1 // RUN: %clang_cc1 -fsyntax-only -verify -Wformat-nonliteral -isystem %S/Inputs %s 2 // RUN: %clang_cc1 -fsyntax-only -verify -Wformat-nonliteral -isystem %S/Inputs -fno-signed-char %s 3 4 #include <stdarg.h> 5 #include <stddef.h> 6 #define __need_wint_t 7 #include <stddef.h> // For wint_t and wchar_t 8 9 typedef struct _FILE FILE; 10 int fprintf(FILE *, const char *restrict, ...); 11 int printf(const char *restrict, ...); // expected-note{{passing argument to parameter here}} 12 int snprintf(char *restrict, size_t, const char *restrict, ...); 13 int sprintf(char *restrict, const char *restrict, ...); 14 int vasprintf(char **, const char *, va_list); 15 int asprintf(char **, const char *, ...); 16 int vfprintf(FILE *, const char *restrict, va_list); 17 int vprintf(const char *restrict, va_list); 18 int vsnprintf(char *, size_t, const char *, va_list); 19 int vsprintf(char *restrict, const char *restrict, va_list); // expected-note{{passing argument to parameter here}} 20 21 int vscanf(const char *restrict format, va_list arg); 22 23 char * global_fmt; 24 25 void check_string_literal( FILE* fp, const char* s, char *buf, ... ) { 26 27 char * b; 28 va_list ap; 29 va_start(ap,buf); 30 31 printf(s); // expected-warning {{format string is not a string literal}} 32 vprintf(s,ap); // expected-warning {{format string is not a string literal}} 33 fprintf(fp,s); // expected-warning {{format string is not a string literal}} 34 vfprintf(fp,s,ap); // expected-warning {{format string is not a string literal}} 35 asprintf(&b,s); // expected-warning {{format string is not a string lit}} 36 vasprintf(&b,s,ap); // expected-warning {{format string is not a string literal}} 37 sprintf(buf,s); // expected-warning {{format string is not a string literal}} 38 snprintf(buf,2,s); // expected-warning {{format string is not a string lit}} 39 __builtin___sprintf_chk(buf,0,-1,s); // expected-warning {{format string is not a string literal}} 40 __builtin___snprintf_chk(buf,2,0,-1,s); // expected-warning {{format string is not a string lit}} 41 vsprintf(buf,s,ap); // expected-warning {{format string is not a string lit}} 42 vsnprintf(buf,2,s,ap); // expected-warning {{format string is not a string lit}} 43 vsnprintf(buf,2,global_fmt,ap); // expected-warning {{format string is not a string literal}} 44 __builtin___vsnprintf_chk(buf,2,0,-1,s,ap); // expected-warning {{format string is not a string lit}} 45 __builtin___vsnprintf_chk(buf,2,0,-1,global_fmt,ap); // expected-warning {{format string is not a string literal}} 46 47 vscanf(s, ap); // expected-warning {{format string is not a string literal}} 48 49 // rdar://6079877 50 printf("abc" 51 "%*d", 1, 1); // no-warning 52 printf("abc\ 53 def" 54 "%*d", 1, 1); // no-warning 55 56 // <rdar://problem/6079850>, allow 'unsigned' (instead of 'int') to be used for both 57 // the field width and precision. This deviates from C99, but is reasonably safe 58 // and is also accepted by GCC. 59 printf("%*d", (unsigned) 1, 1); // no-warning 60 } 61 62 // When calling a non-variadic format function (vprintf, vscanf, NSLogv, ...), 63 // warn only if the format string argument is a parameter that is not itself 64 // declared as a format string with compatible format. 