svn commit: r321342 - head/contrib/llvm/tools/clang/lib/AST

[Dimitry Andric]

Author: dim
Date: Fri Jul 21 17:59:54 2017
New Revision: 321342
URL: https://svnweb.freebsd.org/changeset/base/321342

Log:
  Pull in r295886 from upstream clang trunk (by Richard Smith):
  
    PR32034: Evaluate _Atomic(T) in-place when T is a class or array type.
  
    This is necessary in order for the evaluation of an _Atomic
    initializer for those types to have an associated object, which an
    initializer for class or array type needs.
  
  This fixes an assertion when building recent versions of LinuxCNC.
  
  Reported by:	trasz
  PR:		220883
  MFC after:	1 week

Modified:
  head/contrib/llvm/tools/clang/lib/AST/ExprConstant.cpp

Modified: head/contrib/llvm/tools/clang/lib/AST/ExprConstant.cpp
==============================================================================
--- head/contrib/llvm/tools/clang/lib/AST/ExprConstant.cpp	Fri Jul 21 17:58:06 2017	(r321341)
+++ head/contrib/llvm/tools/clang/lib/AST/ExprConstant.cpp	Fri Jul 21 17:59:54 2017	(r321342)
@@ -1404,7 +1404,8 @@ static bool EvaluateIntegerOrLValue(const Expr *E, APV
                                     EvalInfo &Info);
 static bool EvaluateFloat(const Expr *E, APFloat &Result, EvalInfo &Info);
 static bool EvaluateComplex(const Expr *E, ComplexValue &Res, EvalInfo &Info);
-static bool EvaluateAtomic(const Expr *E, APValue &Result, EvalInfo &Info);
+static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
+                           EvalInfo &Info);
 static bool EvaluateAsRValue(EvalInfo &Info, const Expr *E, APValue &Result);
 
 //===----------------------------------------------------------------------===//
@@ -4691,7 +4692,10 @@ class ExprEvaluatorBase (public)
 
     case CK_AtomicToNonAtomic: {
       APValue AtomicVal;
-      if (!EvaluateAtomic(E->getSubExpr(), AtomicVal, Info))
+      // This does not need to be done in place even for class/array types:
+      // atomic-to-non-atomic conversion implies copying the object
+      // representation.
+      if (!Evaluate(AtomicVal, Info, E->getSubExpr()))
         return false;
       return DerivedSuccess(AtomicVal, E);
     }
@@ -9565,10 +9569,11 @@ bool ComplexExprEvaluator::VisitInitListExpr(const Ini
 namespace {
 class AtomicExprEvaluator :
     public ExprEvaluatorBase<AtomicExprEvaluator> {
+  const LValue *This;
   APValue &Result;
 public:
-  AtomicExprEvaluator(EvalInfo &Info, APValue &Result)
-      : ExprEvaluatorBaseTy(Info), Result(Result) {}
+  AtomicExprEvaluator(EvalInfo &Info, const LValue *This, APValue &Result)
+      : ExprEvaluatorBaseTy(Info), This(This), Result(Result) {}
 
   bool Success(const APValue &V, const Expr *E) {
     Result = V;
@@ -9578,7 +9583,10 @@ class AtomicExprEvaluator : (public)
   bool ZeroInitialization(const Expr *E) {
     ImplicitValueInitExpr VIE(
         E->getType()->castAs<AtomicType>()->getValueType());
-    return Evaluate(Result, Info, &VIE);
+    // For atomic-qualified class (and array) types in C++, initialize the
+    // _Atomic-wrapped subobject directly, in-place.
+    return This ? EvaluateInPlace(Result, Info, *This, &VIE)
+                : Evaluate(Result, Info, &VIE);
   }
 
   bool VisitCastExpr(const CastExpr *E) {
@@ -9586,15 +9594,17 @@ class AtomicExprEvaluator : (public)
     default:
       return ExprEvaluatorBaseTy::VisitCastExpr(E);
     case CK_NonAtomicToAtomic:
-      return Evaluate(Result, Info, E->getSubExpr());
+      return This ? EvaluateInPlace(Result, Info, *This, E->getSubExpr())
+                  : Evaluate(Result, Info, E->getSubExpr());
     }
   }
 };
 } // end anonymous namespace
 
-static bool EvaluateAtomic(const Expr *E, APValue &Result, EvalInfo &Info) {
+static bool EvaluateAtomic(const Expr *E, const LValue *This, APValue &Result,
+                           EvalInfo &Info) {
   assert(E->isRValue() && E->getType()->isAtomicType());
-  return AtomicExprEvaluator(Info, Result).Visit(E);
+  return AtomicExprEvaluator(Info, This, Result).Visit(E);
 }
 
 //===----------------------------------------------------------------------===//
@@ -9699,8 +9709,17 @@ static bool Evaluate(APValue &Result, EvalInfo &Info, 
     if (!EvaluateVoid(E, Info))
       return false;
   } else if (T->isAtomicType()) {
-    if (!EvaluateAtomic(E, Result, Info))
-      return false;
+    QualType Unqual = T.getAtomicUnqualifiedType();
+    if (Unqual->isArrayType() || Unqual->isRecordType()) {
+      LValue LV;
+      LV.set(E, Info.CurrentCall->Index);
+      APValue &Value = Info.CurrentCall->createTemporary(E, false);
+      if (!EvaluateAtomic(E, &LV, Value, Info))
+        return false;
+    } else {
+      if (!EvaluateAtomic(E, nullptr, Result, Info))
+        return false;
+    }
   } else if (Info.getLangOpts().CPlusPlus11) {
     Info.FFDiag(E, diag::note_constexpr_nonliteral) << E->getType();
     return false;
@@ -9725,10 +9744,16 @@ static bool EvaluateInPlace(APValue &Result, EvalInfo 
   if (E->isRValue()) {
     // Evaluate arrays and record types in-place, so that later initializers can
     // refer to earlier-initialized members of the object.
-    if (E->getType()->isArrayType())
+    QualType T = E->getType();
+    if (T->isArrayType())
       return EvaluateArray(E, This, Result, Info);
-    else if (E->getType()->isRecordType())
+    else if (T->isRecordType())
       return EvaluateRecord(E, This, Result, Info);
+    else if (T->isAtomicType()) {
+      QualType Unqual = T.getAtomicUnqualifiedType();
+      if (Unqual->isArrayType() || Unqual->isRecordType())
+        return EvaluateAtomic(E, &This, Result, Info);
+    }
   }
 
   // For any other type, in-place evaluation is unimportant.