diff.c: change return type to bool

Co-authored-by: Wayne Rowcliffe (@war1025)

src/nvim/diff.c

@@ -1531,37 +1531,37 @@ int diff_check(win_T *wp, linenr_T lnum)
   return maxcount - dp->df_count[idx];
 }
 
-/// Compare two entries in diff "*dp" and return TRUE if they are equal.
+/// Compare two entries in diff "dp" and return true if they are equal.
 ///
-/// @param dp
+/// @param  dp    diff
-/// @param idx1 First entry in diff "*dp"
+/// @param  idx1  first entry in diff "dp"
-/// @param idx2 Second entry in diff "*dp"
+/// @param  idx2  second entry in diff "dp"
 ///
-/// @return return TRUE if two entires are equal.
+/// @return true if two entires are equal.
-static int diff_equal_entry(diff_T *dp, int idx1, int idx2)
+static bool diff_equal_entry(diff_T *dp, int idx1, int idx2)
+  FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ARG(1)
 {
   if (dp->df_count[idx1] != dp->df_count[idx2]) {
-    return FALSE;
+    return false;
   }
 
   if (diff_check_sanity(curtab, dp) == FAIL) {
-    return FALSE;
+    return false;
   }
 
-  int i;
+  for (int i = 0; i < dp->df_count[idx1]; i++) {
-  for (i = 0; i < dp->df_count[idx1]; ++i) {
     char_u *line = vim_strsave(ml_get_buf(curtab->tp_diffbuf[idx1],
-                                          dp->df_lnum[idx1] + i, FALSE));
+                                          dp->df_lnum[idx1] + i, false));
 
     int cmp = diff_cmp(line, ml_get_buf(curtab->tp_diffbuf[idx2],
-                                        dp->df_lnum[idx2] + i, FALSE));
+                                        dp->df_lnum[idx2] + i, false));
     xfree(line);
 
     if (cmp != 0) {
-      return FALSE;
+      return false;
     }
   }
-  return TRUE;
+  return true;
 }
 
 /// Compare strings "s1" and "s2" according to 'diffopt'.
@@ -1830,28 +1830,30 @@ int diffopt_changed(void)
   return OK;
 }
 
-/// Return TRUE if 'diffopt' contains "horizontal".
+/// Check that "diffopt" contains "horizontal".
-///
+bool diffopt_horizontal(void)
-/// @return TRUE if 'diffopt' contains "horizontal"
+  FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT
-int diffopt_horizontal(void)
 {
   return (diff_flags & DIFF_HORIZONTAL) != 0;
 }
 
 /// Find the difference within a changed line.
 ///
-/// @param startp first char of the change
+/// @param  wp      window whose current buffer to check
-/// @param endp last char of the change
+/// @param  lnum    line number to check within the buffer
+/// @param  startp  first char of the change
+/// @param  endp    last char of the change
 ///
-/// @returns TRUE if the line was added, no other buffer has it.
+/// @return true if the line was added, no other buffer has it.
-int diff_find_change(win_T *wp, linenr_T lnum, int *startp, int *endp)
+bool diff_find_change(win_T *wp, linenr_T lnum, int *startp, int *endp)
+  FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ALL
 {
   char_u *line_new;
   int si_org;
   int si_new;
   int ei_org;
   int ei_new;
-  int added = TRUE;
+  bool added = true;
 
   // Make a copy of the line, the next ml_get() will invalidate it.
   char_u *line_org = vim_strsave(ml_get_buf(wp->w_buffer, lnum, FALSE));
@@ -1860,7 +1862,7 @@ int diff_find_change(win_T *wp, linenr_T lnum, int *startp, int *endp)
   if (idx == DB_COUNT) {
     // cannot happen
     xfree(line_org);
-    return FALSE;
+    return false;
   }
 
   // search for a change that includes "lnum" in the list of diffblocks.
@@ -1873,7 +1875,7 @@ int diff_find_change(win_T *wp, linenr_T lnum, int *startp, int *endp)
 
   if ((dp == NULL) || (diff_check_sanity(curtab, dp) == FAIL)) {
     xfree(line_org);
-    return FALSE;
+    return false;
   }
 
   int off = lnum - dp->df_lnum[idx];
@@ -1884,7 +1886,7 @@ int diff_find_change(win_T *wp, linenr_T lnum, int *startp, int *endp)
       if (off >= dp->df_count[i]) {
         continue;
       }
-      added = FALSE;
+      added = false;
       line_new = ml_get_buf(curtab->tp_diffbuf[i],
                             dp->df_lnum[i] + off, FALSE);
 
@@ -1956,21 +1958,22 @@ int diff_find_change(win_T *wp, linenr_T lnum, int *startp, int *endp)
   return added;
 }
 
-/// Return TRUE if line "lnum" is not close to a diff block, this line should
+/// Check that line "lnum" is not close to a diff block, this line should
 /// be in a fold.
 ///
-/// @param wp
+/// @param  wp    window containing the buffer to check
-/// @param lnum
+/// @param  lnum  line number to check within the buffer
 ///
-/// @return FALSE if there are no diff blocks at all in this window.
+/// @return false if there are no diff blocks at all in this window.
-int diff_infold(win_T *wp, linenr_T lnum)
+bool diff_infold(win_T *wp, linenr_T lnum)
+  FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ARG(1)
 {
-  int other = FALSE;
+  bool other = false;
   diff_T *dp;
 
   // Return if 'diff' isn't set.
   if (!wp->w_p_diff) {
-    return FALSE;
+    return false;
   }
 
   int idx = -1;
@@ -1979,13 +1982,13 @@ int diff_infold(win_T *wp, linenr_T lnum)
     if (curtab->tp_diffbuf[i] == wp->w_buffer) {
       idx = i;
     } else if (curtab->tp_diffbuf[i] != NULL) {
-      other = TRUE;
+      other = true;
     }
   }
 
   // return here if there are no diffs in the window
   if ((idx == -1) || !other) {
-    return FALSE;
+    return false;
   }
 
   if (curtab->tp_diff_invalid) {
@@ -1995,7 +1998,7 @@ int diff_infold(win_T *wp, linenr_T lnum)
 
   // Return if there are no diff blocks.  All lines will be folded.
   if (curtab->tp_first_diff == NULL) {
-    return TRUE;
+    return true;
   }
 
   for (dp = curtab->tp_first_diff; dp != NULL; dp = dp->df_next) {
@@ -2006,10 +2009,10 @@ int diff_infold(win_T *wp, linenr_T lnum)
 
     // If this change ends before the line we have a match.
     if (dp->df_lnum[idx] + dp->df_count[idx] + diff_context > lnum) {
-      return FALSE;
+      return false;
     }
   }
-  return TRUE;
+  return true;
 }
 
 /// "dp" and "do" commands.
@@ -2372,12 +2375,11 @@ static void diff_fold_update(diff_T *dp, int skip_idx)
   }
 }
 
-/// Checks if the buffer is in diff-mode.
+/// Checks that the buffer is in diff-mode.
 ///
-/// @param buf The buffer to check.
+/// @param  buf  buffer to check.
-///
-/// @return TRUE if buffer "buf" is in diff-mode.
 bool diff_mode_buf(buf_T *buf)
+  FUNC_ATTR_PURE FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ARG(1)
 {
   FOR_ALL_TABS(tp) {
     if (diff_buf_idx_tp(buf, tp) != DB_COUNT) {