PR12086, PR15117

Introduce CXXStdInitializerListExpr node, representing the implicit
construction of a std::initializer_list<T> object from its underlying array.
The AST representation of such an expression goes from an InitListExpr with a
flag set, to a CXXStdInitializerListExpr containing a MaterializeTemporaryExpr
containing an InitListExpr (possibly wrapped in a CXXBindTemporaryExpr).

This more detailed representation has several advantages, the most important of
which is that the new MaterializeTemporaryExpr allows us to directly model
lifetime extension of the underlying temporary array. Using that, this patch
*drastically* simplifies the IR generation of this construct, provides IR
generation support for nested global initializer_list objects, fixes several
bugs where the destructors for the underlying array would accidentally not get
invoked, and provides constant expression evaluation support for
std::initializer_list objects.

llvm-svn: 183872

1 files changed, 74 insertions, 8 deletions

diff --git a/clang/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist.cpp b/clang/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist.cpp
index 54d88f565ee..593367c8f13 100644
--- a/clang/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist.cpp
+++ b/clang/test/CodeGenCXX/cxx0x-initializer-stdinitializerlist.cpp
@@ -47,23 +47,43 @@ struct wantslist1 {
   ~wantslist1();
 };
 
-// CHECK: @_ZL25globalInitList1__initlist = internal global [3 x i32] [i32 1, i32 2, i32 3]
-// CHECK: @globalInitList1 = global %{{[^ ]+}} { i32* getelementptr inbounds ([3 x i32]* @_ZL25globalInitList1__initlist, i32 0, i32 0), i{{32|64}} 3 }
+// CHECK: @_ZGR15globalInitList1 = private constant [3 x i32] [i32 1, i32 2, i32 3]
+// CHECK: @globalInitList1 = global %{{[^ ]+}} { i32* getelementptr inbounds ([3 x i32]* @_ZGR15globalInitList1, i32 0, i32 0), i{{32|64}} 3 }
 std::initializer_list<int> globalInitList1 = {1, 2, 3};
 
 namespace thread_local_global_array {
-  // CHECK: @_ZN25thread_local_global_arrayL11x__initlistE = internal thread_local global [4 x i32] [i32 1, i32 2, i32 3, i32 4]
-  // CHECK: @_ZN25thread_local_global_array1xE = thread_local global {{.*}} @_ZN25thread_local_global_arrayL11x__initlistE, {{.*}} i64 4
+  // FIXME: We should be able to constant-evaluate this even though the
+  // initializer is not a constant expression (pointers to thread_local
+  // objects aren't really a problem).
+  //
+  // CHECK: @_ZN25thread_local_global_array1xE = thread_local global
+  // CHECK: @_ZGRN25thread_local_global_array1xE = private thread_local global [4 x i32]
   std::initializer_list<int> thread_local x = { 1, 2, 3, 4 };
 }
 
