Import Clang, at r72732.vendor/clang/clang-r72732

1 files changed, 345 insertions, 0 deletions

diff --git a/lib/Lex/PPLexerChange.cpp b/lib/Lex/PPLexerChange.cpp
new file mode 100644
index 000000000000..2a05ba336fca
--- /dev/null
+++ b/lib/Lex/PPLexerChange.cpp
@@ -0,0 +1,345 @@
+//===--- PPLexerChange.cpp - Handle changing lexers in the preprocessor ---===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements pieces of the Preprocessor interface that manage the
+// current lexer stack.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/HeaderSearch.h"
+#include "clang/Lex/MacroInfo.h"
+#include "clang/Lex/LexDiagnostic.h"
+#include "clang/Basic/SourceManager.h"
+#include "llvm/Support/MemoryBuffer.h"
+using namespace clang;
+
+PPCallbacks::~PPCallbacks() {}
+
+//===----------------------------------------------------------------------===//
+// Miscellaneous Methods.
+//===----------------------------------------------------------------------===//
+
+/// isInPrimaryFile - Return true if we're in the top-level file, not in a
+/// #include.  This looks through macro expansions and active _Pragma lexers.
+bool Preprocessor::isInPrimaryFile() const {
+  if (IsFileLexer())
+    return IncludeMacroStack.empty();
+  
+  // If there are any stacked lexers, we're in a #include.
+  assert(IsFileLexer(IncludeMacroStack[0]) &&
+         "Top level include stack isn't our primary lexer?");
+  for (unsigned i = 1, e = IncludeMacroStack.size(); i != e; ++i)
+    if (IsFileLexer(IncludeMacroStack[i]))
+      return false;
+  return true;
+}
+
+/// getCurrentLexer - Return the current file lexer being lexed from.  Note
+/// that this ignores any potentially active macro expansions and _Pragma
+/// expansions going on at the time.
+PreprocessorLexer *Preprocessor::getCurrentFileLexer() const {
+  if (IsFileLexer())
+    return CurPPLexer;
+  
+  // Look for a stacked lexer.
+  for (unsigned i = IncludeMacroStack.size(); i != 0; --i) {
+    const IncludeStackInfo& ISI = IncludeMacroStack[i-1];
+    if (IsFileLexer(ISI))
+      return ISI.ThePPLexer;
+  }
+  return 0;
+}
+
+
+//===----------------------------------------------------------------------===//
+// Methods for Entering and Callbacks for leaving various contexts
+//===----------------------------------------------------------------------===//
+
+/// EnterSourceFile - Add a source file to the top of the include stack and
+/// start lexing tokens from it instead of the current buffer.  Return true
+/// on failure.
+void Preprocessor::EnterSourceFile(FileID FID, const DirectoryLookup *CurDir) {
+  assert(CurTokenLexer == 0 && "Cannot #include a file inside a macro!");
+  ++NumEnteredSourceFiles;
+  
+  if (MaxIncludeStackDepth < IncludeMacroStack.size())
+    MaxIncludeStackDepth = IncludeMacroStack.size();
+
+  if (PTH) {
+    if (PTHLexer *PL = PTH->CreateLexer(FID))
+      return EnterSourceFileWithPTH(PL, CurDir);
+  }
+  EnterSourceFileWithLexer(new Lexer(FID, *this), CurDir);
+}  
+
+/// EnterSourceFileWithLexer - Add a source file to the top of the include stack
+///  and start lexing tokens from it instead of the current buffer.
+void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer, 
+                                            const DirectoryLookup *CurDir) {
+    
+  // Add the current lexer to the include stack.
+  if (CurPPLexer || CurTokenLexer)
+    PushIncludeMacroStack();
+
+  CurLexer.reset(TheLexer);
+  CurPPLexer = TheLexer;
+  CurDirLookup = CurDir;
+  
+  // Notify the client, if desired, that we are in a new source file.
+  if (Callbacks && !CurLexer->Is_PragmaLexer) {
+    SrcMgr::CharacteristicKind FileType =
+       SourceMgr.getFileCharacteristic(CurLexer->getFileLoc());
+    
+    Callbacks->FileChanged(CurLexer->getFileLoc(),
+                           PPCallbacks::EnterFile, FileType);
+  }
+}
+
+/// EnterSourceFileWithPTH - Add a source file to the top of the include stack
+/// and start getting tokens from it using the PTH cache.
+void Preprocessor::EnterSourceFileWithPTH(PTHLexer *PL, 
+                                          const DirectoryLookup *CurDir) {
+  
+  if (CurPPLexer || CurTokenLexer)
+    PushIncludeMacroStack();
+
+  CurDirLookup = CurDir;
+  CurPTHLexer.reset(PL);
+  CurPPLexer = CurPTHLexer.get();
+
+  // Notify the client, if desired, that we are in a new source file.
