gtk2/gtk/gtktextsegment.c
Matthias Clasen b4e110920a Merge branch 'wip/kalev/gcc-11' into 'master'
Avoid diagnostics for gcc-11 false positive out of bounds accesses

See merge request GNOME/gtk!3064

(cherry picked from commit 5044031b53)

c514c41d Avoid diagnostics for gcc-11 false positive out of bounds accesses
2021-08-22 19:03:23 +00:00

670 lines
19 KiB
C
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* gtktextsegment.c --
*
* Code for segments in general, and toggle/char segments in particular.
*
* Copyright (c) 1992-1994 The Regents of the University of California.
* Copyright (c) 1994-1995 Sun Microsystems, Inc.
* Copyright (c) 2000 Red Hat, Inc.
* Tk -> Gtk port by Havoc Pennington <hp@redhat.com>
*
* This software is copyrighted by the Regents of the University of
* California, Sun Microsystems, Inc., and other parties. The
* following terms apply to all files associated with the software
* unless explicitly disclaimed in individual files.
*
* The authors hereby grant permission to use, copy, modify,
* distribute, and license this software and its documentation for any
* purpose, provided that existing copyright notices are retained in
* all copies and that this notice is included verbatim in any
* distributions. No written agreement, license, or royalty fee is
* required for any of the authorized uses. Modifications to this
* software may be copyrighted by their authors and need not follow
* the licensing terms described here, provided that the new terms are
* clearly indicated on the first page of each file where they apply.
*
* IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY
* PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL
* DAMAGES ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION,
* OR ANY DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND
* NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS,
* AND THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
* MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* GOVERNMENT USE: If you are acquiring this software on behalf of the
* U.S. government, the Government shall have only "Restricted Rights"
* in the software and related documentation as defined in the Federal
* Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2). If you
* are acquiring the software on behalf of the Department of Defense,
* the software shall be classified as "Commercial Computer Software"
* and the Government shall have only "Restricted Rights" as defined
* in Clause 252.227-7013 (c) (1) of DFARs. Notwithstanding the
* foregoing, the authors grant the U.S. Government and others acting
* in its behalf permission to use and distribute the software in
* accordance with the terms specified in this license.
*
*/
#define GTK_TEXT_USE_INTERNAL_UNSUPPORTED_API
#include "config.h"
#include "gtktextbtree.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "gtktexttag.h"
#include "gtktexttagtable.h"
#include "gtktextlayout.h"
#include "gtktextiterprivate.h"
#include "gtkdebug.h"
/*
*--------------------------------------------------------------
*
* split_segment --
*
* This procedure is called before adding or deleting
* segments. It does three things: (a) it finds the segment
* containing iter; (b) if there are several such
* segments (because some segments have zero length) then
* it picks the first segment that does not have left
* gravity; (c) if the index refers to the middle of
* a segment then it splits the segment so that the
* index now refers to the beginning of a segment.
*
* Results:
* The return value is a pointer to the segment just
* before the segment corresponding to iter (as
* described above). If the segment corresponding to
* iter is the first in its line then the return
* value is NULL.
*
* Side effects:
* The segment referred to by iter is split unless
* iter refers to its first character.
*
*--------------------------------------------------------------
*/
GtkTextLineSegment*
gtk_text_line_segment_split (const GtkTextIter *iter)
{
GtkTextLineSegment *prev, *seg;
GtkTextBTree *tree;
GtkTextLine *line;
int count;
line = _gtk_text_iter_get_text_line (iter);
tree = _gtk_text_iter_get_btree (iter);
count = gtk_text_iter_get_line_index (iter);
if (GTK_DEBUG_CHECK (TEXT))
_gtk_text_iter_check (iter);
prev = NULL;
seg = line->segments;
while (seg != NULL)
{
if (seg->byte_count > count)
{
