format-strings.c revision e030358cc06e1cbce3c2e00ca67c946f9164b2a8 
1// RUN: %clang_cc1 -fsyntax-only -verify -Wformat-nonliteral %s
2
3#include <stdarg.h>
4typedef __typeof(sizeof(int)) size_t;
5typedef struct _FILE FILE;
6int fprintf(FILE *, const char *restrict, ...);
7int printf(const char *restrict, ...);
8int snprintf(char *restrict, size_t, const char *restrict, ...);
9int sprintf(char *restrict, const char *restrict, ...);
10int vasprintf(char **, const char *, va_list);
11int asprintf(char **, const char *, ...);
12int vfprintf(FILE *, const char *restrict, va_list);
13int vprintf(const char *restrict, va_list);
14int vsnprintf(char *, size_t, const char *, va_list);
15int vsprintf(char *restrict, const char *restrict, va_list);
16
17char * global_fmt;
18
19void check_string_literal( FILE* fp, const char* s, char *buf, ... ) {
20
21  char * b;
22  va_list ap;
23  va_start(ap,buf);
24
25  printf(s); // expected-warning {{format string is not a string literal}}
26  vprintf(s,ap); // // no-warning
27  fprintf(fp,s); // expected-warning {{format string is not a string literal}}
28  vfprintf(fp,s,ap); // no-warning
29  asprintf(&b,s); // expected-warning {{format string is not a string lit}}
30  vasprintf(&b,s,ap); // no-warning
31  sprintf(buf,s); // expected-warning {{format string is not a string literal}}
32  snprintf(buf,2,s); // expected-warning {{format string is not a string lit}}
33  __builtin___sprintf_chk(buf,0,-1,s); // expected-warning {{format string is not a string literal}}
34  __builtin___snprintf_chk(buf,2,0,-1,s); // expected-warning {{format string is not a string lit}}
35  vsprintf(buf,s,ap); // no-warning
36  vsnprintf(buf,2,s,ap); // no-warning
37  vsnprintf(buf,2,global_fmt,ap); // expected-warning {{format string is not a string literal}}
38  __builtin___vsnprintf_chk(buf,2,0,-1,s,ap); // no-warning
39  __builtin___vsnprintf_chk(buf,2,0,-1,global_fmt,ap); // expected-warning {{format string is not a string literal}}
40
41  // rdar://6079877
42  printf("abc"
43         "%*d", (unsigned) 1, 1); // expected-warning {{field width should have type 'int'}}
44  printf("abc\
45def"
46         "%*d", (unsigned) 1, 1); // expected-warning {{field width should have type 'int'}}
47
48}
49
50void check_conditional_literal(const char* s, int i) {
51  printf(i == 1 ? "yes" : "no"); // no-warning
52  printf(i == 0 ? (i == 1 ? "yes" : "no") : "dont know"); // no-warning
53  printf(i == 0 ? (i == 1 ? s : "no") : "dont know"); // expected-warning{{format string is not a string literal}}
54  printf("yes" ?: "no %d", 1); // expected-warning{{more data arguments than '%' conversions}}
55}
56
57void check_writeback_specifier()
58{
59  int x;
60  char *b;
61
62  printf("%n",&x); // expected-warning {{'%n' in format string discouraged}}
63  sprintf(b,"%d%%%n",1, &x); // expected-warning {{'%n' in format string dis}}
64}
65
66void check_invalid_specifier(FILE* fp, char *buf)
67{
68  printf("%s%lb%d","unix",10,20); // expected-warning {{lid conversion '%lb'}}
69  fprintf(fp,"%%%l"); // expected-warning {{lid conversion '%l'}}
70  sprintf(buf,"%%%%%ld%d%d", 1, 2, 3); // no-warning
71  snprintf(buf, 2, "%%%%%ld%;%d", 1, 2, 3); // expected-warning {{sion '%;'}}
72}
73
74void check_null_char_string(char* b)
75{
76  printf("\0this is bogus%d",1); // expected-warning {{string contains '\0'}}
77  snprintf(b,10,"%%%%%d\0%d",1,2); // expected-warning {{string contains '\0'}}
78  printf("%\0d",1); // expected-warning {{string contains '\0'}}
79}
80
81void check_empty_format_string(char* buf, ...)
82{
83  va_list ap;
84  va_start(ap,buf);
85  vprintf("",ap); // expected-warning {{format string is empty}}
86  sprintf(buf,""); // expected-warning {{format string is empty}}
87}
88
89void check_wide_string(char* b, ...)
90{
91  va_list ap;
92  va_start(ap,b);
93
94  printf(L"foo %d",2); // expected-warning {{incompatible pointer types}}, expected-warning {{should not be a wide string}}
95  vsprintf(b,L"bar %d",ap); // expected-warning {{incompatible pointer types}}, expected-warning {{should not be a wide string}}
96}
97
98void check_asterisk_precision_width(int x) {
99  printf("%*d"); // expected-warning {{'*' specified field width is missing a matching 'int' argument}}
100  printf("%.*d"); // expected-warning {{'.*' specified field precision is missing a matching 'int' argument}}
101  printf("%*d",12,x); // no-warning
102  printf("%*d","foo",x); // expected-warning {{field width should have type 'int', but argument has type 'char *'}}
103  printf("%.*d","foo",x); // expected-warning {{field precision should have type 'int', but argument has type 'char *'}}
104}
105
106void __attribute__((format(printf,1,3))) myprintf(const char*, int blah, ...);
107
108void test_myprintf() {
109  myprintf("%d", 17, 18); // okay
110}
111
112void test_constant_bindings(void) {
113  const char * const s1 = "hello";
114  const char s2[] = "hello";
115  const char *s3 = "hello";
116  char * const s4 = "hello";
117  extern const char s5[];
118
119  printf(s1); // no-warning
120  printf(s2); // no-warning
121  printf(s3); // expected-warning{{not a string literal}}
122  printf(s4); // expected-warning{{not a string literal}}
123  printf(s5); // expected-warning{{not a string literal}}
124}
125
126
127// Test what happens when -Wformat-security only.
128#pragma GCC diagnostic ignored "-Wformat-nonliteral"
129#pragma GCC diagnostic warning "-Wformat-security"
130
131void test9(char *P) {
132  int x;
133  printf(P);   // expected-warning {{format string is not a string literal (potentially insecure)}}
134  printf(P, 42);
135  printf("%n", &x); // expected-warning {{use of '%n' in format string discouraged }}
136}
137
138void torture(va_list v8) {
139  vprintf ("%*.*d", v8);  // no-warning
140}
141
142