Move pieces of Lexer that the Preprocessor mutates to a new base class 'PreprocessorLexer'. This will also be the base class of the new Preprocessed-Token-Header (PTH) lexer. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59168 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 107 insertions, 0 deletions

diff --git a/include/clang/Lex/PreprocessorLexer.h b/include/clang/Lex/PreprocessorLexer.h
new file mode 100644
index 0000000000..7ac1eea20c
--- /dev/null
+++ b/include/clang/Lex/PreprocessorLexer.h
@@ -0,0 +1,107 @@
+//===--- PreprocessorLexer.h - C Language Family Lexer ----------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the PreprocessorLexer interface.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_PreprocessorLexer_H
+#define LLVM_CLANG_PreprocessorLexer_H
+
+#include "clang/Lex/MultipleIncludeOpt.h"
+#include "clang/Lex/Token.h"
+#include <vector>
+
+namespace clang {
+
+class Preprocessor;
+
+class PreprocessorLexer {
+protected:  
+  // Context-specific lexing flags set by the preprocessor.
+  
+  /// ParsingPreprocessorDirective - This is true when parsing #XXX.  This turns
+  /// '\n' into a tok::eom token.
+  bool ParsingPreprocessorDirective;
+  
+  /// ParsingFilename - True after #include: this turns <xx> into a
+  /// tok::angle_string_literal token.
+  bool ParsingFilename;
+  
+  /// LexingRawMode - True if in raw mode:  This flag disables interpretation of
+  /// tokens and is a far faster mode to lex in than non-raw-mode.  This flag:
+  ///  1. If EOF of the current lexer is found, the include stack isn't popped.
+  ///  2. Identifier information is not looked up for identifier tokens.  As an
+  ///     effect of this, implicit macro expansion is naturally disabled.
+  ///  3. "#" tokens at the start of a line are treated as normal tokens, not
+  ///     implicitly transformed by the lexer.
+  ///  4. All diagnostic messages are disabled.
+  ///  5. No callbacks are made into the preprocessor.
+  ///
+  /// Note that in raw mode that the PP pointer may be null.
+  bool LexingRawMode;
+  
+  /// MIOpt - This is a state machine that detects the #ifndef-wrapping a file 
+  /// idiom for the multiple-include optimization.
+  MultipleIncludeOpt MIOpt;
+  
+  /// ConditionalStack - Information about the set of #if/#ifdef/#ifndef blocks
+  /// we are currently in.
+  std::vector<PPConditionalInfo> ConditionalStack;
+  
+  PreprocessorLexer(const PreprocessorLexer&);          // DO NOT IMPLEMENT
+  void operator=(const PreprocessorLexer&); // DO NOT IMPLEMENT
+  friend class Preprocessor;
+  
+  PreprocessorLexer() {}
+  
+protected:
+  
+  //===--------------------------------------------------------------------===//
+  // #if directive handling.
+  
+  /// pushConditionalLevel - When we enter a #if directive, this keeps track of
+  /// what we are currently in for diagnostic emission (e.g. #if with missing
+  /// #endif).
+  void pushConditionalLevel(SourceLocation DirectiveStart, bool WasSkipping,
+                            bool FoundNonSkip, bool FoundElse) {
+    PPConditionalInfo CI;
+    CI.IfLoc = DirectiveStart;
+    CI.WasSkipping = WasSkipping;
+    CI.FoundNonSkip = FoundNonSkip;
+    CI.FoundElse = FoundElse;
+    ConditionalStack.push_back(CI);
+  }
+  void pushConditionalLevel(const PPConditionalInfo &CI) {
+    ConditionalStack.push_back(CI);
+  }    
+  
+  /// popConditionalLevel - Remove an entry off the top of the conditional
+  /// stack, returning information about it.  If the conditional stack is empty,
+  /// this returns true and does not fill in the arguments.
+  bool popConditionalLevel(PPConditionalInfo &CI) {
+    if (ConditionalStack.empty()) return true;
+    CI = ConditionalStack.back();
+    ConditionalStack.pop_back();
+    return false;
+  }
+  
+  /// peekConditionalLevel - Return the top of the conditional stack.  This
+  /// requires that there be a conditional active.
+  PPConditionalInfo &peekConditionalLevel() {
+    assert(!ConditionalStack.empty() && "No conditionals active!");
+    return ConditionalStack.back();
+  }
+  
+  unsigned getConditionalStackDepth() const { return ConditionalStack.size(); }    
+};
+
+}  // end namespace clang
+
+#endif