-// CHECK: @_ZL25globalInitList2__initlist = internal global [2 x %{{[^ ]*}}] zeroinitializer
-// CHECK: @globalInitList2 = global %{{[^ ]+}} { %[[WITHARG:[^ *]+]]* getelementptr inbounds ([2 x
+// CHECK: @globalInitList2 = global %{{[^ ]+}} zeroinitializer
+// CHECK: @_ZGR15globalInitList2 = private global [2 x %[[WITHARG:[^ ]*]]] zeroinitializer
 // CHECK: appending global
+
+
+// thread_local initializer:
+// CHECK: define internal void
+// CHECK: store i32 1, i32* getelementptr inbounds ([4 x i32]* @_ZGRN25thread_local_global_array1xE, i64 0, i64 0)
+// CHECK: store i32 2, i32* getelementptr inbounds ([4 x i32]* @_ZGRN25thread_local_global_array1xE, i64 0, i64 1)
+// CHECK: store i32 3, i32* getelementptr inbounds ([4 x i32]* @_ZGRN25thread_local_global_array1xE, i64 0, i64 2)
+// CHECK: store i32 4, i32* getelementptr inbounds ([4 x i32]* @_ZGRN25thread_local_global_array1xE, i64 0, i64 3)
+// CHECK: store i32* getelementptr inbounds ([4 x i32]* @_ZGRN25thread_local_global_array1xE, i64 0, i64 0),
+// CHECK:       i32** getelementptr inbounds ({{.*}}* @_ZN25thread_local_global_array1xE, i32 0, i32 0), align 8
+// CHECK: store i64 4, i64* getelementptr inbounds ({{.*}}* @_ZN25thread_local_global_array1xE, i32 0, i32 1), align 8
+
+
 // CHECK: define internal void
-// CHECK: call void @_ZN8witharg1C1ERK10destroyme1(%[[WITHARG]]* getelementptr inbounds ([2 x %[[WITHARG]]]* @_ZL25globalInitList2__initlist, i{{32|64}} 0, i{{32|64}} 0
-// CHECK: call void @_ZN8witharg1C1ERK10destroyme1(%[[WITHARG]]* getelementptr inbounds ([2 x %[[WITHARG]]]* @_ZL25globalInitList2__initlist, i{{32|64}} 0, i{{32|64}} 1
+// CHECK: call void @_ZN8witharg1C1ERK10destroyme1(%[[WITHARG]]* getelementptr inbounds ([2 x %[[WITHARG]]]* @_ZGR15globalInitList2, i{{32|64}} 0, i{{32|64}} 0
+// CHECK: call void @_ZN8witharg1C1ERK10destroyme1(%[[WITHARG]]* getelementptr inbounds ([2 x %[[WITHARG]]]* @_ZGR15globalInitList2, i{{32|64}} 0, i{{32|64}} 1
 // CHECK: __cxa_atexit
+// CHECK: store %[[WITHARG]]* getelementptr inbounds ([2 x %[[WITHARG]]]* @_ZGR15globalInitList2, i64 0, i64 0),
+// CHECK:       %[[WITHARG]]** getelementptr inbounds (%{{.*}}* @globalInitList2, i32 0, i32 0), align 8
+// CHECK: store i64 2, i64* getelementptr inbounds (%{{.*}}* @globalInitList2, i32 0, i32 1), align 8
 // CHECK: call void @_ZN10destroyme1D1Ev
 // CHECK: call void @_ZN10destroyme1D1Ev
 std::initializer_list<witharg1> globalInitList2 = {
@@ -281,10 +301,56 @@ namespace dtors {
     S();
     ~S();
   };
+  void z();
+
+  // CHECK: define void @_ZN5dtors1fEv(
   void f() {
+    // CHECK: call void @_ZN5dtors1SC1Ev(%"struct.dtors::S"* %arrayinit.begin)
+    // CHECK: call void @_ZN5dtors1SC1Ev(%"struct.dtors::S"* %arrayinit.element)
     std::initializer_list<S>{ S(), S() };
+
+    // Destruction loop for underlying array.
+    // CHECK: br label
+    // CHECK: call void @_ZN5dtors1SD1Ev(
+    // CHECK: br i1
+
+    // CHECK: call void @_ZN5dtors1zEv(
+    z();
+
+    // CHECK-NOT: call void @_ZN5dtors1SD1Ev(
   }
+
+  // CHECK: define void @_ZN5dtors1gEv(
   void g() {
+    // CHECK: call void @_ZN5dtors1SC1Ev(%"struct.dtors::S"* %arrayinit.begin)
+    // CHECK: call void @_ZN5dtors1SC1Ev(%"struct.dtors::S"* %arrayinit.element)
     auto x = std::initializer_list<S>{ S(), S() };
+
+    // Destruction loop for underlying array.
+    // CHECK: br label
+    // CHECK: call void @_ZN5dtors1SD1Ev(
+    // CHECK: br i1
+
+    // CHECK: call void @_ZN5dtors1zEv(
+    z();
+
+    // CHECK-NOT: call void @_ZN5dtors1SD1Ev(
+  }
+
+  // CHECK: define void @_ZN5dtors1hEv(
+  void h() {
+    // CHECK: call void @_ZN5dtors1SC1Ev(%"struct.dtors::S"* %arrayinit.begin)
+    // CHECK: call void @_ZN5dtors1SC1Ev(%"struct.dtors::S"* %arrayinit.element)
+    std::initializer_list<S> x = { S(), S() };
+
+    // CHECK-NOT: call void @_ZN5dtors1SD1Ev(
+
+    // CHECK: call void @_ZN5dtors1zEv(
+    z();
+
+    // Destruction loop for underlying array.
+    // CHECK: br label
+    // CHECK: call void @_ZN5dtors1SD1Ev(
+    // CHECK: br i1
   }
 }