Check in LLVM r95781.
diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
new file mode 100644
index 0000000..e9a1d9c
--- /dev/null
+++ b/lib/Sema/Sema.cpp
@@ -0,0 +1,333 @@
+//===--- Sema.cpp - AST Builder and Semantic Analysis Implementation ------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the actions class which performs semantic analysis and
+// builds an AST out of a parse stream.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Sema.h"
+#include "TargetAttributesSema.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallSet.h"
+#include "llvm/ADT/APFloat.h"
+#include "clang/AST/ASTConsumer.h"
+#include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTDiagnostic.h"
+#include "clang/AST/DeclObjC.h"
+#include "clang/AST/Expr.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Basic/PartialDiagnostic.h"
+#include "clang/Basic/TargetInfo.h"
+using namespace clang;
+                                       
+static inline RecordDecl *CreateStructDecl(ASTContext &C, const char *Name) {
+  if (C.getLangOptions().CPlusPlus)
+    return CXXRecordDecl::Create(C, TagDecl::TK_struct,
+                                 C.getTranslationUnitDecl(),
+                                 SourceLocation(), &C.Idents.get(Name));
+
+  return RecordDecl::Create(C, TagDecl::TK_struct,
+                            C.getTranslationUnitDecl(),
+                            SourceLocation(), &C.Idents.get(Name));
+}
+
+void Sema::ActOnTranslationUnitScope(SourceLocation Loc, Scope *S) {
+  TUScope = S;
+  PushDeclContext(S, Context.getTranslationUnitDecl());
+
+  if (PP.getTargetInfo().getPointerWidth(0) >= 64) {
+    TypeSourceInfo *TInfo;
+
+    // Install [u]int128_t for 64-bit targets.
+    TInfo = Context.getTrivialTypeSourceInfo(Context.Int128Ty);
+    PushOnScopeChains(TypedefDecl::Create(Context, CurContext,
+                                          SourceLocation(),
+                                          &Context.Idents.get("__int128_t"),
+                                          TInfo), TUScope);
+
+    TInfo = Context.getTrivialTypeSourceInfo(Context.UnsignedInt128Ty);
+    PushOnScopeChains(TypedefDecl::Create(Context, CurContext,
+                                          SourceLocation(),
+                                          &Context.Idents.get("__uint128_t"),
+                                          TInfo), TUScope);
+  }
+
+
+  if (!PP.getLangOptions().ObjC1) return;
+
+  // Built-in ObjC types may already be set by PCHReader (hence isNull checks).
+  if (Context.getObjCSelType().isNull()) {
+    // Create the built-in typedef for 'SEL'.
+    QualType SelT = Context.getPointerType(Context.ObjCBuiltinSelTy);
+    TypeSourceInfo *SelInfo = Context.getTrivialTypeSourceInfo(SelT);
+    TypedefDecl *SelTypedef
+      = TypedefDecl::Create(Context, CurContext, SourceLocation(),
+                            &Context.Idents.get("SEL"), SelInfo);
+    PushOnScopeChains(SelTypedef, TUScope);
+    Context.setObjCSelType(Context.getTypeDeclType(SelTypedef));
+    Context.ObjCSelRedefinitionType = Context.getObjCSelType();
+  }
+
+  // Synthesize "@class Protocol;
+  if (Context.getObjCProtoType().isNull()) {
+    ObjCInterfaceDecl *ProtocolDecl =
+      ObjCInterfaceDecl::Create(Context, CurContext, SourceLocation(),
+                                &Context.Idents.get("Protocol"),
+                                SourceLocation(), true);
+    Context.setObjCProtoType(Context.getObjCInterfaceType(ProtocolDecl));
+    PushOnScopeChains(ProtocolDecl, TUScope, false);
+  }
+  // Create the built-in typedef for 'id'.
+  if (Context.getObjCIdType().isNull()) {
+    QualType IdT = Context.getObjCObjectPointerType(Context.ObjCBuiltinIdTy);
+    TypeSourceInfo *IdInfo = Context.getTrivialTypeSourceInfo(IdT);
+    TypedefDecl *IdTypedef
+      = TypedefDecl::Create(Context, CurContext, SourceLocation(),
+                            &Context.Idents.get("id"), IdInfo);
+    PushOnScopeChains(IdTypedef, TUScope);
+    Context.setObjCIdType(Context.getTypeDeclType(IdTypedef));
+    Context.ObjCIdRedefinitionType = Context.getObjCIdType();
+  }
+  // Create the built-in typedef for 'Class'.