if (count == 0)
{
return prev;
}
else
{
g_assert (count != seg->byte_count);
g_assert (seg->byte_count > 0);
_gtk_text_btree_segments_changed (tree);
seg = (*seg->type->splitFunc)(seg, count);
if (prev == NULL)
line->segments = seg;
else
prev->next = seg;
return seg;
}
}
else if ((seg->byte_count == 0) && (count == 0)
&& !seg->type->leftGravity)
{
return prev;
}
count -= seg->byte_count;
prev = seg;
seg = seg->next;
}
g_error ("split_segment reached end of line!");
return NULL;
}
/*
* Macros that determine how much space to allocate for new segments:
*/
#define CSEG_SIZE(chars) ((unsigned) (G_STRUCT_OFFSET (GtkTextLineSegment, body) \
+ 1 + (chars)))
#define TSEG_SIZE ((unsigned) (G_STRUCT_OFFSET (GtkTextLineSegment, body) \
+ sizeof (GtkTextToggleBody)))
/*
* Type functions
*/
static void
char_segment_self_check (GtkTextLineSegment *seg)
{
/* This function checks the segment itself, but doesn't
assume the segment has been validly inserted into
the btree. */
g_assert (seg != NULL);
if (seg->byte_count <= 0)
{
g_error ("segment has size <= 0");
}
if (strlen (seg->body.chars) != seg->byte_count)
{
g_error ("segment has wrong size");
}
if (g_utf8_strlen (seg->body.chars, seg->byte_count) != seg->char_count)
{
g_error ("char segment has wrong character count");
}
}
GtkTextLineSegment*
_gtk_char_segment_new (const gchar *text, guint len)
{
GtkTextLineSegment *seg;
g_assert (gtk_text_byte_begins_utf8_char (text));
seg = g_slice_alloc (CSEG_SIZE (len));
seg->type = (GtkTextLineSegmentClass *)&gtk_text_char_type;
seg->next = NULL;
seg->byte_count = len;
memcpy (seg->body.chars, text, len);
seg->body.chars[len] = '\0';
seg->char_count = g_utf8_strlen (seg->body.chars, seg->byte_count);
if (GTK_DEBUG_CHECK (TEXT))
char_segment_self_check (seg);
return seg;
}
GtkTextLineSegment*
_gtk_char_segment_new_from_two_strings (const gchar *text1,
guint len1,
guint chars1,
const gchar *text2,
guint len2,
guint chars2)
{
GtkTextLineSegment *seg;
g_assert (gtk_text_byte_begins_utf8_char (text1));
g_assert (gtk_text_byte_begins_utf8_char (text2));
seg = g_slice_alloc (CSEG_SIZE (len1+len2));
seg->type = &gtk_text_char_type;
seg->next = NULL;
seg->byte_count = len1 + len2;
memcpy (seg->body.chars, text1, len1);
memcpy (seg->body.chars + len1, text2, len2);
seg->body.chars[len1+len2] = '\0';
seg->char_count = chars1 + chars2;
if (GTK_DEBUG_CHECK (TEXT))
char_segment_self_check (seg);
return seg;
}
static void
_gtk_char_segment_free (GtkTextLineSegment *seg)
{
if (seg == NULL)
return;
g_assert (seg->type == &gtk_text_char_type);
g_slice_free1 (CSEG_SIZE (seg->byte_count), seg);
}
/*
*--------------------------------------------------------------
*
* char_segment_split_func --
*
* This procedure implements splitting for character segments.
*
* Results:
* The return value is a pointer to a chain of two segments
* that have the same characters as segPtr except split
* among the two segments.
*
* Side effects:
* Storage for segPtr is freed.
*
*--------------------------------------------------------------
*/
static GtkTextLineSegment *
char_segment_split_func (GtkTextLineSegment *seg, int index)
{
GtkTextLineSegment *new1, *new2;
g_assert (index < seg->byte_count);
if (GTK_DEBUG_CHECK (TEXT))
{
char_segment_self_check (seg);
}
new1 = _gtk_char_segment_new (seg->body.chars, index);
new2 = _gtk_char_segment_new (seg->body.chars + index, seg->byte_count - index);
g_assert (gtk_text_byte_begins_utf8_char (new1->body.chars));
g_assert (gtk_text_byte_begins_utf8_char (new2->body.chars));
g_assert (new1->byte_count + new2->byte_count == seg->byte_count);
g_assert (new1->char_count + new2->char_count == seg->char_count);
new1->next = new2;
new2->next = seg->next;
if (GTK_DEBUG_CHECK (TEXT))
{
char_segment_self_check (new1);
char_segment_self_check (new2);
}
_gtk_char_segment_free (seg);
return new1;
}
/*
*--------------------------------------------------------------
*
* char_segment_cleanup_func --
*
* This procedure merges adjacent character segments into
* a single character segment, if possible.
*
* Arguments:
* segPtr: Pointer to the first of two adjacent segments to
* join.
* line: Line containing segments (not used).
*
* Results:
* The return value is a pointer to the first segment in
* the (new) list of segments that used to start with segPtr.
*
* Side effects:
* Storage for the segments may be allocated and freed.
