[FileCollector] Fix that the file system case-sensitivity check was inverted

real_path returns an `std::error_code` which evaluates to `true` in case an
error happens and `false` if not. This code was checking the inverse, so
case-insensitive file systems ended up being detected as case sensitive.

Tested using an LLDB reproducer test as we anyway need a real file system and
also some matching logic to detect whether the respective file system is
case-sensitive (which the test is doing via some Python checks that we can't
really emulate with the usual FileCheck logic).

Fixes rdar://67003004

Reviewed By: JDevlieghere

Differential Revision: https://reviews.llvm.org/D96795

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Support/FileCollector.cpp b/llvm/lib/Support/FileCollector.cpp
index 9948207..7d23d03 100644
--- a/llvm/lib/Support/FileCollector.cpp
+++ b/llvm/lib/Support/FileCollector.cpp
@@ -35,7 +35,7 @@ static bool isCaseSensitivePath(StringRef Path) {
   SmallString<256> TmpDest = Path, UpperDest, RealDest;
 
   // Remove component traversals, links, etc.
-  if (!sys::fs::real_path(Path, TmpDest))
+  if (sys::fs::real_path(Path, TmpDest))
     return true; // Current default value in vfs.yaml
   Path = TmpDest;
 
@@ -44,7 +44,7 @@ static bool isCaseSensitivePath(StringRef Path) {
   // sensitive in the absence of real_path, since this is the YAMLVFSWriter
   // default.
   UpperDest = Path.upper();
-  if (sys::fs::real_path(UpperDest, RealDest) && Path.equals(RealDest))
+  if (!sys::fs::real_path(UpperDest, RealDest) && Path.equals(RealDest))
     return false;
   return true;
 }