Removing an "if (this == nullptr)" check from two print methods. The condition

will never be true in a well-defined context.  The checking for null pointers
has been moved into the caller logic so it does not rely on undefined behavior.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@210498 91177308-0d34-0410-b5e6-96231b3b80d8

16 files changed, 57 insertions, 23 deletions

diff --git a/lib/AST/APValue.cpp b/lib/AST/APValue.cpp
index e7b5a6be34..0fa0216d9d 100644
--- a/lib/AST/APValue.cpp
+++ b/lib/AST/APValue.cpp
@@ -403,9 +403,13 @@ void APValue::printPretty(raw_ostream &Out, ASTContext &Ctx, QualType Ty) const{
 
       if (const ValueDecl *VD = Base.dyn_cast<const ValueDecl*>())
         Out << *VD;
-      else
+      else {
+        assert(Base.get<const Expr *>() != nullptr &&
+               "Expecting non-null Expr");
         Base.get<const Expr*>()->printPretty(Out, nullptr,
                                              Ctx.getPrintingPolicy());
+      }
+
       if (!O.isZero()) {
         Out << " + " << (O / S);
         if (IsReference)
@@ -426,6 +430,7 @@ void APValue::printPretty(raw_ostream &Out, ASTContext &Ctx, QualType Ty) const{
       ElemTy = VD->getType();
     } else {
       const Expr *E = Base.get<const Expr*>();
+      assert(E != nullptr && "Expecting non-null Expr");
       E->printPretty(Out, nullptr, Ctx.getPrintingPolicy());
       ElemTy = E->getType();
     }
diff --git a/lib/AST/DeclPrinter.cpp b/lib/AST/DeclPrinter.cpp
index 558654d887..e5e5130f69 100644
--- a/lib/AST/DeclPrinter.cpp
+++ b/lib/AST/DeclPrinter.cpp
@@ -536,6 +536,7 @@ void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
             SimpleInit->printPretty(Out, nullptr, Policy, Indentation);
           else {
             for (unsigned I = 0; I != NumArgs; ++I) {
+              assert(Args[I] != nullptr && "Expected non-null Expr");
               if (isa<CXXDefaultArgExpr>(Args[I]))
                 break;
               
@@ -586,7 +587,8 @@ void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
     } else
       Out << ' ';
 
-    D->getBody()->printPretty(Out, nullptr, SubPolicy, Indentation);
+    if (D->getBody())
+      D->getBody()->printPretty(Out, nullptr, SubPolicy, Indentation);
     Out << '\n';
   }
 }
diff --git a/lib/AST/StmtPrinter.cpp b/lib/AST/StmtPrinter.cpp
index 1daab32e5b..0651405618 100644
--- a/lib/AST/StmtPrinter.cpp
+++ b/lib/AST/StmtPrinter.cpp
@@ -645,6 +645,7 @@ void OMPClausePrinter::VisitOMPClauseList(T *Node, char StartSym) {
   for (typename T::varlist_iterator I = Node->varlist_begin(),
                                     E = Node->varlist_end();
          I != E; ++I) {
+    assert(*I && "Expected non-null Stmt");
     if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(*I)) {
       OS << (I == Node->varlist_begin() ? StartSym : ',');
       cast<NamedDecl>(DRE->getDecl())->printQualifiedName(OS);
@@ -2025,11 +2026,6 @@ void Stmt::printPretty(raw_ostream &OS,
                        PrinterHelper *Helper,
                        const PrintingPolicy &Policy,
                        unsigned Indentation) const {
-  if (this == nullptr) {
-    OS << "<NULL>";
-    return;
-  }
-
   StmtPrinter P(OS, Helper, Policy, Indentation);
   P.Visit(const_cast<Stmt*>(this));
 }
diff --git a/lib/AST/TypePrinter.cpp b/lib/AST/TypePrinter.cpp
index dfb43a0a84..8e2cea3f88 100644
--- a/lib/AST/TypePrinter.cpp
+++ b/lib/AST/TypePrinter.cpp
@@ -593,7 +593,8 @@ FunctionProtoType::printExceptionSpecification(raw_ostream &OS,
     OS << " noexcept";
     if (getExceptionSpecType() == EST_ComputedNoexcept) {
       OS << '(';
-      getNoexceptExpr()->printPretty(OS, nullptr, Policy);
+      if (getNoexceptExpr())
+        getNoexceptExpr()->printPretty(OS, nullptr, Policy);
       OS << ')';
     }
   }
@@ -761,7 +762,8 @@ void TypePrinter::printTypedefAfter(const TypedefType *T, raw_ostream &OS) { }
 void TypePrinter::printTypeOfExprBefore(const TypeOfExprType *T,
                                         raw_ostream &OS) {
   OS << "typeof ";
-  T->getUnderlyingExpr()->printPretty(OS, nullptr, Policy);
+  if (T->getUnderlyingExpr())
+    T->getUnderlyingExpr()->printPretty(OS, nullptr, Policy);
   spaceBeforePlaceHolder(OS);
 }
 void TypePrinter::printTypeOfExprAfter(const TypeOfExprType *T,
@@ -777,7 +779,8 @@ void TypePrinter::printTypeOfAfter(const TypeOfType *T, raw_ostream &OS) { }
 
