diff options
Diffstat (limited to 'src/Backtrace/fallback.c')
| -rw-r--r-- | src/Backtrace/fallback.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/Backtrace/fallback.c b/src/Backtrace/fallback.c new file mode 100644 index 0000000..0442533 --- /dev/null +++ b/src/Backtrace/fallback.c @@ -0,0 +1,194 @@ +/* + Copyright (C) 2009 RedHat inc. + + 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. +*/ +#include "fallback.h" +#include <stdlib.h> +#include <stdbool.h> + +/* Too large files are trimmed. */ +#define FILE_SIZE_LIMIT 10000000 /* ~ 10 MB */ + +struct header +{ + struct strbuf *text; + struct header *next; +}; + +static struct header *header_new() +{ + struct header *head = malloc(sizeof(struct header)); + if (!head) + { + puts("Error while allocating memory for backtrace header."); + exit(5); + } + head->text = NULL; + head->next = NULL; + return head; +} + +/* Recursively frees siblings. */ +static void header_free(struct header *head) +{ + strbuf_free(head->text); + if (head->next) + header_free(head->next); + free(head); +} + +/* Inserts new header to array if it is not already there. */ +static void header_set_insert(struct header *cur, struct strbuf *new) +{ + /* Duplicate found case. */ + if (strcmp(cur->text->buf, new->buf) == 0) + return; + + /* Last item case, insert new header here. */ + if (cur->next == NULL) + { + cur->next = header_new(); + cur->next->text = new; + return; + } + + /* Move to next item in array case. */ + header_set_insert(cur->next, new); +} + +struct strbuf *independent_backtrace(FILE *fp) +{ + long pos = ftell(fp); + fseek(fp, 0, SEEK_END); + long size = ftell(fp) - pos; + fseek(fp, pos, SEEK_SET); + + /* Silently handle large files. */ + if (size > FILE_SIZE_LIMIT) + size = FILE_SIZE_LIMIT; + + char *contents = malloc(size); + if (!contents) + { + puts("Error while allocating memory for independent backtrace."); + exit(5); + } + + if (fread(contents, size, 1, fp) != 1) + { + puts("Error while reading input file."); + exit(6); + } + + struct strbuf *header = strbuf_new(); + bool in_bracket = false; + bool in_quote = false; + bool in_header = false; + bool in_digit = false; + bool has_at = false; + bool has_filename = false; + bool has_bracket = false; + struct header *headers = NULL; + + const char *bk = contents; + while (*bk) + { + if (bk[0] == '#' + && bk[1] >= '0' && bk[1] <= '7' + && bk[2] == ' ' /* take only #0...#7 (8 last stack frames) */ + && !in_quote) + { + if (in_header && !has_filename) + strbuf_clear(header); + in_header = true; + } + + if (!in_header) + { + ++bk; + continue; + } + + if (isdigit(*bk) && !in_quote && !has_at) + in_digit = true; + else if (bk[0] == '\\' && bk[1] == '\"') + bk++; + else if (*bk == '\"') + in_quote = in_quote == true ? false : true; + else if (*bk == '(' && !in_quote) + { + in_bracket = true; + in_digit = false; + strbuf_append_char(header, '('); + } + else if (*bk == ')' && !in_quote) + { + in_bracket = false; + has_bracket = true; + in_digit = false; + strbuf_append_char(header, '('); + } + else if (*bk == '\n' && has_filename) + { + if (headers == NULL) + { + headers = header_new(); + headers->text = header; + } + else + header_set_insert(headers, header); + + header = strbuf_new(); + in_bracket = false; + in_quote = false; + in_header = false; + in_digit = false; + has_at = false; + has_filename = false; + has_bracket = false; + } + else if (*bk == ',' && !in_quote) + in_digit = false; + else if (isspace(*bk) && !in_quote) + in_digit = false; + else if (bk[0] == 'a' && bk[1] == 't' && has_bracket && !in_quote) + { + has_at = true; + strbuf_append_char(header, 'a'); + } + else if (bk[0] == ':' && has_at && isdigit(bk[1]) && !in_quote) + has_filename = true; + else if (in_header && !in_digit && !in_quote && !in_bracket) + strbuf_append_char(header, *bk); + + bk++; + } + + strbuf_free(header); + free(contents); + + struct strbuf *result = strbuf_new(); + struct header *loop = headers; + while (loop) + { + strbuf_append_str(result, loop->text->buf); + strbuf_append_char(result, '\n'); + loop = loop->next; + } + + header_free(headers); /* recursive */ + return result; +} |