move IdentifierTable.h from liblex to libbasic.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@42730 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 374 insertions, 0 deletions

diff --git a/Basic/IdentifierTable.cpp b/Basic/IdentifierTable.cpp
new file mode 100644
index 0000000000..51abcd22b5
--- /dev/null
+++ b/Basic/IdentifierTable.cpp
@@ -0,0 +1,374 @@
+//===--- IdentifierTable.cpp - Hash table for identifier lookup -----------===//
+//
+//                     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 file implements the IdentifierInfo, IdentifierVisitor, and
+// IdentifierTable interfaces.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/IdentifierTable.h"
+#include "clang/Basic/LangOptions.h"
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/DenseMap.h"
+using namespace clang;
+
+//===----------------------------------------------------------------------===//
+// IdentifierInfo Implementation
+//===----------------------------------------------------------------------===//
+
+IdentifierInfo::IdentifierInfo() {
+  TokenID = tok::identifier;
+  ObjCID = tok::objc_not_keyword;
+  BuiltinID = 0;
+  HasMacro = false;
+  IsExtension = false;
+  IsPoisoned = false;
+  IsOtherTargetMacro = false;
+  IsCPPOperatorKeyword = false;
+  IsNonPortableBuiltin = false;
+  FETokenInfo = 0;
+}
+
+//===----------------------------------------------------------------------===//
+// IdentifierTable Implementation
+//===----------------------------------------------------------------------===//
+
+IdentifierTable::IdentifierTable(const LangOptions &LangOpts)
+  // Start with space for 8K identifiers.
+  : HashTable(8192) {
+
+  // Populate the identifier table with info about keywords for the current
+  // language.
+  AddKeywords(LangOpts);
+}
+
+//===----------------------------------------------------------------------===//
+// Language Keyword Implementation
+//===----------------------------------------------------------------------===//
+
+/// AddKeyword - This method is used to associate a token ID with specific
+/// identifiers because they are language keywords.  This causes the lexer to
+/// automatically map matching identifiers to specialized token codes.
+///
+/// The C90/C99/CPP/CPP0x flags are set to 0 if the token should be
+/// enabled in the specified langauge, set to 1 if it is an extension
+/// in the specified language, and set to 2 if disabled in the
+/// specified language.
+static void AddKeyword(const char *Keyword, unsigned KWLen,
+                       tok::TokenKind TokenCode,
+                       int C90, int C99, int CXX, int CXX0x,
+                       const LangOptions &LangOpts, IdentifierTable &Table) {
+  int Flags = LangOpts.CPlusPlus ? (LangOpts.CPlusPlus0x? CXX0x : CXX)
+                                 : (LangOpts.C99 ? C99 : C90);
+  
+  // Don't add this keyword if disabled in this language or if an extension
+  // and extensions are disabled.
+  if (Flags + LangOpts.NoExtensions >= 2) return;
+  
+  IdentifierInfo &Info = Table.get(Keyword, Keyword+KWLen);
+  Info.setTokenID(TokenCode);
+  Info.setIsExtensionToken(Flags == 1);
+}
+
+static void AddAlias(const char *Keyword, unsigned KWLen,
+                     const char *AliaseeKeyword, unsigned AliaseeKWLen,
+                     const LangOptions &LangOpts, IdentifierTable &Table) {
+  IdentifierInfo &AliasInfo = Table.get(Keyword, Keyword+KWLen);
+  IdentifierInfo &AliaseeInfo = Table.get(AliaseeKeyword,
+                                          AliaseeKeyword+AliaseeKWLen);
+  AliasInfo.setTokenID(AliaseeInfo.getTokenID());
+  AliasInfo.setIsExtensionToken(AliaseeInfo.isExtensionToken());
+}  
+
+/// AddCXXOperatorKeyword - Register a C++ operator keyword alternative
+/// representations.
+static void AddCXXOperatorKeyword(const char *Keyword, unsigned KWLen,
+                                  tok::TokenKind TokenCode,
+                                  IdentifierTable &Table) {
+  IdentifierInfo &Info = Table.get(Keyword, Keyword + KWLen);
+  Info.setTokenID(TokenCode);
+  Info.setIsCPlusplusOperatorKeyword();
+}
+
+/// AddObjCKeyword - Register an Objective-C @keyword like "class" "selector" or 
+/// "property".