65 __attribute__((__format__ (__printf__, 2, 4))) 66 void check_string_literal2( FILE* fp, const char* s, char *buf, ... ) { 67 char * b; 68 va_list ap; 69 va_start(ap,buf); 70 71 printf(s); // expected-warning {{format string is not a string literal}} 72 vprintf(s,ap); // no-warning 73 fprintf(fp,s); // expected-warning {{format string is not a string literal}} 74 vfprintf(fp,s,ap); // no-warning 75 asprintf(&b,s); // expected-warning {{format string is not a string lit}} 76 vasprintf(&b,s,ap); // no-warning 77 sprintf(buf,s); // expected-warning {{format string is not a string literal}} 78 snprintf(buf,2,s); // expected-warning {{format string is not a string lit}} 79 __builtin___vsnprintf_chk(buf,2,0,-1,s,ap); // no-warning 80 81 vscanf(s, ap); // expected-warning {{format string is not a string literal}} 82 } 83 84 void check_conditional_literal(const char* s, int i) { 85 printf(i == 1 ? "yes" : "no"); // no-warning 86 printf(i == 0 ? (i == 1 ? "yes" : "no") : "dont know"); // no-warning 87 printf(i == 0 ? (i == 1 ? s : "no") : "dont know"); // expected-warning{{format string is not a string literal}} 88 printf("yes" ?: "no %d", 1); // expected-warning{{data argument not used by format string}} 89 } 90 91 void check_writeback_specifier() 92 { 93 int x; 94 char *b; 95 printf("%n", b); // expected-warning{{format specifies type 'int *' but the argument has type 'char *'}} 96 printf("%n", &x); // no-warning 97 98 printf("%hhn", (signed char*)0); // no-warning 99 printf("%hhn", (char*)0); // no-warning 100 printf("%hhn", (unsigned char*)0); // no-warning 101 printf("%hhn", (int*)0); // expected-warning{{format specifies type 'signed char *' but the argument has type 'int *'}} 102 103 printf("%hn", (short*)0); // no-warning 104 printf("%hn", (unsigned short*)0); // no-warning 105 printf("%hn", (int*)0); // expected-warning{{format specifies type 'short *' but the argument has type 'int *'}} 106 107 printf("%n", (int*)0); // no-warning 108 printf("%n", (unsigned int*)0); // no-warning 109 printf("%n", (char*)0); // expected-warning{{format specifies type 'int *' but the argument has type 'char *'}} 110 111 printf("%ln", (long*)0); // no-warning 112 printf("%ln", (unsigned long*)0); // no-warning 113 printf("%ln", (int*)0); // expected-warning{{format specifies type 'long *' but the argument has type 'int *'}} 114 115 printf("%lln", (long long*)0); // no-warning 116 printf("%lln", (unsigned long long*)0); // no-warning 117 printf("%lln", (int*)0); // expected-warning{{format specifies type 'long long *' but the argument has type 'int *'}} 118 119 printf("%qn", (long long*)0); // no-warning 120 printf("%qn", (unsigned long long*)0); // no-warning 121 printf("%qn", (int*)0); // expected-warning{{format specifies type 'long long *' but the argument has type 'int *'}} 122 123 printf("%Ln", 0); // expected-warning{{length modifier 'L' results in undefined behavior or no effect with 'n' conversion specifier}} 124 // expected-note@-1{{did you mean to use 'll'?}} 125 } 126 127 void check_invalid_specifier(FILE* fp, char *buf) 128 { 129 printf("%s%lb%d","unix",10,20); // expected-warning {{invalid conversion specifier 'b'}} 130 fprintf(fp,"%%%l"); // expected-warning {{incomplete format specifier}} 131 sprintf(buf,"%%%%%ld%d%d", 1, 2, 3); // expected-warning{{format specifies type 'long' but the argument has type 'int'}} 132 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 ';'}} 133 } 134 135 void check_null_char_string(char* b) 136 { 137 printf("\0this is bogus%d",1); // expected-warning {{string contains '\0'}} 138 snprintf(b,10,"%%%%%d\0%d",1,2); // expected-warning {{string contains '\0'}} 139 printf("%\0d",1); // expected-warning {{string contains '\0'}} 140 } 141 142 void check_empty_format_string(char* buf, ...) 143 { 144 va_list ap; 145 va_start(ap,buf); 146 vprintf("",ap); // expected-warning {{format string is empty}} 147 sprintf(buf, "", 1); // expected-warning {{format string is empty}} 148 149 // Don't warn about empty format strings when there are no data arguments. 150 // This can arise from macro expansions and non-standard format string 151 // functions. 152 sprintf(buf, ""); // no-warning 153 } 154 155 void check_wide_string(char* b, ...) 