Add two new AST nodes to represent initialization of an array in terms of

initialization of each array element:

 * ArrayInitLoopExpr is a prvalue of array type with two subexpressions:
   a common expression (an OpaqueValueExpr) that represents the up-front
   computation of the source of the initialization, and a subexpression
   representing a per-element initializer
 * ArrayInitIndexExpr is a prvalue of type size_t representing the current
   position in the loop

This will be used to replace the creation of explicit index variables in lambda
capture of arrays and copy/move construction of classes with array elements,
and also C++17 structured bindings of arrays by value (which inexplicably allow
copying an array by value, unlike all of C++'s other array declarations).

No uses of these nodes are introduced by this change, however.

llvm-svn: 289413

1 files changed, 18 insertions, 0 deletions

diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 032ceefbf34..461bb9f8d46 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -845,6 +845,16 @@ void ASTStmtReader::VisitNoInitExpr(NoInitExpr *E) {
   VisitExpr(E);
 }
 
+void ASTStmtReader::VisitArrayInitLoopExpr(ArrayInitLoopExpr *E) {
+  VisitExpr(E);
+  E->SubExprs[0] = Reader.ReadSubExpr();
+  E->SubExprs[1] = Reader.ReadSubExpr();
+}
+
+void ASTStmtReader::VisitArrayInitIndexExpr(ArrayInitIndexExpr *E) {
+  VisitExpr(E);
+}
+
 void ASTStmtReader::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) {
   VisitExpr(E);
 }
@@ -3231,6 +3241,14 @@ Stmt *ASTReader::ReadStmtFromStream(ModuleFile &F) {
       S = new (Context) NoInitExpr(Empty);
       break;
 
+    case EXPR_ARRAY_INIT_LOOP:
+      S = new (Context) ArrayInitLoopExpr(Empty);
+      break;
+
+    case EXPR_ARRAY_INIT_INDEX:
+      S = new (Context) ArrayInitIndexExpr(Empty);
+      break;
+
     case EXPR_VA_ARG:
       S = new (Context) VAArgExpr(Empty);
       break;