Merge #605

605: Merge both module classes in one r=philberty a=CohenArthur

This PR merges both kinds of Modules (formerly `ModuleBodied` and `ModuleNoBody`) as one class with an enum. This is the [behavior used by rustc](https://github.com/rust-lang/rust/blob/2939249f294dd54a9ce78a8ee1f2922a44e7fb7c/compiler/rustc_ast/src/ast.rs#L2274), where both variants are kept in an enum with one holding a vector of items.

This change is important for multiple file parsing: An external mod (`mod foo; // defined in foo.rs or foo/mod.rs`) will see its items expanded during expansion, which occurs after parsing. This means that the previous directive will be "replaced" by `mod foo { <items> }` at the AST level. In order to achieve this, we need to be able to modify a previously parsed instance of an AST element.

In rustc, this is done [here](https://github.com/rust-lang/rust/blob/2939249f294dd54a9ce78a8ee1f2922a44e7fb7c/compiler/rustc_expand/src/expand.rs#L1427), where `mod_kind` was previously `ModKind::Unloaded` and becomes `ModKind::Loaded(parsed_items, ...)`. 

Co-authored-by: CohenArthur <arthur.cohen@epita.fr>

1 files changed, 10 insertions, 16 deletions

diff --git a/gcc/rust/expand/rust-macro-expand.cc b/gcc/rust/expand/rust-macro-expand.cc
index 28d14ba..0a25471 100644
--- a/gcc/rust/expand/rust-macro-expand.cc
+++ b/gcc/rust/expand/rust-macro-expand.cc
@@ -2015,7 +2015,7 @@ public:
 		     "cannot strip block expression in this position - outer "
 		     "attributes not allowed");
   }
-  void visit (AST::ModuleBodied &module) override
+  void visit (AST::Module &module) override
   {
     // strip test based on outer attrs
     expander.expand_cfg_attrs (module.get_outer_attrs ());
@@ -2025,27 +2025,21 @@ public:
 	return;
       }
 
-    // strip test based on inner attrs
-    expander.expand_cfg_attrs (module.get_inner_attrs ());
-    if (expander.fails_cfg_with_expand (module.get_inner_attrs ()))
+    // A loaded module might have inner attributes
+    if (module.get_kind () == AST::Module::ModuleKind::LOADED)
       {
-	module.mark_for_strip ();
-	return;
+	// strip test based on inner attrs
+	expander.expand_cfg_attrs (module.get_inner_attrs ());
+	if (expander.fails_cfg_with_expand (module.get_inner_attrs ()))
+	  {
+	    module.mark_for_strip ();
+	    return;
+	  }
       }
 
     // strip items if required
     expand_pointer_allow_strip (module.get_items ());
   }
-  void visit (AST::ModuleNoBody &module) override
-  {
-    // strip test based on outer attrs
-    expander.expand_cfg_attrs (module.get_outer_attrs ());
-    if (expander.fails_cfg_with_expand (module.get_outer_attrs ()))
-      {
-	module.mark_for_strip ();
-	return;
-      }
-  }
   void visit (AST::ExternCrate &crate) override
   {
     // strip test based on outer attrs