1 // RUN: %clang_cc1 %s -verify
2 // RUN: %clang_cc1 %s -DCODEGEN -emit-llvm -o - | FileCheck %s
3 
4 #define O_CREAT 0x100
5 typedef int mode_t;
6 typedef unsigned long size_t;
7 
8 enum { TRUE = 1 };
9 
10 int open(const char *pathname, int flags) __attribute__((enable_if(!(flags & O_CREAT), "must specify mode when using O_CREAT"))) __attribute__((overloadable));  // expected-note{{candidate disabled: must specify mode when using O_CREAT}}
11 int open(const char *pathname, int flags, mode_t mode) __attribute__((overloadable));  // expected-note{{candidate function not viable: requires 3 arguments, but 2 were provided}}
12 
test1()13 void test1() {
14 #ifndef CODEGEN
15   open("path", O_CREAT);  // expected-error{{no matching function for call to 'open'}}
16 #endif
17   open("path", O_CREAT, 0660);
18   open("path", 0);
19   open("path", 0, 0);
20 }
21 
22 size_t __strnlen_chk(const char *s, size_t requested_amount, size_t s_len);
23 
24 size_t strnlen(const char *s, size_t maxlen)
25   __attribute__((overloadable))
26   __asm__("strnlen_real1");
27 
28 __attribute__((always_inline))
strnlen(const char * s,size_t maxlen)29 inline size_t strnlen(const char *s, size_t maxlen)
30   __attribute__((overloadable))
31   __attribute__((enable_if(__builtin_object_size(s, 0) != -1,
32                            "chosen when target buffer size is known")))
33 {
34   return __strnlen_chk(s, maxlen, __builtin_object_size(s, 0));
35 }
36 
37 size_t strnlen(const char *s, size_t maxlen)
38   __attribute__((overloadable))
39   __attribute__((enable_if(__builtin_object_size(s, 0) != -1,
40                            "chosen when target buffer size is known")))
41   __attribute__((enable_if(maxlen <= __builtin_object_size(s, 0),
42                            "chosen when 'maxlen' is known to be less than or equal to the buffer size")))
43   __asm__("strnlen_real2");
44 
45 size_t strnlen(const char *s, size_t maxlen) // expected-note {{'strnlen' has been explicitly marked unavailable here}}
46   __attribute__((overloadable))
47   __attribute__((enable_if(__builtin_object_size(s, 0) != -1,
48                            "chosen when target buffer size is known")))
49   __attribute__((enable_if(maxlen > __builtin_object_size(s, 0),
50                            "chosen when 'maxlen' is larger than the buffer size")))
51   __attribute__((unavailable("'maxlen' is larger than the buffer size")));
52 
test2(const char * s,int i)53 void test2(const char *s, int i) {
54 // CHECK: define {{.*}}void @test2
55   const char c[123];
56   strnlen(s, i);
57 // CHECK: call {{.*}}strnlen_real1
58   strnlen(s, 999);
59 // CHECK: call {{.*}}strnlen_real1
60   strnlen(c, 1);
61 // CHECK: call {{.*}}strnlen_real2
62   strnlen(c, i);
63 // CHECK: call {{.*}}strnlen_chk
64 #ifndef CODEGEN
65   strnlen(c, 999);  // expected-error{{'strnlen' is unavailable: 'maxlen' is larger than the buffer size}}
66 #endif
67 }
68 
69 int isdigit(int c) __attribute__((overloadable));
70 int isdigit(int c) __attribute__((overloadable)) // expected-note {{'isdigit' has been explicitly marked unavailable here}}
71   __attribute__((enable_if(c <= -1 || c > 255, "'c' must have the value of an unsigned char or EOF")))
72   __attribute__((unavailable("'c' must have the value of an unsigned char or EOF")));
73 
test3(int c)74 void test3(int c) {
75   isdigit(c); // expected-warning{{ignoring return value of function declared with pure attribute}}
76   isdigit(10); // expected-warning{{ignoring return value of function declared with pure attribute}}
77 #ifndef CODEGEN
78   isdigit(-10);  // expected-error{{'isdigit' is unavailable: 'c' must have the value of an unsigned char or EOF}}
79 #endif
80 }
81 
82 // Verify that the alternate spelling __enable_if__ works as well.
