return false;
}
+typedef struct count_depth_data {
+ /* The depth of the current subobject, with "1" as the depth of the
+ most derived object in the hierarchy. */
+ size_t depth;
+ /* The maximum depth found so far. */
+ size_t max_depth;
+} count_depth_data;
+
+/* Called from find_final_overrider via dfs_walk. */
+
+static tree
+dfs_depth_post (tree binfo ATTRIBUTE_UNUSED, void *data)
+{
+ count_depth_data *cd = (count_depth_data *) data;
+ if (cd->depth > cd->max_depth)
+ cd->max_depth = cd->depth;
+ cd->depth--;
+ return NULL_TREE;
+}
+
+/* Called from find_final_overrider via dfs_walk. */
+
+static tree
+dfs_depth_q (tree derived, int i, void *data)
+{
+ count_depth_data *cd = (count_depth_data *) data;
+ cd->depth++;
+ return BINFO_BASE_BINFO (derived, i);
+}
+
typedef struct find_final_overrider_data_s {
/* The function for which we are trying to find a final overrider. */
tree fn;
tree most_derived_type;
/* The candidate overriders. */
tree candidates;
- /* Binfos which inherited virtually on the current path. */
- tree vpath;
+ /* Each entry in this array is the next-most-derived class for a
+ virtual base class along the current path. */
+ tree *vpath_list;
+ /* A pointer one past the top of the VPATH_LIST. */
+ tree *vpath;
} find_final_overrider_data;
-/* Called from find_final_overrider via dfs_walk. */
+/* Add the overrider along the current path to FFOD->CANDIDATES.
+ Returns true if an overrider was found; false otherwise. */
-static tree
-dfs_find_final_overrider (tree binfo, void* data)
+static bool
+dfs_find_final_overrider_1 (tree binfo,
+ tree *vpath,
+ find_final_overrider_data *ffod)
{
- find_final_overrider_data *ffod = (find_final_overrider_data *) data;
-
- if (binfo == ffod->declaring_base)
+ /* If BINFO is not the most derived type, try a more derived class.
+ A definition there will overrider a definition here. */
+ if (!same_type_p (BINFO_TYPE (binfo), ffod->most_derived_type))
{
- /* We've found a path to the declaring base. Walk the path from
- derived to base, looking for an overrider for FN. */
- tree path, probe, vpath;
+ tree derived;
- /* Build the path, using the inheritance chain and record of
- virtual inheritance. */
- for (path = NULL_TREE, probe = binfo, vpath = ffod->vpath;;)
+ if (BINFO_VIRTUAL_P (binfo))
+ derived = *--vpath;
+ else
+ derived = BINFO_INHERITANCE_CHAIN (binfo);
+ if (dfs_find_final_overrider_1 (derived, vpath, ffod))
+ return true;
+ }
+
+ tree method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
+
+ if (method)
+ {
+ tree *candidate = &ffod->candidates;
+
+ /* Remove any candidates overridden by this new function. */
+ while (*candidate)
{
- path = tree_cons (NULL_TREE, probe, path);
- if (same_type_p (BINFO_TYPE (probe), ffod->most_derived_type))
- break;
- if (BINFO_VIRTUAL_P (probe))
- {
- probe = TREE_VALUE (vpath);
- vpath = TREE_CHAIN (vpath);
- }
+ /* If *CANDIDATE overrides METHOD, then METHOD
+ cannot override anything else on the list. */
+ if (base_derived_from (TREE_VALUE (*candidate), binfo))
+ return true;
+ /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
+ if (base_derived_from (binfo, TREE_VALUE (*candidate)))
+ *candidate = TREE_CHAIN (*candidate);
else
- probe = BINFO_INHERITANCE_CHAIN (probe);
- }
- /* Now walk path, looking for overrides. */
- for (; path; path = TREE_CHAIN (path))
- {
- tree method = look_for_overrides_here
- (BINFO_TYPE (TREE_VALUE (path)), ffod->fn);
-
- if (method)
- {
- tree *candidate = &ffod->candidates;
- path = TREE_VALUE (path);
-
- /* Remove any candidates overridden by this new function. */
- while (*candidate)
- {
- /* If *CANDIDATE overrides METHOD, then METHOD
- cannot override anything else on the list. */
- if (base_derived_from (TREE_VALUE (*candidate), path))
- return NULL_TREE;
- /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
- if (base_derived_from (path, TREE_VALUE (*candidate)))
- *candidate = TREE_CHAIN (*candidate);
- else
- candidate = &TREE_CHAIN (*candidate);
- }
-
- /* Add the new function. */
- ffod->candidates = tree_cons (method, path, ffod->candidates);
- break;
- }
+ candidate = &TREE_CHAIN (*candidate);
}
+
+ /* Add the new function. */
+ ffod->candidates = tree_cons (method, binfo, ffod->candidates);
+ return true;
}
+ return false;
+}
+
+/* Called from find_final_overrider via dfs_walk. */
+
+static tree
+dfs_find_final_overrider (tree binfo, void* data)
+{
+ find_final_overrider_data *ffod = (find_final_overrider_data *) data;
+
+ if (binfo == ffod->declaring_base)
+ dfs_find_final_overrider_1 (binfo, ffod->vpath, ffod);
+
return NULL_TREE;
}
find_final_overrider_data *ffod = (find_final_overrider_data *) data;
if (BINFO_VIRTUAL_P (binfo))
- ffod->vpath = tree_cons (NULL_TREE, derived, ffod->vpath);
+ *ffod->vpath++ = derived;
return binfo;
}
{
find_final_overrider_data *ffod = (find_final_overrider_data *) data;
- if (BINFO_VIRTUAL_P (binfo) && TREE_CHAIN (ffod->vpath))
- ffod->vpath = TREE_CHAIN (ffod->vpath);
+ if (BINFO_VIRTUAL_P (binfo))
+ ffod->vpath--;
return NULL_TREE;
}
find_final_overrider (tree derived, tree binfo, tree fn)
{
find_final_overrider_data ffod;
+ count_depth_data cd;
/* Getting this right is a little tricky. This is valid:
different overriders along any two, then there is a problem. */
if (DECL_THUNK_P (fn))
fn = THUNK_TARGET (fn);
-
+
+ /* Determine the depth of the hierarchy. */
+ cd.depth = 0;
+ cd.max_depth = 0;
+ dfs_walk (derived, dfs_depth_post, dfs_depth_q, &cd);
+
ffod.fn = fn;
ffod.declaring_base = binfo;
ffod.most_derived_type = BINFO_TYPE (derived);
ffod.candidates = NULL_TREE;
- ffod.vpath = NULL_TREE;
+ ffod.vpath_list = (tree *) xcalloc (cd.max_depth, sizeof (tree));
+ ffod.vpath = ffod.vpath_list;
dfs_walk_real (derived,
dfs_find_final_overrider,
dfs_find_final_overrider_q,
&ffod);
+ free (ffod.vpath_list);
+
/* If there was no winner, issue an error message. */
if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
{
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