+  if (Context.getObjCClassType().isNull()) {
+    QualType ClassType
+      = Context.getObjCObjectPointerType(Context.ObjCBuiltinClassTy);
+    TypeSourceInfo *ClassInfo = Context.getTrivialTypeSourceInfo(ClassType);
+    TypedefDecl *ClassTypedef
+      = TypedefDecl::Create(Context, CurContext, SourceLocation(),
+                            &Context.Idents.get("Class"), ClassInfo);
+    PushOnScopeChains(ClassTypedef, TUScope);
+    Context.setObjCClassType(Context.getTypeDeclType(ClassTypedef));
+    Context.ObjCClassRedefinitionType = Context.getObjCClassType();
+  }
+}
+
+Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
+           bool CompleteTranslationUnit,
+           CodeCompleteConsumer *CodeCompleter)
+  : TheTargetAttributesSema(0),
+    LangOpts(pp.getLangOptions()), PP(pp), Context(ctxt), Consumer(consumer),
+    Diags(PP.getDiagnostics()), SourceMgr(PP.getSourceManager()),
+    ExternalSource(0), CodeCompleter(CodeCompleter), CurContext(0), 
+    CurBlock(0), PackContext(0), ParsingDeclDepth(0),
+    IdResolver(pp.getLangOptions()), StdNamespace(0), StdBadAlloc(0),
+    GlobalNewDeleteDeclared(false), 
+    CompleteTranslationUnit(CompleteTranslationUnit),
+    NumSFINAEErrors(0), NonInstantiationEntries(0), 
+    CurrentInstantiationScope(0), TyposCorrected(0)
+{
+  TUScope = 0;
+  if (getLangOptions().CPlusPlus)
+    FieldCollector.reset(new CXXFieldCollector());
+
+  // Tell diagnostics how to render things from the AST library.
+  PP.getDiagnostics().SetArgToStringFn(&FormatASTNodeDiagnosticArgument, 
+                                       &Context);
+
+  ExprEvalContexts.push_back(
+                  ExpressionEvaluationContextRecord(PotentiallyEvaluated, 0));
+}
+
+Sema::~Sema() {
+  if (PackContext) FreePackedContext();
+  delete TheTargetAttributesSema;
+}
+
+/// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.
+/// If there is already an implicit cast, merge into the existing one.
+/// If isLvalue, the result of the cast is an lvalue.
+void Sema::ImpCastExprToType(Expr *&Expr, QualType Ty,
+                             CastExpr::CastKind Kind, bool isLvalue) {
+  QualType ExprTy = Context.getCanonicalType(Expr->getType());
+  QualType TypeTy = Context.getCanonicalType(Ty);
+
+  if (ExprTy == TypeTy)
+    return;
+
+  if (Expr->getType()->isPointerType() && Ty->isPointerType()) {
+    QualType ExprBaseType = cast<PointerType>(ExprTy)->getPointeeType();
+    QualType BaseType = cast<PointerType>(TypeTy)->getPointeeType();
+    if (ExprBaseType.getAddressSpace() != BaseType.getAddressSpace()) {
+      Diag(Expr->getExprLoc(), diag::err_implicit_pointer_address_space_cast)
+        << Expr->getSourceRange();
+    }
+  }
+
+  CheckImplicitConversion(Expr, Ty);
+
+  if (ImplicitCastExpr *ImpCast = dyn_cast<ImplicitCastExpr>(Expr)) {
+    if (ImpCast->getCastKind() == Kind) {
+      ImpCast->setType(Ty);
+      ImpCast->setLvalueCast(isLvalue);
+      return;
+    }
+  }
+
+  Expr = new (Context) ImplicitCastExpr(Ty, Kind, Expr, isLvalue);
+}
+
+void Sema::DeleteExpr(ExprTy *E) {
+  if (E) static_cast<Expr*>(E)->Destroy(Context);
+}
+void Sema::DeleteStmt(StmtTy *S) {
+  if (S) static_cast<Stmt*>(S)->Destroy(Context);
+}
+
+/// ActOnEndOfTranslationUnit - This is called at the very end of the
+/// translation unit when EOF is reached and all but the top-level scope is
+/// popped.
+void Sema::ActOnEndOfTranslationUnit() {
+  
+  while (1) {
+    // C++: Perform implicit template instantiations.
+    //
+    // FIXME: When we perform these implicit instantiations, we do not carefully
+    // keep track of the point of instantiation (C++ [temp.point]). This means
+    // that name lookup that occurs within the template instantiation will
+    // always happen at the end of the translation unit, so it will find
+    // some names that should not be found. Although this is common behavior
+    // for C++ compilers, it is technically wrong. In the future, we either need
+    // to be able to filter the results of name lookup or we need to perform
+    // template instantiations earlier.
+    PerformPendingImplicitInstantiations();
+    
+    /// If ProcessPendingClassesWithUnmarkedVirtualMembers ends up marking 
+    /// any virtual member functions it might lead to more pending template
+    /// instantiations, which is why we need to loop here.
+    if (!ProcessPendingClassesWithUnmarkedVirtualMembers())
+      break;
+  }
+  
+  // Check for #pragma weak identifiers that were never declared
+  // FIXME: This will cause diagnostics to be emitted in a non-determinstic
+  // order!  Iterating over a densemap like this is bad.