156 { 157 va_list ap; 158 va_start(ap,b); 159 160 printf(L"foo %d",2); // expected-warning {{incompatible pointer types}}, expected-warning {{should not be a wide string}} 161 vsprintf(b,L"bar %d",ap); // expected-warning {{incompatible pointer types}}, expected-warning {{should not be a wide string}} 162 } 163 164 void check_asterisk_precision_width(int x) { 165 printf("%*d"); // expected-warning {{'*' specified field width is missing a matching 'int' argument}} 166 printf("%.*d"); // expected-warning {{'.*' specified field precision is missing a matching 'int' argument}} 167 printf("%*d",12,x); // no-warning 168 printf("%*d","foo",x); // expected-warning {{field width should have type 'int', but argument has type 'char *'}} 169 printf("%.*d","foo",x); // expected-warning {{field precision should have type 'int', but argument has type 'char *'}} 170 } 171 172 void __attribute__((format(printf,1,3))) myprintf(const char*, int blah, ...); 173 174 void test_myprintf() { 175 myprintf("%d", 17, 18); // okay 176 } 177 178 void test_constant_bindings(void) { 179 const char * const s1 = "hello"; 180 const char s2[] = "hello"; 181 const char *s3 = "hello"; 182 char * const s4 = "hello"; 183 extern const char s5[]; 184 185 printf(s1); // no-warning 186 printf(s2); // no-warning 187 printf(s3); // expected-warning{{not a string literal}} 188 printf(s4); // expected-warning{{not a string literal}} 189 printf(s5); // expected-warning{{not a string literal}} 190 } 191 192 193 // Test what happens when -Wformat-security only. 194 #pragma GCC diagnostic ignored "-Wformat-nonliteral" 195 #pragma GCC diagnostic warning "-Wformat-security" 196 197 void test9(char *P) { 198 int x; 199 printf(P); // expected-warning {{format string is not a string literal (potentially insecure)}} 200 printf(P, 42); 201 } 202 203 void torture(va_list v8) { 204 vprintf ("%*.*d", v8); // no-warning 205 206 } 207 208 void test10(int x, float f, int i, long long lli) { 209 printf("%s"); // expected-warning{{more '%' conversions than data arguments}} 210 printf("%@", 12); // expected-warning{{invalid conversion specifier '@'}} 211 printf("\0"); // expected-warning{{format string contains '\0' within the string body}} 212 printf("xs\0"); // expected-warning{{format string contains '\0' within the string body}} 213 printf("%*d\n"); // expected-warning{{'*' specified field width is missing a matching 'int' argument}} 214 printf("%*.*d\n", x); // expected-warning{{'.*' specified field precision is missing a matching 'int' argument}} 215 printf("%*d\n", f, x); // expected-warning{{field width should have type 'int', but argument has type 'double'}} 216 printf("%*.*d\n", x, f, x); // expected-warning{{field precision should have type 'int', but argument has type 'double'}} 217 printf("%**\n"); // expected-warning{{invalid conversion specifier '*'}} 218 printf("%d%d\n", x); // expected-warning{{more '%' conversions than data arguments}} 219 printf("%d\n", x, x); // expected-warning{{data argument not used by format string}} 220 printf("%W%d%Z\n", x, x, x); // expected-warning{{invalid conversion specifier 'W'}} expected-warning{{invalid conversion specifier 'Z'}} 221 printf("%"); // expected-warning{{incomplete format specifier}} 222 printf("%.d", x); // no-warning 223 printf("%.", x); // expected-warning{{incomplete format specifier}} 224 printf("%f", 4); // expected-warning{{format specifies type 'double' but the argument has type 'int'}} 225 printf("%qd", lli); // no-warning 226 printf("%qd", x); // expected-warning{{format specifies type 'long long' but the argument has type 'int'}} 227 printf("%qp", (void *)0); // expected-warning{{length modifier 'q' results in undefined behavior or no effect with 'p' conversion specifier}} 228 printf("hhX %hhX", (unsigned char)10); // no-warning 229 printf("llX %llX", (long long) 10); // no-warning 