1 // RUN: %clang_cc1 -fsyntax-only -verify -Wformat-nonliteral %s 2 3 #include <stdarg.h> 4 typedef __typeof(sizeof(int)) size_t; 5 typedef struct _FILE FILE; 6 int fprintf(FILE *, const char *restrict, ...); 7 int printf(const char *restrict, ...); // expected-note{{passing argument to parameter here}} 8 int snprintf(char *restrict, size_t, const char *restrict, ...); 9 int sprintf(char *restrict, const char *restrict, ...); 10 int vasprintf(char **, const char *, va_list); 11 int asprintf(char **, const char *, ...); 12 int vfprintf(FILE *, const char *restrict, va_list); 13 int vprintf(const char *restrict, va_list); 14 int vsnprintf(char *, size_t, const char *, va_list); 15 int vsprintf(char *restrict, const char *restrict, va_list); // expected-note{{passing argument to parameter here}} 16 17 int vscanf(const char *restrict format, va_list arg); 18 19 char * global_fmt; 20 21 void check_string_literal( FILE* fp, const char* s, char *buf, ... ) { 22 23 char * b; 24 va_list ap; 25 va_start(ap,buf); 26 27 printf(s); // expected-warning {{format string is not a string literal}} 28 vprintf(s,ap); // expected-warning {{format string is not a string literal}} 29 fprintf(fp,s); // expected-warning {{format string is not a string literal}} 30 vfprintf(fp,s,ap); // expected-warning {{format string is not a string literal}} 31 asprintf(&b,s); // expected-warning {{format string is not a string lit}} 32 vasprintf(&b,s,ap); // expected-warning {{format string is not a string literal}} 33 sprintf(buf,s); // expected-warning {{format string is not a string literal}} 34 snprintf(buf,2,s); // expected-warning {{format string is not a string lit}} 35 __builtin___sprintf_chk(buf,0,-1,s); // expected-warning {{format string is not a string literal}} 36 __builtin___snprintf_chk(buf,2,0,-1,s); // expected-warning {{format string is not a string lit}} 37 vsprintf(buf,s,ap); // expected-warning {{format string is not a string lit}} 38 vsnprintf(buf,2,s,ap); // expected-warning {{format string is not a string lit}} 39 vsnprintf(buf,2,global_fmt,ap); // expected-warning {{format string is not a string literal}} 40 __builtin___vsnprintf_chk(buf,2,0,-1,s,ap); // expected-warning {{format string is not a string lit}} 41 __builtin___vsnprintf_chk(buf,2,0,-1,global_fmt,ap); // expected-warning {{format string is not a string literal}} 42 43 vscanf(s, ap); // expected-warning {{format string is not a string literal}} 44 45 // rdar://6079877 46 printf("abc" 47 "%*d", 1, 1); // no-warning 48 printf("abc\ 49 def" 50 "%*d", 1, 1); // no-warning 51 52 // <rdar://problem/6079850>, allow 'unsigned' (instead of 'int') to be used for both 53 // the field width and precision. This deviates from C99, but is reasonably safe 54 // and is also accepted by GCC. 55 printf("%*d", (unsigned) 1, 1); // no-warning 56 } 57 58 __attribute__((__format__ (__printf__, 2, 4))) 59 void check_string_literal2( FILE* fp, const char* s, char *buf, ... ) { 60 char * b; 61 va_list ap; 62 va_start(ap,buf); 63 64 printf(s); // expected-warning {{format string is not a string literal}} 65 vprintf(s,ap); // no-warning 66 fprintf(fp,s); // expected-warning {{format string is not a string literal}} 67 vfprintf(fp,s,ap); // no-warning 68 asprintf(&b,s); // expected-warning {{format string is not a string lit}} 69 vasprintf(&b,s,ap); // no-warning 70 sprintf(buf,s); // expected-warning {{format string is not a string literal}} 71 snprintf(buf,2,s); // expected-warning {{format string is not a string lit}} 72 __builtin___vsnprintf_chk(buf,2,0,-1,s,ap); // no-warning 73 74 vscanf(s, ap); // expected-warning {{format string is not a string literal}} 75 } 76 77 void check_conditional_literal(const char* s, int i) { 78 printf(i == 1 ? "yes" : "no"); // no-warning 79 printf(i == 0 ? (i == 1 ? "yes" : "no") : "dont know"); // no-warning 80 printf(i == 0 ? (i == 1 ? s : "no") : "dont know"); // expected-warning{{format string is not a string literal}} 81 