[pango/pango2: 27/301] Drop PangoItem hackery

[Matthias Clasen <matthiasc src gnome org>]

commit c56ea84ff66f42b0fa4353fe2cc850d6678ec8fb
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Feb 8 15:33:52 2022 -0500

    Drop PangoItem hackery
    
    Drop the abi hacks for PangoItem and just
    add the char_offset field. Same for the
    size_font field in PangoAnalysis.

 pango/glyphstring.c        | 18 +++++++-------
 pango/itemize.c            |  4 +--
 pango/pango-item-private.h | 61 ----------------------------------------------
 pango/pango-item.c         | 43 ++++++++++++--------------------
 pango/pango-item.h         |  9 +++----
 pango/pango-layout.c       | 21 +++-------------
 tests/test-itemize.c       |  5 +---
 7 files changed, 35 insertions(+), 126 deletions(-)
---
diff --git a/pango/glyphstring.c b/pango/glyphstring.c
index ea9a63981..20ee58ce3 100644
--- a/pango/glyphstring.c
+++ b/pango/glyphstring.c
@@ -331,17 +331,17 @@ pango_glyph_string_get_width (PangoGlyphString *glyphs)
  */
 void
 pango_glyph_string_get_logical_widths (PangoGlyphString *glyphs,
-                                      const char       *text,
-                                      int               length,
-                                      int               embedding_level,
-                                      int              *logical_widths)
+                                       const char       *text,
+                                       int               length,
+                                       int               embedding_level,
+                                       int              *logical_widths)
 {
   /* Build a PangoGlyphItem and call the other API */
-  PangoItem item = {0, length, pango_utf8_strlen (text, length),
-                   {NULL, NULL, NULL,
-                    embedding_level, PANGO_GRAVITY_AUTO, 0,
-                    PANGO_SCRIPT_UNKNOWN, NULL,
-                    NULL}};
+  PangoItem item = {0, length, pango_utf8_strlen (text, length), 0,
+                    {NULL, NULL,
+                     embedding_level, PANGO_GRAVITY_AUTO, 0,
+                     PANGO_SCRIPT_UNKNOWN, NULL,
+                     NULL}};
   PangoGlyphItem glyph_item = {&item, glyphs};
 
   pango_glyph_item_get_logical_widths (&glyph_item, text, logical_widths);
diff --git a/pango/itemize.c b/pango/itemize.c
index 728ad7d98..2f5376bff 100644
--- a/pango/itemize.c
+++ b/pango/itemize.c
@@ -1373,7 +1373,7 @@ split_item_for_variant (const char   *text,
 
   start = text + item->offset;
   end = start + item->length;
-  offset = ((PangoItemPrivate *)item)->char_offset;
+  offset = item->char_offset;
 
   p = start;
   while (p < end)
@@ -1511,7 +1511,7 @@ reorder_items (PangoContext *context,
   /* Also cmpute the char offset for each item here */
   for (GList *l = items; l; l = l->next)
     {
-      PangoItemPrivate *item = l->data;
+      PangoItem *item = l->data;
       item->char_offset = char_offset;
       char_offset += item->num_chars;
     }
diff --git a/pango/pango-item-private.h b/pango/pango-item-private.h
index 9d2fa8057..dc2509827 100644
--- a/pango/pango-item-private.h
+++ b/pango/pango-item-private.h
@@ -26,67 +26,6 @@
 
