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31 * Keywords are multichar, punctuation lexing is a bit more complicated
32 * than keyword lexing.
34 static const char *const lex_keywords[] = {
35 "do", "else", "if", "while",
36 "break", "continue", "return", "goto",
48 struct lex_file *lex_open(FILE *fp) {
49 struct lex_file *lex = mem_a(sizeof(struct lex_file));
52 fseek(lex->file, 0, SEEK_END);
53 lex->length = ftell(lex->file);
54 lex->size = lex->length; /* copy, this is never changed */
55 fseek(lex->file, 0, SEEK_SET);
58 memset(lex->peek, 0, sizeof(lex->peek));
63 int lex_close(struct lex_file *file) {
66 ret = fclose(file->file);
72 static void lex_addch(int ch, struct lex_file *file) {
73 if (file->current < sizeof(file->lastok)-1)
74 file->lastok[file->current++] = (char)ch;
75 if (file->current == sizeof(file->lastok)-1)
76 file->lastok[file->current] = (char)'\0';
78 static inline void lex_clear(struct lex_file *file) {
83 * read in inget/unget character from a lexer stream.
84 * This doesn't play with file streams, the lexer has
85 * it's own internal state for this.
87 static int lex_inget(struct lex_file *file) {
90 return file->peek[--file->last];
91 return fgetc(file->file);
93 static void lex_unget(int ch, struct lex_file *file) {
94 if (file->last < sizeof(file->peek))
95 file->peek[file->last++] = ch;
100 * This is trigraph and digraph support, a feature not qc compiler
101 * supports. Moving up in this world!
103 static int lex_trigraph(struct lex_file *file) {
105 if ((ch = lex_inget(file)) != '?') {
110 ch = lex_inget(file);
112 case '(' : return '[' ;
113 case ')' : return ']' ;
114 case '/' : return '\\';
115 case '\'': return '^' ;
116 case '<' : return '{' ;
117 case '>' : return '}' ;
118 case '!' : return '|' ;
119 case '-' : return '~' ;
120 case '=' : return '#' ;
122 lex_unget('?', file);
123 lex_unget(ch , file);
128 static int lex_digraph(struct lex_file *file, int first) {
129 int ch = lex_inget(file);
132 if (ch == '%') return '{';
133 if (ch == ':') return '[';
136 if (ch == '>') return '}';
137 if (ch == ':') return '#';
140 if (ch == '>') return ']';
148 static int lex_getch(struct lex_file *file) {
149 int ch = lex_inget(file);
151 return lex_trigraph(file);
152 if (ch == '<' || ch == ':' || ch == '%')
153 return lex_digraph (file, ch);
158 static int lex_get(struct lex_file *file) {
160 if (!isspace(ch = lex_getch(file)))
163 /* skip over all spaces */
164 while (isspace(ch) && ch != '\n')
165 ch = lex_getch(file);
173 static int lex_skipchr(struct lex_file *file) {
178 lex_addch('\'', file);
180 for (it = 0; it < 2 && ((ch = lex_inget(file)) != '\''); it++) {
186 lex_addch(lex_getch(file), file);
188 lex_addch('\'', file);
189 lex_addch('\0', file);
197 static int lex_skipstr(struct lex_file *file) {
200 lex_addch('"', file);
202 while ((ch = lex_getch(file)) != '"') {
203 if (ch == '\n' || ch == EOF)
208 lex_addch(lex_inget(file), file);
211 lex_addch('"', file);
212 lex_addch('\0', file);
216 static int lex_skipcmt(struct lex_file *file) {
219 ch = lex_getch(file);
222 lex_addch('/', file);
223 lex_addch('/', file);
225 while ((ch = lex_getch(file)) != '\n') {
228 lex_addch(lex_getch(file), file);
233 lex_addch('\0', file);
242 lex_addch('/', file);
247 while ((ch = lex_getch(file)) != '*') {
249 return error(ERROR_LEX, "malformatted comment at line %d", file->line);
254 } while ((ch = lex_getch(file)) != '/');
256 lex_addch('/', file);
257 lex_addch('\0', file);
262 static int lex_getsource(struct lex_file *file) {
263 int ch = lex_get(file);
265 /* skip char/string/comment */
267 case '\'': return lex_skipchr(file);
268 case '"': return lex_skipstr(file);
269 case '/': return lex_skipcmt(file);
274 int lex_token(struct lex_file *file) {
275 int ch = lex_getsource(file);
278 /* valid identifier */
279 if (ch > 0 && (ch == '_' || isalpha(ch))) {
281 while (ch > 0 && (isalpha(ch) || ch == '_')) {
283 ch = lex_getsource(file);
286 lex_addch('\0', file);
288 /* look inside the table for a keyword .. */
289 for (it = 0; it < sizeof(lex_keywords)/sizeof(*lex_keywords); it++)
290 if (!strncmp(file->lastok, lex_keywords[it], sizeof(lex_keywords[it])))
293 /* try the hashtable for typedefs? */
294 if (typedef_find(file->lastok))
295 for (it = 0; it < sizeof(lex_keywords)/sizeof(*lex_keywords); it++)
296 if (!strncmp(typedef_find(file->lastok)->name, lex_keywords[it], sizeof(lex_keywords[it])))
305 void lex_reset(struct lex_file *file) {
308 file->length = file->size;
309 fseek(file->file, 0, SEEK_SET);
311 memset(file->peek, 0, sizeof(file->peek ));
312 memset(file->lastok, 0, sizeof(file->lastok));