printf("yes" ?: "no %d", 1); // expected-warning{{data argument not used by format string}} 82 } 83 84 void check_writeback_specifier() 85 { 86 int x; 87 char *b; 88 89 printf("%n",&x); // expected-warning {{'%n' in format string discouraged}} 90 sprintf(b,"%d%%%n",1, &x); // expected-warning {{'%n' in format string dis}} 91 } 92 93 void check_invalid_specifier(FILE* fp, char *buf) 94 { 95 printf("%s%lb%d","unix",10,20); // expected-warning {{invalid conversion specifier 'b'}} 96 fprintf(fp,"%%%l"); // expected-warning {{incomplete format specifier}} 97 sprintf(buf,"%%%%%ld%d%d", 1, 2, 3); // expected-warning{{format specifies type 'long' but the argument has type 'int'}} 98 snprintf(buf, 2, "%%%%%ld%;%d", 1, 2, 3); // expected-warning{{format specifies type 'long' but the argument has type 'int'}} expected-warning {{invalid conversion specifier ';'}} 99 } 100 101 void check_null_char_string(char* b) 102 { 103 printf("\0this is bogus%d",1); // expected-warning {{string contains '\0'}} 104 snprintf(b,10,"%%%%%d\0%d",1,2); // expected-warning {{string contains '\0'}} 105 printf("%\0d",1); // expected-warning {{string contains '\0'}} 106 } 107 108 void check_empty_format_string(char* buf, ...) 109 { 110 va_list ap; 111 va_start(ap,buf); 112 vprintf("",ap); // expected-warning {{format string is empty}} 113 sprintf(buf, "", 1); // expected-warning {{format string is empty}} 114 115 // Don't warn about empty format strings when there are no data arguments. 116 // This can arise from macro expansions and non-standard format string 117 // functions. 118 sprintf(buf, ""); // no-warning 119 } 120 121 void check_wide_string(char* b, ...) 122 { 123 va_list ap; 124 va_start(ap,b); 125 126 printf(L"foo %d",2); // expected-warning {{incompatible pointer types}}, expected-warning {{should not be a wide string}} 127 vsprintf(b,L"bar %d",ap); // expected-warning {{incompatible pointer types}}, expected-warning {{should not be a wide string}} 128 } 129 130 void check_asterisk_precision_width(int x) { 131 printf("%*d"); // expected-warning {{'*' specified field width is missing a matching 'int' argument}} 132 printf("%.*d"); // expected-warning {{'.*' specified field precision is missing a matching 'int' argument}} 133 printf("%*d",12,x); // no-warning 134 printf("%*d","foo",x); // expected-warning {{field width should have type 'int', but argument has type 'char *'}} 135 printf("%.*d","foo",x); // expected-warning {{field precision should have type 'int', but argument has type 'char *'}} 136 } 137 138 void __attribute__((format(printf,1,3))) myprintf(const char*, int blah, ...); 139 140 void test_myprintf() { 141 myprintf("%d", 17, 18); // okay 142 } 143 144 void test_constant_bindings(void) { 145 const char * const s1 = "hello"; 146 const char s2[] = "hello"; 147 const char *s3 = "hello"; 148 char * const s4 = "hello"; 149 extern const char s5[]; 150 151 printf(s1); // no-warning 152 printf(s2); // no-warning 153 printf(s3); // expected-warning{{not a string literal}} 154 printf(s4); // expected-warning{{not a string literal}} 155 printf(s5); // expected-warning{{not a string literal}} 156 } 157 158 159 // Test what happens when -Wformat-security only. 160 #pragma GCC diagnostic ignored "-Wformat-nonliteral" 161 #pragma GCC diagnostic warning "-Wformat-security" 162 163 void test9(char *P) { 164 int x; 165 printf(P); // expected-warning {{format string is not a string literal (potentially insecure)}} 166 printf(P, 42); 167 printf("%n", &x); // expected-warning {{use of '%n' in format string discouraged }} 168 } 169 170 void torture(va_list v8) { 171 vprintf ("%*.*d", v8); // no-warning 172 173 } 174 175 void test10(int x, float f, int i, long long lli) { 176 printf("%s"); // expected-warning{{more '%' conversions than data arguments}} 177 printf("%@", 12); // expected-warning{{invalid conversion specifier '@'}} 178 printf("\0"); // expected-warning{{format string contains '\0' within the string body}} 179 printf("xs\0"); // expected-warning{{format string contains '\0' within the string body}} 180 printf("%*d\n"); // expected-warning{{'*' specified field width is missing a matching 'int' argument}} 181 printf("%*.