Parse expression instead of literal in attributes

gcc/rust/ChangeLog:

	* ast/rust-ast.cc (AttributeParser::parse_path_meta_item): Parse
	expression instead of literal. Update variant name.
	(MetaItemPathLit::to_attribute): Remove function.
	(AttributeParser::parse_path_meta_item): Update name.
	(MetaItemPathLit::check_cfg_predicate): Likewise.
	(MetaItemPathExpr::check_cfg_predicate): Likewise.
	(MetaItemPathLit::accept_vis): Likewise.
	(MetaItemPathExpr::accept_vis): Likewise.
	* ast/rust-ast-collector.h: Update prototype and adapt code to new
	expression.
	* ast/rust-ast-full-decls.h (class MetaItemPathLit): Likewise.
	(class MetaItemPathExpr): Likewise.
	* ast/rust-ast-visitor.cc (DefaultASTVisitor::visit): Likewise.
	* ast/rust-ast-visitor.h: Likewise.
	* ast/rust-ast.h (class MetaItemPathLit): Rename class from here...
	(class MetaItemPathExpr): ... to here.
	* ast/rust-expr.h (class MetaItemPathLit): Rename class from here...
	(class MetaItemPathExpr): ...to here.
	* expand/rust-derive.h: Update class name.
	* expand/rust-expand-visitor.cc (ExpandVisitor::visit): Likewise.
	* expand/rust-expand-visitor.h: Likewise.
	* hir/rust-ast-lower-base.cc (ASTLoweringBase::visit): Likewise.
	* hir/rust-ast-lower-base.h: Likewise.
	* resolve/rust-ast-resolve-base.cc (ResolverBase::visit): Likewise.
	* resolve/rust-ast-resolve-base.h: Likewise.
	* resolve/rust-early-name-resolver.cc (EarlyNameResolver::visit):
	Likewise.
	* resolve/rust-early-name-resolver.h: Likewise.
	* util/rust-attributes.cc (AttributeChecker::visit): Likewise.
	* util/rust-attributes.h: Likewise.

Signed-off-by: Pierre-Emmanuel Patry <pierre-emmanuel.patry@embecosm.com>

Author: P-E-P

gcc/rust/ast/rust-ast-collector.cc

@@ -839,13 +839,13 @@ TokenCollector::visit (MetaItemLitExpr &item)
 }
 
 void
-TokenCollector::visit (MetaItemPathLit &item)
+TokenCollector::visit (MetaItemPathExpr &item)
 {
-  auto path = item.get_path ();
-  auto lit = item.get_literal ();
+  auto &path = item.get_path ();
+  auto &expr = item.get_expr ();
   visit (path);
   push (Rust::Token::make (COLON, item.get_locus ()));
-  visit (lit);
+  visit (expr);
 }
 
 void

gcc/rust/ast/rust-ast-collector.h

@@ -246,7 +246,7 @@ class TokenCollector : public ASTVisitor
   void visit (AttrInputLiteral &attr_input);
   void visit (AttrInputMacro &attr_input);
   void visit (MetaItemLitExpr &meta_item);
-  void visit (MetaItemPathLit &meta_item);
+  void visit (MetaItemPathExpr &meta_item);
   void visit (BorrowExpr &expr);
   void visit (DereferenceExpr &expr);
   void visit (ErrorPropagationExpr &expr);

gcc/rust/ast/rust-ast-full-decls.h

@@ -78,7 +78,7 @@ class LiteralExpr;
 class AttrInputLiteral;
 class AttrInputMacro;
 class MetaItemLitExpr;
-class MetaItemPathLit;
+class MetaItemPathExpr;
 class OperatorExpr;
 class BorrowExpr;
 class DereferenceExpr;

gcc/rust/ast/rust-ast-visitor.cc

@@ -223,10 +223,10 @@ DefaultASTVisitor::visit (AST::SimplePath &path)
 }
 
 void
-DefaultASTVisitor::visit (AST::MetaItemPathLit &meta_item)
+DefaultASTVisitor::visit (AST::MetaItemPathExpr &meta_item)
 {
   visit (meta_item.get_path ());
-  visit (meta_item.get_literal ());
+  visit (meta_item.get_expr ());
 }
 