+static void AddObjCKeyword(tok::ObjCKeywordKind ObjCID, 
+                           const char *Name, unsigned NameLen,
+                           IdentifierTable &Table) {
+  Table.get(Name, Name+NameLen).setObjCKeywordID(ObjCID);
+}
+
+/// AddKeywords - Add all keywords to the symbol table.
+///
+void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {
+  enum {
+    C90Shift = 0,
+    EXTC90   = 1 << C90Shift,
+    NOTC90   = 2 << C90Shift,
+    C99Shift = 2,
+    EXTC99   = 1 << C99Shift,
+    NOTC99   = 2 << C99Shift,
+    CPPShift = 4,
+    EXTCPP   = 1 << CPPShift,
+    NOTCPP   = 2 << CPPShift,
+    CPP0xShift = 6,
+    EXTCPP0x   = 1 << CPP0xShift,
+    NOTCPP0x   = 2 << CPP0xShift,
+    Mask     = 3
+  };
+  
+  // Add keywords and tokens for the current language.
+#define KEYWORD(NAME, FLAGS) \
+  AddKeyword(#NAME, strlen(#NAME), tok::kw_ ## NAME,  \
+             ((FLAGS) >> C90Shift) & Mask, \
+             ((FLAGS) >> C99Shift) & Mask, \
+             ((FLAGS) >> CPPShift) & Mask, \
+             ((FLAGS) >> CPP0xShift) & Mask, LangOpts, *this);
+#define ALIAS(NAME, TOK) \
+  AddAlias(NAME, strlen(NAME), #TOK, strlen(#TOK), LangOpts, *this);
+#define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \
+  if (LangOpts.CXXOperatorNames)          \
+    AddCXXOperatorKeyword(#NAME, strlen(#NAME), tok::ALIAS, *this);
+#define OBJC1_AT_KEYWORD(NAME) \
+  if (LangOpts.ObjC1)          \
+    AddObjCKeyword(tok::objc_##NAME, #NAME, strlen(#NAME), *this);
+#define OBJC2_AT_KEYWORD(NAME) \
+  if (LangOpts.ObjC2)          \
+    AddObjCKeyword(tok::objc_##NAME, #NAME, strlen(#NAME), *this);
+#include "clang/Basic/TokenKinds.def"
+}
+
+tok::PPKeywordKind IdentifierInfo::getPPKeywordID() const {
+  // We use a perfect hash function here involving the length of the keyword,
+  // the first and third character.  For preprocessor ID's there are no
+  // collisions (if there were, the switch below would complain about duplicate
+  // case values).  Note that this depends on 'if' being null terminated.
+  
+#define HASH(LEN, FIRST, THIRD) \
+  (LEN << 5) + (((FIRST-'a') + (THIRD-'a')) & 31)
+#define CASE(LEN, FIRST, THIRD, NAME) \
+  case HASH(LEN, FIRST, THIRD): \
+    return memcmp(Name, #NAME, LEN) ? tok::pp_not_keyword : tok::pp_ ## NAME
+    
+  unsigned Len = getLength();
+  const char *Name = getName();
+  switch (HASH(Len, Name[0], Name[2])) {
+  default: return tok::pp_not_keyword;
+  CASE( 2, 'i', '\0', if);
+  CASE( 4, 'e', 'i', elif);
+  CASE( 4, 'e', 's', else);
+  CASE( 4, 'l', 'n', line);
+  CASE( 4, 's', 'c', sccs);
+  CASE( 5, 'e', 'd', endif);
+  CASE( 5, 'e', 'r', error);
+  CASE( 5, 'i', 'e', ident);
+  CASE( 5, 'i', 'd', ifdef);
+  CASE( 5, 'u', 'd', undef);
+
+  CASE( 6, 'a', 's', assert);
+  CASE( 6, 'd', 'f', define);
+  CASE( 6, 'i', 'n', ifndef);
+  CASE( 6, 'i', 'p', import);
+  CASE( 6, 'p', 'a', pragma);
+
+  CASE( 7, 'd', 'f', defined);
+  CASE( 7, 'i', 'c', include);
+  CASE( 7, 'w', 'r', warning);
+
+  CASE( 8, 'u', 'a', unassert);
+  CASE(12, 'i', 'c', include_next);
+  CASE(13, 'd', 'f', define_target);
+  CASE(19, 'd', 'f', define_other_target);
+#undef CASE
+#undef HASH
+  }
+}
+
+//===----------------------------------------------------------------------===//
+// Stats Implementation
+//===----------------------------------------------------------------------===//
+
+/// PrintStats - Print statistics about how well the identifier table is doing
+/// at hashing identifiers.
