/* * Mach Operating System * Copyright (c) 1991,1990 Carnegie Mellon University * All Rights Reserved. * * Permission to use, copy, modify and distribute this software and its * documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * Author: David B. Golub, Carnegie Mellon University * Date: 7/90 */ /* * Lexical analyzer. */ #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); #include <sys/param.h> #include <ddb/ddb.h> #include <ddb/db_lex.h> static char db_line[120]; static char * db_lp, *db_endlp; static int db_lex(void); static void db_flush_line(void); static int db_read_char(void); static void db_unread_char(int); int db_read_line() { int i; i = db_readline(db_line, sizeof(db_line)); if (i == 0) return (0); /* EOI */ db_lp = db_line; db_endlp = db_lp + i; return (i); } static void db_flush_line() { db_lp = db_line; db_endlp = db_line; } static int db_look_char = 0; static int db_read_char() { int c; if (db_look_char != 0) { c = db_look_char; db_look_char = 0; } else if (db_lp >= db_endlp) c = -1; else c = *db_lp++; return (c); } static void db_unread_char(c) int c; { db_look_char = c; } static int db_look_token = 0; void db_unread_token(t) int t; { db_look_token = t; } int db_read_token() { int t; if (db_look_token) { t = db_look_token; db_look_token = 0; } else t = db_lex(); return (t); } db_expr_t db_tok_number; char db_tok_string[TOK_STRING_SIZE]; db_expr_t db_radix = 16; void db_flush_lex() { db_flush_line(); db_look_char = 0; db_look_token = 0; } static int db_lex() { int c; c = db_read_char(); while (c <= ' ' || c > '~') { if (c == '\n' || c == -1) return (tEOL); c = db_read_char(); } if (c >= '0' && c <= '9') { /* number */ int r, digit = 0; if (c > '0') r = db_radix; else { c = db_read_char(); if (c == 'O' || c == 'o') r = 8; else if (c == 'T' || c == 't') r = 10; else if (c == 'X' || c == 'x') r = 16; else { r = db_radix; db_unread_char(c); } c = db_read_char(); } db_tok_number = 0; for (;;) { if (c >= '0' && c <= ((r == 8) ? '7' : '9')) digit = c - '0'; else if (r == 16 && ((c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f'))) { if (c >= 'a') digit = c - 'a' + 10; else if (c >= 'A') digit = c - 'A' + 10; } else break; db_tok_number = db_tok_number * r + digit; c = db_read_char(); } if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c == '_')) { db_error("Bad character in number\n"); db_flush_lex(); return (tEOF); } db_unread_char(c); return (tNUMBER); } if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || c == '_' || c == '\\') { /* string */ char *cp; cp = db_tok_string; if (c == '\\') { c = db_read_char(); if (c == '\n' || c == -1) db_error("Bad escape\n"); } *cp++ = c; while (1) { c = db_read_char(); if ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '_' || c == '\\' || c == ':' || c == '.') { if (c == '\\') { c = db_read_char(); if (c == '\n' || c == -1) db_error("Bad escape\n"); } *cp++ = c; if (cp == db_tok_string+sizeof(db_tok_string)) { db_error("String too long\n"); db_flush_lex(); return (tEOF); } continue; } else { *cp = '\0'; break; } } db_unread_char(c); return (tIDENT); } switch (c) { case '+': return (tPLUS); case '-': return (tMINUS); case '.': c = db_read_char(); if (c == '.') return (tDOTDOT); db_unread_char(c); return (tDOT); case '*': return (tSTAR); case '/': return (tSLASH); case '=': return (tEQ); case '%': return (tPCT); case '#': return (tHASH); case '(': return (tLPAREN); case ')': return (tRPAREN); case ',': return (tCOMMA); case '"': return (tDITTO); case '$': return (tDOLLAR); case '!': return (tEXCL); case '<': c = db_read_char(); if (c == '<') return (tSHIFT_L); db_unread_char(c); break; case '>': c = db_read_char(); if (c == '>') return (tSHIFT_R); db_unread_char(c); break; case -1: return (tEOF); } db_printf("Bad character\n"); db_flush_lex(); return (tEOF); }