*
*--------------------------------------------------------------
*/
/* ARGSUSED */
static GtkTextLineSegment *
char_segment_cleanup_func (GtkTextLineSegment *segPtr, GtkTextLine *line)
{
GtkTextLineSegment *segPtr2, *newPtr;
if (GTK_DEBUG_CHECK (TEXT))
char_segment_self_check (segPtr);
segPtr2 = segPtr->next;
if ((segPtr2 == NULL) || (segPtr2->type != &gtk_text_char_type))
{
return segPtr;
}
newPtr =
_gtk_char_segment_new_from_two_strings (segPtr->body.chars,
segPtr->byte_count,
segPtr->char_count,
segPtr2->body.chars,
segPtr2->byte_count,
segPtr2->char_count);
newPtr->next = segPtr2->next;
if (GTK_DEBUG_CHECK (TEXT))
char_segment_self_check (newPtr);
_gtk_char_segment_free (segPtr);
_gtk_char_segment_free (segPtr2);
return newPtr;
}
/*
*--------------------------------------------------------------
*
* char_segment_delete_func --
*
* This procedure is invoked to delete a character segment.
*
* Arguments:
* segPtr : Segment to delete
* line : Line containing segment
* treeGone : Non-zero means the entire tree is being
* deleted, so everything must get cleaned up.
*
* Results:
* Always returns 0 to indicate that the segment was deleted.
*
* Side effects:
* Storage for the segment is freed.
*
*--------------------------------------------------------------
*/
/* ARGSUSED */
static int
char_segment_delete_func (GtkTextLineSegment *segPtr, GtkTextLine *line, int treeGone)
{
_gtk_char_segment_free (segPtr);
return 0;
}
/*
*--------------------------------------------------------------
*
* char_segment_check_func --
*
* This procedure is invoked to perform consistency checks
* on character segments.
*
* Arguments:
* segPtr : Segment to check
* line : Line containing segment
*
* Results:
* None.
*
* Side effects:
* If the segment isnt inconsistent then the procedure
* g_errors.
*
*--------------------------------------------------------------
*/
/* ARGSUSED */
static void
char_segment_check_func (GtkTextLineSegment *segPtr, GtkTextLine *line)
{
char_segment_self_check (segPtr);
if (segPtr->next != NULL)
{
if (segPtr->next->type == &gtk_text_char_type)
{
g_error ("adjacent character segments weren't merged");
}
}
}
GtkTextLineSegment*
_gtk_toggle_segment_new (GtkTextTagInfo *info, gboolean on)
{
/* gcc-11 issues a diagnostic here because the size allocated
for SEG does not cover the entire size of a GtkTextLineSegment
and gcc has no way to know that the union will only be used
for limited types and the additional space is not needed. */
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Warray-bounds"
GtkTextLineSegment *seg;
seg = g_slice_alloc (TSEG_SIZE);
seg->type = on ? &gtk_text_toggle_on_type : &gtk_text_toggle_off_type;
seg->next = NULL;
seg->byte_count = 0;
seg->char_count = 0;
seg->body.toggle.info = info;
seg->body.toggle.inNodeCounts = 0;
return seg;
#pragma GCC diagnostic pop
}
void
_gtk_toggle_segment_free (GtkTextLineSegment *seg)
{
if (seg == NULL)
return;
g_assert (seg->type == &gtk_text_toggle_on_type ||
seg->type == &gtk_text_toggle_off_type);
g_slice_free1 (TSEG_SIZE, seg);
}
/*
*--------------------------------------------------------------
*
* toggle_segment_delete_func --
*
* This procedure is invoked to delete toggle segments.
*
* Arguments:
* segPtr : Segment to check
* line : Line containing segment
* treeGone : Non-zero means the entire tree is being
* deleted so everything must get cleaned up
*
* Results:
* Returns 1 to indicate that the segment may not be deleted,
* unless the entire B-tree is going away.
*
* Side effects:
* If the tree is going away then the toggles memory is
* freed; otherwise the toggle counts in GtkTextBTreeNodes above the
* segment get updated.
*
*--------------------------------------------------------------
*/
static int
toggle_segment_delete_func (GtkTextLineSegment *segPtr, GtkTextLine *line, int treeGone)
{
if (treeGone)
{
_gtk_toggle_segment_free (segPtr);
return 0;
}
/*
* This toggle is in the middle of a range of characters that's
* being deleted. Refuse to die. We'll be moved to the end of
* the deleted range and our cleanup procedure will be called
* later. Decrement GtkTextBTreeNode toggle counts here, and set a flag
* so we'll re-increment them in the cleanup procedure.
