AtomicExpr: make ASTStmtReader a friend and remove setters. Also fix saving
of an uninitialized Stmt* in serialization of __atomic_init and add a test of
atomics serialization.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@154448 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 1947e61..2bb79a0 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -3841,6 +3841,7 @@
          false, false, false, false),
     NumSubExprs(nexpr), BuiltinLoc(BLoc), RParenLoc(RP), Op(op)
 {
+  assert(nexpr == getNumSubExprs(op) && "wrong number of subexpressions");
   for (unsigned i = 0; i < nexpr; i++) {
     if (args[i]->isTypeDependent())
       ExprBits.TypeDependent = true;
@@ -3854,3 +3855,23 @@
     SubExprs[i] = args[i];
   }
 }
+
+unsigned AtomicExpr::getNumSubExprs(AtomicOp Op) {
+  switch (Op) {
+  case Init:
+  case Load:
+    return 2;
+  case Store:
+  case Xchg:
+  case Add:
+  case Sub:
+  case And:
+  case Or:
+  case Xor:
+    return 3;
+  case CmpXchgStrong:
+  case CmpXchgWeak:
+    return 5;
+  }
+  llvm_unreachable("unknown atomic op");
+}
diff --git a/lib/Serialization/ASTReaderStmt.cpp b/lib/Serialization/ASTReaderStmt.cpp
index 1c9817b..2eeb090 100644
--- a/lib/Serialization/ASTReaderStmt.cpp
+++ b/lib/Serialization/ASTReaderStmt.cpp
@@ -790,21 +790,12 @@
 
 void ASTStmtReader::VisitAtomicExpr(AtomicExpr *E) {
   VisitExpr(E);
-  E->setOp(AtomicExpr::AtomicOp(Record[Idx++]));
-  E->setPtr(Reader.ReadSubExpr());
-  E->setOrder(Reader.ReadSubExpr());
-  E->setNumSubExprs(2);
-  if (E->getOp() != AtomicExpr::Load) {
-    E->setVal1(Reader.ReadSubExpr());
-    E->setNumSubExprs(3);
-  }
-  if (E->isCmpXChg()) {
-    E->setOrderFail(Reader.ReadSubExpr());
-    E->setVal2(Reader.ReadSubExpr());
-    E->setNumSubExprs(5);
-  }
-  E->setBuiltinLoc(ReadSourceLocation(Record, Idx));
-  E->setRParenLoc(ReadSourceLocation(Record, Idx));
+  E->Op = AtomicExpr::AtomicOp(Record[Idx++]);
+  E->NumSubExprs = AtomicExpr::getNumSubExprs(E->Op);
+  for (unsigned I = 0; I != E->NumSubExprs; ++I)
+    E->SubExprs[I] = Reader.ReadSubExpr();
+  E->BuiltinLoc = ReadSourceLocation(Record, Idx);
+  E->RParenLoc = ReadSourceLocation(Record, Idx);
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/lib/Serialization/ASTWriterStmt.cpp b/lib/Serialization/ASTWriterStmt.cpp
index eac7e1f..827caa0 100644
--- a/lib/Serialization/ASTWriterStmt.cpp
+++ b/lib/Serialization/ASTWriterStmt.cpp
@@ -751,14 +751,8 @@
 void ASTStmtWriter::VisitAtomicExpr(AtomicExpr *E) {
   VisitExpr(E);
   Record.push_back(E->getOp());
-  Writer.AddStmt(E->getPtr());
-  Writer.AddStmt(E->getOrder());
-  if (E->getOp() != AtomicExpr::Load)
-    Writer.AddStmt(E->getVal1());
-  if (E->isCmpXChg()) {
-    Writer.AddStmt(E->getOrderFail());
-    Writer.AddStmt(E->getVal2());
-  }
+  for (unsigned I = 0, N = E->getNumSubExprs(); I != N; ++I)
+    Writer.AddStmt(E->getSubExprs()[I]);
   Writer.AddSourceLocation(E->getBuiltinLoc(), Record);
   Writer.AddSourceLocation(E->getRParenLoc(), Record);
   Code = serialization::EXPR_ATOMIC;