*d\n", x); // expected-warning{{'.*' specified field precision is missing a matching 'int' argument}} 182 printf("%*d\n", f, x); // expected-warning{{field width should have type 'int', but argument has type 'double'}} 183 printf("%*.*d\n", x, f, x); // expected-warning{{field precision should have type 'int', but argument has type 'double'}} 184 printf("%**\n"); // expected-warning{{invalid conversion specifier '*'}} 185 printf("%n", &i); // expected-warning{{use of '%n' in format string discouraged (potentially insecure)}} 186 printf("%d%d\n", x); // expected-warning{{more '%' conversions than data arguments}} 187 printf("%d\n", x, x); // expected-warning{{data argument not used by format string}} 188 printf("%W%d%Z\n", x, x, x); // expected-warning{{invalid conversion specifier 'W'}} expected-warning{{invalid conversion specifier 'Z'}} 189 printf("%"); // expected-warning{{incomplete format specifier}} 190 printf("%.d", x); // no-warning 191 printf("%.", x); // expected-warning{{incomplete format specifier}} 192 printf("%f", 4); // expected-warning{{format specifies type 'double' but the argument has type 'int'}} 193 printf("%qd", lli); // no-warning 194 printf("%qd", x); // expected-warning{{format specifies type 'long long' but the argument has type 'int'}} 195 printf("%qp", (void *)0); // expected-warning{{length modifier 'q' results in undefined behavior or no effect with 'p' conversion specifier}} 196 printf("hhX %hhX", (unsigned char)10); // no-warning 197 printf("llX %llX", (long long) 10); // no-warning 198 // This is fine, because there is an implicit conversion to an int. 199 printf("%d", (unsigned char) 10); // no-warning 200 printf("%d", (long long) 10); // expected-warning{{format specifies type 'int' but the argument has type 'long long'}} 201 printf("%Lf\n", (long double) 1.0); // no-warning 202 printf("%f\n", (long double) 1.0); // expected-warning{{format specifies type 'double' but the argument has type 'long double'}} 203 // The man page says that a zero precision is okay. 204 printf("%.0Lf", (long double) 1.0); // no-warning 205 printf("%c\n", "x"); // expected-warning{{format specifies type 'int' but the argument has type 'char *'}} 206 printf("%c\n", 1.23); // expected-warning{{format specifies type 'int' but the argument has type 'double'}} 207 printf("Format %d, is %! %f", 1, 2, 4.4); // expected-warning{{invalid conversion specifier '!'}} 208 } 209 210 typedef unsigned char uint8_t; 211 212 void should_understand_small_integers() { 213 printf("%hhu", (short) 10); // expected-warning{{format specifies type 'unsigned char' but the argument has type 'short'}} 214 printf("%hu\n", (unsigned char) 1); // expected-warning{{format specifies type 'unsigned short' but the argument has type 'unsigned char'}} 215 printf("%hu\n", (uint8_t)1); // expected-warning{{format specifies type 'unsigned short' but the argument has type 'uint8_t'}} 216 } 217 218 void test11(void *p, char *s) { 219 printf("%p", p); // no-warning 220 printf("%p", 123); // expected-warning{{format specifies type 'void *' but the argument has type 'int'}} 221 printf("%.4p", p); // expected-warning{{precision used with 'p' conversion specifier, resulting in undefined behavior}} 222 printf("%+p", p); // expected-warning{{flag '+' results in undefined behavior with 'p' conversion specifier}} 223 printf("% p", p); // expected-warning{{flag ' ' results in undefined behavior with 'p' conversion specifier}} 224 printf("%0p", p); // expected-warning{{flag '0' results in undefined behavior with 'p' conversion specifier}} 225 printf("%s", s); // no-warning 226 printf("%+s", p); // expected-warning{{flag '+' results in undefined behavior with 's' conversion specifier}} 227 printf("% s", p); // expected-warning{{flag ' ' results in undefined behavior with 's' conversion specifier}} 228 printf("%0s", p); // expected-warning{{flag '0' results in undefined behavior with 's' conversion specifier}} 229 } 230 231 void test12(char *b) { 232 unsigned char buf[4]; 233 printf ("%.4s\n", buf); // no-warning 234 printf ("%.4s\n", &buf); // expected-warning{{format specifies type 'char *' but the argument has type 'unsigned char (*)[4]'}} 235 236 // Verify that we are checking asprintf 237 asprintf(&b, "%d", "asprintf"); // expected-warning{{format specifies type 'int' but the argument has type 'char *'}} 238 } 239 240 void test13(short x) { 241 char bel = 007; 242 printf("bel: '0%hhd'\n", bel); // no-warning 243 printf("x: '0%hhd'\n", x); // expected-warning {{format specifies type 'char' but the argument has type 'short'}} 244 } 245 246 typedef struct __aslclient *aslclient; 247 typedef struct __aslmsg *aslmsg; 248 int asl_log(aslclient asl, aslmsg msg, int level, const char *format, ...) __attribute__((__format__ (__printf__, 4, 5))); 249 void test_asl(aslclient asl) { 250 // Test case from <rdar://problem/7341605>. 251 asl_log(asl, 0, 3, "Error: %m"); // no-warning 252 asl_log(asl, 0, 3, "Error: %W"); // expected-warning{{invalid conversion specifier 'W'}} 253 } 254 255 // <rdar://problem/7595366> 256 typedef enum { A } int_t; 257 void f0(int_t x) { printf("%d\n", x); } 258 259 // Unicode test cases. These are possibly specific to Mac OS X. If so, they should 260 // eventually be moved into a separate test. 261 typedef __WCHAR_TYPE__ wchar_t; 262 263 void test_unicode_conversions(wchar_t *s) { 264 printf("%S", s); // no-warning 265 printf("%s", s); // expected-warning{{format specifies type 'char *' but the argument has type 'wchar_t *'}} 266 printf("%C", s[0]); // no-warning 267 printf("%c", s[0]); 268 // FIXME: This test reports inconsistent results. On Windows, '%C' expects 269 // 'unsigned short'. 270 // printf("%C", 10); 271 printf("%S", "hello"); // expected-warning{{but the argument has type 'char *'}} 272 } 273 274 // Mac OS X supports positional arguments in format strings. 275 // This is an IEEE extension (IEEE Std 1003.1). 276 // FIXME: This is probably not portable everywhere. 277 void test_positional_arguments() { 278 printf("%0$", (int)2); // expected-warning{{position arguments in format strings start counting at 1 (not 0)}} 279 printf("%1$*0$d", (int) 2); // expected-warning{{position arguments in format strings start counting at 1 (not 0)}} 280 printf("%1$d", (int) 2); // no-warning 281 printf("%1$d", (int) 2, 2); // expected-warning{{data argument not used by format string}} 282 printf("%1$d%1$f", (int) 2); // expected-warning{{format specifies type 'double' but the argument has type 'int'}} 283 printf("%1$2.2d", (int) 2); // no-warning 284 printf("%2$*1$.2d", (int) 2, (int) 3); // no-warning 285 printf("%2$*8$d", (int) 2, (int) 3); // expected-warning{{specified field width is missing a matching 'int' argument}} 286 printf("%%%1$d", (int) 2); // no-warning 287 printf("%1$d%%", (int) 2); // no-warning 288 } 289 290 // PR 6697 - Handle format strings where the data argument is not adjacent to the format string 291 void myprintf_PR_6697(const char *format, int x, ...) __attribute__((__format__(printf,1, 3))); 292 void test_pr_6697() { 293 myprintf_PR_6697("%s\n", 1, "foo"); // no-warning 294 myprintf_PR_6697("%s\n", 1, (int)0); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 295 // FIXME: Not everything should clearly support positional arguments, 296 // but we need a way to identify those cases. 