clang/test/CodeGenCXX/dynamic-cast-exact.cpp

   1 // RUN: %clang_cc1 -I%S %s -triple x86_64-apple-darwin10 -emit-llvm -fcxx-exceptions -fexceptions -std=c++11 -o - -O1 -disable-llvm-passes | FileCheck %s --implicit-check-not='call {{.*}} @__dynamic_cast'
   2 struct Offset { virtual ~Offset(); };
   3 struct A { virtual ~A(); };
   4 struct B final : Offset, A { };
   5
   6 struct C { virtual ~C(); int c; };
   7 struct D : A { int d; };
   8 struct E : A { int e; };
   9 struct F : virtual A { int f; };
  10 struct G : virtual A { int g; };
  11 struct H final : C, D, E, F, G { int h; };
  12
  13 // CHECK-LABEL: @_Z7inexactP1A
  14 C *inexact(A *a) {
  15   // CHECK: call {{.*}} @__dynamic_cast
  16   return dynamic_cast<C*>(a);
  17 }
  18
  19 // CHECK-LABEL: @_Z12exact_singleP1A
  20 B *exact_single(A *a) {
  21   // CHECK: %[[PTR_NULL:.*]] = icmp eq ptr %[[PTR:.*]], null
  22   // CHECK: br i1 %[[PTR_NULL]], label %[[LABEL_FAILED:.*]], label %[[LABEL_NOTNULL:.*]]
  23
  24   // CHECK: [[LABEL_NOTNULL]]:
  25   // CHECK: %[[VPTR:.*]] = load ptr, ptr %[[PTR]]
  26   // CHECK: %[[MATCH:.*]] = icmp eq ptr %[[VPTR]], getelementptr inbounds ({ [4 x ptr], [4 x ptr] }, ptr @_ZTV1B, i32 0, inrange i32 1, i32 2)
  27   // CHECK: %[[RESULT:.*]] = getelementptr inbounds i8, ptr %[[PTR]], i64 -8
  28   // CHECK: br i1 %[[MATCH]], label %[[LABEL_END:.*]], label %[[LABEL_FAILED]]
  29
  30   // CHECK: [[LABEL_FAILED]]:
  31   // CHECK: br label %[[LABEL_END]]
  32
  33   // CHECK: [[LABEL_END]]:
  34   // CHECK: phi ptr [ %[[RESULT]], %[[LABEL_NOTNULL]] ], [ null, %[[LABEL_FAILED]] ]
  35   return dynamic_cast<B*>(a);
  36 }
  37
  38 // CHECK-LABEL: @_Z9exact_refR1A
  39 B &exact_ref(A &a) {
  40   // CHECK: %[[PTR_NULL:.*]] = icmp eq ptr %[[PTR:.*]], null
  41   // CHECK: br i1 %[[PTR_NULL]], label %[[LABEL_FAILED:.*]], label %[[LABEL_NOTNULL:.*]]
  42
  43   // CHECK: [[LABEL_NOTNULL]]:
  44   // CHECK: %[[VPTR:.*]] = load ptr, ptr %[[PTR]]
  45   // CHECK: %[[MATCH:.*]] = icmp eq ptr %[[VPTR]], getelementptr inbounds ({ [4 x ptr], [4 x ptr] }, ptr @_ZTV1B, i32 0, inrange i32 1, i32 2)
  46   // CHECK: %[[RESULT:.*]] = getelementptr inbounds i8, ptr %[[PTR]], i64 -8
  47   // CHECK: br i1 %[[MATCH]], label %[[LABEL_END:.*]], label %[[LABEL_FAILED]]
  48
  49   // CHECK: [[LABEL_FAILED]]:
  50   // CHECK: call {{.*}} @__cxa_bad_cast
  51   // CHECK: unreachable
  52
  53   // CHECK: [[LABEL_END]]:
  54   // CHECK: ret ptr %[[RESULT]]
  55   return dynamic_cast<B&>(a);
  56 }
  57
  58 // CHECK-LABEL: @_Z11exact_multiP1A
  59 H *exact_multi(A *a) {
  60   // CHECK: %[[PTR_NULL:.*]] = icmp eq ptr %[[PTR:.*]], null
  61   // CHECK: br i1 %[[PTR_NULL]], label %[[LABEL_FAILED:.*]], label %[[LABEL_NOTNULL:.*]]
  62
  63   // CHECK: [[LABEL_NOTNULL]]:
  64   // CHECK: %[[VPTR:.*]] = load ptr, ptr %[[PTR]]
  65   // CHECK: %[[OFFSET_TO_TOP_SLOT:.*]] = getelementptr inbounds i64, ptr %[[VPTR]], i64 -2
  66   // CHECK: %[[OFFSET_TO_TOP:.*]] = load i64, ptr %[[OFFSET_TO_TOP_SLOT]]
  67   // CHECK: %[[RESULT:.*]] = getelementptr inbounds i8, ptr %[[PTR]], i64 %[[OFFSET_TO_TOP]]
  68   // CHECK: %[[DERIVED_VPTR:.*]] = load ptr, ptr %[[RESULT]]
  69   // CHECK: %[[MATCH:.*]] = icmp eq ptr %[[DERIVED_VPTR]], getelementptr inbounds ({ [5 x ptr], [4 x ptr], [4 x ptr], [6 x ptr], [6 x ptr] }, ptr @_ZTV1H, i32 0, inrange i32 0, i32 3)
  70   // CHECK: br i1 %[[MATCH]], label %[[LABEL_END:.*]], label %[[LABEL_FAILED]]
  71
  72   // CHECK: [[LABEL_FAILED]]:
  73   // CHECK: br label %[[LABEL_END]]
  74
  75   // CHECK: [[LABEL_END]]:
  76   // CHECK: phi ptr [ %[[RESULT]], %[[LABEL_NOTNULL]] ], [ null, %[[LABEL_FAILED]] ]
  77   return dynamic_cast<H*>(a);
  78 }
  79
  80 namespace GH64088 {
  81   // Ensure we mark the B vtable as used here, because we're going to emit a
  82   // reference to it.
  83   // CHECK: define {{.*}} @_ZN7GH640881BD0
  84   struct A { virtual ~A(); };
  85   struct B final : A { virtual ~B() = default; };
  86   B *cast(A *p) { return dynamic_cast<B*>(p); }
  87 }