Index: cfe/trunk/lib/CrossTU/CrossTranslationUnit.cpp
===================================================================
--- cfe/trunk/lib/CrossTU/CrossTranslationUnit.cpp
+++ cfe/trunk/lib/CrossTU/CrossTranslationUnit.cpp
@@ -269,7 +269,9 @@
 
   ASTImporter &Importer = getOrCreateASTImporter(FD->getASTContext());
   auto *ToDecl =
-      cast<FunctionDecl>(Importer.Import(const_cast<FunctionDecl *>(FD)));
+      cast_or_null<FunctionDecl>(Importer.Import(const_cast<FunctionDecl *>(FD)));
+  if (!ToDecl)
+    return llvm::make_error<IndexError>(index_error_code::failed_import);
   assert(ToDecl->hasBody());
   assert(FD->hasBody() && "Functions already imported should have body.");
   ++NumGetCTUSuccess;
Index: cfe/trunk/test/Analysis/Inputs/ctu-other.c
===================================================================
--- cfe/trunk/test/Analysis/Inputs/ctu-other.c
+++ cfe/trunk/test/Analysis/Inputs/ctu-other.c
@@ -0,0 +1,49 @@
+// Test typedef and global variable in function.
+typedef struct {
+  int a;
+  int b;
+} FooBar;
+FooBar fb;
+int f(int i) {
+  if (fb.a) {
+    fb.b = i;
+  }
+  return 1;
+}
+
+// Test enums.
+enum B { x = 42,
+         l,
+         s };
+int enumCheck(void) {
+  return x;
+}
+
+// Test reporting an error in macro definition
+#define MYMACRO(ctx) \
+  ctx->a;
+struct S {
+  int a;
+};
+int g(struct S *ctx) {
+  MYMACRO(ctx);
+  return 0;
+}
+
+// Test that asm import does not fail.
+int inlineAsm() {
+  int res;
+  asm("mov $42, %0"
+      : "=r"(res));
+  return res;
+}
+
+// Implicit function.
+int identImplicit(int in) {
+  return in;
+}
+
+// ASTImporter doesn't support this construct.
+int structInProto(struct DataType {int a;int b; } * d) {
+  return 0;
+}
Index: cfe/trunk/test/Analysis/Inputs/ctu-other.c.externalFnMap.txt
===================================================================
--- cfe/trunk/test/Analysis/Inputs/ctu-other.c.externalFnMap.txt
+++ cfe/trunk/test/Analysis/Inputs/ctu-other.c.externalFnMap.txt
@@ -0,0 +1,6 @@
+c:@F@inlineAsm ctu-other.c.ast
+c:@F@g ctu-other.c.ast
+c:@F@f ctu-other.c.ast
+c:@F@enumCheck ctu-other.c.ast
+c:@F@identImplicit ctu-other.c.ast
+c:@F@structInProto ctu-other.c.ast
Index: cfe/trunk/test/Analysis/Inputs/ctu-other.cpp.externalFnMap.txt
===================================================================
--- cfe/trunk/test/Analysis/Inputs/ctu-other.cpp.externalFnMap.txt
+++ cfe/trunk/test/Analysis/Inputs/ctu-other.cpp.externalFnMap.txt
@@ -0,0 +1,15 @@
+c:@N@chns@F@chf1#I# ctu-other.cpp.ast
+c:@N@myns@N@embed_ns@F@fens#I# ctu-other.cpp.ast
+c:@F@g#I# ctu-other.cpp.ast
+c:@S@mycls@F@fscl#I#S ctu-other.cpp.ast
+c:@S@mycls@F@fcl#I# ctu-other.cpp.ast
+c:@N@myns@S@embed_cls@F@fecl#I# ctu-other.cpp.ast
+c:@S@mycls@S@embed_cls2@F@fecl2#I# ctu-other.cpp.ast
+c:@F@f#I# ctu-other.cpp.ast
+c:@N@myns@F@fns#I# ctu-other.cpp.ast
+c:@F@h#I# ctu-other.cpp.ast
+c:@F@h_chain#I# ctu-chain.cpp.ast
+c:@N@chns@S@chcls@F@chf4#I# ctu-chain.cpp.ast
+c:@N@chns@F@chf2#I# ctu-chain.cpp.ast
+c:@F@fun_using_anon_struct#I# ctu-other.cpp.ast
+c:@F@other_macro_diag#I# ctu-other.cpp.ast
Index: cfe/trunk/test/Analysis/Inputs/externalFnMap.txt
===================================================================
--- cfe/trunk/test/Analysis/Inputs/externalFnMap.txt
+++ cfe/trunk/test/Analysis/Inputs/externalFnMap.txt
@@ -1,15 +0,0 @@
-c:@N@chns@F@chf1#I# ctu-other.cpp.ast
-c:@N@myns@N@embed_ns@F@fens#I# ctu-other.cpp.ast
-c:@F@g#I# ctu-other.cpp.ast
