Fix PR5633 by making the preprocessor handle the case where we can

stat a file but where mmaping it fails.  In this case, we emit an
error like:
t.c:1:10: fatal error: error opening file '../../foo.h'

instead of "cannot find file".

llvm-svn: 90110

1 files changed, 2 insertions, 1 deletions

diff --git a/clang/lib/Frontend/CacheTokens.cpp b/clang/lib/Frontend/CacheTokens.cpp
index 98126c89ebe..7296246df21 100644
--- a/clang/lib/Frontend/CacheTokens.cpp
+++ b/clang/lib/Frontend/CacheTokens.cpp
@@ -482,7 +482,8 @@ void PTHWriter::GeneratePTH(const std::string *MainFile) {
     if (!B) continue;
 
     FileID FID = SM.createFileID(FE, SourceLocation(), SrcMgr::C_User);
-    Lexer L(FID, SM, LOpts);
+    const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
+    Lexer L(FID, FromFile, SM, LOpts);
     PM.insert(FE, LexTokens(L));
   }