From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Thu, 22 Jan 2015 03:50:31 +0000 (+0000)
Subject: [modules] If we add an implicit special member to a class through an update
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=03b1425999b71d0ecacc94d7a5cc696a77a49bb8;p=clang

[modules] If we add an implicit special member to a class through an update
record, and that class declaration is not the canonical definition of the
class, be sure to add the class to the list of classes that are consulted when
we look up a special member in the canonical definition.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@226778 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index b82f987210..d43f3eaacb 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -3523,13 +3523,25 @@ void ASTDeclReader::UpdateDecl(Decl *D, ModuleFile &ModuleFile,
   while (Idx < Record.size()) {
     switch ((DeclUpdateKind)Record[Idx++]) {
     case UPD_CXX_ADDED_IMPLICIT_MEMBER: {
+      auto *RD = cast<CXXRecordDecl>(D);
       // FIXME: If we also have an update record for instantiating the
       // definition of D, we need that to happen before we get here.
       Decl *MD = Reader.ReadDecl(ModuleFile, Record, Idx);
       assert(MD && "couldn't read decl from update record");
       // FIXME: We should call addHiddenDecl instead, to add the member
       // to its DeclContext.
-      cast<CXXRecordDecl>(D)->addedMember(MD);
+      RD->addedMember(MD);
+
+      // If we've added a new special member to a class definition that is not
+      // the canonical definition, then we need special member lookups in the
+      // canonical definition to also look into our class.
+      auto *DD = RD->DefinitionData.getNotUpdated();
+      if (DD && DD->Definition != RD) {
+        auto &Merged = Reader.MergedLookups[DD->Definition];
+        // FIXME: Avoid the linear-time scan here.
+        if (std::find(Merged.begin(), Merged.end(), RD) == Merged.end())
+          Merged.push_back(RD);
+      }
       break;
     }
 
diff --git a/test/Modules/Inputs/merge-implicit-special-members/a.h b/test/Modules/Inputs/merge-implicit-special-members/a.h
new file mode 100644
index 0000000000..3029e4afb8
--- /dev/null
+++ b/test/Modules/Inputs/merge-implicit-special-members/a.h
@@ -0,0 +1 @@
+struct pthread_mutex_t { int lock; };
diff --git a/test/Modules/Inputs/merge-implicit-special-members/b.h b/test/Modules/Inputs/merge-implicit-special-members/b.h
new file mode 100644
index 0000000000..3029e4afb8
--- /dev/null
+++ b/test/Modules/Inputs/merge-implicit-special-members/b.h
@@ -0,0 +1 @@
+struct pthread_mutex_t { int lock; };
diff --git a/test/Modules/Inputs/merge-implicit-special-members/c.h b/test/Modules/Inputs/merge-implicit-special-members/c.h
new file mode 100644
index 0000000000..ee0bebb2ee
--- /dev/null
+++ b/test/Modules/Inputs/merge-implicit-special-members/c.h
@@ -0,0 +1,3 @@
+#include "a.h"
+#include "b.h"
+int k = pthread_mutex_t().lock;
diff --git a/test/Modules/Inputs/merge-implicit-special-members/module.modulemap b/test/Modules/Inputs/merge-implicit-special-members/module.modulemap
new file mode 100644
index 0000000000..77e0a89e39
--- /dev/null
+++ b/test/Modules/Inputs/merge-implicit-special-members/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-implicit-special-members.cpp b/test/Modules/merge-implicit-special-members.cpp
new file mode 100644
index 0000000000..a8b917cb01
--- /dev/null
+++ b/test/Modules/merge-implicit-special-members.cpp
@@ -0,0 +1,5 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t -I%S/Inputs/merge-implicit-special-members -verify %s
+// expected-no-diagnostics
+#include "c.h"
+int n = pthread_mutex_t().lock;