Add new `swap` macro and use it

A `swap` macro prevents programming errors and is more concise.
It is a natural addition to our existing `min` and `max` macros.

* src/lisp.h (swap): New macro.
* lwlib/xlwmenu.c (draw_shadow_rectangle, draw_shadow_rhombus):
* src/androidterm.c (android_get_surrounding_text):
* src/buffer.c (Fmake_overlay, modify_overlay, Fmove_overlay):
* src/dispnew.c (swap_glyphs_in_rows, reverse_rows):
* src/editfns.c (Finsert_buffer_substring)
(Fcompare_buffer_substrings):
* src/eval.c (run_hook_wrapped_funcall):
* src/fns.c (extract_data_from_object):
* src/regex-emacs.c (forall_firstchar_1):
* src/textconv.c (textconv_query, get_extracted_text)
(get_surrounding_text):
* src/textprop.c (validate_interval_range)
(verify_interval_modification):
* src/w32uniscribe.c (OTF_INT16_VAL):
* src/xfaces.c (load_face_colors):
* src/xterm.c (SWAPCARD32): Prefer using above macro to open-coding.

1 files changed, 3 insertions, 17 deletions

diff --git a/src/dispnew.c b/src/dispnew.c
index d0f259eef6c..78ec3537a35 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -649,14 +649,7 @@ reverse_rows (struct glyph_matrix *matrix, int start, int end)
   int i, j;
 
   for (i = start, j = end - 1; i < j; ++i, --j)
-    {
-      /* Non-ISO HP/UX compiler doesn't like auto struct
-	 initialization.  */
-      struct glyph_row temp;
-      temp = matrix->rows[i];
-      matrix->rows[i] = matrix->rows[j];
-      matrix->rows[j] = temp;
-    }
+    swap (matrix->rows[i], matrix->rows[j]);
 }
 
 
@@ -966,9 +959,7 @@ increment_row_positions (struct glyph_row *row,
 static void
 swap_glyphs_in_rows (struct glyph_row *a, struct glyph_row *b)
 {
-  int area;
-
-  for (area = 0; area < LAST_AREA; ++area)
+  for (int area = 0; area < LAST_AREA; ++area)
     {
       /* Number of glyphs to swap.  */
       int max_used = max (a->used[area], b->used[area]);
@@ -984,12 +975,7 @@ swap_glyphs_in_rows (struct glyph_row *a, struct glyph_row *b)
 
       while (glyph_a < glyph_a_end)
 	{
-	  /* Non-ISO HP/UX compiler doesn't like auto struct
-             initialization.  */
-	  struct glyph temp;
-	  temp = *glyph_a;
-	  *glyph_a = *glyph_b;
-	  *glyph_b = temp;
+	  swap (*glyph_a, *glyph_b);
 	  ++glyph_a;
 	  ++glyph_b;
 	}