+  if (Callbacks) {
+    FileID FID = CurPPLexer->getFileID();
+    SourceLocation EnterLoc = SourceMgr.getLocForStartOfFile(FID);
+    SrcMgr::CharacteristicKind FileType =
+      SourceMgr.getFileCharacteristic(EnterLoc);
+    Callbacks->FileChanged(EnterLoc, PPCallbacks::EnterFile, FileType);
+  }
+}
+
+/// EnterMacro - Add a Macro to the top of the include stack and start lexing
+/// tokens from it instead of the current buffer.
+void Preprocessor::EnterMacro(Token &Tok, SourceLocation ILEnd,
+                              MacroArgs *Args) {
+  PushIncludeMacroStack();
+  CurDirLookup = 0;
+  
+  if (NumCachedTokenLexers == 0) {
+    CurTokenLexer.reset(new TokenLexer(Tok, ILEnd, Args, *this));
+  } else {
+    CurTokenLexer.reset(TokenLexerCache[--NumCachedTokenLexers]);
+    CurTokenLexer->Init(Tok, ILEnd, Args);
+  }
+}
+
+/// EnterTokenStream - Add a "macro" context to the top of the include stack,
+/// which will cause the lexer to start returning the specified tokens.
+///
+/// If DisableMacroExpansion is true, tokens lexed from the token stream will
+/// not be subject to further macro expansion.  Otherwise, these tokens will
+/// be re-macro-expanded when/if expansion is enabled.
+///
+/// If OwnsTokens is false, this method assumes that the specified stream of
+/// tokens has a permanent owner somewhere, so they do not need to be copied.
+/// If it is true, it assumes the array of tokens is allocated with new[] and
+/// must be freed.
+///
+void Preprocessor::EnterTokenStream(const Token *Toks, unsigned NumToks,
+                                    bool DisableMacroExpansion,
+                                    bool OwnsTokens) {
+  // Save our current state.
+  PushIncludeMacroStack();
+  CurDirLookup = 0;
+
+  // Create a macro expander to expand from the specified token stream.
+  if (NumCachedTokenLexers == 0) {
+    CurTokenLexer.reset(new TokenLexer(Toks, NumToks, DisableMacroExpansion,
+                                       OwnsTokens, *this));
+  } else {
+    CurTokenLexer.reset(TokenLexerCache[--NumCachedTokenLexers]);
+    CurTokenLexer->Init(Toks, NumToks, DisableMacroExpansion, OwnsTokens);
+  }
+}
+
+/// HandleEndOfFile - This callback is invoked when the lexer hits the end of
+/// the current file.  This either returns the EOF token or pops a level off
+/// the include stack and keeps going.
+bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
+  assert(!CurTokenLexer &&
+         "Ending a file when currently in a macro!");
+  
+  // See if this file had a controlling macro.
+  if (CurPPLexer) {  // Not ending a macro, ignore it.
+    if (const IdentifierInfo *ControllingMacro = 
+          CurPPLexer->MIOpt.GetControllingMacroAtEndOfFile()) {
+      // Okay, this has a controlling macro, remember in HeaderFileInfo.
+      if (const FileEntry *FE = 
+            SourceMgr.getFileEntryForID(CurPPLexer->getFileID()))
+        HeaderInfo.SetFileControllingMacro(FE, ControllingMacro);
+    }
+  }
+  
+  // If this is a #include'd file, pop it off the include stack and continue
+  // lexing the #includer file.
+  if (!IncludeMacroStack.empty()) {
+    // We're done with the #included file.
+    RemoveTopOfLexerStack();
+
+    // Notify the client, if desired, that we are in a new source file.
+    if (Callbacks && !isEndOfMacro && CurPPLexer) {
+      SrcMgr::CharacteristicKind FileType =
+        SourceMgr.getFileCharacteristic(CurPPLexer->getSourceLocation());
+      Callbacks->FileChanged(CurPPLexer->getSourceLocation(),
+                             PPCallbacks::ExitFile, FileType); 
+    }
+
+    // Client should lex another token.
+    return false;
+  }
+
+  // If the file ends with a newline, form the EOF token on the newline itself,
+  // rather than "on the line following it", which doesn't exist.  This makes
+  // diagnostics relating to the end of file include the last file that the user
+  // actually typed, which is goodness.
+  if (CurLexer) {
+    const char *EndPos = CurLexer->BufferEnd;
+    if (EndPos != CurLexer->BufferStart && 
+        (EndPos[-1] == '\n' || EndPos[-1] == '\r')) {
+      --EndPos;
+      
+      // Handle \n\r and \r\n:
+      if (EndPos != CurLexer->BufferStart && 
+          (EndPos[-1] == '\n' || EndPos[-1] == '\r') &&
+          EndPos[-1] != EndPos[0])
+        --EndPos;
+    }
+    
+    Result.startToken();
+    CurLexer->BufferPtr = EndPos;
+    CurLexer->FormTokenWithChars(Result, EndPos, tok::eof);
+    
+    // We're done with the #included file.
+    CurLexer.reset();
+  } else {
+    assert(CurPTHLexer && "Got EOF but no current lexer set!");
+    CurPTHLexer->getEOF(Result);
+    CurPTHLexer.reset();
+  }
+  
+  CurPPLexer = 0;
+
+  // This is the end of the top-level file.  If the diag::pp_macro_not_used
+  // diagnostic is enabled, look for macros that have not been used.