297 myprintf_PR_6697("%1$s\n", 1, "foo"); // no-warning 298 myprintf_PR_6697("%2$s\n", 1, "foo"); // expected-warning{{data argument position '2' exceeds the number of data arguments (1)}} 299 myprintf_PR_6697("%18$s\n", 1, "foo"); // expected-warning{{data argument position '18' exceeds the number of data arguments (1)}} 300 myprintf_PR_6697("%1$s\n", 1, (int) 0); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 301 } 302 303 void rdar8026030(FILE *fp) { 304 fprintf(fp, "\%"); // expected-warning{{incomplete format specifier}} 305 } 306 307 void bug7377_bad_length_mod_usage() { 308 // Bad length modifiers 309 printf("%hhs", "foo"); // expected-warning{{length modifier 'hh' results in undefined behavior or no effect with 's' conversion specifier}} 310 printf("%1$zp", (void *)0); // expected-warning{{length modifier 'z' results in undefined behavior or no effect with 'p' conversion specifier}} 311 printf("%ls", L"foo"); // no-warning 312 printf("%#.2Lf", (long double)1.234); // no-warning 313 314 // Bad flag usage 315 printf("%#p", (void *) 0); // expected-warning{{flag '#' results in undefined behavior with 'p' conversion specifier}} 316 printf("%0d", -1); // no-warning 317 printf("%#n", (void *) 0); // expected-warning{{flag '#' results in undefined behavior with 'n' conversion specifier}} expected-warning{{use of '%n' in format string discouraged (potentially insecure)}} 318 printf("%-n", (void *) 0); // expected-warning{{flag '-' results in undefined behavior with 'n' conversion specifier}} expected-warning{{use of '%n' in format string discouraged (potentially insecure)}} 319 printf("%-p", (void *) 0); // no-warning 320 321 // Bad optional amount use 322 printf("%.2c", 'a'); // expected-warning{{precision used with 'c' conversion specifier, resulting in undefined behavior}} 323 printf("%1n", (void *) 0); // expected-warning{{field width used with 'n' conversion specifier, resulting in undefined behavior}} expected-warning{{use of '%n' in format string discouraged (potentially insecure)}} 324 printf("%.9n", (void *) 0); // expected-warning{{precision used with 'n' conversion specifier, resulting in undefined behavior}} expected-warning{{use of '%n' in format string discouraged (potentially insecure)}} 325 326 // Ignored flags 327 printf("% +f", 1.23); // expected-warning{{flag ' ' is ignored when flag '+' is present}} 328 printf("%+ f", 1.23); // expected-warning{{flag ' ' is ignored when flag '+' is present}} 329 printf("%0-f", 1.23); // expected-warning{{flag '0' is ignored when flag '-' is present}} 330 printf("%-0f", 1.23); // expected-warning{{flag '0' is ignored when flag '-' is present}} 331 printf("%-+f", 1.23); // no-warning 332 } 333 334 // PR 7981 - handle '%lc' (wint_t) 335 #ifndef wint_t 336 typedef int __darwin_wint_t; 337 typedef __darwin_wint_t wint_t; 338 #endif 339 340 void pr7981(wint_t c, wchar_t c2) { 341 printf("%lc", c); // no-warning 342 printf("%lc", 1.0); // expected-warning{{the argument has type 'double'}} 343 printf("%lc", (char) 1); // no-warning 344 printf("%lc", &c); // expected-warning{{the argument has type 'wint_t *' (aka 'int *')}} 345 printf("%lc", c2); // no-warning 346 } 347 348 // <rdar://problem/8269537> -Wformat-security says NULL is not a string literal 349 void rdar8269537() { 350 // This is likely to crash in most cases, but -Wformat-nonliteral technically 351 // doesn't warn in this case. 352 printf(0); // no-warning 353 } 354 355 // Handle functions with multiple format attributes. 356 extern void rdar8332221_vprintf_scanf(const char *, va_list, const char *, ...) 357 __attribute__((__format__(__printf__, 1, 0))) 358 __attribute__((__format__(__scanf__, 3, 4))); 359 360 void rdar8332221(va_list ap, int *x, long *y) { 361 rdar8332221_vprintf_scanf("%", ap, "%d", x); // expected-warning{{incomplete format specifier}} 362 } 363 364 // PR8641 365 void pr8641() { 366 printf("%#x\n", 10); 367 printf("%#X\n", 10); 368 } 369 370 void posix_extensions() { 371 // Test %'d, "thousands grouping". 