Teach CodeGenFunction::EmitCastLValue() to handle casts to an lvalue

that involve binding a reference to a pure rvalue temporary (e.g., not
a class temporary), by creating a new temporary and copying the result
there. Fixes PR6024.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@108431 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 170 insertions, 0 deletions

diff --git a/test/CodeGenCXX/reference-cast.cpp b/test/CodeGenCXX/reference-cast.cpp
new file mode 100644
index 0000000000..49409d7be1
--- /dev/null
+++ b/test/CodeGenCXX/reference-cast.cpp
@@ -0,0 +1,170 @@
+// RUN: %clang_cc1 -emit-llvm -triple x86_64-apple-darwin10 -o - %s | FileCheck %s
+
+// PR6024
+extern int i;
+
+// CHECK: define i32* @_Z16lvalue_noop_castv() nounwind
+const int &lvalue_noop_cast() {
+  if (i == 0)
+    // CHECK: store i32 17, i32*
+    return (const int&)17;
+  else if (i == 1)
+    // CHECK: store i32 17, i32*
+    return static_cast<const int&>(17);
+    // CHECK: store i32 17, i32*
+  return 17;
+}
+
+// CHECK: define i16* @_Z20lvalue_integral_castv() 
+const short &lvalue_integral_cast() {
+  if (i == 0)
+    // CHECK: store i16 17, i16*
+    return (const short&)17;
+  else if (i == 1)
+    // CHECK: store i16 17, i16*
+    return static_cast<const short&>(17);
+  // CHECK: store i16 17, i16*
+  return 17;
+}
+
+// CHECK: define i16* @_Z29lvalue_floating_integral_castv()
+const short &lvalue_floating_integral_cast() {
+  if (i == 0)
+    // CHECK: store i16 17, i16*
+    return (const short&)17.5;
+  else if (i == 1)
+    // CHECK: store i16 17, i16*
+    return static_cast<const short&>(17.5);
+  // CHECK: store i16 17, i16*
+  return 17.5;
+}
+
+// CHECK: define float* @_Z29lvalue_integral_floating_castv()
+const float &lvalue_integral_floating_cast() {
+  if (i == 0)
+    // CHECK: store float 1.700000e+01, float*
+    return (const float&)17;
+  else if (i == 1)
+    // CHECK: store float 1.700000e+01, float*
+    return static_cast<const float&>(17);
+  // CHECK: store float 1.700000e+01, float*
+  return 17;
+}
+
+// CHECK: define float* @_Z20lvalue_floating_castv()
+const float &lvalue_floating_cast() {
+  if (i == 0)
+    // CHECK: store float 1.700000e+01, float*
+    return (const float&)17.0;
+  else if (i == 1)
+    // CHECK: store float 1.700000e+01, float*
+    return static_cast<const float&>(17.0);
+  // CHECK: store float 1.700000e+01, float*
+  return 17.0;
+}
+
+int get_int();
+
+// CHECK: define i8* @_Z24lvalue_integer_bool_castv()
+const bool &lvalue_integer_bool_cast() {
+  if (i == 0)
+    // CHECK: call i32 @_Z7get_intv()
+    // CHECK: store i8
+    return (const bool&)get_int();
+  else if (i == 1)
+    // CHECK: call i32 @_Z7get_intv()
+    // CHECK: store i8
+    return static_cast<const bool&>(get_int());
+  // CHECK: call i32 @_Z7get_intv()
+  // CHECK: store i8
+  return get_int();
+}
+
+float get_float();
+
+// CHECK: define i8* @_Z25lvalue_floating_bool_castv()
+const bool &lvalue_floating_bool_cast() {
+  if (i == 0)
+    // CHECK: call float @_Z9get_floatv()
+    // CHECK: fcmp une float
+    // CHECK: store i8
+    return (const bool&)get_float();
+  else if (i == 1)
+    // CHECK: call float @_Z9get_floatv()
+    // CHECK: fcmp une float
+    // CHECK: store i8
+    return static_cast<const bool&>(get_float());
+  // CHECK: call float @_Z9get_floatv()
+  // CHECK: fcmp une float
+  // CHECK: store i8
+  return get_float();
+}
+
+struct X { };
+typedef int X::*pm;
+typedef int (X::*pmf)(int);
+
+pm get_pointer_to_member_data();
+pmf get_pointer_to_member_function();
+
+// CHECK: define i8* @_Z26lvalue_ptrmem_to_bool_castv()
+const bool &lvalue_ptrmem_to_bool_cast() {
+  if (i == 0)
+    // CHECK: call i64 @_Z26get_pointer_to_member_datav()
+    // CHECK: store i8
+    // CHECK: store i8*
+    return (const bool&)get_pointer_to_member_data();
+  else if (i == 1)
+    // CHECK: call i64 @_Z26get_pointer_to_member_datav()
+    // CHECK: store i8
+    // CHECK: store i8*
+    return static_cast<const bool&>(get_pointer_to_member_data());
+  // CHECK: call i64 @_Z26get_pointer_to_member_datav()
+  // CHECK: store i8
+  // CHECK: store i8*
+  return get_pointer_to_member_data();
+}
+
+// CHECK: define i8* @_Z27lvalue_ptrmem_to_bool_cast2v
+const bool &lvalue_ptrmem_to_bool_cast2() {
+  if (i == 0)
+    // CHECK: {{call.*_Z30get_pointer_to_member_functionv}}
+    // CHECK: store i8
+    // CHECK: store i8*
+    return (const bool&)get_pointer_to_member_function();
+  else if (i == 1)
+    // CHECK: {{call.*_Z30get_pointer_to_member_functionv}}
+    // CHECK: store i8
+    // CHECK: store i8*
+    return static_cast<const bool&>(get_pointer_to_member_function());
+  // CHECK: {{call.*_Z30get_pointer_to_member_functionv}}
+  // CHECK: store i8
+  // CHECK: store i8*
+  return get_pointer_to_member_function();
+}
+
+_Complex double get_complex_double();
+
+// CHECK: {{define.*_Z2f1v}}
+const _Complex float &f1() {
+  if (i == 0)
+    // CHECK: {{call.*_Z18get_complex_doublev}}
+    // CHECK: fptrunc
+    // CHECK: fptrunc
+    // CHECK: store float
+    // CHECK: store float
+    return (const _Complex float&)get_complex_double();
+  else if (i == 1)
+    // CHECK: {{call.*_Z18get_complex_doublev}}
+    // CHECK: fptrunc
+    // CHECK: fptrunc
+    // CHECK: store float
+    // CHECK: store float
+    return static_cast<const _Complex float&>(get_complex_double());
+  // CHECK: {{call.*_Z18get_complex_doublev}}
+  // CHECK: fptrunc
+  // CHECK: fptrunc
+  // CHECK: store float
+  // CHECK: store float
+  return get_complex_double();
+}