From: David Majnemer <david.majnemer@gmail.com>
Date: Tue, 12 Apr 2016 16:33:53 +0000 (+0000)
Subject: [FileManager] Don't crash if reading from stdin and stat(".") fails
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8250364e5008fd7a8c0109022d60fd62698838d9;p=clang

[FileManager] Don't crash if reading from stdin and stat(".") fails

addAncestorsAsVirtualDirs("<stdin>") quickly returns without doing work
because "<stdin>" has no parent_path.  This violates the expectation
that a subsequent call to getDirectoryFromFile("<stdin>") would succeed.
Instead, it fails because it uses the "." if the file has no path
component.

Fix this by keeping the behavior between addAncestorsAsVirtualDirs and
getDirectoryFromFile symmetric.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@266089 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Basic/FileManager.cpp b/lib/Basic/FileManager.cpp
index ba016db011..c4cc8dc541 100644
--- a/lib/Basic/FileManager.cpp
+++ b/lib/Basic/FileManager.cpp
@@ -123,7 +123,7 @@ static const DirectoryEntry *getDirectoryFromFile(FileManager &FileMgr,
 void FileManager::addAncestorsAsVirtualDirs(StringRef Path) {
   StringRef DirName = llvm::sys::path::parent_path(Path);
   if (DirName.empty())
-    return;
+    DirName = ".";
 
   auto &NamedDirEnt =
       *SeenDirEntries.insert(std::make_pair(DirName, nullptr)).first;