xref: /llvm-project/clang/test/Sema/format-strings.c (revision dfd72c2b441adfbd6872e10e4b45d49a846dd5cd)
1 // RUN: clang -fsyntax-only -verify %s
2 
3 // Define this to get vasprintf on Linux
4 #define _GNU_SOURCE
5 
6 #include <stdio.h>
7 #include <stdarg.h>
8 
9 char * global_fmt;
10 
11 void check_string_literal( FILE* fp, const char* s, char *buf, ... ) {
12 
13   char * b;
14   va_list ap;
15   va_start(ap,buf);
16 
17   printf(s); // expected-warning {{format string is not a string literal}}
18   vprintf(s,ap); // // no-warning
19   fprintf(fp,s); // expected-warning {{format string is not a string literal}}
20   vfprintf(fp,s,ap); // no-warning
21   asprintf(&b,s); // expected-warning {{format string is not a string lit}}
22   vasprintf(&b,s,ap); // no-warning
23   sprintf(buf,s); // expected-warning {{format string is not a string literal}}
24   snprintf(buf,2,s); // expected-warning {{format string is not a string lit}}
25   __builtin___sprintf_chk(buf,0,-1,s); // expected-warning {{format string is not a string literal}}
26   __builtin___snprintf_chk(buf,2,0,-1,s); // expected-warning {{format string is not a string lit}}
27   vsprintf(buf,s,ap); // no-warning
28   vsnprintf(buf,2,s,ap); // no-warning
29   vsnprintf(buf,2,global_fmt,ap); // expected-warning {{format string is not a string literal}}
30   __builtin___vsnprintf_chk(buf,2,0,-1,s,ap); // no-warning
31   __builtin___vsnprintf_chk(buf,2,0,-1,global_fmt,ap); // expected-warning {{format string is not a string literal}}
32 
33   // rdar://6079877
34   printf("abc"
35          "%*d", (unsigned) 1, 1); // expected-warning {{field width should have type 'int'}}
36   printf("abc\
37 def"
38          "%*d", (unsigned) 1, 1); // expected-warning {{field width should have type 'int'}}
39 
40 }
41 
42 void check_conditional_literal(const char* s, int i) {
43   printf(i == 1 ? "yes" : "no"); // no-warning
44   printf(i == 0 ? (i == 1 ? "yes" : "no") : "dont know"); // no-warning
45   printf(i == 0 ? (i == 1 ? s : "no") : "dont know"); // expected-warning{{format string is not a string literal}}
46 }
47 
48 void check_writeback_specifier()
49 {
50   int x;
51   char *b;
52 
53   printf("%n",&x); // expected-warning {{'%n' in format string discouraged}}
54   sprintf(b,"%d%%%n",1, &x); // expected-warning {{'%n' in format string dis}}
55 }
56 
57 void check_invalid_specifier(FILE* fp, char *buf)
58 {
59   printf("%s%lb%d","unix",10,20); // expected-warning {{lid conversion '%lb'}}
60   fprintf(fp,"%%%l"); // expected-warning {{lid conversion '%l'}}
61   sprintf(buf,"%%%%%ld%d%d", 1, 2, 3); // no-warning
62   snprintf(buf, 2, "%%%%%ld%;%d", 1, 2, 3); // expected-warning {{sion '%;'}}
63 }
64 
65 void check_null_char_string(char* b)
66 {
67   printf("\0this is bogus%d",1); // expected-warning {{string contains '\0'}}
68   snprintf(b,10,"%%%%%d\0%d",1,2); // expected-warning {{string contains '\0'}}
69   printf("%\0d",1); // expected-warning {{string contains '\0'}}
70 }
71 
72 void check_empty_format_string(char* buf, ...)
73 {
74   va_list ap;
75   va_start(ap,buf);
76   vprintf("",ap); // expected-warning {{format string is empty}}
77   sprintf(buf,""); // expected-warning {{format string is empty}}
78 }
79 
80 void check_wide_string(char* b, ...)
81 {
82   va_list ap;
83   va_start(ap,b);
84 
85   printf(L"foo %d",2); // expected-warning {{incompatible pointer types}}, expected-warning {{should not be a wide string}}
86   vasprintf(&b,L"bar %d",ap); // expected-warning {{incompatible pointer types}}, expected-warning {{should not be a wide string}}
87 }
88 
89 void check_asterisk_precision_width(int x) {
90   printf("%*d"); // expected-warning {{'*' specified field width is missing a matching 'int' argument}}
91   printf("%.*d"); // expected-warning {{'.*' specified field precision is missing a matching 'int' argument}}
92   printf("%*d",12,x); // no-warning
93   printf("%*d","foo",x); // expected-warning {{field width should have type 'int', but argument has type 'char *'}}
94   printf("%.*d","foo",x); // expected-warning {{field precision should have type 'int', but argument has type 'char *'}}
95 }
96 
97 void __attribute__((format(printf,1,3))) myprintf(const char*, int blah, ...);
98 
99 void test_myprintf() {
100   myprintf("%d", 17, 18); // okay
101 }
102 
103 void test_constant_bindings(void) {
104   const char * const s1 = "hello";
105   const char s2[] = "hello";
106   const char *s3 = "hello";
107   char * const s4 = "hello";
108   extern const char s5[];
109 
110   printf(s1); // no-warning
111   printf(s2); // no-warning
112   printf(s3); // expected-warning{{not a string literal}}
113   printf(s4); // expected-warning{{not a string literal}}
114   printf(s5); // expected-warning{{not a string literal}}
115 }
116