this massive patch introduces a simple new abstraction: it makes

"FileID" a concept that is now enforced by the compiler's type checker
instead of yet-another-random-unsigned floating around.

This is an important distinction from the "FileID" currently tracked by
SourceLocation.  *That* FileID may refer to the start of a file or to a
chunk within it.  The new FileID *only* refers to the file (and its 
#include stack and eventually #line data), it cannot refer to a chunk.

FileID is a completely opaque datatype to all clients, only SourceManager
is allowed to poke and prod it.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62407 91177308-0d34-0410-b5e6-96231b3b80d8

Author: lattner

Driver/ASTConsumers.cpp

@@ -903,10 +903,10 @@ class BuildSerializer : public ASTSerializer {
       return;
 
     SourceManager& SourceMgr = TU.getContext().getSourceManager();
-    unsigned ID = SourceMgr.getMainFileID();
-    assert (ID && "MainFileID not set!");
+    FileID ID = SourceMgr.getMainFileID();
+    assert(!ID.isInvalid() && "MainFileID not set!");
     const FileEntry* FE = SourceMgr.getFileEntryForID(ID);
-    assert (FE && "No FileEntry for main file.");
+    assert(FE && "No FileEntry for main file.");
 
     // FIXME: This is not portable to Windows.
     // FIXME: This logic should probably be moved elsewhere later.

Driver/CacheTokens.cpp

@@ -485,8 +485,8 @@ void PTHWriter::GeneratePTH() {
     const llvm::MemoryBuffer *B = C.getBuffer();
     if (!B) continue;
 
-    unsigned FID = SM.createFileID(FE, SourceLocation(), SrcMgr::C_User);
-    Lexer L(SourceLocation::getFileLoc(FID, 0), LOpts,
+    FileID FID = SM.createFileID(FE, SourceLocation(), SrcMgr::C_User);
+    Lexer L(SM.getLocForStartOfFile(FID), LOpts,
             B->getBufferStart(), B->getBufferEnd(), B);
     PM[FE] = LexTokens(L);
   }

Driver/DiagChecker.cpp

@@ -117,12 +117,12 @@ static void FindExpectedDiags(Preprocessor &PP,
                               DiagList &ExpectedNotes) {
   // Create a raw lexer to pull all the comments out of the main file.  We don't
   // want to look in #include'd headers for expected-error strings.
-  unsigned FileID = PP.getSourceManager().getMainFileID();
+  FileID FID = PP.getSourceManager().getMainFileID();
   std::pair<const char*,const char*> File =
-    PP.getSourceManager().getBufferData(FileID);
+    PP.getSourceManager().getBufferData(FID);
 
   // Create a lexer to lex all the tokens of the main file in raw mode.
-  Lexer RawLex(SourceLocation::getFileLoc(FileID, 0),
+  Lexer RawLex(PP.getSourceManager().getLocForStartOfFile(FID),
                PP.getLangOptions(), File.first, File.second);
 
   // Return comments as tokens, this is how we find expected diagnostics.

Driver/HTMLPrint.cpp

@@ -60,19 +60,19 @@ HTMLPrinter::~HTMLPrinter() {
     return;
 
   // Format the file.
-  unsigned FileID = R.getSourceMgr().getMainFileID();
-  const FileEntry* Entry = R.getSourceMgr().getFileEntryForID(FileID);
+  FileID FID = R.getSourceMgr().getMainFileID();
+  const FileEntry* Entry = R.getSourceMgr().getFileEntryForID(FID);
 
-  html::AddLineNumbers(R, FileID);
-  html::AddHeaderFooterInternalBuiltinCSS(R, FileID, Entry->getName());
+  html::AddLineNumbers(R, FID);
+  html::AddHeaderFooterInternalBuiltinCSS(R, FID, Entry->getName());
 
   // If we have a preprocessor, relex the file and syntax highlight.
   // We might not have a preprocessor if we come from a deserialized AST file,
   // for example.
 
