Introduce a new PresumedLoc class to represent the concept of a location
as reported to the user and as manipulated by #line.  This is what __FILE__,
__INCLUDE_LEVEL__, diagnostics and other things should follow (but not 
dependency generation!).  

This patch also includes several cleanups along the way: 

- SourceLocation now has a dump method, and several other places 
  that did similar things now use it.
- I cleaned up some code in AnalysisConsumer, but it should probably be
  simplified further now that NamedDecl is better.
- TextDiagnosticPrinter is now simplified and cleaned up a bit.

This patch is a prerequisite for #line, but does not actually provide 
any #line functionality.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63098 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Driver/DependencyFile.cpp b/Driver/DependencyFile.cpp
index 282164f..0d4ee91 100644
--- a/Driver/DependencyFile.cpp
+++ b/Driver/DependencyFile.cpp
@@ -13,6 +13,7 @@
 
 #include "clang.h"
 #include "clang/Basic/SourceManager.h"
+#include "clang/Basic/FileManager.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/DirectoryLookup.h"
@@ -167,8 +168,14 @@
                                          SrcMgr::CharacteristicKind FileType) {
   if (Reason != PPCallbacks::EnterFile)
     return;
-
-  const char *Filename = PP->getSourceManager().getSourceName(Loc);
+  
+  // Depedency generation really does want to go all the way to the file entry
+  // for a source location to find out what is depended on.  We do not want
+  // #line markers to affect dependency generation!
+  SourceManager &SM = PP->getSourceManager();
+  
+  FileID FID = SM.getFileID(SM.getInstantiationLoc(Loc));
+  const char *Filename = SM.getFileEntryForID(FID)->getName();
   if (!FileMatchesDepCriteria(Filename, FileType))
     return;