clang/test/CodeGenCXX/no-unique-address.cpp

   1 // RUN: %clang_cc1 -std=c++2a %s -emit-llvm -o - -triple x86_64-linux-gnu | FileCheck %s
   2 // RUN: %clang_cc1 -std=c++2a %s -emit-llvm -o - -triple x86_64-linux-gnu -O2 -disable-llvm-passes | FileCheck %s --check-prefix=CHECK-OPT
   3
   4 struct A { ~A(); int n; char c[3]; };
   5 struct B { [[no_unique_address]] A a; char k; };
   6 // CHECK-DAG: @b ={{.*}} global { i32, [3 x i8], i8 } { i32 1, [3 x i8] c"\02\03\04", i8 5 }
   7 B b = {1, 2, 3, 4, 5};
   8
   9 struct C : A {};
  10 struct D : C {};
  11 struct E { int e; [[no_unique_address]] D d; char k; };
  12 // CHECK-DAG: @e ={{.*}} global { i32, i32, [3 x i8], i8 } { i32 1, i32 2, [3 x i8] c"\03\04\05", i8 6 }
  13 E e = {1, 2, 3, 4, 5, 6};
  14
  15 struct Empty1 {};
  16 struct Empty2 {};
  17 struct Empty3 {};
  18 struct HasEmpty {
  19   [[no_unique_address]] Empty1 e1;
  20   int a;
  21   [[no_unique_address]] Empty2 e2;
  22   int b;
  23   [[no_unique_address]] Empty3 e3;
  24 };
  25 // CHECK-DAG: @he ={{.*}} global %{{[^ ]*}} { i32 1, i32 2 }
  26 HasEmpty he = {{}, 1, {}, 2, {}};
  27
  28 struct HasEmptyDuplicates {
  29   [[no_unique_address]] Empty1 e1; // +0
  30   int a;
  31   [[no_unique_address]] Empty1 e2; // +4
  32   int b;
  33   [[no_unique_address]] Empty1 e3; // +8
  34 };
  35 // CHECK-DAG: @off1 ={{.*}} global i64 0
  36 Empty1 HasEmptyDuplicates::*off1 = &HasEmptyDuplicates::e1;
  37 // CHECK-DAG: @off2 ={{.*}} global i64 4
  38 Empty1 HasEmptyDuplicates::*off2 = &HasEmptyDuplicates::e2;
  39 // CHECK-DAG: @off3 ={{.*}} global i64 8
  40 Empty1 HasEmptyDuplicates::*off3 = &HasEmptyDuplicates::e3;
  41
  42 // CHECK-DAG: @hed ={{.*}} global %{{[^ ]*}} { i32 1, i32 2, [4 x i8] undef }
  43 HasEmptyDuplicates hed = {{}, 1, {}, 2, {}};
  44
  45 struct __attribute__((packed, aligned(2))) PackedAndPadded {
  46   ~PackedAndPadded();
  47   char c;
  48   int n;
  49 };
  50 struct WithPackedAndPadded {
  51   [[no_unique_address]] PackedAndPadded pap;
  52   char d;
  53 };
  54 // CHECK-DAG: @wpap ={{.*}} global <{ i8, i32, i8 }> <{ i8 1, i32 2, i8 3 }>
  55 WithPackedAndPadded wpap = {1, 2, 3};
  56
  57 struct FieldOverlap {
  58   [[no_unique_address]] Empty1 e1, e2, e3, e4;
  59   int n;
  60 };
  61 static_assert(sizeof(FieldOverlap) == 4);
  62 // CHECK-DAG: @fo ={{.*}} global %{{[^ ]*}} { i32 1234 }
  63 FieldOverlap fo = {{}, {}, {}, {}, 1234};
  64
  65 // CHECK-DAG: @e1 ={{.*}} constant ptr @fo
  66 Empty1 &e1 = fo.e1;
  67 // CHECK-DAG: @e2 ={{.*}} constant ptr getelementptr (i8, ptr @fo, i64 1)
  68 Empty1 &e2 = fo.e2;
  69
  70 // CHECK-LABEL: accessE1
  71 // CHECK: ret ptr %{{.*}}
  72 Empty1 &accessE1(FieldOverlap &fo) { return fo.e1; }
  73
  74 // CHECK-LABEL: accessE2
  75 // CHECK: %[[ADJUSTED:.*]] = getelementptr inbounds i8, ptr %{{.*}}, i64 1
  76 // CHECK: ret ptr %[[ADJUSTED]]
  77 Empty1 &accessE2(FieldOverlap &fo) { return fo.e2; }
  78
  79 struct LaterDeclaredFieldHasLowerOffset {
  80   int a;
  81   int b;
  82   [[no_unique_address]] Empty1 e;
  83 };
  84 // CHECK-OPT-LABEL: @_Z41loadWhereLaterDeclaredFieldHasLowerOffset
  85 int loadWhereLaterDeclaredFieldHasLowerOffset(LaterDeclaredFieldHasLowerOffset &a) {
  86   // CHECK-OPT: getelementptr
  87   // CHECK-OPT: load {{.*}}, !tbaa ![[TBAA_AB:[0-9]*]]
  88   return a.b;
  89 }
  90 // Note, never emit TBAA for zero-size fields.
  91 // CHECK-OPT: ![[TBAA_AB]] = !{![[TBAA_A:[0-9]*]], ![[TBAA_INT:[0-9]*]], i64 4}
  92 // CHECK-OPT: ![[TBAA_A]] = !{!"_ZTS32LaterDeclaredFieldHasLowerOffset", ![[TBAA_INT]], i64 0, ![[TBAA_INT]], i64 4}
  93
  94 struct NonTrivialInit {
  95   NonTrivialInit();
  96 };
  97 struct HasZeroSizedFieldWithNonTrivialInit {
  98   int a;
  99   [[no_unique_address]] NonTrivialInit b;
 100 };
 101 HasZeroSizedFieldWithNonTrivialInit testHasZeroSizedFieldWithNonTrivialInit = {.a = 1};
 102 // CHECK-LABEL: define {{.*}}cxx_global_var_init
 103 // CHECK: call {{.*}}@_ZN14NonTrivialInitC1Ev({{.*}}@testHasZeroSizedFieldWithNonTrivialInit