[Preprocessor] Fix crash emitting note with framework location for "file not found" error.

A filename can be remapped with a header map to point to a framework
header and we can find the corresponding framework without the header.
But if the original filename doesn't have a remapped framework name,
we'll fail to find its location and will dereference a null pointer
during diagnostics emission.

Fix by tracking remappings better and emit the note only if a framework
is found before any of the remappings.

rdar://problem/48883447

Reviewers: arphaman, erik.pilkington, jkorous

Reviewed By: arphaman

Subscribers: dexonsmith, cfe-commits

Differential Revision: https://reviews.llvm.org/D61707

llvm-svn: 361779

1 files changed, 7 insertions, 0 deletions

diff --git a/clang/test/Preprocessor/Inputs/include-header-missing-in-framework/TestFramework.hmap.json b/clang/test/Preprocessor/Inputs/include-header-missing-in-framework/TestFramework.hmap.json
new file mode 100644
index 00000000000..193c7a779c6
--- /dev/null
+++ b/clang/test/Preprocessor/Inputs/include-header-missing-in-framework/TestFramework.hmap.json
@@ -0,0 +1,7 @@
+{
+  "mappings" :
+    {
+     "RemappedHeader.h" : "TestFramework/RemappedHeader.h",
+     "TestFramework/BeforeRemapping.h" : "TestFramework/AfterRemapping.h"
+    }
+}