[ASTImporter] Import default expression of param before creating the param.

Summary:
The default expression of a parameter variable should be imported before
the parameter variable object is created. Otherwise the function is created
with an incomplete parameter variable (default argument is nullptr) and in
this intermediary state the expression is imported. This import can have
a reference to the incomplete parameter variable that causes crash.

Reviewers: martong, a.sidorin, shafik

Reviewed By: martong

Subscribers: rnkovacs, dkrupp, Szelethus, gamesh411, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D65577

llvm-svn: 368818

1 files changed, 5 insertions, 0 deletions

diff --git a/clang/test/Analysis/ctu-main.cpp b/clang/test/Analysis/ctu-main.cpp
index aae4808e90f..c4aee409ee2 100644
--- a/clang/test/Analysis/ctu-main.cpp
+++ b/clang/test/Analysis/ctu-main.cpp
@@ -125,6 +125,8 @@ public:
   static const int Test;
 };
 
+extern int testImportOfIncompleteDefaultParmDuringImport(int);
+
 int main() {
   clang_analyzer_eval(f(3) == 2); // expected-warning{{TRUE}}
   clang_analyzer_eval(f(4) == 3); // expected-warning{{TRUE}}
@@ -157,5 +159,8 @@ int main() {
   clang_analyzer_eval(extSubSCN.a == 1); // expected-warning{{TRUE}}
   // clang_analyzer_eval(extSCC.a == 7); // TODO
   clang_analyzer_eval(extU.a == 4); // expected-warning{{TRUE}}
+
   clang_analyzer_eval(TestAnonUnionUSR::Test == 5); // expected-warning{{TRUE}}
+
+  clang_analyzer_eval(testImportOfIncompleteDefaultParmDuringImport(9) == 9); // expected-warning{{TRUE}}
 }