From: Lang Hames <lhames@gmail.com>
Date: Sat, 17 Jun 2017 00:12:38 +0000 (+0000)
Subject: Call setMustBuildLookupTable on TagDecls in ExternalASTMerger
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=30060bff5b4cb49e17c27672d1aa60e6bc7a95e8;p=clang

Call setMustBuildLookupTable on TagDecls in ExternalASTMerger

Summary:
setMustBuildLookupTable should be called on imported TagDecls otherwise we may fail
to import their member decls (if they have any).

Not calling the setMustBuildLookupTable method results in a failure in the attached test
case when lookup for the 'x' member fails on struct S, which hasn't had its decls imported
elsewhere. (By contrast the member-in-struct testcase hasn't run into this issue
because the import of its decls is triggered when the struct instance is defined, and the
member access follows this).

Reviewers: spyffe, rsmith

Reviewed By: spyffe, rsmith

Differential Revision: https://reviews.llvm.org/D34253

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@305619 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/AST/ExternalASTMerger.cpp b/lib/AST/ExternalASTMerger.cpp
index 1dc472a5f7..b746edaf64 100644
--- a/lib/AST/ExternalASTMerger.cpp
+++ b/lib/AST/ExternalASTMerger.cpp
@@ -41,6 +41,7 @@ public:
   Decl *Imported(Decl *From, Decl *To) override {
     if (auto ToTag = dyn_cast<TagDecl>(To)) {
       ToTag->setHasExternalLexicalStorage();
+      ToTag->setMustBuildLookupTable();
     } else if (auto ToNamespace = dyn_cast<NamespaceDecl>(To)) {
       ToNamespace->setHasExternalVisibleStorage();
     }
diff --git a/test/Import/indirect-struct-member-access/Inputs/S.c b/test/Import/indirect-struct-member-access/Inputs/S.c
new file mode 100644
index 0000000000..b0876d27df
--- /dev/null
+++ b/test/Import/indirect-struct-member-access/Inputs/S.c
@@ -0,0 +1,3 @@
+struct S {
+  int a;
+};
diff --git a/test/Import/indirect-struct-member-access/test.c b/test/Import/indirect-struct-member-access/test.c
new file mode 100644
index 0000000000..cbf7e65ec1
--- /dev/null
+++ b/test/Import/indirect-struct-member-access/test.c
@@ -0,0 +1,4 @@
+// RUN: clang-import-test -import %S/Inputs/S.c -expression %s
+void expr(struct S *MyS) {
+  MyS->a = 3;
+}