Replace an unreachable error path with an assert

(SourceManager::createFileID cannot return an invalid file ID).
Also update a comment to reflect this.

llvm-svn: 134168

2 files changed, 3 insertions, 6 deletions

diff --git a/clang/include/clang/Basic/SourceManager.h b/clang/include/clang/Basic/SourceManager.h
index 4227add5673..f2a8bf35155 100644
--- a/clang/include/clang/Basic/SourceManager.h
+++ b/clang/include/clang/Basic/SourceManager.h
@@ -500,8 +500,8 @@ public:
   //===--------------------------------------------------------------------===//
 
   /// createFileID - Create a new FileID that represents the specified file
-  /// being #included from the specified IncludePosition.  This returns 0 on
-  /// error and translates NULL into standard input.
+  /// being #included from the specified IncludePosition.  This translates NULL
+  /// into standard input.
   /// PreallocateID should be non-zero to specify which pre-allocated,
   /// lazily computed source location is being filled in by this operation.
   FileID createFileID(const FileEntry *SourceFile, SourceLocation IncludePos,
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index b6925b70b70..f74aad3c816 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -1208,10 +1208,7 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
   // Look up the file, create a File ID for it.
   FileID FID = SourceMgr.createFileID(File, FilenameTok.getLocation(),
                                       FileCharacter);
-  if (FID.isInvalid()) {
-    Diag(FilenameTok, diag::err_pp_file_not_found) << Filename;
-    return;
-  }
+  assert(!FID.isInvalid() && "Expected valid file ID");
 
   // Finally, if all is good, enter the new file!
   EnterSourceFile(FID, CurDir, FilenameTok.getLocation());