1*89a1d03eSRichard // RUN: %check_clang_tidy %s cppcoreguidelines-interfaces-global-init %t
2*89a1d03eSRichard 
makesInt()3*89a1d03eSRichard constexpr int makesInt() { return 3; }
takesInt(int i)4*89a1d03eSRichard constexpr int takesInt(int i) { return i + 1; }
takesIntPtr(int * i)5*89a1d03eSRichard constexpr int takesIntPtr(int *i) { return *i; }
6*89a1d03eSRichard 
7*89a1d03eSRichard extern int ExternGlobal;
8*89a1d03eSRichard static int GlobalScopeBadInit1 = ExternGlobal;
9*89a1d03eSRichard // CHECK-MESSAGES: [[@LINE-1]]:12: warning: initializing non-local variable with non-const expression depending on uninitialized non-local variable 'ExternGlobal'
10*89a1d03eSRichard static int GlobalScopeBadInit2 = takesInt(ExternGlobal);
11*89a1d03eSRichard // CHECK-MESSAGES: [[@LINE-1]]:12: warning: initializing non-local variable with non-const expression depending on uninitialized non-local variable 'ExternGlobal'
12*89a1d03eSRichard static int GlobalScopeBadInit3 = takesIntPtr(&ExternGlobal);
13*89a1d03eSRichard // CHECK-MESSAGES: [[@LINE-1]]:12: warning: initializing non-local variable with non-const expression depending on uninitialized non-local variable 'ExternGlobal'
14*89a1d03eSRichard static int GlobalScopeBadInit4 = 3 * (ExternGlobal + 2);
15*89a1d03eSRichard // CHECK-MESSAGES: [[@LINE-1]]:12: warning: initializing non-local variable with non-const expression depending on uninitialized non-local variable 'ExternGlobal'
16*89a1d03eSRichard 
17*89a1d03eSRichard namespace ns {
18*89a1d03eSRichard static int NamespaceScope = makesInt();
19*89a1d03eSRichard static int NamespaceScopeBadInit = takesInt(ExternGlobal);
20*89a1d03eSRichard // CHECK-MESSAGES: [[@LINE-1]]:12: warning: initializing non-local variable with non-const expression depending on uninitialized non-local variable 'ExternGlobal'
21*89a1d03eSRichard 
22*89a1d03eSRichard struct A {
23*89a1d03eSRichard   static int ClassScope;
24*89a1d03eSRichard   static int ClassScopeBadInit;
25*89a1d03eSRichard };
26*89a1d03eSRichard 
27*89a1d03eSRichard int A::ClassScopeBadInit = takesInt(ExternGlobal);
28*89a1d03eSRichard // CHECK-MESSAGES: [[@LINE-1]]:8: warning: initializing non-local variable with non-const expression depending on uninitialized non-local variable 'ExternGlobal'
29*89a1d03eSRichard 
30*89a1d03eSRichard static int FromClassBadInit = takesInt(A::ClassScope);
31*89a1d03eSRichard // CHECK-MESSAGES: [[@LINE-1]]:12: warning: initializing non-local variable with non-const expression depending on uninitialized non-local variable 'ClassScope'
32*89a1d03eSRichard } // namespace ns
33*89a1d03eSRichard 
34*89a1d03eSRichard // "const int B::I;" is fine, it just ODR-defines B::I. See [9.4.3] Static
35*89a1d03eSRichard // members [class.static]. However the ODR-definitions are not in the right
36*89a1d03eSRichard // order (C::I after C::J, see [3.6.2.3]).
37*89a1d03eSRichard class B1 {
38*89a1d03eSRichard   static const int I = 0;
39*89a1d03eSRichard   static const int J = I;
40*89a1d03eSRichard };
41*89a1d03eSRichard const int B1::J;
42*89a1d03eSRichard // CHECK-MESSAGES: [[@LINE-1]]:15: warning: initializing non-local variable with non-const expression depending on uninitialized non-local variable 'I'
43*89a1d03eSRichard const int B1::I;
44*89a1d03eSRichard 
f()45*89a1d03eSRichard void f() {
46*89a1d03eSRichard   // This is fine, it's executed after dynamic initialization occurs.
47*89a1d03eSRichard   static int G = takesInt(ExternGlobal);
48*89a1d03eSRichard }
49*89a1d03eSRichard 
50*89a1d03eSRichard // Declaration then definition then usage is fine.
51*89a1d03eSRichard extern int ExternGlobal2;
52*89a1d03eSRichard extern int ExternGlobal2;
53*89a1d03eSRichard int ExternGlobal2 = 123;
54*89a1d03eSRichard static int GlobalScopeGoodInit1 = ExternGlobal2;
55*89a1d03eSRichard 
56*89a1d03eSRichard 
57*89a1d03eSRichard // Defined global variables are fine:
58*89a1d03eSRichard static int GlobalScope = makesInt();
59*89a1d03eSRichard static int GlobalScopeGoodInit2 = takesInt(GlobalScope);
60*89a1d03eSRichard static int GlobalScope2 = takesInt(ns::NamespaceScope);
61*89a1d03eSRichard // Enums are fine.
62*89a1d03eSRichard enum Enum { kEnumValue = 1 };
63*89a1d03eSRichard static int GlobalScopeFromEnum = takesInt(kEnumValue);
64*89a1d03eSRichard 
65*89a1d03eSRichard // Leave constexprs alone.
66*89a1d03eSRichard extern constexpr int GlobalScopeConstexpr = makesInt();
67*89a1d03eSRichard static constexpr int GlobalScopeConstexprOk =
68*89a1d03eSRichard     takesInt(GlobalScopeConstexpr);
69*89a1d03eSRichard 
70*89a1d03eSRichard // This is a pretty common instance: People are usually not using constexpr, but
71*89a1d03eSRichard // this is what they should write:
72*89a1d03eSRichard static constexpr const char kValue[] = "value";
Fingerprint(const char * value)73*89a1d03eSRichard constexpr int Fingerprint(const char *value) { return 0; }
74*89a1d03eSRichard static int kFingerprint = Fingerprint(kValue);
75*89a1d03eSRichard 
76*89a1d03eSRichard // This is fine because the ODR-definitions are in the right order (C::J after
77*89a1d03eSRichard // C::I).
78*89a1d03eSRichard class B2 {
79*89a1d03eSRichard   static const int I = 0;
80*89a1d03eSRichard   static const int J = I;
81*89a1d03eSRichard };
82*89a1d03eSRichard const int B2::I;
83*89a1d03eSRichard const int B2::J;
84*89a1d03eSRichard 
85