Changeset 4c868cb2

Timestamp:

Sep 14, 2020, 1:36:21 PM (4 years ago)

Author:

Fangren Yu <f37yu@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

7a8f62c3

Parents:

9a05b81

Message:

fix a potential issue with pure function interface

this makes pure passes no longer exactly pure, however
most likely required to make patterns like RenameVars?
work without deep copying. truly pure passes should not
overwrite decl nodes so there should be no effect.

File:

• src/AST/Pass.impl.hpp (modified) (1 diff)

src/AST/Pass.impl.hpp

@@ -67 +67 @@
                 }
 
+                /// mutate should NEVER create new decl since it risks invalidating weak refs
+                /// called by visit template with correct type information so static type checking should suffice
                 template< typename core_t, typename node_t >
                 static inline node_t* mutate(const node_t *node) {
-                        return std::is_base_of<PureVisitor, core_t>::value ? ::ast::shallowCopy(node) : ::ast::mutate(node);
+                        // force copying non-decl nodes as a pure function
+                        return std::is_base_of<PureVisitor, core_t>::value && !std::is_base_of<ast::Decl, node_t>::value
+                        ? ::ast::shallowCopy(node) : ::ast::mutate(node);
                 }