-  if (PP) html::SyntaxHighlight(R, FileID, *PP);
-  if (PPF) html::HighlightMacros(R, FileID, *PP);
-  html::EscapeText(R, FileID, false, true);
+  if (PP) html::SyntaxHighlight(R, FID, *PP);
+  if (PPF) html::HighlightMacros(R, FID, *PP);
+  html::EscapeText(R, FID, false, true);
 
   // Open the output.
   FILE *OutputFILE;
@@ -87,7 +87,7 @@ HTMLPrinter::~HTMLPrinter() {
   }
 
   // Emit the HTML.
-  const RewriteBuffer &RewriteBuf = R.getEditBuffer(FileID);
+  const RewriteBuffer &RewriteBuf = R.getEditBuffer(FID);
   char *Buffer = (char*)malloc(RewriteBuf.size());
   std::copy(RewriteBuf.begin(), RewriteBuf.end(), Buffer);
   fwrite(Buffer, 1, RewriteBuf.size(), OutputFILE);

Driver/RewriteBlocks.cpp

@@ -37,7 +37,7 @@ class RewriteBlocks : public ASTConsumer {
 
   ASTContext *Context;
   SourceManager *SM;
-  unsigned MainFileID;
+  FileID MainFileID;
   const char *MainFileStart, *MainFileEnd;
 
   // Block expressions.
@@ -223,7 +223,7 @@ void RewriteBlocks::Initialize(ASTContext &context) {
   Preamble += "__OBJC_RW_EXTERN void *_NSConcreteStackBlock;\n";
   Preamble += "#endif\n";
 
-  InsertText(SourceLocation::getFileLoc(MainFileID, 0), 
+  InsertText(SM->getLocForStartOfFile(MainFileID), 
              Preamble.c_str(), Preamble.size());
 }
 

Driver/RewriteMacros.cpp

@@ -65,7 +65,7 @@ static void LexRawTokensFromMainFile(Preprocessor &PP,
 
   // Create a lexer to lex all the tokens of the main file in raw mode.  Even
   // though it is in raw mode, it will not return comments.
-  Lexer RawLex(SourceLocation::getFileLoc(SM.getMainFileID(), 0),
+  Lexer RawLex(SM.getLocForStartOfFile(SM.getMainFileID()),
                PP.getLangOptions(), File.first, File.second);
 
   // Switch on comment lexing because we really do want them.

Driver/RewriteObjC.cpp

@@ -47,7 +47,7 @@ namespace {
     ASTContext *Context;
     SourceManager *SM;
     TranslationUnitDecl *TUDecl;
-    unsigned MainFileID;
+    FileID MainFileID;
     const char *MainFileStart, *MainFileEnd;
     SourceLocation LastIncLoc;
 
@@ -597,7 +597,7 @@ void RewriteObjC::HandleTopLevelDecl(Decl *D) {
 //===----------------------------------------------------------------------===//
 
 void RewriteObjC::RewriteInclude() {
-  SourceLocation LocStart = SourceLocation::getFileLoc(MainFileID, 0);
+  SourceLocation LocStart = SM->getLocForStartOfFile(MainFileID);
   std::pair<const char*, const char*> MainBuf = SM->getBufferData(MainFileID);
   const char *MainBufStart = MainBuf.first;
   const char *MainBufEnd = MainBuf.second;
@@ -645,8 +645,8 @@ void RewriteObjC::RewriteTabs() {
     unsigned Spaces = 8-(VCol & 7);
 
     // Get the location of the tab.
-    SourceLocation TabLoc =
-      SourceLocation::getFileLoc(MainFileID, BufPtr-MainBufStart);
+    SourceLocation TabLoc = SM->getLocForStartOfFile(MainFileID);
+    TabLoc = TabLoc.getFileLocWithOffset(BufPtr-MainBufStart);
 
     // Rewrite the single tab character into a sequence of spaces.
     ReplaceText(TabLoc, 1, "        ", Spaces);
@@ -4501,7 +4501,7 @@ void RewriteObjC::HandleTranslationUnit(TranslationUnit& TU) {
 
   RewriteInclude();
 
-  InsertText(SourceLocation::getFileLoc(MainFileID, 0), 
+  InsertText(SM->getLocForStartOfFile(MainFileID), 
              Preamble.c_str(), Preamble.size(), false);
 
   if (ClassImplementation.size() || CategoryImplementation.size())