 void

gcc/rust/ast/rust-ast-visitor.h

@@ -73,7 +73,7 @@ class ASTVisitor
   virtual void visit (AttrInputLiteral &attr_input) = 0;
   virtual void visit (AttrInputMacro &attr_input) = 0;
   virtual void visit (MetaItemLitExpr &meta_item) = 0;
-  virtual void visit (MetaItemPathLit &meta_item) = 0;
+  virtual void visit (MetaItemPathExpr &meta_item) = 0;
   virtual void visit (BorrowExpr &expr) = 0;
   virtual void visit (DereferenceExpr &expr) = 0;
   virtual void visit (ErrorPropagationExpr &expr) = 0;
@@ -267,7 +267,7 @@ class DefaultASTVisitor : public ASTVisitor
   virtual void visit (AST::AttrInputLiteral &attr_input) override;
   virtual void visit (AST::AttrInputMacro &attr_input) override;
   virtual void visit (AST::MetaItemLitExpr &meta_item) override;
-  virtual void visit (AST::MetaItemPathLit &meta_item) override;
+  virtual void visit (AST::MetaItemPathExpr &meta_item) override;
   virtual void visit (AST::BorrowExpr &expr) override;
   virtual void visit (AST::DereferenceExpr &expr) override;
   virtual void visit (AST::ErrorPropagationExpr &expr) override;

gcc/rust/ast/rust-ast.cc

@@ -288,7 +288,7 @@ Attribute::get_traits_to_derive ()
 		      break;
 		    case AST::MetaItem::ItemKind::ListPaths:
 		    case AST::MetaItem::ItemKind::NameValueStr:
-		    case AST::MetaItem::ItemKind::PathLit:
+		    case AST::MetaItem::ItemKind::PathExpr:
 		    case AST::MetaItem::ItemKind::Seq:
 		    case AST::MetaItem::ItemKind::ListNameValueStr:
 		    default:
@@ -3712,20 +3712,12 @@ AttributeParser::parse_path_meta_item ()
       {
 	skip_token ();
 
-	location_t locus = peek_token ()->get_locus ();
-	Literal lit = parse_literal ();
-	if (lit.is_error ())
-	  {
-	    rust_error_at (peek_token ()->get_locus (),
-			   "failed to parse literal in attribute");
-	    return nullptr;
-	  }
-	LiteralExpr expr (std::move (lit), {}, locus);
+	std::unique_ptr<Expr> expr = parser->parse_expr ();
 	// stream_pos++;
 	/* shouldn't be required anymore due to parsing literal actually
 	 * skipping the token */
-	return std::unique_ptr<MetaItemPathLit> (
-	  new MetaItemPathLit (std::move (path), std::move (expr)));
+	return std::unique_ptr<MetaItemPathExpr> (
+	  new MetaItemPathExpr (std::move (path), std::move (expr)));
       }
     case COMMA:
       // just simple path
@@ -4144,10 +4136,10 @@ MetaNameValueStr::check_cfg_predicate (const Session &session) const
 }
 
 bool
-MetaItemPathLit::check_cfg_predicate (const Session &session) const
+MetaItemPathExpr::check_cfg_predicate (const Session &session) const
 {
   return session.options.target_data.has_key_value_pair (path.as_string (),
-							 lit.as_string ());
+							 expr->as_string ());
 }
 
 std::vector<std::unique_ptr<Token>>
@@ -4234,13 +4226,6 @@ MetaListNameValueStr::to_attribute () const
 		    std::move (new_seq_container));
 }
 
-Attribute
-MetaItemPathLit::to_attribute () const
-{
-  return Attribute (path, std::unique_ptr<AttrInputLiteral> (
-			    new AttrInputLiteral (lit)));
-}
-
 std::vector<Attribute>
 AttrInputMetaItemContainer::separate_cfg_attrs () const
 {
@@ -4405,7 +4390,7 @@ MetaItemLitExpr::accept_vis (ASTVisitor &vis)
 }
 
 void
-MetaItemPathLit::accept_vis (ASTVisitor &vis)
+MetaItemPathExpr::accept_vis (ASTVisitor &vis)
 {
   vis.visit (*this);
 }

gcc/rust/ast/rust-ast.h

@@ -1072,7 +1072,7 @@ class MetaItem : public MetaItemInner
     Path,
     Word,
     NameValueStr,
-    PathLit,
+    PathExpr,
     Seq,
     ListPaths,
     ListNameValueStr,
@@ -1090,7 +1090,7 @@ class MetaItem : public MetaItemInner
 class MetaItemLitExpr;
 
