From f85ac283c57eacb34d8673ab91a56c44f9e4115f Mon Sep 17 00:00:00 2001
From: Tim Keith <tkeith@nvidia.com>
Date: Wed, 6 Mar 2019 14:15:13 -0800
Subject: [PATCH] [flang] Move ExprChecker into separate pass

DoConcurrentChecker depends on expressions being fully resolved so it
can't be in the same pass as ExprChecker. The same will probably
apply to AssignmentChecker when its finished.

Checks that don't depend on expressions can go in the first pass
with ExprChecker.

Original-commit: flang-compiler/f18@c0785ec06f58098d262cf2f791a98e74bdcef11b
Reviewed-on: https://github.com/flang-compiler/f18/pull/315
---
 flang/lib/semantics/semantics.cc | 13 +++++++++----
 flang/lib/semantics/semantics.h  |  4 ++--
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/flang/lib/semantics/semantics.cc b/flang/lib/semantics/semantics.cc
index d51823e..c48abef 100644
--- a/flang/lib/semantics/semantics.cc
+++ b/flang/lib/semantics/semantics.cc
@@ -48,10 +48,12 @@ template<typename... C> struct SemanticsVisitor : public virtual C... {
     return true;
   }
   template<typename N> void Post(const N &node) { Leave(node); }
+  void Walk(const parser::Program &program) { parser::Walk(program, *this); }
 };
 
-using StatementSemantics =
-    SemanticsVisitor<ExprChecker, AssignmentChecker, DoConcurrentChecker>;
+using StatementSemanticsPass1 = SemanticsVisitor<ExprChecker>;
+using StatementSemanticsPass2 =
+    SemanticsVisitor<AssignmentChecker, DoConcurrentChecker>;
 
 SemanticsContext::SemanticsContext(
     const common::IntrinsicTypeDefaultKinds &defaultKinds)
@@ -102,8 +104,11 @@ bool Semantics::Perform() {
   if (AnyFatalError()) {
     return false;
   }
-  StatementSemantics visitor{context_};
-  parser::Walk(program_, visitor);
+  StatementSemanticsPass1{context_}.Walk(program_);
+  if (AnyFatalError()) {
+    return false;
+  }
+  StatementSemanticsPass2{context_}.Walk(program_);
   if (AnyFatalError()) {
     return false;
   }
diff --git a/flang/lib/semantics/semantics.h b/flang/lib/semantics/semantics.h
index bf8df01..73c16a1 100644
--- a/flang/lib/semantics/semantics.h
+++ b/flang/lib/semantics/semantics.h
@@ -122,8 +122,8 @@ private:
 
 // Base class for semantics checkers.
 struct BaseChecker {
-  template<typename C> void Enter(const C &x) {}
-  template<typename C> void Leave(const C &x) {}
+  template<typename N> void Enter(const N &) {}
+  template<typename N> void Leave(const N &) {}
 };
 
 }
-- 
2.7.4