+void IdentifierTable::PrintStats() const {
+  unsigned NumBuckets = HashTable.getNumBuckets();
+  unsigned NumIdentifiers = HashTable.getNumItems();
+  unsigned NumEmptyBuckets = NumBuckets-NumIdentifiers;
+  unsigned AverageIdentifierSize = 0;
+  unsigned MaxIdentifierLength = 0;
+  
+  // TODO: Figure out maximum times an identifier had to probe for -stats.
+  for (llvm::StringMap<IdentifierInfo, llvm::BumpPtrAllocator>::const_iterator
+       I = HashTable.begin(), E = HashTable.end(); I != E; ++I) {
+    unsigned IdLen = I->getKeyLength();
+    AverageIdentifierSize += IdLen;
+    if (MaxIdentifierLength < IdLen)
+      MaxIdentifierLength = IdLen;
+  }
+  
+  fprintf(stderr, "\n*** Identifier Table Stats:\n");
+  fprintf(stderr, "# Identifiers:   %d\n", NumIdentifiers);
+  fprintf(stderr, "# Empty Buckets: %d\n", NumEmptyBuckets);
+  fprintf(stderr, "Hash density (#identifiers per bucket): %f\n",
+          NumIdentifiers/(double)NumBuckets);
+  fprintf(stderr, "Ave identifier length: %f\n",
+          (AverageIdentifierSize/(double)NumIdentifiers));
+  fprintf(stderr, "Max identifier length: %d\n", MaxIdentifierLength);
+  
+  // Compute statistics about the memory allocated for identifiers.
+  HashTable.getAllocator().PrintStats();
+}
+
+//===----------------------------------------------------------------------===//
+// SelectorTable Implementation
+//===----------------------------------------------------------------------===//
+
+unsigned llvm::DenseMapInfo<clang::Selector>::getHashValue(clang::Selector S) {
+  return DenseMapInfo<void*>::getHashValue(S.getAsOpaquePtr());
+}
+
+
+/// MultiKeywordSelector - One of these variable length records is kept for each
+/// selector containing more than one keyword. We use a folding set
+/// to unique aggregate names (keyword selectors in ObjC parlance). Access to 
+/// this class is provided strictly through Selector.
+namespace clang {
+class MultiKeywordSelector : public llvm::FoldingSetNode {
+public:  
+  unsigned NumArgs;
+
+  // Constructor for keyword selectors.
+  MultiKeywordSelector(unsigned nKeys, IdentifierInfo **IIV) {
+    assert((nKeys > 1) && "not a multi-keyword selector");
+    NumArgs = nKeys;
+    // Fill in the trailing keyword array.
+    IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(this+1);
+    for (unsigned i = 0; i != nKeys; ++i)
+      KeyInfo[i] = IIV[i];
+  }
+  // getName - Derive the full selector name and return it.
