PR22877: When constructing an array via a constructor with a default argument

in list-initialization, run cleanups for the default argument after each
iteration of the initialization loop.

We previously only ran the destructor for any temporary once, at the end of the
complete loop, rather than once per iteration!

Re-commit of r302750, reverted in r302776.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@302817 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/CGExprAgg.cpp b/lib/CodeGen/CGExprAgg.cpp
index 49bbb4808eaa2c0df167e5c82719c4ede0c5d892..a05a088f09191a96aaebdcacabfd9faa46251cfd 100644 (file)
--- a/lib/CodeGen/CGExprAgg.cpp
+++ b/lib/CodeGen/CGExprAgg.cpp
@@ -512,12 +512,20 @@ void AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType,
     currentElement->addIncoming(element, entryBB);
 
     // Emit the actual filler expression.
-    LValue elementLV =
-      CGF.MakeAddrLValue(Address(currentElement, elementAlign), elementType);
-    if (filler)
-      EmitInitializationToLValue(filler, elementLV);
-    else
-      EmitNullInitializationToLValue(elementLV);
+    {
+      // C++1z [class.temporary]p5:
+      //   when a default constructor is called to initialize an element of
+      //   an array with no corresponding initializer [...] the destruction of
+      //   every temporary created in a default argument is sequenced before
+      //   the construction of the next array element, if any
+      CodeGenFunction::RunCleanupsScope CleanupsScope(CGF);
+      LValue elementLV =
+        CGF.MakeAddrLValue(Address(currentElement, elementAlign), elementType);
+      if (filler)
+        EmitInitializationToLValue(filler, elementLV);
+      else
+        EmitNullInitializationToLValue(elementLV);
+    }
 
     // Move on to the next element.
     llvm::Value *nextElement =

diff --git a/test/CodeGenCXX/array-default-argument.cpp b/test/CodeGenCXX/array-default-argument.cpp
new file mode 100644 (file)
index 0000000..8376b4f
--- /dev/null
+++ b/test/CodeGenCXX/array-default-argument.cpp
@@ -0,0 +1,36 @@
+// RUN: %clang_cc1 -emit-llvm -o - %s -triple %itanium_abi_triple | FileCheck %s
+// RUN: %clang_cc1 -emit-llvm -o - %s -triple %itanium_abi_triple -fexceptions -fcxx-exceptions | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-EH
+
+struct A {
+  A();
+  ~A();
+};
+
+struct B {
+  B(A = A());
+  ~B();
+};
+
+void f();
+// CHECK-LABEL: define void @_Z1gv()
+void g() {
+  // CHECK: br label %[[LOOP:.*]]
+
+  // [[LOOP]]:
+  // CHECK: {{call|invoke}} {{.*}} @_ZN1AC1Ev([[TEMPORARY:.*]])
+  // CHECK-EH:  unwind label %[[PARTIAL_ARRAY_LPAD:.*]]
+  // CHECK: {{call|invoke}} {{.*}} @_ZN1BC1E1A({{.*}}, [[TEMPORARY]])
+  // CHECK-EH:  unwind label %[[A_AND_PARTIAL_ARRAY_LPAD:.*]]
+  // CHECK: {{call|invoke}} {{.*}} @_ZN1AD1Ev([[TEMPORARY]])
+  // CHECK-EH:  unwind label %[[PARTIAL_ARRAY_LPAD]]
+  // CHECK: getelementptr {{.*}}, i{{[0-9]*}} 1
+  // CHECK: icmp eq
+  // CHECK: br i1 {{.*}} label %[[LOOP]]
+  B b[5];
+
+  // CHECK: {{call|invoke}} void @_Z1fv()
+  f();
+
+  // CHECK-NOT: @_ZN1AD1Ev(
+  // CHECK: {{call|invoke}} {{.*}} @_ZN1BD1Ev(
+}