From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Thu, 22 Jan 2015 01:41:56 +0000 (+0000)
Subject: [modules] It's possible to merge into the pattern of a class template before we
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=197904daa1fc67d7069153e4b5f61ef86b74938d;p=clang

[modules] It's possible to merge into the pattern of a class template before we
load the definition data from the declaration itself. In that case, merge
properly; don't assume the prior definition is the same as our own.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@226761 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index a783183d2e..8c03b0b8b2 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -1457,9 +1457,13 @@ void ASTDeclReader::ReadCXXRecordDefinition(CXXRecordDecl *D) {
 
   ReadCXXDefinitionData(*DD, Record, Idx);
 
-  // If we're reading an update record, we might already have a definition for
-  // this record. If so, just merge into it.
-  if (D->DefinitionData.getNotUpdated()) {
+  // We might already have a definition for this record. This can happen either
+  // because we're reading an update record, or because we've already done some
+  // merging. Either way, just merge into it.
+  if (auto *CanonDD = D->DefinitionData.getNotUpdated()) {
+    if (CanonDD->Definition != DD->Definition)
+      Reader.MergedDeclContexts.insert(
+          std::make_pair(DD->Definition, CanonDD->Definition));
     MergeDefinitionData(D, *DD);
     return;
   }
diff --git a/test/Modules/Inputs/merge-anon-in-template/a.h b/test/Modules/Inputs/merge-anon-in-template/a.h
new file mode 100644
index 0000000000..82540e397b
--- /dev/null
+++ b/test/Modules/Inputs/merge-anon-in-template/a.h
@@ -0,0 +1,4 @@
+template<typename T> struct is_floating {
+  enum { value = 0 };
+  typedef int type;
+};
diff --git a/test/Modules/Inputs/merge-anon-in-template/b.h b/test/Modules/Inputs/merge-anon-in-template/b.h
new file mode 100644
index 0000000000..87c053d962
--- /dev/null
+++ b/test/Modules/Inputs/merge-anon-in-template/b.h
@@ -0,0 +1,2 @@
+#include "a.h"
+bool k = is_floating<int>::value;
diff --git a/test/Modules/Inputs/merge-anon-in-template/c.h b/test/Modules/Inputs/merge-anon-in-template/c.h
new file mode 100644
index 0000000000..e0b9b0a331
--- /dev/null
+++ b/test/Modules/Inputs/merge-anon-in-template/c.h
@@ -0,0 +1,6 @@
+template<typename T> struct is_floating {
+  enum { value = 0 };
+  typedef int type;
+};
+#include "b.h"
+bool n20 = is_floating<int>::value;
diff --git a/test/Modules/Inputs/merge-anon-in-template/module.modulemap b/test/Modules/Inputs/merge-anon-in-template/module.modulemap
new file mode 100644
index 0000000000..77e0a89e39
--- /dev/null
+++ b/test/Modules/Inputs/merge-anon-in-template/module.modulemap
@@ -0,0 +1,3 @@
+module a { header "a.h" export * }
+module b { header "b.h" export * }
+module c { header "c.h" export * }
diff --git a/test/Modules/merge-anon-in-template.cc b/test/Modules/merge-anon-in-template.cc
new file mode 100644
index 0000000000..6e4e6e09e9
--- /dev/null
+++ b/test/Modules/merge-anon-in-template.cc
@@ -0,0 +1,6 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t -I%S/Inputs/merge-anon-in-template -verify %s
+// expected-no-diagnostics
+#include "a.h"
+#include "c.h"
+is_floating<int>::type t;