 void TypePrinter::printDecltypeBefore(const DecltypeType *T, raw_ostream &OS) { 
   OS << "decltype(";
-  T->getUnderlyingExpr()->printPretty(OS, nullptr, Policy);
+  if (T->getUnderlyingExpr())
+    T->getUnderlyingExpr()->printPretty(OS, nullptr, Policy);
   OS << ')';
   spaceBeforePlaceHolder(OS);
 }
diff --git a/lib/Analysis/CFG.cpp b/lib/Analysis/CFG.cpp
index 5d2926c0f0..61e5f5acf0 100644
--- a/lib/Analysis/CFG.cpp
+++ b/lib/Analysis/CFG.cpp
@@ -3926,7 +3926,8 @@ public:
 
   void VisitIfStmt(IfStmt *I) {
     OS << "if ";
-    I->getCond()->printPretty(OS,Helper,Policy);
+    if (Stmt *C = I->getCond())
+      C->printPretty(OS, Helper, Policy);
   }
 
   // Default case.
@@ -3974,19 +3975,22 @@ public:
   }
 
   void VisitAbstractConditionalOperator(AbstractConditionalOperator* C) {
-    C->getCond()->printPretty(OS, Helper, Policy);
+    if (Stmt *Cond = C->getCond())
+      Cond->printPretty(OS, Helper, Policy);
     OS << " ? ... : ...";
   }
 
   void VisitChooseExpr(ChooseExpr *C) {
     OS << "__builtin_choose_expr( ";
-    C->getCond()->printPretty(OS, Helper, Policy);
+    if (Stmt *Cond = C->getCond())
+      Cond->printPretty(OS, Helper, Policy);
     OS << " )";
   }
 
   void VisitIndirectGotoStmt(IndirectGotoStmt *I) {
     OS << "goto *";
-    I->getTarget()->printPretty(OS, Helper, Policy);
+    if (Stmt *T = I->getTarget())
+      T->printPretty(OS, Helper, Policy);
   }
 
   void VisitBinaryOperator(BinaryOperator* B) {
@@ -3995,7 +3999,8 @@ public:
       return;
     }
 
-    B->getLHS()->printPretty(OS, Helper, Policy);
+    if (B->getLHS())
+      B->getLHS()->printPretty(OS, Helper, Policy);
 
     switch (B->getOpcode()) {
       case BO_LOr:
@@ -4026,7 +4031,8 @@ static void print_elem(raw_ostream &OS, StmtPrinterHelper &Helper,
                        const CFGElement &E) {
   if (Optional<CFGStmt> CS = E.getAs<CFGStmt>()) {
     const Stmt *S = CS->getStmt();
-    
+    assert(S != nullptr && "Expecting non-null Stmt");
+
     // special printing for statement-expressions.
     if (const StmtExpr *SE = dyn_cast<StmtExpr>(S)) {
       const CompoundStmt *Sub = SE->getSubStmt();
@@ -4172,8 +4178,9 @@ static void print_block(raw_ostream &OS, const CFG* cfg,
       OS << L->getName();
     else if (CaseStmt *C = dyn_cast<CaseStmt>(Label)) {
       OS << "case ";
-      C->getLHS()->printPretty(OS, &Helper,
-                               PrintingPolicy(Helper.getLangOpts()));
+      if (C->getLHS())
+        C->getLHS()->printPretty(OS, &Helper,
+                                 PrintingPolicy(Helper.getLangOpts()));
       if (C->getRHS()) {
         OS << " ... ";
         C->getRHS()->printPretty(OS, &Helper,
diff --git a/lib/Rewrite/Core/Rewriter.cpp b/lib/Rewrite/Core/Rewriter.cpp
index 8b17b654d6..eb123ad702 100644
--- a/lib/Rewrite/Core/Rewriter.cpp
+++ b/lib/Rewrite/Core/Rewriter.cpp
@@ -332,6 +332,8 @@ bool Rewriter::ReplaceText(SourceRange range, SourceRange replacementRange) {
 /// printer to generate the replacement code.  This returns true if the input
 /// could not be rewritten, or false if successful.
 bool Rewriter::ReplaceStmt(Stmt *From, Stmt *To) {
+  assert(From != nullptr && To != nullptr && "Expected non-null Stmt's");
+
   // Measaure the old text.
   int Size = getRangeSize(From->getSourceRange());
   if (Size == -1)
@@ -348,6 +350,7 @@ bool Rewriter::ReplaceStmt(Stmt *From, Stmt *To) {
 }
 
