PTH:

- Use canonical FileID when using getSpelling() caching.  This
  addresses some cache misses we were seeing with -fsyntax-only on
  Cocoa.h
- Added Preprocessor::getPhysicalCharacterAt() utility method for
  clients to grab the first character at a specified sourcelocation.
  This uses the PTH spelling cache.
- Modified Sema::ActOnNumericConstant() to use
  Preprocessor::getPhysicalCharacterAt() instead of
  SourceManager::getCharacterData() (to get PTH hits).

These changes cause -fsyntax-only to not page in any sources from
Cocoa.h.  We see a speedup of 27%.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62193 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 0 deletions

diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 54dc1b62df..5ee8378d52 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -449,6 +449,20 @@ public:
   /// if an internal buffer is returned.
   unsigned getSpelling(const Token &Tok, const char *&Buffer) const;
   
+  /// getPhysicalCharacterAt - Return a pointer to the start of the specified
+  ///  location in the appropriate MemoryBuffer.
+  char getPhysicalCharacterAt(SourceLocation SL) const {
+    if (PTH) {
+      SL = SourceMgr.getPhysicalLoc(SL);
+      unsigned fid = SourceMgr.getCanonicalFileID(SL);
+      unsigned fpos = SourceMgr.getFullFilePos(SL);      
+      const char* data;
+      if (PTH->getSpelling(fid, fpos, data))
+        return *data;
+    }
+
+    return *SourceMgr.getCharacterData(SL);
+  }
   
   /// CreateString - Plop the specified string into a scratch buffer and return
   /// a location for it.  If specified, the source location provides a source