Revamp the SourceManager to separate the representation of parsed

source locations from source locations loaded from an AST/PCH file.

Previously, loading an AST/PCH file involved carefully pre-allocating
space at the beginning of the source manager for the source locations
and FileIDs that correspond to the prefix, and then appending the
source locations/FileIDs used for parsing the remaining translation
unit. This design forced us into loading PCH files early, as a prefix,
whic has become a rather significant limitation.

This patch splits the SourceManager space into two parts: for source
location "addresses", the lower values (growing upward) are used to
describe parsed code, while upper values (growing downward) are used
for source locations loaded from AST/PCH files. Similarly, positive
FileIDs are used to describe parsed code while negative FileIDs are
used to file/macro locations loaded from AST/PCH files. As a result,
we can load PCH/AST files even during parsing, making various
improvemnts in the future possible, e.g., teaching #include <foo.h> to
look for and load <foo.h.gch> if it happens to be already available.

This patch was originally written by Sebastian Redl, then brought
forward to the modern age by Jonathan Turner, and finally
polished/finished by me to be committed.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135484 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 6 deletions

diff --git a/include/clang/Basic/SourceManagerInternals.h b/include/clang/Basic/SourceManagerInternals.h
index 3f5d1a35e5..6a74d41b54 100644
--- a/include/clang/Basic/SourceManagerInternals.h
+++ b/include/clang/Basic/SourceManagerInternals.h
@@ -84,7 +84,7 @@ class LineTableInfo {
 
   /// LineEntries - This is a map from FileIDs to a list of line entries (sorted
   /// by the offset they occur in the file.
-  std::map<unsigned, std::vector<LineEntry> > LineEntries;
+  std::map<int, std::vector<LineEntry> > LineEntries;
 public:
   LineTableInfo() {
   }
@@ -104,25 +104,25 @@ public:
   }
   unsigned getNumFilenames() const { return FilenamesByID.size(); }
 
-  void AddLineNote(unsigned FID, unsigned Offset,
+  void AddLineNote(int FID, unsigned Offset,
                    unsigned LineNo, int FilenameID);
-  void AddLineNote(unsigned FID, unsigned Offset,
+  void AddLineNote(int FID, unsigned Offset,
                    unsigned LineNo, int FilenameID,
                    unsigned EntryExit, SrcMgr::CharacteristicKind FileKind);
 
 
   /// FindNearestLineEntry - Find the line entry nearest to FID that is before
   /// it.  If there is no line entry before Offset in FID, return null.
-  const LineEntry *FindNearestLineEntry(unsigned FID, unsigned Offset);
+  const LineEntry *FindNearestLineEntry(int FID, unsigned Offset);
 
   // Low-level access
-  typedef std::map<unsigned, std::vector<LineEntry> >::iterator iterator;
+  typedef std::map<int, std::vector<LineEntry> >::iterator iterator;
   iterator begin() { return LineEntries.begin(); }
   iterator end() { return LineEntries.end(); }
 
   /// \brief Add a new line entry that has already been encoded into
   /// the internal representation of the line table.
-  void AddEntry(unsigned FID, const std::vector<LineEntry> &Entries);
+  void AddEntry(int FID, const std::vector<LineEntry> &Entries);
 };
 
 } // end namespace clang