 G_BEGIN_DECLS
 
-/**
- * We have to do some extra work for adding the char_offset field
- * to PangoItem to preserve ABI in the face of pango's open-coded
- * structs.
- *
- * Internally, pango uses the PangoItemPrivate type, and we use
- * a bit in the PangoAnalysis flags to indicate whether we are
- * dealing with a PangoItemPrivate struct or not.
- */
-
-#define PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET (1 << 7)
-
-typedef struct _PangoAnalysisPrivate PangoAnalysisPrivate;
-
-struct _PangoAnalysisPrivate
-{
-  gpointer reserved;
-  PangoFont *size_font;
-  PangoFont *font;
-
-  guint8 level;
-  guint8 gravity;
-  guint8 flags;
-
-  guint8 script;
-  PangoLanguage *language;
-
-  GSList *extra_attrs;
-};
-
-typedef struct _PangoItemPrivate PangoItemPrivate;
-
-#if defined(__x86_64__) && !defined(__ILP32__)
-
-struct _PangoItemPrivate
-{
-  int offset;
-  int length;
-  int num_chars;
-  int char_offset;
-  PangoAnalysis analysis;
-};
-
-#else
-
-struct _PangoItemPrivate
-{
-  int offset;
-  int length;
-  int num_chars;
-  PangoAnalysis analysis;
-  int char_offset;
-};
-
-#endif
-
-G_STATIC_ASSERT (offsetof (PangoItem, offset) == offsetof (PangoItemPrivate, offset));
-G_STATIC_ASSERT (offsetof (PangoItem, length) == offsetof (PangoItemPrivate, length));
-G_STATIC_ASSERT (offsetof (PangoItem, num_chars) == offsetof (PangoItemPrivate, num_chars));
-G_STATIC_ASSERT (offsetof (PangoItem, analysis) == offsetof (PangoItemPrivate, analysis));
-
 void               pango_analysis_collect_features    (const PangoAnalysis        *analysis,
                                                        hb_feature_t               *features,
                                                        guint                       length,
diff --git a/pango/pango-item.c b/pango/pango-item.c
index 944bfe2d7..131094e6a 100644
--- a/pango/pango-item.c
+++ b/pango/pango-item.c
@@ -35,9 +35,7 @@
 PangoItem *
 pango_item_new (void)
 {
-  PangoItemPrivate *result = g_slice_new0 (PangoItemPrivate);
-
-  result->analysis.flags |= PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET;
+  PangoItem *result = g_slice_new0 (PangoItem);
 
   return (PangoItem *)result;
 }
@@ -64,12 +62,11 @@ pango_item_copy (PangoItem *item)
   result->offset = item->offset;
   result->length = item->length;
   result->num_chars = item->num_chars;
-  if (item->analysis.flags & PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET)
-    ((PangoItemPrivate *)result)->char_offset = ((PangoItemPrivate *)item)->char_offset;
+  result->char_offset = item->char_offset;
 
   result->analysis = item->analysis;
-  if (result->analysis.lang_engine)
-    g_object_ref (result->analysis.lang_engine);
+  if (result->analysis.size_font)
+    g_object_ref (result->analysis.size_font);
 
   if (result->analysis.font)
     g_object_ref (result->analysis.font);
@@ -105,16 +102,13 @@ pango_item_free (PangoItem *item)
       g_slist_free (item->analysis.extra_attrs);
     }
 
-  if (item->analysis.lang_engine)
-    g_object_unref (item->analysis.lang_engine);
+  if (item->analysis.size_font)
+    g_object_unref (item->analysis.size_font);
 
   if (item->analysis.font)
     g_object_unref (item->analysis.font);
 
-  if (item->analysis.flags & PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET)
-    g_slice_free (PangoItemPrivate, (PangoItemPrivate *)item);
-  else
-    g_slice_free (PangoItem, item);
+  g_slice_free (PangoItem, item);
 }
 
 G_DEFINE_BOXED_TYPE (PangoItem, pango_item,
@@ -164,8 +158,7 @@ pango_item_split (PangoItem *orig,
   orig->offset += split_index;
   orig->length -= split_index;
   orig->num_chars -= split_offset;
-  if (orig->analysis.flags & PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET)
-    ((PangoItemPrivate *)orig)->char_offset += split_offset;
+  orig->char_offset += split_offset;
 
   return new_item;
 }
@@ -190,9 +183,7 @@ pango_item_unsplit (PangoItem *orig,
   orig->offset -= split_index;
   orig->length += split_index;
   orig->num_chars += split_offset;
-
-  if (orig->analysis.flags & PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET)
-    ((PangoItemPrivate *)orig)->char_offset -= split_offset;
+  orig->char_offset -= split_offset;
 }
 
 static int
@@ -346,13 +337,11 @@ void
 pango_analysis_set_size_font (PangoAnalysis *analysis,
                               PangoFont     *font)
 {
-  PangoAnalysisPrivate *priv = (PangoAnalysisPrivate *)analysis;
-
-  if (priv->size_font)
-    g_object_unref (priv->size_font);
-  priv->size_font = font;
-  if (priv->size_font)
-    g_object_ref (priv->size_font);
+  if (analysis->size_font)
+    g_object_unref (analysis->size_font);
+  analysis->size_font = font;
+  if (analysis->size_font)
+    g_object_ref (analysis->size_font);
 }
 
