Fix an inconsistency in the syntactic form of InitListExpr in case of initialization that involves a ConstructorConversion

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@146766 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 37 insertions, 6 deletions

diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index 7dbf830431..18fd3876e7 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -171,6 +171,9 @@ class InitListChecker {
   bool hadError;
   bool VerifyOnly; // no diagnostics, no structure building
   bool AllowBraceElision;
+  Expr *LastCheckedSubobject;
+  unsigned LastCheckedSubobjectIndex;
+  
   std::map<InitListExpr *, InitListExpr *> SyntacticToSemantic;
   InitListExpr *FullyStructuredList;
 
@@ -470,7 +473,8 @@ InitListChecker::FillInValueInitializations(const InitializedEntity &Entity,
 InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity,
                                  InitListExpr *IL, QualType &T,
                                  bool VerifyOnly, bool AllowBraceElision)
-  : SemaRef(S), VerifyOnly(VerifyOnly), AllowBraceElision(AllowBraceElision) {
+  : SemaRef(S), VerifyOnly(VerifyOnly), AllowBraceElision(AllowBraceElision),
+    LastCheckedSubobject(0), LastCheckedSubobjectIndex(0) {
   hadError = false;
 
   unsigned newIndex = 0;
@@ -792,13 +796,40 @@ void InitListChecker::CheckSubElementType(const InitializedEntity &Entity,
 
     if (Seq) {
       if (!VerifyOnly) {
-        ExprResult Result =
-          Seq.Perform(SemaRef, Entity, Kind, MultiExprArg(&expr, 1));
-        if (Result.isInvalid())
-          hadError = true;
+        // struct S {
+        //   S(int);
+        // };
+        //
+        // S s[] = { [0 ... 2] = 3 };
+        //
+        // In code like this, we want to perform the initialization and then
+        // update the syntactic list with the result. However, we reach this
+        // point once for each subobject, but the update needs
+        // to be done only once for each syntactic element. For this reason,
+        // the initialization result and its syntactic Index are cached in
+        // LastCheckedSubobject and LastCheckedSubobjectIndex and reused until
+        // we move to the next Index.
+        Expr *ResultExpr = LastCheckedSubobject;
+        
+        if (!ResultExpr || Index != LastCheckedSubobjectIndex) {
+          ExprResult Result = Seq.Perform(SemaRef, Entity, Kind, MultiExprArg(&expr, 1));
+
+          if (Result.isInvalid()) {
+            hadError = true;
+            ResultExpr = 0;
+          } else {
+            ResultExpr = Result.takeAs<Expr>();
+          }
+          
+          LastCheckedSubobject = ResultExpr;
+          LastCheckedSubobjectIndex = Index;
+        }
+
+        // Update the syntactic list
+        IList->setInit(Index, ResultExpr);
 
         UpdateStructuredListElement(StructuredList, StructuredIndex,
-                                    Result.takeAs<Expr>());
+                                    ResultExpr);
       }
       ++Index;
       return;