230 // This is fine, because there is an implicit conversion to an int. 231 printf("%d", (unsigned char) 10); // no-warning 232 printf("%d", (long long) 10); // expected-warning{{format specifies type 'int' but the argument has type 'long long'}} 233 printf("%Lf\n", (long double) 1.0); // no-warning 234 printf("%f\n", (long double) 1.0); // expected-warning{{format specifies type 'double' but the argument has type 'long double'}} 235 // The man page says that a zero precision is okay. 236 printf("%.0Lf", (long double) 1.0); // no-warning 237 printf("%c\n", "x"); // expected-warning{{format specifies type 'int' but the argument has type 'char *'}} 238 printf("%c\n", 1.23); // expected-warning{{format specifies type 'int' but the argument has type 'double'}} 239 printf("Format %d, is %! %f", 1, 2, 4.4); // expected-warning{{invalid conversion specifier '!'}} 240 } 241 242 typedef unsigned char uint8_t; 243 244 void should_understand_small_integers() { 245 printf("%hhu", (short) 10); // expected-warning{{format specifies type 'unsigned char' but the argument has type 'short'}} 246 printf("%hu\n", (unsigned char) 1); // expected-warning{{format specifies type 'unsigned short' but the argument has type 'unsigned char'}} 247 printf("%hu\n", (uint8_t)1); // expected-warning{{format specifies type 'unsigned short' but the argument has type 'uint8_t'}} 248 } 249 250 void test11(void *p, char *s) { 251 printf("%p", p); // no-warning 252 printf("%p", 123); // expected-warning{{format specifies type 'void *' but the argument has type 'int'}} 253 printf("%.4p", p); // expected-warning{{precision used with 'p' conversion specifier, resulting in undefined behavior}} 254 printf("%+p", p); // expected-warning{{flag '+' results in undefined behavior with 'p' conversion specifier}} 255 printf("% p", p); // expected-warning{{flag ' ' results in undefined behavior with 'p' conversion specifier}} 256 printf("%0p", p); // expected-warning{{flag '0' results in undefined behavior with 'p' conversion specifier}} 257 printf("%s", s); // no-warning 258 printf("%+s", p); // expected-warning{{flag '+' results in undefined behavior with 's' conversion specifier}} 259 printf("% s", p); // expected-warning{{flag ' ' results in undefined behavior with 's' conversion specifier}} 260 printf("%0s", p); // expected-warning{{flag '0' results in undefined behavior with 's' conversion specifier}} 261 } 262 263 void test12(char *b) { 264 unsigned char buf[4]; 265 printf ("%.4s\n", buf); // no-warning 266 printf ("%.4s\n", &buf); // expected-warning{{format specifies type 'char *' but the argument has type 'unsigned char (*)[4]'}} 267 268 // Verify that we are checking asprintf 269 asprintf(&b, "%d", "asprintf"); // expected-warning{{format specifies type 'int' but the argument has type 'char *'}} 270 } 271 272 void test13(short x) { 273 char bel = 007; 274 printf("bel: '0%hhd'\n", bel); // no-warning 275 printf("x: '0%hhd'\n", x); // expected-warning {{format specifies type 'char' but the argument has type 'short'}} 276 } 277 278 typedef struct __aslclient *aslclient; 279 typedef struct __aslmsg *aslmsg; 280 int asl_log(aslclient asl, aslmsg msg, int level, const char *format, ...) __attribute__((__format__ (__printf__, 4, 5))); 281 void test_asl(aslclient asl) { 282 // Test case from <rdar://problem/7341605>. 283 asl_log(asl, 0, 3, "Error: %m"); // no-warning 284 asl_log(asl, 0, 3, "Error: %W"); // expected-warning{{invalid conversion specifier 'W'}} 285 } 286 287 // <rdar://problem/7595366> 288 typedef enum { A } int_t; 289 void f0(int_t x) { printf("%d\n", x); } 290 291 // Unicode test cases. These are possibly specific to Mac OS X. If so, they should 292 // eventually be moved into a separate test. 293 294 void test_unicode_conversions(wchar_t *s) { 295 printf("%S", s); // no-warning 296 printf("%s", s); // expected-warning{{format specifies type 'char *' but the argument has type 'wchar_t *'}} 297 printf("%C", s[0]); // no-warning 298 printf("%c", s[0]); 299 // FIXME: This test reports inconsistent results. On Windows, '%C' expects 300 // 'unsigned short'. 