xref: /llvm-project/clang/test/CodeGenCXX/global-init.cpp (revision 0f1c1be1968076d6f96f8a7bcc4a15cf195ecd97)
1 // RUN: %clang_cc1 %std_cxx98-14 -triple=x86_64-apple-darwin10 -emit-llvm -fexceptions %s -o - |FileCheck %s --check-prefixes=CHECK,PRE17
2 // RUN: %clang_cc1 %std_cxx98-14 -triple=x86_64-apple-darwin10 -emit-llvm %s -o - |FileCheck %s --check-prefixes=CHECK-NOEXC,PRE17
3 // RUN: %clang_cc1 %std_cxx98-14 -triple=x86_64-apple-darwin10 -emit-llvm -mframe-pointer=non-leaf %s -o - \
4 // RUN:   | FileCheck -check-prefix CHECK-FP %s
5 // RUN: %clang_cc1 %std_cxx98-14 -triple=x86_64-apple-darwin10 -emit-llvm %s -o - -fno-builtin \
6 // RUN:   | FileCheck -check-prefix CHECK-NOBUILTIN %s
7 // RUN: %clang_cc1 %std_cxx17- -triple=x86_64-apple-darwin10 -emit-llvm -fexceptions %s -o - | FileCheck %s
8 
9 struct A {
10   A();
11   ~A();
12 };
13 
14 struct B { B(); ~B(); };
15 
16 struct C { void *field; };
17 
18 struct D { ~D(); };
19 
20 // CHECK: @__dso_handle = external hidden global i8
21 // CHECK: @c ={{.*}} global %struct.C zeroinitializer, align 8
22 
23 // PR6205: The casts should not require global initializers
24 // CHECK: @_ZN6PR59741cE = external global %"struct.PR5974::C"
25 // CHECK: @_ZN6PR59741aE ={{.*}} global ptr @_ZN6PR59741cE
26 // CHECK: @_ZN6PR59741bE ={{.*}} global ptr getelementptr (i8, ptr @_ZN6PR59741cE, i64 4), align 8
27 
28 // CHECK: call void @_ZN1AC1Ev(ptr {{[^,]*}} @a)
29 // CHECK: call i32 @__cxa_atexit(ptr @_ZN1AD1Ev, ptr @a, ptr @__dso_handle)
30 A a;
31 
32 // CHECK: call void @_ZN1BC1Ev(ptr {{[^,]*}} @b)
33 // CHECK: call i32 @__cxa_atexit(ptr @_ZN1BD1Ev, ptr @b, ptr @__dso_handle)
34 B b;
35 
36 // PR6205: this should not require a global initializer
37 // CHECK-NOT: call void @_ZN1CC1Ev(ptr @c)
38 C c;
39 
40 // CHECK: call i32 @__cxa_atexit(ptr @_ZN1DD1Ev, ptr @d, ptr @__dso_handle)
41 D d;
42 
43 namespace test1 {
44   int f();
45   const int x = f();   // This has side-effects and gets emitted immediately.
46   const int y = x - 1; // This gets deferred.
47   const int z = ~y;    // This also gets deferred, but gets "undeferred" before y.
test()48   int test() { return z; }
49 // CHECK-LABEL:      define{{.*}} i32 @_ZN5test14testEv()
50 
51   // All of these initializers end up delayed, so we check them later.
52 }
53 
54 namespace test2 {
55   struct allocator { allocator(); ~allocator(); };
56   struct A { A(const allocator &a = allocator()); ~A(); };
57 
58   A a;
59 // CHECK: call void @_ZN5test29allocatorC1Ev(
60 // CHECK: invoke void @_ZN5test21AC1ERKNS_9allocatorE(
61 // CHECK: call void @_ZN5test29allocatorD1Ev(
62 // CHECK: call i32 @__cxa_atexit({{.*}} @_ZN5test21AD1Ev, {{.*}} @_ZN5test21aE
63 }
64 
65 namespace test3 {
66   // Tested at the beginning of the file.
67   const char * const var = "string";
68   extern const char * const var;
69 
test()70   const char *test() { return var; }
71 }
72 
73 namespace test4 {
74   struct A {
75     A();
76   };
77   extern int foo();
78 
79   // This needs an initialization function and guard variables.
80   // CHECK: load i8, ptr @_ZGVN5test41xE
81   // CHECK: store i8 1, ptr @_ZGVN5test41xE
82   // CHECK-NEXT: [[CALL:%.*]] = call noundef i32 @_ZN5test43fooEv
83   // CHECK-NEXT: store i32 [[CALL]], ptr @_ZN5test41xE
84   __attribute__((weak)) int x = foo();
85 }
86 
87 namespace PR5974 {
88   struct A { int a; };
89   struct B { int b; };
90   struct C : A, B { int c; };
91 
92   extern C c;
93 
94   // These should not require global initializers.
95   A* a = &c;
96   B* b = &c;
97 }
98 
99 // PR9570: the indirect field shouldn't crash IR gen.
100 namespace test5 {
101   static union {
102     unsigned bar[4096] __attribute__((aligned(128)));
103   };
104 }
105 
106 namespace std { struct type_info; }
107 
108 namespace test6 {
109   struct A { virtual ~A(); };
110   struct B : A {};
111   extern A *p;
112 
113   // We must emit a dynamic initializer for 'q', because it could throw.
114   B *const q = &dynamic_cast<B&>(*p);
115   // CHECK: call void @__cxa_bad_cast()
116   // CHECK: store {{.*}} @_ZN5test6L1qE
117 
118   // We don't need to emit 'r' at all, because it has internal linkage, is
119   // unused, and its initialization has no side-effects.