 std::string Rewriter::ConvertToString(Stmt *From) {
+  assert(From != nullptr && "Expected non-null Stmt");
   std::string SStr;
   llvm::raw_string_ostream S(SStr);
   From->printPretty(S, nullptr, PrintingPolicy(*LangOpts));
diff --git a/lib/Rewrite/Frontend/RewriteModernObjC.cpp b/lib/Rewrite/Frontend/RewriteModernObjC.cpp
index 3cacbdddf3..43de31c516 100644
--- a/lib/Rewrite/Frontend/RewriteModernObjC.cpp
+++ b/lib/Rewrite/Frontend/RewriteModernObjC.cpp
@@ -267,6 +267,7 @@ namespace {
     }
 
     void ReplaceStmtWithRange(Stmt *Old, Stmt *New, SourceRange SrcRange) {
+      assert(Old != nullptr && New != nullptr && "Expected non-null Stmt's");
       if (DisableReplaceStmt)
         return;
 
@@ -2587,6 +2588,7 @@ void RewriteModernObjC::SynthGetMetaClassFunctionDecl() {
 }
 
 Stmt *RewriteModernObjC::RewriteObjCStringLiteral(ObjCStringLiteral *Exp) {
+  assert (Exp != nullptr && "Expected non-null ObjCStringLiteral");
   QualType strType = getConstantStringStructType();
 
   std::string S = "__NSConstantStringImpl_";
diff --git a/lib/Rewrite/Frontend/RewriteObjC.cpp b/lib/Rewrite/Frontend/RewriteObjC.cpp
index beadb931a9..dfeb11a9aa 100644
--- a/lib/Rewrite/Frontend/RewriteObjC.cpp
+++ b/lib/Rewrite/Frontend/RewriteObjC.cpp
@@ -216,6 +216,7 @@ namespace {
     }
 
     void ReplaceStmtWithRange(Stmt *Old, Stmt *New, SourceRange SrcRange) {
+      assert(Old != nullptr && New != nullptr && "Expected non-null Stmt's");
       if (DisableReplaceStmt)
         return;
 
@@ -1697,6 +1698,7 @@ Stmt *RewriteObjC::RewriteObjCSynchronizedStmt(ObjCAtSynchronizedStmt *S) {
                                       CK, syncExpr);
   std::string syncExprBufS;
   llvm::raw_string_ostream syncExprBuf(syncExprBufS);
+  assert(syncExpr != nullptr && "Expected non-null Expr");
   syncExpr->printPretty(syncExprBuf, nullptr, PrintingPolicy(LangOpts));
   syncBuf += syncExprBuf.str();
   syncBuf += ");";
@@ -2485,6 +2487,7 @@ void RewriteObjC::SynthGetMetaClassFunctionDecl() {
 }
 
 Stmt *RewriteObjC::RewriteObjCStringLiteral(ObjCStringLiteral *Exp) {
+  assert(Exp != nullptr && "Expected non-null ObjCStringLiteral");
   QualType strType = getConstantStringStructType();
 
   std::string S = "__NSConstantStringImpl_";
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index 570f749815..fc87b231d6 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -6181,6 +6181,8 @@ enum {
 void Sema::DiagnoseAlwaysNonNullPointer(Expr *E,
                                         Expr::NullPointerConstantKind NullKind,
                                         bool IsEqual, SourceRange Range) {
+  if (!E)
+    return;
 
   // Don't warn inside macros.
   if (E->getExprLoc().isMacroID())
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 3f8034a49f..3b660fdd42 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -11407,6 +11407,8 @@ Decl *Sema::BuildStaticAssertDeclaration(SourceLocation StaticAssertLoc,
                                          StringLiteral *AssertMessage,
                                          SourceLocation RParenLoc,
                                          bool Failed) {
+  assert(AssertExpr != nullptr && AssertMessage != nullptr &&
+         "Expected non-null Expr's");
   if (!AssertExpr->isTypeDependent() && !AssertExpr->isValueDependent() &&
       !Failed) {
     // In a static_assert-declaration, the constant-expression shall be a
diff --git a/lib/Sema/SemaExceptionSpec.cpp b/lib/Sema/SemaExceptionSpec.cpp
index 24d82224dd..6eccb9f85d 100644
--- a/lib/Sema/SemaExceptionSpec.cpp
+++ b/lib/Sema/SemaExceptionSpec.cpp
@@ -283,6 +283,7 @@ bool Sema::CheckEquivalentExceptionSpec(FunctionDecl *Old, FunctionDecl *New) {
 
