string, "]b4_rhs_location(%d, %d)[", rule_length, n); } else complain_at (at_loc, _("integer out of range: %s"), quote (text)); } } /*-------------------------. | Initialize the scanner. | `-------------------------*/ /* Translate the dollars and ats in \a a, whose location is l. Depending on the \a sc_context (SC_RULE_ACTION, SC_SYMBOL_ACTION, INITIAL), the processing is different. */ static const char * translate_action (int sc_context, const char *a, location l) { const char *res; static bool initialized = false; if (!initialized) { obstack_init (&obstack_for_string); /* The initial buffer, never used. */ yy_delete_buffer (YY_CURRENT_BUFFER); yy_flex_debug = 0; initialized = true; } loc->start = loc->end = l.start; yy_switch_to_buffer (yy_scan_string (a)); res = code_lex (sc_context); yy_delete_buffer (YY_CURRENT_BUFFER); return res; } const char * translate_rule_action (symbol_list *r, const char *a, location l) { current_rule = r; return translate_action (SC_RULE_ACTION, a, l); } const char * translate_symbol_action (const char *a, location l) { return translate_action (SC_SYMBOL_ACTION, a, l); } const char * translate_code (const char *a, location l) { return translate_action (INITIAL, a, l); } /*-----------------------------------------------. | Free all the memory allocated to the scanner. | `-----------------------------------------------*/ void code_scanner_free (void) { obstack_free (&obstack_for_string, 0); /* Reclaim Flex's buffers. */ yy_delete_buffer (YY_CURRENT_BUFFER); }