xref: /llvm-project/clang/test/Sema/format-strings.c (revision df18c6a9af34550404058f80f9d2e74b42bb4a74)
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    printf("abc"
34           "%*d", (unsigned) 1, 1); // expected-warning {{field width should have type 'int'}}
35 }
36 
37 void check_conditional_literal(const char* s, int i) {
38   printf(i == 1 ? "yes" : "no"); // no-warning
39   printf(i == 0 ? (i == 1 ? "yes" : "no") : "dont know"); // no-warning
40   printf(i == 0 ? (i == 1 ? s : "no") : "dont know"); // expected-warning{{format string is not a string literal}}
41 }
42 
43 void check_writeback_specifier()
44 {
45   int x;
46   char *b;
47 
48   printf("%n",&x); // expected-warning {{'%n' in format string discouraged}}
49   sprintf(b,"%d%%%n",1, &x); // expected-warning {{'%n' in format string dis}}
50 }
51 
52 void check_invalid_specifier(FILE* fp, char *buf)
53 {
54   printf("%s%lb%d","unix",10,20); // expected-warning {{lid conversion '%lb'}}
55   fprintf(fp,"%%%l"); // expected-warning {{lid conversion '%l'}}
56   sprintf(buf,"%%%%%ld%d%d", 1, 2, 3); // no-warning
57   snprintf(buf, 2, "%%%%%ld%;%d", 1, 2, 3); // expected-warning {{sion '%;'}}
58 }
59 
60 void check_null_char_string(char* b)
61 {
62   printf("\0this is bogus%d",1); // expected-warning {{string contains '\0'}}
63   snprintf(b,10,"%%%%%d\0%d",1,2); // expected-warning {{string contains '\0'}}
64   printf("%\0d",1); // expected-warning {{string contains '\0'}}
65 }
66 
67 void check_empty_format_string(char* buf, ...)
68 {
69   va_list ap;
70   va_start(ap,buf);
71   vprintf("",ap); // expected-warning {{format string is empty}}
72   sprintf(buf,""); // expected-warning {{format string is empty}}
73 }
74 
75 void check_wide_string(char* b, ...)
76 {
77   va_list ap;
78   va_start(ap,b);
79 
80   printf(L"foo %d",2); // expected-warning {{incompatible pointer types}}, expected-warning {{should not be a wide string}}
81   vasprintf(&b,L"bar %d",ap); // expected-warning {{incompatible pointer types}}, expected-warning {{should not be a wide string}}
82 }
83 
84 void check_asterisk_precision_width(int x) {
85   printf("%*d"); // expected-warning {{'*' specified field width is missing a matching 'int' argument}}
86   printf("%.*d"); // expected-warning {{'.*' specified field precision is missing a matching 'int' argument}}
87   printf("%*d",12,x); // no-warning
88   printf("%*d","foo",x); // expected-warning {{field width should have type 'int', but argument has type 'char *'}}
89   printf("%.*d","foo",x); // expected-warning {{field precision should have type 'int', but argument has type 'char *'}}
90 }
91 
92 void __attribute__((format(printf,1,3))) myprintf(const char*, int blah, ...);
93 
94 void test_myprintf() {
95   myprintf("%d", 17, 18); // okay
96 }
97