diff options
Diffstat (limited to 'libio/genops.c')
| -rw-r--r-- | libio/genops.c | 94 |
1 files changed, 49 insertions, 45 deletions
diff --git a/libio/genops.c b/libio/genops.c index b1ccb289b3..6f560dec53 100644 --- a/libio/genops.c +++ b/libio/genops.c @@ -64,13 +64,14 @@ _IO_link_in (fp) /* Return minimum _pos markers Assumes the current get area is the main get area. */ -static _IO_size_t _IO_least_marker __P ((_IO_FILE *fp)); +static _IO_ssize_t _IO_least_marker __P ((_IO_FILE *fp, char *end_p)); -static _IO_size_t -_IO_least_marker (fp) +static _IO_ssize_t +_IO_least_marker (fp, end_p) _IO_FILE *fp; + char *end_p; { - _IO_ssize_t least_so_far = fp->_IO_read_end - fp->_IO_read_base; + _IO_ssize_t least_so_far = end_p - fp->_IO_read_base; struct _IO_marker *mark; for (mark = fp->_markers; mark != NULL; mark = mark->_next) if (mark->_pos < least_so_far) @@ -94,10 +95,8 @@ _IO_switch_to_main_get_area (fp) tmp = fp->_IO_read_base; fp->_IO_read_base = fp->_IO_save_base; fp->_IO_save_base = tmp; - /* Swap _IO_read_ptr and _IO_save_ptr. */ - tmp = fp->_IO_read_ptr; - fp->_IO_read_ptr = fp->_IO_save_ptr; - fp->_IO_save_ptr = tmp; + /* Set _IO_read_ptr. */ + fp->_IO_read_ptr = fp->_IO_read_base; } /* Switch current get area from main get area to (end of) backup area. */ @@ -112,12 +111,11 @@ _IO_switch_to_backup_area (fp) tmp = fp->_IO_read_end; fp->_IO_read_end = fp->_IO_save_end; fp->_IO_save_end = tmp; - /* Swap _gbase and _IO_save_base. */ + /* Swap _IO_read_base and _IO_save_base. */ tmp = fp->_IO_read_base; fp->_IO_read_base = fp->_IO_save_base; fp->_IO_save_base = tmp; - /* read _IO_read_ptr. */ - fp->_IO_save_ptr = fp->_IO_read_ptr; + /* Set _IO_read_ptr. */ fp->_IO_read_ptr = fp->_IO_read_end; } @@ -183,26 +181,28 @@ __overflow (f, ch) return _IO_OVERFLOW (f, ch); } -static int save_for_backup __P ((_IO_FILE *fp)) +static int save_for_backup __P ((_IO_FILE *fp, char *end_p)) #ifdef _LIBC internal_function #endif ; - static int +static int #ifdef _LIBC - internal_function +internal_function #endif -save_for_backup (fp) +save_for_backup (fp, end_p) _IO_FILE *fp; + char *end_p; { - /* Append [_IO_read_base.._IO_read_end] to backup area. */ - int least_mark = _IO_least_marker (fp); + /* Append [_IO_read_base..end_p] to backup area. */ + _IO_ssize_t least_mark = _IO_least_marker (fp, end_p); /* needed_size is how much space we need in the backup area. */ - int needed_size = (fp->_IO_read_end - fp->_IO_read_base) - least_mark; - int current_Bsize = fp->_IO_save_end - fp->_IO_save_base; - int avail; /* Extra space available for future expansion. */ - int delta; + _IO_size_t needed_size = (end_p - fp->_IO_read_base) - least_mark; + /* FIXME: Dubious arithmetic if pointers are NULL */ + _IO_size_t current_Bsize = fp->_IO_save_end - fp->_IO_save_base; + _IO_size_t avail; /* Extra space available for future expansion. */ + _IO_ssize_t delta; struct _IO_marker *mark; if (needed_size > current_Bsize) { @@ -218,14 +218,14 @@ save_for_backup (fp) fp->_IO_save_end + least_mark, -least_mark), fp->_IO_read_base, - fp->_IO_read_end - fp->_IO_read_base); + end_p - fp->_IO_read_base); #else memcpy (new_buffer + avail, fp->_IO_save_end + least_mark, -least_mark); memcpy (new_buffer + avail - least_mark, fp->_IO_read_base, - fp->_IO_read_end - fp->_IO_read_base); + end_p - fp->_IO_read_base); #endif } else @@ -247,17 +247,16 @@ save_for_backup (fp) -least_mark); memcpy (fp->_IO_save_base + avail - least_mark, fp->_IO_read_base, - fp->_IO_read_end - fp->_IO_read_base); + end_p - fp->_IO_read_base); } else if (needed_size > 0) memcpy (fp->_IO_save_base + avail, fp->_IO_read_base + least_mark, needed_size); } - /* FIXME: Dubious arithmetic if pointers are NULL */ fp->_IO_backup_base = fp->_IO_save_base + avail; /* Adjust all the streammarkers. */ - delta = fp->_IO_read_end - fp->_IO_read_base; + delta = end_p - fp->_IO_read_base; for (mark = fp->_markers; mark != NULL; mark = mark->_next) mark->_pos -= delta; return 0; @@ -280,7 +279,7 @@ __underflow (fp) } if (_IO_have_markers (fp)) { - if (save_for_backup (fp)) + if (save_for_backup (fp, fp->_IO_read_end)) return EOF; } else if (_IO_have_backup (fp)) @@ -305,7 +304,7 @@ __uflow (fp) } if (_IO_have_markers (fp)) { - if (save_for_backup (fp)) + if (save_for_backup (fp, fp->_IO_read_end)) return EOF; } else if (_IO_have_backup (fp)) @@ -817,10 +816,7 @@ _IO_seekmark (fp, mark, delta) else { if (!_IO_in_backup (fp)) - { - fp->_IO_read_ptr = fp->_IO_read_base; - _IO_switch_to_backup_area (fp); - } + _IO_switch_to_backup_area (fp); fp->_IO_read_ptr = fp->_IO_read_end + mark->_pos; } return 0; @@ -880,20 +876,28 @@ _IO_default_pbackfail (fp, c) else { /* Need to handle a filebuf in write mode (switch to read mode). FIXME!*/ - if (_IO_have_backup (fp) && !_IO_in_backup (fp)) - _IO_switch_to_backup_area (fp); - - if (!_IO_have_backup (fp)) + if (!_IO_in_backup (fp)) { - /* No backup buffer: allocate one. */ - /* Use nshort buffer, if unused? (probably not) FIXME */ - int backup_size = 128; - char *bbuf = (char *) malloc (backup_size); - if (bbuf == NULL) - return EOF; - fp->_IO_save_base = bbuf; - fp->_IO_save_end = fp->_IO_save_base + backup_size; - fp->_IO_backup_base = fp->_IO_save_end; + /* We need to keep the invariant that the main get area + logically follows the backup area. */ + if (fp->_IO_read_ptr > fp->_IO_read_base && _IO_have_backup (fp)) + { + if (save_for_backup (fp, fp->_IO_read_ptr)) + return EOF; + } + else if (!_IO_have_backup (fp)) + { + /* No backup buffer: allocate one. */ + /* Use nshort buffer, if unused? (probably not) FIXME */ + int backup_size = 128; + char *bbuf = (char *) malloc (backup_size); + if (bbuf == NULL) + return EOF; + fp->_IO_save_base = bbuf; + fp->_IO_save_end = fp->_IO_save_base + backup_size; + fp->_IO_backup_base = fp->_IO_save_end; + } + fp->_IO_read_base = fp->_IO_read_ptr; _IO_switch_to_backup_area (fp); } else if (fp->_IO_read_ptr <= fp->_IO_read_base) |