-c:@S@mycls@F@fscl#I#S ctu-other.cpp.ast
-c:@S@mycls@F@fcl#I# ctu-other.cpp.ast
-c:@N@myns@S@embed_cls@F@fecl#I# ctu-other.cpp.ast
-c:@S@mycls@S@embed_cls2@F@fecl2#I# ctu-other.cpp.ast
-c:@F@f#I# ctu-other.cpp.ast
-c:@N@myns@F@fns#I# ctu-other.cpp.ast
-c:@F@h#I# ctu-other.cpp.ast
-c:@F@h_chain#I# ctu-chain.cpp.ast
-c:@N@chns@S@chcls@F@chf4#I# ctu-chain.cpp.ast
-c:@N@chns@F@chf2#I# ctu-chain.cpp.ast
-c:@F@fun_using_anon_struct#I# ctu-other.cpp.ast
-c:@F@other_macro_diag#I# ctu-other.cpp.ast
Index: cfe/trunk/test/Analysis/ctu-main.c
===================================================================
--- cfe/trunk/test/Analysis/ctu-main.c
+++ cfe/trunk/test/Analysis/ctu-main.c
@@ -0,0 +1,67 @@
+// RUN: rm -rf %t && mkdir %t
+// RUN: mkdir -p %t/ctudir2
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu \
+// RUN:   -emit-pch -o %t/ctudir2/ctu-other.c.ast %S/Inputs/ctu-other.c
+// RUN: cp %S/Inputs/ctu-other.c.externalFnMap.txt %t/ctudir2/externalFnMap.txt
+// RUN: %clang_cc1 -triple x86_64-pc-linux-gnu -fsyntax-only -std=c89 -analyze \
+// RUN:   -analyzer-checker=core,debug.ExprInspection \
+// RUN:   -analyzer-config experimental-enable-naive-ctu-analysis=true \
+// RUN:   -analyzer-config ctu-dir=%t/ctudir2 \
+// RUN:   -verify %s
+
+void clang_analyzer_eval(int);
+
+// Test typedef and global variable in function.
+typedef struct {
+  int a;
+  int b;
+} FooBar;
+extern FooBar fb;
+int f(int);
+void testGlobalVariable() {
+  clang_analyzer_eval(f(5) == 1);         // expected-warning{{TRUE}}
+}
+
+// Test enums.
+int enumCheck(void);
+enum A { x,
+         y,
+         z };
+void testEnum() {
+  clang_analyzer_eval(x == 0);            // expected-warning{{TRUE}}
+  clang_analyzer_eval(enumCheck() == 42); // expected-warning{{TRUE}}
+}
+
+// Test that asm import does not fail.
+int inlineAsm();
+int testInlineAsm() {
+  return inlineAsm();
+}
+
+// Test reporting error in a macro.
+struct S;
+int g(struct S *);
+void testMacro(void) {
+  g(0); // expected-warning@Inputs/ctu-other.c:29 {{Access to field 'a' results in a dereference of a null pointer (loaded from variable 'ctx')}}
+}
+
+// The external function prototype is incomplete.
+// warning:implicit functions are prohibited by c99
+void testImplicit() {
+  int res = identImplicit(6);   // external implicit functions are not inlined
+  clang_analyzer_eval(res == 6); // expected-warning{{TRUE}}
+}
+
+// Tests the import of functions that have a struct parameter
+// defined in its prototype.
+struct DataType {
+  int a;
+  int b;
+};
+int structInProto(struct DataType *d);
+void testStructDefInArgument() {
+  struct DataType d;
+  d.a = 1;
+  d.b = 0;
+  clang_analyzer_eval(structInProto(&d) == 0); // expected-warning{{TRUE}} expected-warning{{FALSE}}
+}
Index: cfe/trunk/test/Analysis/ctu-main.cpp
===================================================================
--- cfe/trunk/test/Analysis/ctu-main.cpp
+++ cfe/trunk/test/Analysis/ctu-main.cpp
@@ -4,7 +4,7 @@
 // RUN:   -emit-pch -o %t/ctudir/ctu-other.cpp.ast %S/Inputs/ctu-other.cpp
 // RUN: %clang_cc1 -triple x86_64-pc-linux-gnu \
 // RUN:   -emit-pch -o %t/ctudir/ctu-chain.cpp.ast %S/Inputs/ctu-chain.cpp
-// RUN: cp %S/Inputs/externalFnMap.txt %t/ctudir/
+// RUN: cp %S/Inputs/ctu-other.cpp.externalFnMap.txt %t/ctudir/externalFnMap.txt
 // RUN: %clang_analyze_cc1 -triple x86_64-pc-linux-gnu \
 // RUN:   -analyzer-checker=core,debug.ExprInspection \
 // RUN:   -analyzer-config experimental-enable-naive-ctu-analysis=true \