From 86132a15dc5dd551b48f5abc12e57f4324475701 Mon Sep 17 00:00:00 2001
From: Tim Keith <tkeith@nvidia.com>
Date: Mon, 24 Jun 2019 12:35:17 -0700
Subject: [PATCH] [flang] Fix bug in writing PRIVATE subprograms to .mod file

Subprograms can't have the PRIVATE prefix on them when they are defined.
So if they are private, add a private-stmt for them.

Fixes flang-compiler/f18#519

Original-commit: flang-compiler/f18@d3670aa176cbc79a7d26fc927e9d1e1349900756
Reviewed-on: https://github.com/flang-compiler/f18/pull/523
---
 flang/lib/semantics/mod-file.cc    | 14 ++++++++--
 flang/test/semantics/modfile01.f90 | 45 +++++++++++++++++++++++++++++-
 2 files changed, 56 insertions(+), 3 deletions(-)

diff --git a/flang/lib/semantics/mod-file.cc b/flang/lib/semantics/mod-file.cc
index 19afac34e045..a50d2cea7b20 100644
--- a/flang/lib/semantics/mod-file.cc
+++ b/flang/lib/semantics/mod-file.cc
@@ -52,6 +52,7 @@ static void PutBound(std::ostream &, const Bound &);
 static std::ostream &PutAttrs(std::ostream &, Attrs,
     const MaybeExpr & = std::nullopt, std::string before = ","s,
     std::string after = ""s);
+static std::ostream &PutAttr(std::ostream &, Attr);
 static std::ostream &PutLower(std::ostream &, const Symbol &);
 static std::ostream &PutLower(std::ostream &, const DeclTypeSpec &);
 static std::ostream &PutLower(std::ostream &, const std::string &);
@@ -284,6 +285,11 @@ void ModFileWriter::PutSubprogram(const Symbol &symbol) {
     bindAttrs.set(Attr::BIND_C, true);
     attrs.set(Attr::BIND_C, false);
   }
+  if (attrs.test(Attr::PRIVATE)) {
+    PutAttr(decls_, Attr::PRIVATE) << "::";
+    PutLower(decls_, symbol) << "\n";
+    attrs.set(Attr::PRIVATE, false);
+  }
   bool isInterface{details.isInterface()};
   std::ostream &os{isInterface ? decls_ : contains_};
   if (isInterface) {
@@ -365,7 +371,7 @@ void ModFileWriter::PutUse(const Symbol &symbol) {
 void ModFileWriter::PutUseExtraAttr(
     Attr attr, const Symbol &local, const Symbol &use) {
   if (local.attrs().test(attr) && !use.attrs().test(attr)) {
-    PutLower(useExtraAttrs_, AttrToString(attr)) << "::";
+    PutAttr(useExtraAttrs_, attr) << "::";
     PutLower(useExtraAttrs_, local) << '\n';
   }
 }
@@ -552,12 +558,16 @@ std::ostream &PutAttrs(std::ostream &os, Attrs attrs, const MaybeExpr &bindName,
   for (std::size_t i{0}; i < Attr_enumSize; ++i) {
     Attr attr{static_cast<Attr>(i)};
     if (attrs.test(attr)) {
-      PutLower(os << before, AttrToString(attr)) << after;
+      PutAttr(os << before, attr) << after;
     }
   }
   return os;
 }
 
+std::ostream &PutAttr(std::ostream &os, Attr attr) {
+  return PutLower(os, AttrToString(attr));
+}
+
 std::ostream &PutLower(std::ostream &os, const Symbol &symbol) {
   return PutLower(os, symbol.name().ToString());
 }
diff --git a/flang/test/semantics/modfile01.f90 b/flang/test/semantics/modfile01.f90
index 56b8f80ab644..8de9f1b90686 100644
--- a/flang/test/semantics/modfile01.f90
+++ b/flang/test/semantics/modfile01.f90
@@ -1,4 +1,4 @@
-! Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
+! Copyright (c) 2018-2019, NVIDIA CORPORATION.  All rights reserved.
 !
 ! Licensed under the Apache License, Version 2.0 (the "License");
 ! you may not use this file except in compliance with the License.
@@ -37,3 +37,46 @@ end
 !end type
 !type(t)::x
 !end
+
+! Check correct modfile generation for type with private module procedure.
+
+module m2
+  private :: s1
+contains
+  subroutine s1()
+  end
+  subroutine s2()
+  end
+end
+
+!Expect: m2.mod
+!module m2
+! private::s1
+!contains
+! subroutine s1()
+! end
+! subroutine s2()
+! end
+!end
+
+module m3
+  private
+  public :: f1
+contains
+  real function f1()
+  end
+  real function f2()
+  end
+end
+
+!Expect: m3.mod
+!module m3
+! private::f2
+!contains
+! function f1()
+!  real(4)::f1
+! end
+! function f2()
+!  real(4)::f2
+! end
+!end