Get rid of get_locus_slow

In various places there was the following hack:

  /* HACK: slow way of getting location from base expression through
     virtual methods. */
  virtual Location get_locus_slow () const { return Location (); }

The problem with get_locus_slow () is that if a subclass didn't
override it then there was no real location. get_locus_slow was
missing for Module, ExternCrate, UseDeclaration, Function, TypeAlias,
StructStruct, TupleStruct, Enum, Union, ConstantItem, StaticItem,
Trait, ImplBlock, ExternBlock, EmptyStmt, ExprStmtWithoutBlock and
ExprStmtWithBlock. All do have a get_locus () function.

Simply replace the get_locus_slow virtual method with a real virtual
Location get_locus () const = 0 method so we know if something
really doesn't have a location. This was only the case for
MacroRulesDefinition.

1 files changed, 3 insertions, 2 deletions

diff --git a/gcc/rust/ast/rust-macro.h b/gcc/rust/ast/rust-macro.h
index 51220e4..0fb16d6 100644
--- a/gcc/rust/ast/rust-macro.h
+++ b/gcc/rust/ast/rust-macro.h
@@ -345,6 +345,8 @@ public:
   std::vector<MacroRule> &get_macro_rules () { return rules; }
   const std::vector<MacroRule> &get_macro_rules () const { return rules; }
 
+  Location get_locus () const override final { return locus; }
+
 protected:
   /* Use covariance to implement clone function as returning this object rather
    * than base */
@@ -373,8 +375,7 @@ public:
       invoc_data (std::move (invoc_data)), locus (locus)
   {}
 
-  Location get_locus () const { return locus; }
-  Location get_locus_slow () const final override { return get_locus (); }
+  Location get_locus () const override final { return locus; }
 
   void accept_vis (ASTVisitor &vis) override;