session-manager: Add all desugars to fixed point

gcc/rust/ChangeLog:

	* ast/rust-desugar-apit.cc: Mark as clean when starting a desugar,
	and as dirty when actually doing a desugar.
	* ast/rust-expression-yeast.cc (ExpressionYeast::go): Likewise.
	* ast/rust-desugar-apit.h: Add dirty flag.
	* ast/rust-expression-yeast.h: Likewise.
	* rust-session-manager.cc (Session::expansion): Move desugars to fixed point.

Author: CohenArthur

gcc/rust/ast/rust-desugar-apit.cc

@@ -489,6 +489,8 @@ DesugarApit::DesugarApit () {}
 void
 DesugarApit::go (AST::Crate &crate)
 {
+  dirty = false;
+
   DefaultASTVisitor::visit (crate);
 }
 
@@ -523,6 +525,7 @@ DesugarApit::visit (AST::Function &function)
       ApitBoundProcessor processor (function.get_where_clause (),
 				    function.get_generic_params ());
       processor.go (implicit_generics);
+      dirty = true;
     }
 }
 

gcc/rust/ast/rust-desugar-apit.h

@@ -32,8 +32,12 @@ class DesugarApit : public DefaultASTVisitor
   DesugarApit ();
   void go (AST::Crate &);
 
+  bool has_changed () const { return dirty; }
+
 private:
   void visit (AST::Function &) override;
+
+  bool dirty = false;
 };
 
 } // namespace AST

gcc/rust/ast/rust-expression-yeast.cc

@@ -32,6 +32,8 @@ namespace AST {
 void
 ExpressionYeast::go (AST::Crate &crate)
 {
+  dirty = false;
+
   DefaultASTVisitor::visit (crate);
 }
 
@@ -69,8 +71,10 @@ ExpressionYeast::dispatch (std::unique_ptr<Expr> &expr)
       break;
 
     default:
-      break;
+      return;
     }
+
+  dirty = true;
 }
 
 void

gcc/rust/ast/rust-expression-yeast.h

@@ -35,6 +35,8 @@ class ExpressionYeast : public AST::DefaultASTVisitor
 public:
   void go (AST::Crate &);
 
+  bool has_changed () const { return dirty; }
+
 private:
   // Dispatch to the proper desugar
   void dispatch (std::unique_ptr<Expr> &expr);
@@ -44,6 +46,8 @@ class ExpressionYeast : public AST::DefaultASTVisitor
   void visit (AST::CallExpr &) override;
   void visit (AST::LetStmt &) override;
   void visit (AST::BlockExpr &) override;
+
+  bool dirty = false;
 };
 
 } // namespace AST

gcc/rust/rust-session-manager.cc

@@ -936,6 +936,9 @@ Session::expansion (AST::Crate &crate, Resolver2_0::NameResolutionContext &ctx)
   MacroExpander expander (crate, cfg, *this);
   std::vector<Error> macro_errors;
 
+  auto yeast = AST::ExpressionYeast ();
+  auto desugar_apit = AST::DesugarApit ();
+
   while (!fixed_point_reached && iterations < cfg.recursion_limit)
     {
       CfgStrip (cfg).go (crate);
@@ -955,9 +958,15 @@ Session::expansion (AST::Crate &crate, Resolver2_0::NameResolutionContext &ctx)
       if (saw_errors ())
 	break;
 
+      yeast.go (crate);
+      desugar_apit.go (crate);
+
       ExpandVisitor (expander).go (crate);
 
-      fixed_point_reached = !expander.has_changed () && !visitor_dirty;
+      fixed_point_reached = !expander.has_changed () && !visitor_dirty
+			    && !yeast.has_changed ()
+			    && !desugar_apit.has_changed ();
+
       expander.reset_changed_state ();
       iterations++;
 
@@ -985,10 +994,6 @@ Session::expansion (AST::Crate &crate, Resolver2_0::NameResolutionContext &ctx)
   // handle AST desugaring
   if (!saw_errors ())
     {
-      AST::ExpressionYeast ().go (crate);
-
-      AST::DesugarApit ().go (crate);
-
       // HACK: we may need a final TopLevel pass
       // however, this should not count towards the recursion limit
       // and we don't need a full Early pass