diff options
Diffstat (limited to 'src/lexer.c')
| -rw-r--r-- | src/lexer.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/src/lexer.c b/src/lexer.c new file mode 100644 index 0000000..41d6784 --- /dev/null +++ b/src/lexer.c @@ -0,0 +1,253 @@ +/* +Copyright (C) 2016 Paweł Redman + +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 3 +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 +*/ + +#include "common.h" +#include <ctype.h> + +int lexer_open(lexer_state_t *ls, const char *path, vstr_t *token) +{ + ls->error = 0; + ls->path = path; + + ls->fp = fopen(path, "r"); + if (!ls->fp) + return -errno; + + ls->eof = false; + + ls->token = token; + ls->buf_e = ls->buf_c = ls->buf; + ls->cc = ls->lc = ls->Cc = 0; + + ls->in_token = false; + ls->in_quote = false; + ls->in_comment = false; + + return 0; +} + +//RETURN VALUES +// <0 on error +// 0 on success +// note: sets ls->eof to true if there's no more data left +static int fill_buffer(lexer_state_t *ls) +{ + size_t read; + + read = fread(ls->buf, 1, sizeof(ls->buf), ls->fp); + debug("read = %zu\n", read); + if (read < sizeof(ls->buf)) { + if (ferror(ls->fp)) { + fclose(ls->fp); + return -errno; + } + + ls->eof = true; + fclose(ls->fp); + debug("no data left, ls->fp closed\n"); + } + + ls->buf_c = ls->buf; + ls->buf_e = ls->buf + read; + return 0; +} + +//RETURN VALUES +// -ENOMEM +// -EAGAIN when the buffer runs out +// 0 on success +// 1 when no data is left +static int read_buffer(lexer_state_t *ls) +{ + while (ls->buf_c < ls->buf_e) { + bool ret_token = false; + + debug("*ls->buf_c = %c, ls->last = %c\n", *ls->buf_c, ls->last); + + if (*ls->buf_c == '\n') { + ls->lc++; + ls->Cc = 0; + } + + if (ls->in_comment) { + if (*ls->buf_c == '\n') + ls->in_comment = false; + } else if (isspace(*ls->buf_c) && !ls->in_quote) { + if (ls->in_token) { + ls->in_token = false; + ret_token = true; + } + } else if (*ls->buf_c == '/' && ls->last == '/') { + ls->in_comment = true; + ls->in_token = false; + + ls->token->size--; // remove the first slash + if (ls->token->size) + ret_token = true; + } else if (*ls->buf_c == '\"' && + (ls->cc && ls->last != '\\')) { + ls->in_quote = !ls->in_quote; + + if (!ls->in_quote) { + ls->in_token = false; + ret_token = true; + } + } else { + if (!ls->in_token) { + ls->in_token = true; + } + } + + if (ls->in_token) + if (vstr_putc(ls->token, *ls->buf_c)) { + ls->error = ENOMEM; + return -ENOMEM; + } + + ls->last = *ls->buf_c; + ls->buf_c++; + ls->cc++; + ls->Cc++; + + if (ret_token) + return 0; + } + + if (ls->eof) { + if (ls->token->size > 0) + return 0; + return 1; + } + + return -EAGAIN; +} + +//RETURN VALUES +// <0 on error +// 0 on success +// 1 when no data is left +int lexer_get_token(lexer_state_t *ls) +{ + int ret; + + vstr_clear(ls->token); + + while (1) { + ret = read_buffer(ls); + debug("read_buffer = %i\n", ret); + if (ret != -EAGAIN) + return ret; + + ret = fill_buffer(ls); + debug("fill_buffer = %i\n", ret); + if (ret < 0) + return ret; + } +} + +void lexer_perror(lexer_state_t *ls, const char *fmt, ...) +{ + va_list vl; + + fprintf(stderr, "%s:%zu:%zu: ", ls->path, ls->lc + 1, ls->Cc + 1); + + if (ls->error) { + perror(NULL); + } else { + va_start(vl, fmt); + vfprintf(stderr, fmt, vl); + va_end(vl); + } +} + +void lexer_perror_eg(lexer_state_t *ls, const char *expected) +{ + if (ls->eof && ls->buf_c == ls->buf_e) + lexer_perror(ls, "expected %s, got EOF\n", expected); + else { + vstr_termz(ls->token); + lexer_perror(ls, "expected %s, got \"%s\"\n", expected, + ls->token->data); + } +} + +int lexer_assert(lexer_state_t *ls, const char *match, const char *desc) +{ + int ret; + + ret = lexer_get_token(ls); + if (ret) { + lexer_perror(ls, "expected %s%s\"%s\", got EOF\n", + (desc ? desc : ""), (desc ? " " : ""), match); + return 1; + } + + if (vstr_cmp(ls->token, match)) { + vstr_termz(ls->token); + lexer_perror(ls, "expected %s%s\"%s\", got \"%s\"\n", + (desc ? desc : ""), (desc ? " " : ""), match, + ls->token->data); + return 1; + } + + return 0; +} + +//RETURN VALUE +// -1 on eof (also success) +// 0 on success +// 1 on error +int lexer_assert_or_eof(lexer_state_t *ls, const char *match, const char *desc) +{ + int ret; + + ret = lexer_get_token(ls); + if (ret < 0) { + perror("lexer"); + return 1; + } + + if (ret == 1) { + return -1; + } + + if (vstr_cmp(ls->token, match)) { + lexer_perror(ls, "expected %s%s\"%s\" or EOF, got \"%.*s\"\n", + (desc ? desc : ""), (desc ? " " : ""), match, + (int)ls->token->size, ls->token->data); + return 1; + } + + return 0; +} + +int lexer_get_floats(lexer_state_t *ls, float *out, size_t count) +{ + size_t i; + + for (i = 0; i < count; i++) { + if (lexer_get_token(ls)) { + lexer_perror_eg(ls, "a number"); + return 1; + } + + out[i] = vstr_atof(ls->token); + } + + return 0; +} |