   case EST_ComputedNoexcept:
     OS << "noexcept(";
+    assert(OldProto->getNoexceptExpr() != nullptr && "Expected non-null Expr");
     OldProto->getNoexceptExpr()->printPretty(OS, nullptr, getPrintingPolicy());
     OS << ")";
     break;
diff --git a/lib/StaticAnalyzer/Core/Environment.cpp b/lib/StaticAnalyzer/Core/Environment.cpp
index 6a26650aea..ae5a4cc8b4 100644
--- a/lib/StaticAnalyzer/Core/Environment.cpp
+++ b/lib/StaticAnalyzer/Core/Environment.cpp
@@ -205,7 +205,8 @@ void Environment::print(raw_ostream &Out, const char *NL,
     }
     
     const Stmt *S = En.getStmt();
-    
+    assert(S != nullptr && "Expected non-null Stmt");
+
     Out << " (" << (const void*) En.getLocationContext() << ','
       << (const void*) S << ") ";
     LangOptions LO; // FIXME.
diff --git a/lib/StaticAnalyzer/Core/ExprEngine.cpp b/lib/StaticAnalyzer/Core/ExprEngine.cpp
index ac87d5819e..1afeee9c71 100644
--- a/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -2428,7 +2428,8 @@ struct DOTGraphTraits<ExplodedNode*> :
               if (const CaseStmt *C = dyn_cast<CaseStmt>(Label)) {
                 Out << "\\lcase ";
                 LangOptions LO; // FIXME.
-                C->getLHS()->printPretty(Out, nullptr, PrintingPolicy(LO));
+                if (C->getLHS())
+                  C->getLHS()->printPretty(Out, nullptr, PrintingPolicy(LO));
 
                 if (const Stmt *RHS = C->getRHS()) {
                   Out << " .. ";
@@ -2471,6 +2472,7 @@ struct DOTGraphTraits<ExplodedNode*> :
 
       default: {
         const Stmt *S = Loc.castAs<StmtPoint>().getStmt();
+        assert(S != nullptr && "Expecting non-null Stmt");
 
         Out << S->getStmtClassName() << ' ' << (const void*) S << ' ';
         LangOptions LO; // FIXME.
diff --git a/lib/StaticAnalyzer/Core/MemRegion.cpp b/lib/StaticAnalyzer/Core/MemRegion.cpp
index 12bbfdf62d..22711f5423 100644
--- a/lib/StaticAnalyzer/Core/MemRegion.cpp
+++ b/lib/StaticAnalyzer/Core/MemRegion.cpp
@@ -508,10 +508,12 @@ void ObjCIvarRegion::dumpToStream(raw_ostream &os) const {
 }
 
 void StringRegion::dumpToStream(raw_ostream &os) const {
+  assert(Str != nullptr && "Expecting non-null StringLiteral");
   Str->printPretty(os, nullptr, PrintingPolicy(getContext().getLangOpts()));
 }
 
 void ObjCStringRegion::dumpToStream(raw_ostream &os) const {
+  assert(Str != nullptr && "Expecting non-null ObjCStringLiteral");
   Str->printPretty(os, nullptr, PrintingPolicy(getContext().getLangOpts()));
 }
 
diff --git a/unittests/AST/StmtPrinterTest.cpp b/unittests/AST/StmtPrinterTest.cpp
index 0b334e768f..c75cbdefbf 100644
--- a/unittests/AST/StmtPrinterTest.cpp
+++ b/unittests/AST/StmtPrinterTest.cpp
@@ -32,6 +32,7 @@ using namespace tooling;
 namespace {
 
 void PrintStmt(raw_ostream &Out, const ASTContext *Context, const Stmt *S) {
+  assert(S != nullptr && "Expected non-null Stmt");
   PrintingPolicy Policy = Context->getPrintingPolicy();
   S->printPretty(Out, /*Helper*/ nullptr, Policy);
 }
diff --git a/utils/TableGen/ClangAttrEmitter.cpp b/utils/TableGen/ClangAttrEmitter.cpp
index c03ff901d1..11c64eac7b 100644
--- a/utils/TableGen/ClangAttrEmitter.cpp
+++ b/utils/TableGen/ClangAttrEmitter.cpp
@@ -484,9 +484,11 @@ namespace {
          << "Type(), Record);\n";
     }
     void writeValue(raw_ostream &OS) const override {
-      OS << "\";\n"
-         << "  " << getLowerName() << "Expr->printPretty(OS, 0, Policy);\n"
-         << "  OS << \"";
+      OS << "\";\n";
+      OS << "    assert(is" << getLowerName() << "Expr && " << getLowerName()
+         << "Expr != nullptr);\n";
+      OS << "    " << getLowerName() << "Expr->printPretty(OS, 0, Policy);\n";
+      OS << "    OS << \"";
     }
     void writeDump(raw_ostream &OS) const override {
     }