*/
if (segPtr->body.toggle.inNodeCounts)
{
_gtk_change_node_toggle_count (line->parent,
segPtr->body.toggle.info, -1);
segPtr->body.toggle.inNodeCounts = 0;
}
return 1;
}
/*
*--------------------------------------------------------------
*
* toggle_segment_cleanup_func --
*
* This procedure is called when a toggle is part of a line that's
* been modified in some way. Its invoked after the
* modifications are complete.
*
* Arguments:
* segPtr : Segment to check
* line : Line that now contains segment
*
* Results:
* The return value is the head segment in a new list
* that is to replace the tail of the line that used to
* start at segPtr. This allows the procedure to delete
* or modify segPtr.
*
* Side effects:
* Toggle counts in the GtkTextBTreeNodes above the new line will be
* updated if theyre not already. Toggles may be collapsed
* if there are duplicate toggles at the same position.
*
*--------------------------------------------------------------
*/
static GtkTextLineSegment *
toggle_segment_cleanup_func (GtkTextLineSegment *segPtr, GtkTextLine *line)
{
GtkTextLineSegment *segPtr2, *prevPtr;
int counts;
/*
* If this is a toggle-off segment, look ahead through the next
* segments to see if there's a toggle-on segment for the same tag
* before any segments with non-zero size. If so then the two
* toggles cancel each other; remove them both.
*/
if (segPtr->type == &gtk_text_toggle_off_type)
{
for (prevPtr = segPtr, segPtr2 = prevPtr->next;
(segPtr2 != NULL) && (segPtr2->byte_count == 0);
prevPtr = segPtr2, segPtr2 = prevPtr->next)
{
if (segPtr2->type != &gtk_text_toggle_on_type)
{
continue;
}
if (segPtr2->body.toggle.info != segPtr->body.toggle.info)
{
continue;
}
counts = segPtr->body.toggle.inNodeCounts
+ segPtr2->body.toggle.inNodeCounts;
if (counts != 0)
{
_gtk_change_node_toggle_count (line->parent,
segPtr->body.toggle.info, -counts);
}
prevPtr->next = segPtr2->next;
_gtk_toggle_segment_free (segPtr2);
segPtr2 = segPtr->next;
_gtk_toggle_segment_free (segPtr);
return segPtr2;
}
}
if (!segPtr->body.toggle.inNodeCounts)
{
_gtk_change_node_toggle_count (line->parent,
segPtr->body.toggle.info, 1);
segPtr->body.toggle.inNodeCounts = 1;
}
return segPtr;
}
/*
*--------------------------------------------------------------
*
* toggle_segment_line_change_func --
*
* This procedure is invoked when a toggle segment is about
* to move from one line to another.
*
* Arguments:
* segPtr : Segment to check
* line : Line that used to contain segment
*
* Results:
* None.
*
* Side effects:
* Toggle counts are decremented in the GtkTextBTreeNodes above the line.
*
*--------------------------------------------------------------
*/
static void
toggle_segment_line_change_func (GtkTextLineSegment *segPtr, GtkTextLine *line)
{
if (segPtr->body.toggle.inNodeCounts)
{
_gtk_change_node_toggle_count (line->parent,
segPtr->body.toggle.info, -1);
segPtr->body.toggle.inNodeCounts = 0;
}
}
/*
* Virtual tables
*/
const GtkTextLineSegmentClass gtk_text_char_type = {
"character", /* name */
0, /* leftGravity */
char_segment_split_func, /* splitFunc */
char_segment_delete_func, /* deleteFunc */
char_segment_cleanup_func, /* cleanupFunc */
NULL, /* lineChangeFunc */
char_segment_check_func /* checkFunc */
};
/*
* Type record for segments marking the beginning of a tagged
* range:
*/
const GtkTextLineSegmentClass gtk_text_toggle_on_type = {
"toggleOn", /* name */
0, /* leftGravity */
NULL, /* splitFunc */
toggle_segment_delete_func, /* deleteFunc */
toggle_segment_cleanup_func, /* cleanupFunc */
toggle_segment_line_change_func, /* lineChangeFunc */
_gtk_toggle_segment_check_func /* checkFunc */
};
/*
* Type record for segments marking the end of a tagged
* range:
*/
const GtkTextLineSegmentClass gtk_text_toggle_off_type = {
"toggleOff", /* name */
1, /* leftGravity */
NULL, /* splitFunc */
toggle_segment_delete_func, /* deleteFunc */
toggle_segment_cleanup_func, /* cleanupFunc */
toggle_segment_line_change_func, /* lineChangeFunc */
_gtk_toggle_segment_check_func /* checkFunc */
};