reimplement the tblgen lexer with a simple hand-written lexer. This eliminates

one dependency on flex and gets rid of two ".cvs" files.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44210 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 74 insertions, 0 deletions

diff --git a/utils/TableGen/TGLexer.h b/utils/TableGen/TGLexer.h
new file mode 100644
index 0000000000..517b81a496
--- /dev/null
+++ b/utils/TableGen/TGLexer.h
@@ -0,0 +1,74 @@
+//===- TGLexer.h - Lexer for TableGen Files ---------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by Chris Lattner and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class represents the Lexer for tablegen files.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef TGLEXER_H
+#define TGLEXER_H
+
+#include <vector>
+#include <string>
+#include <iosfwd>
+
+namespace llvm {
+class MemoryBuffer;
+
+class TGLexer {
+  const char *CurPtr;
+  unsigned CurLineNo;
+  MemoryBuffer *CurBuf;
+
+  /// IncludeRec / IncludeStack - This captures the current set of include
+  /// directives we are nested within.
+  struct IncludeRec {
+    MemoryBuffer *Buffer;
+    const char *CurPtr;
+    unsigned LineNo;
+    IncludeRec(MemoryBuffer *buffer, const char *curPtr, unsigned lineNo)
+      : Buffer(buffer), CurPtr(curPtr), LineNo(lineNo) {}
+  };
+  std::vector<IncludeRec> IncludeStack;
+  
+  // IncludeDirectories - This is the list of directories we should search for
+  // include files in.
+  std::vector<std::string> IncludeDirectories;
+  
+  std::string TheError;
+public:
+  TGLexer(MemoryBuffer *StartBuf);
+  ~TGLexer();
+  
+  void setIncludeDirs(const std::vector<std::string> &Dirs) {
+    IncludeDirectories = Dirs;
+  }
+  
+  int LexToken();
+
+  const std::string getError() const { return TheError; }
+  
+  std::ostream &err();
+  void PrintIncludeStack(std::ostream &OS);
+private:
+  int getNextChar();
+  void SkipBCPLComment();
+  bool SkipCComment();
+  int LexIdentifier();
+  bool LexInclude();
+  int LexString();
+  int LexVarName();
+  int LexNumber();
+  int LexBracket();
+  int LexExclaim();
+};
+  
+} // end namespace llvm
+
+#endif