 // Forward decl - defined in rust-expr.h
-class MetaItemPathLit;
+class MetaItemPathExpr;
 
 // Forward decl - defined in rust-macro.h
 class MetaItemPath;

gcc/rust/ast/rust-expr.h

@@ -245,36 +245,45 @@ class MetaItemLitExpr : public MetaItemInner
   }
 };
 
-// more generic meta item "path = lit" form
-class MetaItemPathLit : public MetaItem
+// more generic meta item "path = expr" form
+class MetaItemPathExpr : public MetaItem
 {
   SimplePath path;
-  LiteralExpr lit;
+  std::unique_ptr<Expr> expr;
 
 public:
-  MetaItemPathLit (SimplePath path, LiteralExpr lit_expr)
-    : path (std::move (path)), lit (std::move (lit_expr))
+  MetaItemPathExpr (SimplePath path, std::unique_ptr<Expr> expr)
+    : path (std::move (path)), expr (std::move (expr))
+  {}
+
+  MetaItemPathExpr (const MetaItemPathExpr &other)
+    : path (other.path), expr (other.expr->clone_expr ())
   {}
 
+  MetaItemPathExpr operator= (const MetaItemPathExpr &other)
+  {
+    path = other.path;
+    expr = other.expr->clone_expr ();
+    return *this;
+  }
+
   SimplePath get_path () const { return path; }
 
   SimplePath &get_path () { return path; }
 
-  LiteralExpr get_literal () const { return lit; }
-
-  LiteralExpr &get_literal () { return lit; }
+  Expr &get_expr () { return *expr; }
 
   std::string as_string () const override
   {
-    return path.as_string () + " = " + lit.as_string ();
+    return path.as_string () + " = " + expr->as_string ();
   }
 
   MetaItem::ItemKind get_item_kind () const override
   {
-    return MetaItem::ItemKind::PathLit;
+    return MetaItem::ItemKind::PathExpr;
   }
 
-  // There are two Locations in MetaItemPathLit (path and lit_expr),
+  // There are two Locations in MetaItemPathExpr (path and lit_expr),
   //  we have no idea use which of them, just simply return UNKNOWN_LOCATION
   //  now.
   // Maybe we will figure out when we really need the location in the future.
@@ -286,13 +295,11 @@ class MetaItemPathLit : public MetaItem
   /* TODO: return true if "ident" is defined and value of it is "lit", return
    * false otherwise */
 
-  Attribute to_attribute () const override;
-
 protected:
   // Use covariance to implement clone function as returning this type
-  MetaItemPathLit *clone_meta_item_inner_impl () const override
+  MetaItemPathExpr *clone_meta_item_inner_impl () const override
   {
-    return new MetaItemPathLit (*this);
+    return new MetaItemPathExpr (*this);
   }
 };
 

gcc/rust/expand/rust-derive.h

@@ -118,7 +118,7 @@ class DeriveVisitor : public AST::ASTVisitor
   virtual void visit (LiteralExpr &expr) override final{};
   virtual void visit (AttrInputLiteral &attr_input) override final{};
   virtual void visit (MetaItemLitExpr &meta_item) override final{};
-  virtual void visit (MetaItemPathLit &meta_item) override final{};
+  virtual void visit (MetaItemPathExpr &meta_item) override final{};
   virtual void visit (BorrowExpr &expr) override final{};
   virtual void visit (DereferenceExpr &expr) override final{};
   virtual void visit (ErrorPropagationExpr &expr) override final{};

gcc/rust/expand/rust-expand-visitor.cc

@@ -538,7 +538,7 @@ ExpandVisitor::visit (AST::MetaItemLitExpr &)
 {}
 
 void
-ExpandVisitor::visit (AST::MetaItemPathLit &)
+ExpandVisitor::visit (AST::MetaItemPathExpr &)
 {}
 
 void