format-strings-scanf.c revision 220947bd5a66b0f25f5e74d6029769dfb34f07b4 
1// RUN: %clang_cc1 -fsyntax-only -verify -triple i386-apple-darwin9 -Wformat-nonliteral %s
2
3// Test that -Wformat=0 works:
4// RUN: %clang_cc1 -fsyntax-only -Werror -Wformat=0 %s
5
6#include <stdarg.h>
7typedef __typeof(sizeof(int)) size_t;
8typedef struct _FILE FILE;
9typedef __WCHAR_TYPE__ wchar_t;
10
11int fscanf(FILE * restrict, const char * restrict, ...) ;
12int scanf(const char * restrict, ...) ;
13int sscanf(const char * restrict, const char * restrict, ...) ;
14int my_scanf(const char * restrict, ...) __attribute__((__format__(__scanf__, 1, 2)));
15
16int vscanf(const char * restrict, va_list);
17int vfscanf(FILE * restrict, const char * restrict, va_list);
18int vsscanf(const char * restrict, const char * restrict, va_list);
19
20void test(const char *s, int *i) {
21  scanf(s, i); // expected-warning{{ormat string is not a string literal}}
22  scanf("%0d", i); // expected-warning{{zero field width in scanf format string is unused}}
23  scanf("%00d", i); // expected-warning{{zero field width in scanf format string is unused}}
24  scanf("%d%[asdfasdfd", i, s); // expected-warning{{no closing ']' for '%[' in scanf format string}}
25
26  unsigned short s_x;
27  scanf ("%" "hu" "\n", &s_x); // no-warning
28  scanf("%y", i); // expected-warning{{invalid conversion specifier 'y'}}
29  scanf("%%"); // no-warning
30  scanf("%%%1$d", i); // no-warning
31  scanf("%1$d%%", i); // no-warning
32  scanf("%d", i, i); // expected-warning{{data argument not used by format string}}
33  scanf("%*d", i); // // expected-warning{{data argument not used by format string}}
34  scanf("%*d", i); // // expected-warning{{data argument not used by format string}}
35  scanf("%*d%1$d", i); // no-warning
36}
37
38void bad_length_modifiers(char *s, void *p, wchar_t *ws, long double *ld) {
39  scanf("%hhs", "foo"); // expected-warning{{length modifier 'hh' results in undefined behavior or no effect with 's' conversion specifier}}
40  scanf("%1$zp", &p); // expected-warning{{length modifier 'z' results in undefined behavior or no effect with 'p' conversion specifier}}
41  scanf("%ls", ws); // no-warning
42  scanf("%#.2Lf", ld); // expected-warning{{invalid conversion specifier '#'}}
43}
44
45// Test that the scanf call site is where the warning is attached.  If the
46// format string is somewhere else, point to it in a note.
47void pr9751() {
48  int *i;
49  char str[100];
50  const char kFormat1[] = "%00d"; // expected-note{{format string is defined here}}}
51  scanf(kFormat1, i); // expected-warning{{zero field width in scanf format string is unused}}
52  scanf("%00d", i); // expected-warning{{zero field width in scanf format string is unused}}
53  const char kFormat2[] = "%["; // expected-note{{format string is defined here}}}
54  scanf(kFormat2, str); // expected-warning{{no closing ']' for '%[' in scanf format string}}
55  scanf("%[", str); // expected-warning{{no closing ']' for '%[' in scanf format string}}
56  const char kFormat3[] = "%hu"; // expected-note{{format string is defined here}}}
57  scanf(kFormat3, &i); // expected-warning {{format specifies type 'unsigned short *' but the argument}}
58  const char kFormat4[] = "%lp"; // expected-note{{format string is defined here}}}
59  scanf(kFormat4, &i); // expected-warning {{length modifier 'l' results in undefined behavior or no effect with 'p' conversion specifier}}
60}
61
62void test_variants(int *i, const char *s, ...) {
63  FILE *f = 0;
64  char buf[100];
65
66  fscanf(f, "%ld", i); // expected-warning{{format specifies type 'long *' but the argument has type 'int *'}}
67  sscanf(buf, "%ld", i); // expected-warning{{format specifies type 'long *' but the argument has type 'int *'}}
68  my_scanf("%ld", i); // expected-warning{{format specifies type 'long *' but the argument has type 'int *'}}
69
70  va_list ap;
71  va_start(ap, s);
72
73  vscanf("%[abc", ap); // expected-warning{{no closing ']' for '%[' in scanf format string}}
74  vfscanf(f, "%[abc", ap); // expected-warning{{no closing ']' for '%[' in scanf format string}}
75  vsscanf(buf, "%[abc", ap); // expected-warning{{no closing ']' for '%[' in scanf format string}}
76}
77
78void test_scanlist(int *ip, char *sp, wchar_t *ls) {
79  scanf("%[abc]", ip); // expected-warning{{format specifies type 'char *' but the argument has type 'int *'}}
80  scanf("%h[abc]", sp); // expected-warning{{length modifier 'h' results in undefined behavior or no effect with '[' conversion specifier}}
81  scanf("%l[xyx]", ls); // no-warning
82  scanf("%ll[xyx]", ls); // expected-warning {{length modifier 'll' results in undefined behavior or no effect with '[' conversion specifier}}
83}
84
85void test_alloc_extension(char **sp, wchar_t **lsp, float *fp) {
86  /* Make sure "%a" gets parsed as a conversion specifier for float,
87   * even when followed by an 's', 'S' or '[', which would cause it to be
88   * parsed as a length modifier in C90. */
89  scanf("%as", sp); // expected-warning{{format specifies type 'float *' but the argument has type 'char **'}}
90  scanf("%aS", lsp); // expected-warning{{format specifies type 'float *' but the argument has type 'wchar_t **'}}
91  scanf("%a[bcd]", sp); // expected-warning{{format specifies type 'float *' but the argument has type 'char **'}}
92
93  // Test that the 'm' length modifier is only allowed with s, S, c, C or [.
94  // TODO: Warn that 'm' is an extension.
95  scanf("%ms", sp); // No warning.
96  scanf("%mS", lsp); // No warning.
97  scanf("%mc", sp); // No warning.
98  scanf("%mC", lsp); // No warning.
99  scanf("%m[abc]", sp); // No warning.
100  scanf("%md", sp); // expected-warning{{length modifier 'm' results in undefined behavior or no effect with 'd' conversion specifier}}
101
102  // Test argument type check for the 'm' length modifier.
103  scanf("%ms", fp); // expected-warning{{format specifies type 'char **' but the argument has type 'float *'}}
104  scanf("%mS", fp); // expected-warning{{format specifies type 'wchar_t **' (aka 'int **') but the argument has type 'float *'}}
105  scanf("%mc", fp); // expected-warning{{format specifies type 'char **' but the argument has type 'float *'}}
106  scanf("%mC", fp); // expected-warning{{format specifies type 'wchar_t **' (aka 'int **') but the argument has type 'float *'}}
107  scanf("%m[abc]", fp); // expected-warning{{format specifies type 'char **' but the argument has type 'float *'}}
108}
109
110void test_longlong(long long *x, unsigned long long *y) {
111  scanf("%Ld", y); // no-warning
112  scanf("%Lu", y); // no-warning
113  scanf("%Lx", y); // no-warning
114  scanf("%Ld", x); // no-warning
115  scanf("%Lu", x); // no-warning
116  scanf("%Lx", x); // no-warning
117  scanf("%Ls", "hello"); // expected-warning {{length modifier 'L' results in undefined behavior or no effect with 's' conversion specifier}}
118}
119
120