refactor some common initialization code out of the two lexer ctors.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62411 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Lex/Lexer.h

@@ -69,6 +69,8 @@ class Lexer : public PreprocessorLexer {
   Lexer(const Lexer&);          // DO NOT IMPLEMENT
   void operator=(const Lexer&); // DO NOT IMPLEMENT
   friend class Preprocessor;
+  
+  void InitLexer(const char *BufStart, const char *BufPtr, const char *BufEnd);
 public:
     
   /// Lexer constructor - Create a new lexer object for the specified buffer

lib/Lex/Lexer.cpp

@@ -57,39 +57,20 @@ tok::ObjCKeywordKind Token::getObjCKeywordID() const {
 // Lexer Class Implementation
 //===----------------------------------------------------------------------===//
 
-
-/// Lexer constructor - Create a new lexer object for the specified buffer
-/// with the specified preprocessor managing the lexing process.  This lexer
-/// assumes that the associated file buffer and Preprocessor objects will
-/// outlive it, so it doesn't take ownership of either of them.
-Lexer::Lexer(SourceLocation fileloc, Preprocessor &PP,
-             const char *BufStart, const char *BufEnd)
-// FIXME: This is really horrible and only needed for _Pragma lexers, split this
-// out of the main lexer path!
-  : PreprocessorLexer(&PP, 
-                      PP.getSourceManager().getCanonicalFileID(
-                      PP.getSourceManager().getSpellingLoc(fileloc))),
-                      FileLoc(fileloc),
-    Features(PP.getLangOptions()) {
-      
-  SourceManager &SourceMgr = PP.getSourceManager();
-  const llvm::MemoryBuffer *InputFile = SourceMgr.getBuffer(getFileID());
-      
-  Is_PragmaLexer = false;
+void Lexer::InitLexer(const char *BufStart, const char *BufPtr, 
+                      const char *BufEnd) {
   InitCharacterInfo();
   
-  // BufferStart must always be InputFile->getBufferStart().
-  BufferStart = InputFile->getBufferStart();
+  BufferStart = BufStart;
+  BufferPtr = BufPtr;
+  BufferEnd = BufEnd;
   
-  // BufferPtr and BufferEnd can start out somewhere inside the current buffer.
-  // If unspecified, they starts at the start/end of the buffer.
-  BufferPtr = BufStart ? BufStart : BufferStart;
-  BufferEnd = BufEnd ? BufEnd : InputFile->getBufferEnd();
-
-  assert(BufferEnd[0] == 0 &&
+  assert(BufEnd[0] == 0 &&
          "We assume that the input buffer has a null character at the end"
          " to simplify lexing!");
   
+  Is_PragmaLexer = false;
+
   // Start of the file is a start of line.
   IsAtStartOfLine = true;
   
@@ -105,8 +86,37 @@ Lexer::Lexer(SourceLocation fileloc, Preprocessor &PP,
   // or otherwise skipping over tokens.
   LexingRawMode = false;
   
-  // Default to keeping comments if the preprocessor wants them.
+  // Default to not keeping comments.
   ExtendedTokenMode = 0;
+}
+
+
+/// Lexer constructor - Create a new lexer object for the specified buffer
+/// with the specified preprocessor managing the lexing process.  This lexer
+/// assumes that the associated file buffer and Preprocessor objects will
+/// outlive it, so it doesn't take ownership of either of them.
+Lexer::Lexer(SourceLocation fileloc, Preprocessor &PP,
+             const char *BufPtr, const char *BufEnd)
+// FIXME: This is really horrible and only needed for _Pragma lexers, split this
+// out of the main lexer path!
+  : PreprocessorLexer(&PP, 
+                      PP.getSourceManager().getCanonicalFileID(
+                      PP.getSourceManager().getSpellingLoc(fileloc))),
+                      FileLoc(fileloc),
+    Features(PP.getLangOptions()) {
+      
+  SourceManager &SourceMgr = PP.getSourceManager();
+  const llvm::MemoryBuffer *InputFile = SourceMgr.getBuffer(getFileID());
+      
+  // BufferPtr and BufferEnd can start out somewhere inside the current buffer.
+  // If unspecified, they starts at the start/end of the buffer.
+  const char *BufStart = InputFile->getBufferStart();
+  if (BufPtr == 0) BufPtr = BufStart;
+  if (BufEnd == 0) BufEnd = InputFile->getBufferEnd();
+      
+  InitLexer(BufStart, BufPtr, BufEnd);
+  
+  // Default to keeping comments if the preprocessor wants them.
   SetCommentRetentionState(PP.getCommentRetentionState());
 }
 
@@ -114,37 +124,20 @@ Lexer::Lexer(SourceLocation fileloc, Preprocessor &PP,
 /// suitable for calls to 'LexRawToken'.  This lexer assumes that the text
 /// range will outlive it, so it doesn't take ownership of it.
 Lexer::Lexer(SourceLocation fileloc, const LangOptions &features,
-             const char *BufStart, const char *BufEnd,
+             const char *BufPtr, const char *BufEnd,
              const llvm::MemoryBuffer *FromFile)
   : FileLoc(fileloc), Features(features) {
       
-  Is_PragmaLexer = false;
-  InitCharacterInfo();
 
   // If a MemoryBuffer was specified, use its start as BufferStart. This affects
   // the source location objects produced by this lexer.
-  BufferStart = FromFile ? FromFile->getBufferStart() : BufStart;
-  BufferPtr = BufStart;
-  BufferEnd = BufEnd;
+  const char *BufStart = BufPtr;
+  if (FromFile) BufStart = FromFile->getBufferStart();
 
-  assert(BufferEnd[0] == 0 &&
-         "We assume that the input buffer has a null character at the end"
-         " to simplify lexing!");
-  
-  // Start of the file is a start of line.
-  IsAtStartOfLine = true;
-  
-  // We are not after parsing a #.
-  ParsingPreprocessorDirective = false;
-  
-  // We are not after parsing #include.
-  ParsingFilename = false;
+  InitLexer(BufStart, BufPtr, BufEnd);
   
   // We *are* in raw mode.
   LexingRawMode = true;
-  
-  // Default to not keeping comments in raw mode.
-  ExtendedTokenMode = 0;
 }