1 // RUN: %clang_cc1 -std=c++03 -Wno-c++11-extensions -triple i386-pc-unknown -verify %s
2 // RUN: %clang_cc1 -std=c++11 -triple x86_64-apple-darwin9 -verify %s
3
4 __builtin_va_list ap;
5
6 class string;
f(const string & s,...)7 void f(const string& s, ...) { // expected-note {{parameter of type 'const string &' is declared here}}
8 __builtin_va_start(ap, s); // expected-warning {{passing an object of reference type to 'va_start' has undefined behavior}}
9 }
10
g(register int i,...)11 void g(register int i, ...) { // expected-warning 0-1{{deprecated}}
12 __builtin_va_start(ap, i); // UB in C, OK in C++
13 }
14
15 // Don't crash when there is no last parameter.
no_params(...)16 void no_params(...) {
17 int a;
18 __builtin_va_start(ap, a); // expected-warning {{second argument to 'va_start' is not the last named parameter}}
19 }
20
21 // Reject this. The __builtin_va_start would execute in Foo's non-variadic
22 // default ctor.
record_context(int a,...)23 void record_context(int a, ...) {
24 struct Foo {
25 // expected-error@+2 {{'va_start' cannot be used outside a function}}
26 // expected-error@+1 {{default argument references parameter 'a'}}
27 void meth(int a, int b = (__builtin_va_start(ap, a), 0)) {}
28 };
29 }
30
31 // Ensure the correct behavior for promotable type UB checking.
promotable(int a,...)32 void promotable(int a, ...) {
33 enum Unscoped1 { One = 0x7FFFFFFF };
34 (void)__builtin_va_arg(ap, Unscoped1); // ok
35
36 enum Unscoped2 { Two = 0xFFFFFFFF };
37 (void)__builtin_va_arg(ap, Unscoped2); // ok
38
39 enum class Scoped { Three };
40 (void)__builtin_va_arg(ap, Scoped); // ok
41
42 enum Fixed : int { Four };
43 (void)__builtin_va_arg(ap, Fixed); // ok
44
45 enum FixedSmall : char { Five };
46 (void)__builtin_va_arg(ap, FixedSmall); // expected-warning {{second argument to 'va_arg' is of promotable type 'FixedSmall'; this va_arg has undefined behavior because arguments will be promoted to 'int'}}
47
48 enum FixedLarge : long long { Six };
49 (void)__builtin_va_arg(ap, FixedLarge); // ok
50
51 // Ensure that qualifiers are ignored.
52 (void)__builtin_va_arg(ap, const volatile int); // ok
53
54 // Ensure that signed vs unsigned doesn't matter either.
55 (void)__builtin_va_arg(ap, unsigned int);
56
57 (void)__builtin_va_arg(ap, bool); // expected-warning {{second argument to 'va_arg' is of promotable type 'bool'; this va_arg has undefined behavior because arguments will be promoted to 'int'}}
58 }
59
60 #if __cplusplus >= 201103L
61 // We used to have bugs identifying the correct enclosing function scope in a
62 // lambda.
63
fixed_lambda_varargs_function(int a,...)64 void fixed_lambda_varargs_function(int a, ...) {
65 [](int b) {
66 __builtin_va_start(ap, b); // expected-error {{'va_start' used in function with fixed args}}
67 }(42);
68 }
varargs_lambda_fixed_function(int a)69 void varargs_lambda_fixed_function(int a) {
70 [](int b, ...) {
71 __builtin_va_start(ap, b); // correct
72 }(42);
73 }
74
__anon698025940302(int f) 75 auto fixed_lambda_global = [](int f) {
76 __builtin_va_start(ap, f); // expected-error {{'va_start' used in function with fixed args}}
77 };
__anon698025940402(int f, ...) 78 auto varargs_lambda_global = [](int f, ...) {
79 __builtin_va_start(ap, f); // correct
80 };
81
record_member_init(int a,...)82 void record_member_init(int a, ...) {
83 struct Foo {
84 int a = 0;
85 // expected-error@+1 {{'va_start' cannot be used outside a function}}
86 int b = (__builtin_va_start(ap, a), 0);
87 };
88 }
89 #endif
90