+  if (getDiagnostics().getDiagnosticLevel(diag::pp_macro_not_used) != 
+        Diagnostic::Ignored) {
+    for (macro_iterator I = macro_begin(), E = macro_end(); I != E; ++I)
+      if (!I->second->isUsed())
+        Diag(I->second->getDefinitionLoc(), diag::pp_macro_not_used);
+  }
+  return true;
+}
+
+/// HandleEndOfTokenLexer - This callback is invoked when the current TokenLexer
+/// hits the end of its token stream.
+bool Preprocessor::HandleEndOfTokenLexer(Token &Result) {
+  assert(CurTokenLexer && !CurPPLexer &&
+         "Ending a macro when currently in a #include file!");
+
+  // Delete or cache the now-dead macro expander.
+  if (NumCachedTokenLexers == TokenLexerCacheSize)
+    CurTokenLexer.reset();
+  else
+    TokenLexerCache[NumCachedTokenLexers++] = CurTokenLexer.take();
+
+  // Handle this like a #include file being popped off the stack.
+  return HandleEndOfFile(Result, true);
+}
+
+/// RemoveTopOfLexerStack - Pop the current lexer/macro exp off the top of the
+/// lexer stack.  This should only be used in situations where the current
+/// state of the top-of-stack lexer is unknown.
+void Preprocessor::RemoveTopOfLexerStack() {
+  assert(!IncludeMacroStack.empty() && "Ran out of stack entries to load");
+  
+  if (CurTokenLexer) {
+    // Delete or cache the now-dead macro expander.
+    if (NumCachedTokenLexers == TokenLexerCacheSize)
+      CurTokenLexer.reset();
+    else
+      TokenLexerCache[NumCachedTokenLexers++] = CurTokenLexer.take();
+  }   
+  
+  PopIncludeMacroStack();
+}
+
+/// HandleMicrosoftCommentPaste - When the macro expander pastes together a
+/// comment (/##/) in microsoft mode, this method handles updating the current
+/// state, returning the token on the next source line.
+void Preprocessor::HandleMicrosoftCommentPaste(Token &Tok) {
+  assert(CurTokenLexer && !CurPPLexer &&
+         "Pasted comment can only be formed from macro");
+  
+  // We handle this by scanning for the closest real lexer, switching it to
+  // raw mode and preprocessor mode.  This will cause it to return \n as an
+  // explicit EOM token.
+  PreprocessorLexer *FoundLexer = 0;
+  bool LexerWasInPPMode = false;
+  for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) {
+    IncludeStackInfo &ISI = *(IncludeMacroStack.end()-i-1);
+    if (ISI.ThePPLexer == 0) continue;  // Scan for a real lexer.
+    
+    // Once we find a real lexer, mark it as raw mode (disabling macro
+    // expansions) and preprocessor mode (return EOM).  We know that the lexer
+    // was *not* in raw mode before, because the macro that the comment came
+    // from was expanded.  However, it could have already been in preprocessor
+    // mode (#if COMMENT) in which case we have to return it to that mode and
+    // return EOM.
+    FoundLexer = ISI.ThePPLexer;
+    FoundLexer->LexingRawMode = true;
+    LexerWasInPPMode = FoundLexer->ParsingPreprocessorDirective;
+    FoundLexer->ParsingPreprocessorDirective = true;
+    break;
+  }
+  
+  // Okay, we either found and switched over the lexer, or we didn't find a
+  // lexer.  In either case, finish off the macro the comment came from, getting
+  // the next token.
+  if (!HandleEndOfTokenLexer(Tok)) Lex(Tok);
+  
+  // Discarding comments as long as we don't have EOF or EOM.  This 'comments
+  // out' the rest of the line, including any tokens that came from other macros
+  // that were active, as in:
+  //  #define submacro a COMMENT b
+  //    submacro c
+  // which should lex to 'a' only: 'b' and 'c' should be removed.
+  while (Tok.isNot(tok::eom) && Tok.isNot(tok::eof))
+    Lex(Tok);
+  
+  // If we got an eom token, then we successfully found the end of the line.
+  if (Tok.is(tok::eom)) {
+    assert(FoundLexer && "Can't get end of line without an active lexer");
+    // Restore the lexer back to normal mode instead of raw mode.
+    FoundLexer->LexingRawMode = false;
+    
+    // If the lexer was already in preprocessor mode, just return the EOM token
+    // to finish the preprocessor line.
+    if (LexerWasInPPMode) return;
+    
+    // Otherwise, switch out of PP mode and return the next lexed token.
+    FoundLexer->ParsingPreprocessorDirective = false;
+    return Lex(Tok);
+  }
+  
+  // If we got an EOF token, then we reached the end of the token stream but
+  // didn't find an explicit \n.  This can only happen if there was no lexer
+  // active (an active lexer would return EOM at EOF if there was no \n in
+  // preprocessor directive mode), so just return EOF as our token.
+  assert(!FoundLexer && "Lexer should return EOM before EOF in PP mode");
+}