120   B *const r = dynamic_cast<B*>(p);
121   // CHECK-NOT: call void @__cxa_bad_cast()
122   // CHECK-NOT: store {{.*}} @_ZN5test6L1rE
123 
124   // This can throw, so we need to emit it.
125   const std::type_info *const s = &typeid(*p);
126   // CHECK: store {{.*}} @_ZN5test6L1sE
127 
128   // This can't throw, so we don't.
129   const std::type_info *const t = &typeid(p);
130   // CHECK-NOT: @_ZN5test6L1tE
131 
132   extern B *volatile v;
133   // CHECK: store {{.*}} @_ZN5test6L1wE
134   B *const w = dynamic_cast<B*>(v);
135 
136   // CHECK: load volatile
137   // CHECK: store {{.*}} @_ZN5test6L1xE
138   const int x = *(volatile int*)0x1234;
139 
140   namespace {
141     int a = int();
142     volatile int b = int();
143     int c = a;
144     int d = b;
145     // CHECK-NOT: store {{.*}} @_ZN5test6{{[A-Za-z0-9_]*}}1aE
146     // CHECK-NOT: store {{.*}} @_ZN5test6{{[A-Za-z0-9_]*}}1bE
147     // CHECK-NOT: store {{.*}} @_ZN5test6{{[A-Za-z0-9_]*}}1cE
148     // CHECK: load volatile {{.*}} @_ZN5test6{{[A-Za-z0-9_]*}}1bE
149     // CHECK: store {{.*}} @_ZN5test6{{[A-Za-z0-9_]*}}1dE
150   }
151 }
152 
153 namespace test7 {
154   struct A { A(); };
155   struct B { ~B(); int n; };
156   struct C { C() = default; C(const C&); int n; };
157   struct D {};
158 
159   // CHECK: call void @_ZN5test71AC1Ev({{.*}}@_ZN5test7L1aE)
160   const A a = A();
161 
162   // CHECK: call i32 @__cxa_atexit({{.*}} @_ZN5test71BD1Ev{{.*}} @_ZN5test7L2b1E
163   // CHECK: call i32 @__cxa_atexit({{.*}} @_ZN5test71BD1Ev{{.*}} @_ZGRN5test72b2E
164   // CHECK: call void @_ZN5test71BD1Ev(
165   // CHECK: store {{.*}} @_ZN5test7L2b3E
166   const B b1 = B();
167   const B &b2 = B();
168   const int b3 = B().n;
169 
170   // CHECK-NOT: @_ZN5test7L2c1E
171   // PRE17: call void @llvm.memset{{.*}} @_ZN5test7L2c1E
172   // CHECK-NOT: @_ZN5test7L2c1E
173   // CHECK: @_ZN5test7L2c2E
174   // CHECK-NOT: @_ZN5test7L2c3E
175   // PRE17: @_ZN5test7L2c4E
176   const C c1 = C();
177   const C c2 = static_cast<const C&>(C());
178   const int c3 = C().n;
179   const int c4 = C(C()).n;
180 
181   // CHECK-NOT: @_ZN5test7L1dE
182   const D d = D();
183 
184   // CHECK: store {{.*}} @_ZN5test71eE
185   int f(), e = f();
186 }
187 
188 
189 // At the end of the file, we check that y is initialized before z.
190 
191 // CHECK:      define internal void [[TEST1_Z_INIT:@.*]]()
192 // CHECK:        load i32, ptr @_ZN5test1L1yE
193 // CHECK-NEXT:   xor
194 // CHECK-NEXT:   store i32 {{.*}}, ptr @_ZN5test1L1zE
195 // CHECK:      define internal void [[TEST1_Y_INIT:@.*]]()
196 // CHECK:        load i32, ptr @_ZN5test1L1xE
197 // CHECK-NEXT:   sub
198 // CHECK-NEXT:   store i32 {{.*}}, ptr @_ZN5test1L1yE
199 
200 // CHECK: define internal void @_GLOBAL__sub_I_global_init.cpp() #{{[0-9]+}} section "__TEXT,__StaticInit,regular,pure_instructions" {
201 // CHECK:   call void [[TEST1_Y_INIT]]
202 // CHECK:   call void [[TEST1_Z_INIT]]
203 
204 // this should be nounwind
205 // CHECK-NOEXC: define internal void @_GLOBAL__sub_I_global_init.cpp() [[NUW:#[0-9]+]] section "__TEXT,__StaticInit,regular,pure_instructions" {
206 // CHECK-NOEXC: attributes [[NUW]] = { noinline nounwind{{.*}} }
207 
208 // Make sure we mark global initializers with the no-builtins attribute.
209 // CHECK-NOBUILTIN: define internal void @_GLOBAL__sub_I_global_init.cpp() [[NUW:#[0-9]+]] section "__TEXT,__StaticInit,regular,pure_instructions" {
210 // CHECK-NOBUILTIN: attributes [[NUW]] = { noinline nounwind{{.*}}"no-builtins"{{.*}} }
211 
212 // PR21811: attach the appropriate attribute to the global init function
213 // CHECK-FP: define internal void @_GLOBAL__sub_I_global_init.cpp() [[NUX:#[0-9]+]] section "__TEXT,__StaticInit,regular,pure_instructions" {
214 // CHECK-FP: attributes [[NUX]] = { noinline nounwind {{.*}}"frame-pointer"="non-leaf"{{.*}} }
215