+  for (llvm::DenseMap<IdentifierInfo*,WeakInfo>::iterator
+       I = WeakUndeclaredIdentifiers.begin(),
+       E = WeakUndeclaredIdentifiers.end(); I != E; ++I) {
+    if (I->second.getUsed()) continue;
+
+    Diag(I->second.getLocation(), diag::warn_weak_identifier_undeclared)
+      << I->first;
+  }
+
+  if (!CompleteTranslationUnit)
+    return;
+
+  // C99 6.9.2p2:
+  //   A declaration of an identifier for an object that has file
+  //   scope without an initializer, and without a storage-class
+  //   specifier or with the storage-class specifier static,
+  //   constitutes a tentative definition. If a translation unit
+  //   contains one or more tentative definitions for an identifier,
+  //   and the translation unit contains no external definition for
+  //   that identifier, then the behavior is exactly as if the
+  //   translation unit contains a file scope declaration of that
+  //   identifier, with the composite type as of the end of the
+  //   translation unit, with an initializer equal to 0.
+  llvm::SmallSet<VarDecl *, 32> Seen;
+  for (unsigned i = 0, e = TentativeDefinitions.size(); i != e; ++i) {
+    VarDecl *VD = TentativeDefinitions[i]->getActingDefinition();
+
+    // If the tentative definition was completed, getActingDefinition() returns
+    // null. If we've already seen this variable before, insert()'s second
+    // return value is false.
+    if (VD == 0 || VD->isInvalidDecl() || !Seen.insert(VD))
+      continue;
+
+    if (const IncompleteArrayType *ArrayT
+        = Context.getAsIncompleteArrayType(VD->getType())) {
+      if (RequireCompleteType(VD->getLocation(),
+                              ArrayT->getElementType(),
+                              diag::err_tentative_def_incomplete_type_arr)) {
+        VD->setInvalidDecl();
+        continue;
+      }
+
+      // Set the length of the array to 1 (C99 6.9.2p5).
+      Diag(VD->getLocation(), diag::warn_tentative_incomplete_array);
+      llvm::APInt One(Context.getTypeSize(Context.getSizeType()), true);
+      QualType T = Context.getConstantArrayType(ArrayT->getElementType(),
+                                                One, ArrayType::Normal, 0);
+      VD->setType(T);
+    } else if (RequireCompleteType(VD->getLocation(), VD->getType(),
+                                   diag::err_tentative_def_incomplete_type))
+      VD->setInvalidDecl();
+
+    // Notify the consumer that we've completed a tentative definition.
+    if (!VD->isInvalidDecl())
+      Consumer.CompleteTentativeDefinition(VD);
+
+  }
+}
+
+
+//===----------------------------------------------------------------------===//
+// Helper functions.
+//===----------------------------------------------------------------------===//
+
+DeclContext *Sema::getFunctionLevelDeclContext() {
+  DeclContext *DC = CurContext;
+
+  while (isa<BlockDecl>(DC))
+    DC = DC->getParent();
+
+  return DC;
+}
+
+/// getCurFunctionDecl - If inside of a function body, this returns a pointer
+/// to the function decl for the function being parsed.  If we're currently
+/// in a 'block', this returns the containing context.
+FunctionDecl *Sema::getCurFunctionDecl() {
+  DeclContext *DC = getFunctionLevelDeclContext();
+  return dyn_cast<FunctionDecl>(DC);
+}
+
+ObjCMethodDecl *Sema::getCurMethodDecl() {
+  DeclContext *DC = getFunctionLevelDeclContext();
+  return dyn_cast<ObjCMethodDecl>(DC);
+}
+
+NamedDecl *Sema::getCurFunctionOrMethodDecl() {
+  DeclContext *DC = getFunctionLevelDeclContext();
+  if (isa<ObjCMethodDecl>(DC) || isa<FunctionDecl>(DC))
+    return cast<NamedDecl>(DC);
+  return 0;
+}
+
+Sema::SemaDiagnosticBuilder::~SemaDiagnosticBuilder() {
+  if (!this->Emit())
+    return;
+
+  // If this is not a note, and we're in a template instantiation
+  // that is different from the last template instantiation where
+  // we emitted an error, print a template instantiation
+  // backtrace.
+  if (!SemaRef.Diags.isBuiltinNote(DiagID) &&
+      !SemaRef.ActiveTemplateInstantiations.empty() &&
+      SemaRef.ActiveTemplateInstantiations.back()
+        != SemaRef.LastTemplateInstantiationErrorContext) {
+    SemaRef.PrintInstantiationStack();
+    SemaRef.LastTemplateInstantiationErrorContext
+      = SemaRef.ActiveTemplateInstantiations.back();
+  }
+}
+
+Sema::SemaDiagnosticBuilder
+Sema::Diag(SourceLocation Loc, const PartialDiagnostic& PD) {
+  SemaDiagnosticBuilder Builder(Diag(Loc, PD.getDiagID()));
+  PD.Emit(Builder);
+
+  return Builder;
+}
+
+void Sema::ActOnComment(SourceRange Comment) {
+  Context.Comments.push_back(Comment);
+}
+