+  std::string getName() const;
+    
+  unsigned getNumArgs() const { return NumArgs; }
+  
+  typedef IdentifierInfo *const *keyword_iterator;
+  keyword_iterator keyword_begin() const {
+    return reinterpret_cast<keyword_iterator>(this+1);
+  }
+  keyword_iterator keyword_end() const { 
+    return keyword_begin()+NumArgs; 
+  }
+  IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const {
+    assert(i < NumArgs && "getIdentifierInfoForSlot(): illegal index");
+    return keyword_begin()[i];
+  }
+  static void Profile(llvm::FoldingSetNodeID &ID, 
+                      keyword_iterator ArgTys, unsigned NumArgs) {
+    ID.AddInteger(NumArgs);
+    for (unsigned i = 0; i != NumArgs; ++i)
+      ID.AddPointer(ArgTys[i]);
+  }
+  void Profile(llvm::FoldingSetNodeID &ID) {
+    Profile(ID, keyword_begin(), NumArgs);
+  }
+};
+} // end namespace clang.
+
+unsigned Selector::getNumArgs() const {
+  unsigned IIF = getIdentifierInfoFlag();
+  if (IIF == ZeroArg)
+    return 0;
+  if (IIF == OneArg)
+    return 1;
+  // We point to a MultiKeywordSelector (pointer doesn't contain any flags).
+  MultiKeywordSelector *SI = reinterpret_cast<MultiKeywordSelector *>(InfoPtr);
+  return SI->getNumArgs(); 
+}
+
+IdentifierInfo *Selector::getIdentifierInfoForSlot(unsigned argIndex) const {
+  if (IdentifierInfo *II = getAsIdentifierInfo()) {
+    assert(argIndex == 0 && "illegal keyword index");
+    return II;
+  }
+  // We point to a MultiKeywordSelector (pointer doesn't contain any flags).
+  MultiKeywordSelector *SI = reinterpret_cast<MultiKeywordSelector *>(InfoPtr);
+  return SI->getIdentifierInfoForSlot(argIndex);
+}
+
+std::string MultiKeywordSelector::getName() const {
+  std::string Result;
+  unsigned Length = 0;
+  for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) {
+    if (*I)
+      Length += (*I)->getLength();
+    ++Length;  // :
+  }
+  
+  Result.reserve(Length);
+  
+  for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) {
+    if (*I)
+      Result.insert(Result.end(), (*I)->getName(),
+                    (*I)->getName()+(*I)->getLength());
+    Result.push_back(':');
+  }
+  
+  return Result;
+}
+
+std::string Selector::getName() const {
+  if (IdentifierInfo *II = getAsIdentifierInfo()) {
+    if (getNumArgs() == 0)
+      return II->getName();
+    
+    std::string Res = II->getName();
+    Res += ":";
+    return Res;
+  }
+  
+  // We have a multiple keyword selector (no embedded flags).
+  return reinterpret_cast<MultiKeywordSelector *>(InfoPtr)->getName();
+}
+
+
+Selector SelectorTable::getSelector(unsigned nKeys, IdentifierInfo **IIV) {
+  if (nKeys < 2)
+    return Selector(IIV[0], nKeys);
+  
+  llvm::FoldingSet<MultiKeywordSelector> *SelTab;
+  
+  SelTab = static_cast<llvm::FoldingSet<MultiKeywordSelector> *>(Impl);
+    
+  // Unique selector, to guarantee there is one per name.
+  llvm::FoldingSetNodeID ID;
+  MultiKeywordSelector::Profile(ID, IIV, nKeys);
+
+  void *InsertPos = 0;
+  if (MultiKeywordSelector *SI = SelTab->FindNodeOrInsertPos(ID, InsertPos))
+    return Selector(SI);
+  
+  // MultiKeywordSelector objects are not allocated with new because they have a
+  // variable size array (for parameter types) at the end of them.
+  MultiKeywordSelector *SI = 
+    (MultiKeywordSelector*)malloc(sizeof(MultiKeywordSelector) + 
+                                  nKeys*sizeof(IdentifierInfo *));
+  new (SI) MultiKeywordSelector(nKeys, IIV);
+  SelTab->InsertNode(SI, InsertPos);
+  return Selector(SI);
+}
+
+SelectorTable::SelectorTable() {
+  Impl = new llvm::FoldingSet<MultiKeywordSelector>;
+}
+
+SelectorTable::~SelectorTable() {
+  delete static_cast<llvm::FoldingSet<MultiKeywordSelector> *>(Impl);
+}
+
+