[ASTImporter] Add support for importing ChooseExpr AST nodes.

Summary:
This allows ASTs to be merged when they contain ChooseExpr (the GNU
__builtin_choose_expr construction). This is needed, for example, for
cross-CTU analysis of C code that makes use of __builtin_choose_expr.

The node is already supported in the AST, but it didn't have a matcher
in ASTMatchers. So, this change adds the matcher and adds support to
ASTImporter.

Reviewers: shafik, a_sidorin, martong, aaron.ballman

Subscribers: aaron.ballman, rnkovacs, jdoerfert, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58292

llvm-svn: 354832

1 files changed, 5 insertions, 0 deletions

diff --git a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
index fd5b112fae9..3f9981cd6db 100644
--- a/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
+++ b/clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
@@ -754,6 +754,11 @@ TEST(Matcher, NullPtrLiteral) {
   EXPECT_TRUE(matches("int* i = nullptr;", cxxNullPtrLiteralExpr()));
 }
 
+TEST(Matcher, ChooseExpr) {
+  EXPECT_TRUE(matchesC("void f() { (void)__builtin_choose_expr(1, 2, 3); }",
+                       chooseExpr()));
+}
+
 TEST(Matcher, GNUNullExpr) {
   EXPECT_TRUE(matches("int* i = __null;", gnuNullExpr()));
 }