From 4d06bef38d404253266c2e42209f6d036b04f0cc Mon Sep 17 00:00:00 2001
From: Richard Trieu <rtrieu@google.com>
Date: Tue, 13 Feb 2018 19:53:40 +0000
Subject: [PATCH] Update StmtProfile.cpp to handle zero template arguments.

Treat having no templates arguments differently than having zero template
arguments when profiling.

llvm-svn: 325040
---
 clang/lib/AST/StmtProfile.cpp   |  7 +++++--
 clang/test/Modules/odr_hash.cpp | 15 +++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/clang/lib/AST/StmtProfile.cpp b/clang/lib/AST/StmtProfile.cpp
index 00ef0da18bbb..08261205ef01 100644
--- a/clang/lib/AST/StmtProfile.cpp
+++ b/clang/lib/AST/StmtProfile.cpp
@@ -966,8 +966,11 @@ void StmtProfiler::VisitDeclRefExpr(const DeclRefExpr *S) {
   if (!Canonical)
     VisitNestedNameSpecifier(S->getQualifier());
   VisitDecl(S->getDecl());
-  if (!Canonical)
-    VisitTemplateArguments(S->getTemplateArgs(), S->getNumTemplateArgs());
+  if (!Canonical) {
+    ID.AddBoolean(S->hasExplicitTemplateArgs());
+    if (S->hasExplicitTemplateArgs())
+      VisitTemplateArguments(S->getTemplateArgs(), S->getNumTemplateArgs());
+  }
 }
 
 void StmtProfiler::VisitPredefinedExpr(const PredefinedExpr *S) {
diff --git a/clang/test/Modules/odr_hash.cpp b/clang/test/Modules/odr_hash.cpp
index 054e41a9eaea..5991dd0a7335 100644
--- a/clang/test/Modules/odr_hash.cpp
+++ b/clang/test/Modules/odr_hash.cpp
@@ -2924,6 +2924,21 @@ int I10 = F10();
 // expected-note@first.h:* {{but in 'FirstModule' found a different body}}
 }  // namespace FunctionDecl
 
+namespace DeclTemplateArguments {
+#if defined(FIRST)
+int foo() { return 1; }
+int bar() { return foo(); }
+#elif defined(SECOND)
+template <class T = int>
+int foo() { return 2; }
+int bar() { return foo<>(); }
+#else
+int num = bar();
+// expected-error@second.h:* {{'DeclTemplateArguments::bar' has different definitions in different modules; definition in module 'SecondModule' first difference is function body}}
+// expected-note@first.h:* {{but in 'FirstModule' found a different body}}
+#endif
+}
+
 // Keep macros contained to one file.
 #ifdef FIRST
 #undef FIRST