83 int isdigit2(int c) __attribute__((overloadable));
84 int isdigit2(int c) __attribute__((overloadable)) // expected-note {{'isdigit2' has been explicitly marked unavailable here}}
85   __attribute__((__enable_if__(c <= -1 || c > 255, "'c' must have the value of an unsigned char or EOF")))
86   __attribute__((unavailable("'c' must have the value of an unsigned char or EOF")));
87 
test4(int c)88 void test4(int c) {
89   isdigit2(c);
90   isdigit2(10);
91 #ifndef CODEGEN
92   isdigit2(-10);  // expected-error{{'isdigit2' is unavailable: 'c' must have the value of an unsigned char or EOF}}
93 #endif
94 }
95 
test5()96 void test5() {
97   int (*p1)(int) = &isdigit2;
98   int (*p2)(int) = isdigit2;
99   void *p3 = (void *)&isdigit2;
100   void *p4 = (void *)isdigit2;
101 }
102 
103 #ifndef CODEGEN
104 __attribute__((enable_if(n == 0, "chosen when 'n' is zero"))) void f1(int n); // expected-error{{use of undeclared identifier 'n'}}
105 
106 int n __attribute__((enable_if(1, "always chosen"))); // expected-warning{{'enable_if' attribute only applies to functions}}
107 
108 void f(int n) __attribute__((enable_if("chosen when 'n' is zero", n == 0)));  // expected-error{{'enable_if' attribute requires a string}}
109 
110 void f(int n) __attribute__((enable_if()));  // expected-error{{'enable_if' attribute requires exactly 2 arguments}}
111 
112 void f(int n) __attribute__((enable_if(unresolvedid, "chosen when 'unresolvedid' is non-zero")));  // expected-error{{use of undeclared identifier 'unresolvedid'}}
113 
114 int global;
115 void f(int n) __attribute__((enable_if(global == 0, "chosen when 'global' is zero")));  // expected-error{{'enable_if' attribute expression never produces a constant expression}}  // expected-note{{subexpression not valid in a constant expression}}
116 
117 enum { cst = 7 };
118 void return_cst(void) __attribute__((overloadable)) __attribute__((enable_if(cst == 7, "chosen when 'cst' is 7")));
test_return_cst()119 void test_return_cst() { return_cst(); }
120 
121 void f2(void) __attribute__((overloadable)) __attribute__((enable_if(1, "always chosen")));
122 void f2(void) __attribute__((overloadable)) __attribute__((enable_if(0, "never chosen")));
123 void f2(void) __attribute__((overloadable)) __attribute__((enable_if(TRUE, "always chosen #2")));
test6()124 void test6() {
125   void (*p1)(void) = &f2; // expected-error{{initializing 'void (*)(void)' with an expression of incompatible type '<overloaded function type>'}} expected-note@121{{candidate function}} expected-note@122{{candidate function made ineligible by enable_if}} expected-note@123{{candidate function}}
126   void (*p2)(void) = f2; // expected-error{{initializing 'void (*)(void)' with an expression of incompatible type '<overloaded function type>'}} expected-note@121{{candidate function}} expected-note@122{{candidate function made ineligible by enable_if}} expected-note@123{{candidate function}}
127   void *p3 = (void*)&f2; // expected-error{{address of overloaded function 'f2' is ambiguous}} expected-note@121{{candidate function}} expected-note@122{{candidate function made ineligible by enable_if}} expected-note@123{{candidate function}}
128   void *p4 = (void*)f2; // expected-error{{address of overloaded function 'f2' is ambiguous}} expected-note@121{{candidate function}} expected-note@122{{candidate function made ineligible by enable_if}} expected-note@123{{candidate function}}
129 }
130 
131 void f3(int m) __attribute__((overloadable)) __attribute__((enable_if(m >= 0, "positive")));
132 void f3(int m) __attribute__((overloadable)) __attribute__((enable_if(m < 0, "negative")));
test7()133 void test7() {
134   void (*p1)(int) = &f3; // expected-error{{initializing 'void (*)(int)' with an expression of incompatible type '<overloaded function type>'}} expected-note@131{{candidate function made ineligible by enable_if}} expected-note@132{{candidate function made ineligible by enable_if}}
135   void (*p2)(int) = f3; // expected-error{{initializing 'void (*)(int)' with an expression of incompatible type '<overloaded function type>'}} expected-note@131{{candidate function made ineligible by enable_if}} expected-note@132{{candidate function made ineligible by enable_if}}
136   void *p3 = (void*)&f3; // expected-error{{address of overloaded function 'f3' does not match required type 'void'}} expected-note@131{{candidate function made ineligible by enable_if}} expected-note@132{{candidate function made ineligible by enable_if}}
137   void *p4 = (void*)f3; // expected-error{{address of overloaded function 'f3' does not match required type 'void'}} expected-note@131{{candidate function made ineligible by enable_if}} expected-note@132{{candidate function made ineligible by enable_if}}
138 }
139 
140 void f4(int m) __attribute__((enable_if(0, "")));
test8()141 void test8() {
142   void (*p1)(int) = &f4; // expected-error{{cannot take address of function 'f4' because it has one or more non-tautological enable_if conditions}}
143   void (*p2)(int) = f4; // expected-error{{cannot take address of function 'f4' because it has one or more non-tautological enable_if conditions}}
144 }
145 
146 void regular_enable_if(int a) __attribute__((enable_if(a, ""))); // expected-note 3{{declared here}}
PR27122_ext()147 void PR27122_ext() {
148   regular_enable_if(0, 2); // expected-error{{too many arguments}}
149   regular_enable_if(1, 2); // expected-error{{too many arguments}}
150   regular_enable_if(); // expected-error{{too few arguments}}
151 }
152 
153 // We had a bug where we'd crash upon trying to evaluate varargs.
154 void variadic_enable_if(int a, ...) __attribute__((enable_if(a, ""))); // expected-note 6 {{disabled}}
variadic_test()155 void variadic_test() {
156   variadic_enable_if(1);
157   variadic_enable_if(1, 2);
158   variadic_enable_if(1, "c", 3);
159 
160   variadic_enable_if(0); // expected-error{{no matching}}
161   variadic_enable_if(0, 2); // expected-error{{no matching}}
162   variadic_enable_if(0, "c", 3); // expected-error{{no matching}}
163 
164   int m;
165   variadic_enable_if(1);
166   variadic_enable_if(1, m);
167   variadic_enable_if(1, m, "c");
168 
169   variadic_enable_if(0); // expected-error{{no matching}}
170   variadic_enable_if(0, m); // expected-error{{no matching}}
171   variadic_enable_if(0, m, 3); // expected-error{{no matching}}
172 }
173 #endif
174