eolian: clean rollback support

Previously, when an error happened in Eolian, the state was left
in a presumably unusable and inconsistent condition. This work
aims to change that, as all changes are committed into a staging
area before being validated and merged back into main state.

This is not yet complete, as units and by-file lookups are not
currently involved in the rollback. This will change in the
subsequent commits.

@feature

src/lib/eolian/eo_parser.c

@@ -109,6 +109,8 @@ static Eolian_Object *
 _eolian_decl_get(Eo_Lexer *ls, const char *name)
 {
    Eolian_Object *obj = eina_hash_find(ls->state->unit.objects, name);
+   if (!obj)
+     obj = eina_hash_find(ls->state->staging.objects, name);
    if (obj && ((obj->type == EOLIAN_OBJECT_CLASS) ||
                (obj->type == EOLIAN_OBJECT_TYPEDECL) ||
                (obj->type == EOLIAN_OBJECT_VARIABLE)))

src/lib/eolian/eolian_database.c

@@ -13,7 +13,7 @@ database_object_add(Eolian_Unit *unit, const Eolian_Object *obj)
 {
    /* object storage */
    eina_hash_add(unit->objects, obj->name, obj);
-   eina_hash_add(unit->state->unit.objects, obj->name, obj);
+   eina_hash_add(unit->state->staging.objects, obj->name, obj);
    eina_hash_set(unit->state->objects_f, obj->file, eina_list_append
                  ((Eina_List *)eina_hash_find(unit->state->objects_f, obj->file), obj));
 }
@@ -828,6 +828,16 @@ _merge_unit_cb(const Eina_Hash *hash EINA_UNUSED,
    return EINA_TRUE;
 }
 
+static Eina_Bool
+_merge_unit_cb_noref(const Eina_Hash *hash EINA_UNUSED,
+               const void *key, void *data, void *fdata)
+{
+   Eina_Hash *dest = fdata;
+   if (!eina_hash_find(dest, key))
+     eina_hash_add(dest, key, data);
+   return EINA_TRUE;
+}
+
 static void
 _merge_unit(Eolian_Unit *dest, Eolian_Unit *src)
 {
@@ -837,7 +847,7 @@ _merge_unit(Eolian_Unit *dest, Eolian_Unit *src)
    eina_hash_foreach(src->aliases, _merge_unit_cb, dest->aliases);
    eina_hash_foreach(src->structs, _merge_unit_cb, dest->structs);
    eina_hash_foreach(src->enums, _merge_unit_cb, dest->enums);
-   eina_hash_foreach(src->objects, _merge_unit_cb, dest->objects);
+   eina_hash_foreach(src->objects, _merge_unit_cb_noref, dest->objects);
 }
 
 typedef struct _Merge_Data
@@ -885,6 +895,8 @@ eolian_state_file_parse(Eolian_State *state, const char *filepath)
    _merge_units(ret);
    if (!database_validate(ret))
      return NULL;
+   _merge_unit(&state->unit, &state->staging);
+   _state_clean(state);
    return &state->unit;
 }
 
@@ -920,6 +932,9 @@ eolian_state_all_eot_files_parse(Eolian_State *state)
    if (pd.ret && !database_validate(&state->unit))
      return EINA_FALSE;
 
+   _merge_unit(&state->unit, &state->staging);
+   _state_clean(state);
+
    return pd.ret;
 }
 
@@ -949,6 +964,9 @@ eolian_state_all_eo_files_parse(Eolian_State *state)
    if (pd.ret && !database_validate(&state->unit))
      return EINA_FALSE;
 
+   _merge_unit(&state->unit, &state->staging);
+   _state_clean(state);
+
    return pd.ret;
 }
 

src/lib/eolian/eolian_database.h

@@ -107,7 +107,7 @@ eolian_object_add(Eolian_Object *obj, Eina_Stringshare *name, Eina_Hash *hash)
 
 #define EOLIAN_OBJECT_ADD(tunit, name, obj, memb) \
 { \
-   eolian_object_add(&obj->base, name, tunit->state->unit.memb); \
+   eolian_object_add(&obj->base, name, tunit->state->staging.memb); \
    eolian_object_add(&obj->base, name, tunit->memb); \
 }