372 // <rdar://problem/8816343> 373 printf("%'d\n", 123456789); // no-warning 374 printf("%'i\n", 123456789); // no-warning 375 printf("%'f\n", (float) 1.0); // no-warning 376 printf("%'p\n", (void*) 0); // expected-warning{{results in undefined behavior with 'p' conversion specifier}} 377 } 378 379 // PR8486 380 // 381 // Test what happens when -Wformat is on, but -Wformat-security is off. 382 #pragma GCC diagnostic warning "-Wformat" 383 #pragma GCC diagnostic ignored "-Wformat-security" 384 385 void pr8486() { 386 printf("%s", 1); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 387 } 388 389 // PR9314 390 // Don't warn about string literals that are PreDefinedExprs, e.g. __func__. 391 void pr9314() { 392 printf(__PRETTY_FUNCTION__); // no-warning 393 printf(__func__); // no-warning 394 } 395 396 int printf(const char * restrict, ...) __attribute__((__format__ (__printf__, 1, 2))); 397 398 void rdar9612060(void) { 399 printf("%s", 2); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 400 } 401 402 void check_char(unsigned char x, signed char y) { 403 printf("%c", y); // no-warning 404 printf("%hhu", x); // no-warning 405 printf("%hhi", y); // no-warning 406 printf("%hhi", x); // no-warning 407 printf("%c", x); // no-warning 408 printf("%hhu", y); // no-warning 409 } 410 411 // Test suppression of individual warnings. 412 413 void test_suppress_invalid_specifier() { 414 #pragma clang diagnostic push 415 #pragma clang diagnostic ignored "-Wformat-invalid-specifier" 416 printf("%@", 12); // no-warning 417 #pragma clang diagnostic pop 418 } 419 420 // Make sure warnings are on for next test. 421 #pragma GCC diagnostic warning "-Wformat" 422 #pragma GCC diagnostic warning "-Wformat-security" 423 424 // Test that the printf call site is where the warning is attached. If the 425 // format string is somewhere else, point to it in a note. 426 void pr9751() { 427 const char kFormat1[] = "%d %d \n"; // expected-note{{format string is defined here}}} 428 printf(kFormat1, 0); // expected-warning{{more '%' conversions than data arguments}} 429 printf("%d %s\n", 0); // expected-warning{{more '%' conversions than data arguments}} 430 431 const char kFormat2[] = "%18$s\n"; // expected-note{{format string is defined here}} 432 printf(kFormat2, 1, "foo"); // expected-warning{{data argument position '18' exceeds the number of data arguments (2)}} 433 printf("%18$s\n", 1, "foo"); // expected-warning{{data argument position '18' exceeds the number of data arguments (2)}} 434 435 const char kFormat3[] = "%n"; // expected-note{{format string is defined here}} 436 printf(kFormat3, "as"); // expected-warning{{use of '%n' in format string discouraged}} 437 printf("%n", "as"); // expected-warning{{use of '%n' in format string discouraged}} 438 439 const char kFormat4[] = "%y"; // expected-note{{format string is defined here}} 440 printf(kFormat4, 5); // expected-warning{{invalid conversion specifier 'y'}} 441 printf("%y", 5); // expected-warning{{invalid conversion specifier 'y'}} 442 443 const char kFormat5[] = "%."; // expected-note{{format string is defined here}} 444 printf(kFormat5, 5); // expected-warning{{incomplete format specifier}} 445 printf("%.", 5); // expected-warning{{incomplete format specifier}} 446 447 const char kFormat6[] = "%s"; // expected-note{{format string is defined here}} 448 printf(kFormat6, 5); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 449 printf("%s", 5); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 450 451 const char kFormat7[] = "%0$"; // expected-note{{format string is defined here}} 452 printf(kFormat7, 5); // expected-warning{{position arguments in format strings start counting at 1 (not 0)}} 453 printf("%0$", 5); // expected-warning{{position arguments in format strings start counting at 1 (not 0)}} 454 455 const char kFormat8[] = "%1$d %d"; // expected-note{{format string is defined here}} 456 printf(kFormat8, 4, 4); // expected-warning{{cannot mix positional and non-positional arguments in format string}} 457 printf("%1$d %d", 4, 4); // expected-warning{{cannot mix positional and non-positional arguments in format string}} 458 459 const char kFormat9[] = ""; // expected-note{{format string is defined here}} 460 printf(kFormat9, 4, 4); // expected-warning{{format string is empty}} 461 