Perform two more constructor/destructor code-size optimizations:

1) emit base destructors as aliases to their unique base class destructors
under some careful conditions.  This is enabled for the same targets that can
support complete-to-base aliases, i.e. not darwin.

2) Emit non-variadic complete constructors for classes with no virtual bases
as calls to the base constructor.  This is enabled on all targets and in
theory can trigger in situations that the alias optimization can't (mostly
involving virtual bases, mostly not yet supported).

These are bundled together because I didn't think it worthwhile to split them,
not because they really need to be.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@96842 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 94 insertions, 0 deletions

diff --git a/test/CodeGenCXX/constructors.cpp b/test/CodeGenCXX/constructors.cpp
new file mode 100644
index 0000000000..2c95c91e11
--- /dev/null
+++ b/test/CodeGenCXX/constructors.cpp
@@ -0,0 +1,94 @@
+// RUN: %clang_cc1 -triple x86_64-apple-darwin10 %s -emit-llvm -o - | FileCheck %s
+
+struct Member { int x; Member(); Member(int); Member(const Member &); };
+struct VBase { int x; VBase(); VBase(int); VBase(const VBase &); };
+
+struct ValueClass {
+  ValueClass(int x, int y) : x(x), y(y) {}
+  int x;
+  int y;
+}; // subject to ABI trickery
+
+
+
+/* Test basic functionality. */
+class A {
+  A(struct Undeclared &);
+  A(ValueClass);
+  Member mem;
+};
+
+A::A(struct Undeclared &ref) : mem(0) {}
+
+// Check that delegation works.
+// CHECK: define void @_ZN1AC1ER10Undeclared(
+// CHECK: call void @_ZN1AC2ER10Undeclared(
+
+// CHECK: define void @_ZN1AC2ER10Undeclared(
+// CHECK: call void @_ZN6MemberC1Ei(
+
+A::A(ValueClass v) : mem(v.y - v.x) {}
+
+// CHECK: define void @_ZN1AC1E10ValueClass(
+// CHECK: call void @_ZN1AC2E10ValueClass(
+
+// CHECK: define void @_ZN1AC2E10ValueClass(
+// CHECK: call void @_ZN6MemberC1Ei(
+
+
+/* Test that things work for inheritance. */
+struct B : A {
+  B(struct Undeclared &);
+  Member mem;
+};
+
+B::B(struct Undeclared &ref) : A(ref), mem(1) {}
+
+// CHECK: define void @_ZN1BC1ER10Undeclared(
+// CHECK: call void @_ZN1BC2ER10Undeclared(
+
+// CHECK: define void @_ZN1BC2ER10Undeclared(
+// CHECK: call void @_ZN1AC2ER10Undeclared(
+// CHECK: call void @_ZN6MemberC1Ei(
+
+
+
+/* Test that the delegation optimization is disabled for classes with
+   virtual bases (for now).  This is necessary because a vbase
+   initializer could access one of the parameter variables by
+   reference.  That's a solvable problem, but let's not solve it right
+   now. */
+struct C : virtual A {
+  C(int);
+  Member mem;
+};
+C::C(int x) : A(ValueClass(x, x+1)), mem(x * x) {}
+
+// CHECK: define void @_ZN1CC1Ei(
+// CHECK: call void @_ZN10ValueClassC1Eii(
+// CHECK: call void @_ZN1AC2E10ValueClass(
+// CHECK: call void @_ZN6MemberC1Ei(
+
+// CHECK: define void @_ZN1CC2Ei(
+// CHECK: call void @_ZN6MemberC1Ei(
+
+
+
+/* Test that the delegation optimization is disabled for varargs
+   constructors. */
+struct D : A {
+  D(int, ...);
+  Member mem;
+};
+
+D::D(int x, ...) : A(ValueClass(x, x+1)), mem(x*x) {}
+
+// CHECK: define void @_ZN1DC1Eiz(
+// CHECK: call void @_ZN10ValueClassC1Eii(
+// CHECK: call void @_ZN1AC2E10ValueClass(
+// CHECK: call void @_ZN6MemberC1Ei(
+
+// CHECK: define void @_ZN1DC2Eiz(
+// CHECK: call void @_ZN10ValueClassC1Eii(
+// CHECK: call void @_ZN1AC2E10ValueClass(
+// CHECK: call void @_ZN6MemberC1Ei(