Driver/clang.cpp

@@ -919,14 +919,14 @@ static bool InitializePreprocessor(Preprocessor &PP,
     if (InFile != "-") {
       const FileEntry *File = FileMgr.getFile(InFile);
       if (File) SourceMgr.createMainFileID(File, SourceLocation());
-      if (SourceMgr.getMainFileID() == 0) {
+      if (SourceMgr.getMainFileID().isInvalid()) {
         fprintf(stderr, "Error reading '%s'!\n",InFile.c_str());
         return true;
       }
     } else {
       llvm::MemoryBuffer *SB = llvm::MemoryBuffer::getSTDIN();
       if (SB) SourceMgr.createMainFileIDForMemBuffer(SB);
-      if (SourceMgr.getMainFileID() == 0) {
+      if (SourceMgr.getMainFileID().isInvalid()) {
         fprintf(stderr, "Error reading standard input!  Empty?\n");
         return true;
       }
@@ -1335,7 +1335,7 @@ static void ProcessInputFile(Preprocessor &PP, PreprocessorFactory &PPF,
     std::pair<const char*,const char*> File =
       SM.getBufferData(SM.getMainFileID());
     // Start lexing the specified input file.
-    Lexer RawLex(SourceLocation::getFileLoc(SM.getMainFileID(), 0),
+    Lexer RawLex(SM.getLocForStartOfFile(SM.getMainFileID()),
                  PP.getLangOptions(), File.first, File.second);
     RawLex.SetKeepWhitespaceMode(true);
 

include/clang/Basic/SourceLocation.h

@@ -18,13 +18,46 @@
 #include "llvm/Bitcode/SerializationFwd.h"
 
 namespace llvm {
-class MemoryBuffer;
+  class MemoryBuffer;
+  template <typename T> struct DenseMapInfo;
 }
 
 namespace clang {
 
 class SourceManager;
 class FileEntry;
+  
+/// FileID - This is an opaque identifier used by SourceManager which refers to
+/// a source file (MemoryBuffer) along with its #include path and #line data.
+///
+class FileID {
+  /// ID - Opaque identifier, 0 is "invalid".
+  unsigned ID;
+public:
+  FileID() : ID(0) {}
+  
+  bool isInvalid() const { return ID == 0; }
+  
+  bool operator==(const FileID &RHS) const { return ID == RHS.ID; }
+  bool operator<(const FileID &RHS) const { return ID < RHS.ID; }
+  bool operator<=(const FileID &RHS) const { return ID <= RHS.ID; }
+  bool operator!=(const FileID &RHS) const { return !(*this == RHS); }
+  bool operator>(const FileID &RHS) const { return RHS < *this; }
+  bool operator>=(const FileID &RHS) const { return RHS <= *this; }
+  
+  static FileID getSentinel() { return Create(~0U); }
+  unsigned getHashValue() const { return ID; }
+  
+private:
+  friend class SourceManager;
+  static FileID Create(unsigned V) {
+    FileID F;
+    F.ID = V;
+    return F;
+  }
+  unsigned getOpaqueValue() const { return ID; }
+};
+  
 
 /// SourceLocation - This is a carefully crafted 32-bit identifier that encodes
 /// a full include stack, line and column number information for a position in
@@ -269,4 +302,29 @@ class FullSourceLoc : public SourceLocation {
 
 }  // end namespace clang
 
+namespace llvm {
+  /// Define DenseMapInfo so that FileID's can be used as keys in DenseMap and
+  /// DenseSets.
+  template <>
+  struct DenseMapInfo<clang::FileID> {
+    static inline clang::FileID getEmptyKey() {
+      return clang::FileID();
+    }
+    static inline clang::FileID getTombstoneKey() {
+      return clang::FileID::getSentinel(); 
+    }
+    
+    static unsigned getHashValue(clang::FileID S) {
+      return S.getHashValue();
+    }
+    
+    static bool isEqual(clang::FileID LHS, clang::FileID RHS) {
+      return LHS == RHS;
+    }
+    
+    static bool isPod() { return true; }
+  };
+  
+}  // end namespace llvm
+
 #endif