 /*< private >
@@ -368,7 +357,5 @@ pango_analysis_set_size_font (PangoAnalysis *analysis,
 PangoFont *
 pango_analysis_get_size_font (const PangoAnalysis *analysis)
 {
-  PangoAnalysisPrivate *priv = (PangoAnalysisPrivate *)analysis;
-
-  return priv->size_font;
+  return analysis->size_font;
 }
diff --git a/pango/pango-item.h b/pango/pango-item.h
index a23af6659..a67434ade 100644
--- a/pango/pango-item.h
+++ b/pango/pango-item.h
@@ -61,9 +61,8 @@ typedef struct _PangoItem PangoItem;
 
 /**
  * PangoAnalysis:
- * @shape_engine: unused, reserved
- * @lang_engine: unused, reserved
- * @font: the font for this segment.
+ * @size_font: font to use for determining line height
+ * @font: the font for this segment
  * @level: the bidirectional level for this segment.
  * @gravity: the glyph orientation for this segment (A `PangoGravity`).
  * @flags: boolean flags for this segment (Since: 1.16).
@@ -76,8 +75,7 @@ typedef struct _PangoItem PangoItem;
  */
 struct _PangoAnalysis
 {
-  gpointer shape_engine;
-  gpointer lang_engine;
+  PangoFont *size_font;
   PangoFont *font;
 
   guint8 level;
@@ -108,6 +106,7 @@ struct _PangoItem
   int offset;
   int length;
   int num_chars;
+  int char_offset;
   PangoAnalysis analysis;
 };
 
diff --git a/pango/pango-layout.c b/pango/pango-layout.c
index e6be71435..664223976 100644
--- a/pango/pango-layout.c
+++ b/pango/pango-layout.c
@@ -1822,8 +1822,7 @@ pango_layout_line_index_to_x (PangoLayoutLine *line,
           /* Note: we simply assert here, since our items are all internally
            * created. If that ever changes, we need to add a fallback here.
            */
-          g_assert (run->item->analysis.flags & PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET);
-          attr_offset = ((PangoItemPrivate *)run->item)->char_offset;
+          attr_offset = run->item->char_offset;
 
           pango_glyph_string_index_to_x_full (run->glyphs,
                                               layout->text + run->item->offset,
@@ -5426,11 +5425,7 @@ pango_layout_line_get_x_ranges (PangoLayoutLine  *line,
 
               run_end_index = g_utf8_prev_char (line->layout->text + run_end_index) - line->layout->text;
 
-              /* Note: we simply assert here, since our items are all internally
-               * created. If that ever changes, we need to add a fallback here.
-               */
-              g_assert (run->item->analysis.flags & PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET);
-              attr_offset = ((PangoItemPrivate *)run->item)->char_offset;
+              attr_offset = run->item->char_offset;
 
               pango_glyph_string_index_to_x_full (run->glyphs,
                                                   line->layout->text + run->item->offset,
@@ -6373,11 +6368,7 @@ justify_clusters (PangoLayoutLine *line,
 
           dir = run->item->analysis.level % 2 == 0 ? +1 : -1;
 
-          /* Note: we simply assert here, since our items are all internally
-           * created. If that ever changes, we need to add a fallback here.
-           */
-          g_assert (run->item->analysis.flags & PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET);
-          offset = ((PangoItemPrivate *)run->item)->char_offset;
+          offset = run->item->char_offset;
 
           for (have_cluster = dir > 0 ?
                  pango_glyph_item_iter_init_start (&cluster_iter, run, text) :
@@ -6511,11 +6502,7 @@ justify_words (PangoLayoutLine *line,
           gboolean have_cluster;
           int offset;
 
-          /* Note: we simply assert here, since our items are all internally
-           * created. If that ever changes, we need to add a fallback here.
-           */
-          g_assert (run->item->analysis.flags & PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET);
-          offset = ((PangoItemPrivate *)run->item)->char_offset;
+          offset = run->item->char_offset;
 
           for (have_cluster = pango_glyph_item_iter_init_start (&cluster_iter, run, text);
                have_cluster;
diff --git a/tests/test-itemize.c b/tests/test-itemize.c
index e5775985c..a12bddd7f 100644
--- a/tests/test-itemize.c
+++ b/tests/test-itemize.c
@@ -112,10 +112,7 @@ apply_attributes_to_items (GList         *items,
 static int
 get_item_char_offset (PangoItem *item)
 {
-  if (item->analysis.flags & PANGO_ANALYSIS_FLAG_HAS_CHAR_OFFSET)
-    return ((PangoItemPrivate *)item)->char_offset;
-
-  return -1;
+  return item->char_offset;
 }
 
 static void