diff options
Diffstat (limited to 'libcpp/files.cc')
| -rw-r--r-- | libcpp/files.cc | 95 |
1 files changed, 82 insertions, 13 deletions
diff --git a/libcpp/files.cc b/libcpp/files.cc index 52b1850..9d64bff 100644 --- a/libcpp/files.cc +++ b/libcpp/files.cc @@ -90,6 +90,9 @@ struct _cpp_file /* Size for #embed, perhaps smaller than st.st_size. */ size_t limit; + /* Offset for #embed. */ + off_t offset; + /* File descriptor. Invalid if -1, otherwise open. */ int fd; @@ -1242,8 +1245,11 @@ _cpp_stack_embed (cpp_reader *pfile, const char *fname, bool angle, _cpp_file *orig_file = file; if (file->buffer_valid && (!S_ISREG (file->st.st_mode) - || (file->limit < file->st.st_size + (size_t) 0 - && file->limit < params->limit))) + || file->offset + (cpp_num_part) 0 > params->offset + || (file->limit < file->st.st_size - file->offset + (size_t) 0 + && (params->offset - file->offset > (cpp_num_part) file->limit + || file->limit - (params->offset + - file->offset) < params->limit)))) { bool found = false; if (S_ISREG (file->st.st_mode)) @@ -1256,8 +1262,13 @@ _cpp_stack_embed (cpp_reader *pfile, const char *fname, bool angle, && strcmp (file->path, file->next_file->path) == 0) { file = file->next_file; - if (file->limit >= file->st.st_size + (size_t) 0 - || file->limit >= params->limit) + if (file->offset + (cpp_num_part) 0 <= params->offset + && (file->limit >= (file->st.st_size - file->offset + + (size_t) 0) + || (params->offset + - file->offset <= (cpp_num_part) file->limit + && file->limit - (params->offset + - file->offset) >= params->limit))) { found = true; break; @@ -1313,8 +1324,10 @@ _cpp_stack_embed (cpp_reader *pfile, const char *fname, bool angle, if (regular) { cpp_num_part limit; - if (file->st.st_size + (cpp_num_part) 0 < params->limit) - limit = file->st.st_size; + if (file->st.st_size + (cpp_num_part) 0 < params->offset) + limit = 0; + else if (file->st.st_size - params->offset < params->limit) + limit = file->st.st_size - params->offset; else limit = params->limit; if (params->has_embed) @@ -1325,6 +1338,14 @@ _cpp_stack_embed (cpp_reader *pfile, const char *fname, bool angle, "%s is too large", file->path); goto fail; } + if (lseek (file->fd, params->offset, SEEK_CUR) + != (off_t) params->offset) + { + cpp_errno_filename (pfile, CPP_DL_ERROR, file->path, + params->loc); + goto fail; + } + file->offset = params->offset; file->limit = limit; size = limit; } @@ -1337,6 +1358,38 @@ _cpp_stack_embed (cpp_reader *pfile, const char *fname, bool angle, buf = XNEWVEC (uchar, size ? size : 1); total = 0; + if (!regular && params->offset) + { + uchar *buf2 = buf; + ssize_t size2 = size; + cpp_num_part total2 = params->offset; + + if (params->offset > 8 * 1024 && size < 8 * 1024) + { + size2 = 32 * 1024; + buf2 = XNEWVEC (uchar, size2); + } + do + { + if ((cpp_num_part) size2 > total2) + size2 = total2; + count = read (file->fd, buf2, size2); + if (count < 0) + { + cpp_errno_filename (pfile, CPP_DL_ERROR, file->path, + params->loc); + if (buf2 != buf) + free (buf2); + free (buf); + goto fail; + } + total2 -= count; + } + while (total2); + if (buf2 != buf) + free (buf2); + } + while ((count = read (file->fd, buf + total, size - total)) > 0) { total += count; @@ -1377,7 +1430,10 @@ _cpp_stack_embed (cpp_reader *pfile, const char *fname, bool angle, file->limit = total; } else if (!regular) - file->limit = total; + { + file->offset = params->offset; + file->limit = total; + } file->buffer_start = buf; file->buffer = buf; @@ -1386,9 +1442,22 @@ _cpp_stack_embed (cpp_reader *pfile, const char *fname, bool angle, file->fd = -1; } else if (params->has_embed) - return file->limit && params->limit ? 1 : 2; + { + if (params->offset - file->offset > file->limit) + return 2; + size_t limit = file->limit - (params->offset - file->offset); + return limit && params->limit ? 1 : 2; + } + const uchar *buffer = file->buffer; size_t limit = file->limit; + if (params->offset - file->offset > limit) + limit = 0; + else + { + buffer += params->offset - file->offset; + limit -= params->offset - file->offset; + } if (params->limit < limit) limit = params->limit; @@ -1412,20 +1481,20 @@ _cpp_stack_embed (cpp_reader *pfile, const char *fname, bool angle, size_t len = 0; for (size_t i = 0; i < limit; ++i) { - if (file->buffer[i] < 10) + if (buffer[i] < 10) len += 2; - else if (file->buffer[i] < 100) + else if (buffer[i] < 100) len += 3; #if UCHAR_MAX == 255 else len += 4; #else - else if (file->buffer[i] < 1000) + else if (buffer[i] < 1000) len += 4; else { char buf[64]; - len += sprintf (buf, "%d", file->buffer[i]) + 1; + len += sprintf (buf, "%d", buffer[i]) + 1; } #endif if (len > INTTYPE_MAXIMUM (ssize_t)) @@ -1479,7 +1548,7 @@ _cpp_stack_embed (cpp_reader *pfile, const char *fname, bool angle, if (i == 0) tok->flags |= PREV_WHITE; tok->val.str.text = s; - tok->val.str.len = sprintf ((char *) s, "%d", file->buffer[i]); + tok->val.str.len = sprintf ((char *) s, "%d", buffer[i]); s += tok->val.str.len + 1; if (tok == &pfile->directive_result) tok = toks; |