printf("", 4, 4); // expected-warning{{format string is empty}} 462 463 const char kFormat10[] = "\0%d"; // expected-note{{format string is defined here}} 464 printf(kFormat10, 4); // expected-warning{{format string contains '\0' within the string body}} 465 printf("\0%d", 4); // expected-warning{{format string contains '\0' within the string body}} 466 467 const char kFormat11[] = "%*d"; // expected-note{{format string is defined here}} 468 printf(kFormat11); // expected-warning{{'*' specified field width is missing a matching 'int' argument}} 469 printf("%*d"); // expected-warning{{'*' specified field width is missing a matching 'int' argument}} 470 471 const char kFormat12[] = "%*d"; // expected-note{{format string is defined here}} 472 printf(kFormat12, 4.4); // expected-warning{{field width should have type 'int', but argument has type 'double'}} 473 printf("%*d", 4.4); // expected-warning{{field width should have type 'int', but argument has type 'double'}} 474 475 const char kFormat13[] = "%.3p"; // expected-note{{format string is defined here}} 476 void *p; 477 printf(kFormat13, p); // expected-warning{{precision used with 'p' conversion specifier, resulting in undefined behavior}} 478 printf("%.3p", p); // expected-warning{{precision used with 'p' conversion specifier, resulting in undefined behavior}} 479 480 const char kFormat14[] = "%0s"; // expected-note{{format string is defined here}} 481 printf(kFormat14, "a"); // expected-warning{{flag '0' results in undefined behavior with 's' conversion specifier}} 482 printf("%0s", "a"); // expected-warning{{flag '0' results in undefined behavior with 's' conversion specifier}} 483 484 const char kFormat15[] = "%hhs"; // expected-note{{format string is defined here}} 485 printf(kFormat15, "a"); // expected-warning{{length modifier 'hh' results in undefined behavior or no effect with 's' conversion specifier}} 486 printf("%hhs", "a"); // expected-warning{{length modifier 'hh' results in undefined behavior or no effect with 's' conversion specifier}} 487 488 const char kFormat16[] = "%-0d"; // expected-note{{format string is defined here}} 489 printf(kFormat16, 5); // expected-warning{{flag '0' is ignored when flag '-' is present}} 490 printf("%-0d", 5); // expected-warning{{flag '0' is ignored when flag '-' is present}} 491 492 // Make sure that the "format string is defined here" note is not emitted 493 // when the original string is within the argument expression. 494 printf(1 ? "yes %d" : "no %d"); // expected-warning 2{{more '%' conversions than data arguments}} 495 496 const char kFormat17[] = "%hu"; // expected-note{{format string is defined here}}} 497 printf(kFormat17, (int[]){0}); // expected-warning{{format specifies type 'unsigned short' but the argument}} 498 499 printf("%a", (long double)0); // expected-warning{{format specifies type 'double' but the argument has type 'long double'}} 500 } 501 502 // PR 9466: clang: doesn't know about %Lu, %Ld, and %Lx 503 void printf_longlong(long long x, unsigned long long y) { 504 printf("%Ld", y); // no-warning 505 printf("%Lu", y); // no-warning 506 printf("%Lx", y); // no-warning 507 printf("%Ld", x); // no-warning 508 printf("%Lu", x); // no-warning 509 printf("%Lx", x); // no-warning 510 printf("%Ls", "hello"); // expected-warning {{length modifier 'L' results in undefined behavior or no effect with 's' conversion specifier}} 511 } 512 513 void __attribute__((format(strfmon,1,2))) monformat(const char *fmt, ...); 514 void __attribute__((format(strftime,1,0))) dateformat(const char *fmt); 515 516 // Other formats 517 void test_other_formats() { 518 char *str = ""; 519 monformat("", 1); // expected-warning{{format string is empty}} 520 monformat(str); // expected-warning{{format string is not a string literal (potentially insecure)}} 521 dateformat(""); // expected-warning{{format string is empty}} 522 dateformat(str); // no-warning (using strftime non literal is not unsafe) 523 } 524
