Bug 545957 - Fix for brace elision rule

Change-Id: Ie470c1d9a986beb1b177e3d3d571071f6ed1b8f8
Signed-off-by: Hannes Vogt <hannes@havogt.de>

2 files changed, 22 insertions, 10 deletions

diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java
index 37d4cb0e647..a1bdad7bcc1 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java
@@ -13010,6 +13010,19 @@ public class AST2CPPTests extends AST2CPPTestBase {
 		parseAndCheckBindings();
 	}
 
+	//	struct S1 {
+	//	};
+	//	struct S2 {
+	//		S1 s1;
+	//	};
+	//	auto f() {
+	//		auto s1 = S1 { };
+	//		return S2 { s1 };
+	//	}
+	public void testBraceElisionForAggregateInit7_545957() throws Exception {
+		parseAndCheckImplicitNameBindings();
+	}
+
 	//  struct type{
 	//      int a;
 	//  };
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/AggregateInitialization.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/AggregateInitialization.java
index d18585b19d5..292a6886bf7 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/AggregateInitialization.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/AggregateInitialization.java
@@ -66,24 +66,23 @@ class AggregateInitialization {
 			return checkInitializationFromDefaultMemberInitializer(nestedType, initialValue, worstCost);
 		worstCost = new Cost(fInitializers[fIndex].getType(), nestedType, Rank.IDENTITY);
 
-		if (fInitializers[fIndex].isInitializerList() || !isAggregate(nestedType)) { // no braces are elided
+		ICPPEvaluation initializer = fInitializers[fIndex];
+		Cost costWithoutElision = Conversions.checkImplicitConversionSequence(nestedType, initializer.getType(),
+				initializer.getValueCategory(), UDCMode.ALLOWED, Context.ORDINARY);
+		if (costWithoutElision.converts()) {
 			// p3: The elements of the initializer list are taken as initializers for the elements
 			//     of the aggregate, in order.
-			ICPPEvaluation initializer = fInitializers[fIndex];
 			fIndex++;
-			Cost cost = Conversions.checkImplicitConversionSequence(nestedType, initializer.getType(),
-					initializer.getValueCategory(), UDCMode.ALLOWED, Context.ORDINARY);
-			if (!cost.converts()) {
-				return cost;
-			}
 			// [dcl.init.aggr] If the initializer-clause is an expression and a narrowing conversion is
 			// required to convert the expression, the program is ill-formed.
-			if (!(initializer instanceof EvalInitList) && cost.isNarrowingConversion()) {
+			if (!(initializer instanceof EvalInitList) && costWithoutElision.isNarrowingConversion()) {
 				return Cost.NO_CONVERSION;
 			}
-			if (cost.compareTo(worstCost) > 0) {
-				worstCost = cost;
+			if (costWithoutElision.compareTo(worstCost) > 0) {
+				worstCost = costWithoutElision;
 			}
+		} else if (fInitializers[fIndex].isInitializerList() || !isAggregate(nestedType)) { // cannot elide braces
+			return costWithoutElision; // doesn't convert
 		} else { // braces are elided: need to check on subaggregates
 			Cost cost = checkInitializationOfElements(nestedType, worstCost);
 			if (!cost.converts())