301 // printf("%C", 10); 302 printf("%S", "hello"); // expected-warning{{but the argument has type 'char *'}} 303 } 304 305 // Mac OS X supports positional arguments in format strings. 306 // This is an IEEE extension (IEEE Std 1003.1). 307 // FIXME: This is probably not portable everywhere. 308 void test_positional_arguments() { 309 printf("%0$", (int)2); // expected-warning{{position arguments in format strings start counting at 1 (not 0)}} 310 printf("%1$*0$d", (int) 2); // expected-warning{{position arguments in format strings start counting at 1 (not 0)}} 311 printf("%1$d", (int) 2); // no-warning 312 printf("%1$d", (int) 2, 2); // expected-warning{{data argument not used by format string}} 313 printf("%1$d%1$f", (int) 2); // expected-warning{{format specifies type 'double' but the argument has type 'int'}} 314 printf("%1$2.2d", (int) 2); // no-warning 315 printf("%2$*1$.2d", (int) 2, (int) 3); // no-warning 316 printf("%2$*8$d", (int) 2, (int) 3); // expected-warning{{specified field width is missing a matching 'int' argument}} 317 printf("%%%1$d", (int) 2); // no-warning 318 printf("%1$d%%", (int) 2); // no-warning 319 } 320 321 // PR 6697 - Handle format strings where the data argument is not adjacent to the format string 322 void myprintf_PR_6697(const char *format, int x, ...) __attribute__((__format__(printf,1, 3))); 323 void test_pr_6697() { 324 myprintf_PR_6697("%s\n", 1, "foo"); // no-warning 325 myprintf_PR_6697("%s\n", 1, (int)0); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 326 // FIXME: Not everything should clearly support positional arguments, 327 // but we need a way to identify those cases. 328 myprintf_PR_6697("%1$s\n", 1, "foo"); // no-warning 329 myprintf_PR_6697("%2$s\n", 1, "foo"); // expected-warning{{data argument position '2' exceeds the number of data arguments (1)}} 330 myprintf_PR_6697("%18$s\n", 1, "foo"); // expected-warning{{data argument position '18' exceeds the number of data arguments (1)}} 331 myprintf_PR_6697("%1$s\n", 1, (int) 0); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 332 } 333 334 void rdar8026030(FILE *fp) { 335 fprintf(fp, "\%"); // expected-warning{{incomplete format specifier}} 336 } 337 338 void bug7377_bad_length_mod_usage() { 339 // Bad length modifiers 340 printf("%hhs", "foo"); // expected-warning{{length modifier 'hh' results in undefined behavior or no effect with 's' conversion specifier}} 341 printf("%1$zp", (void *)0); // expected-warning{{length modifier 'z' results in undefined behavior or no effect with 'p' conversion specifier}} 342 printf("%ls", L"foo"); // no-warning 343 printf("%#.2Lf", (long double)1.234); // no-warning 344 345 // Bad flag usage 346 printf("%#p", (void *) 0); // expected-warning{{flag '#' results in undefined behavior with 'p' conversion specifier}} 347 printf("%0d", -1); // no-warning 348 printf("%#n", (int *) 0); // expected-warning{{flag '#' results in undefined behavior with 'n' conversion specifier}} 349 printf("%-n", (int *) 0); // expected-warning{{flag '-' results in undefined behavior with 'n' conversion specifier}} 350 printf("%-p", (void *) 0); // no-warning 351 352 // Bad optional amount use 353 printf("%.2c", 'a'); // expected-warning{{precision used with 'c' conversion specifier, resulting in undefined behavior}} 354 printf("%1n", (int *) 0); // expected-warning{{field width used with 'n' conversion specifier, resulting in undefined behavior}} 355 printf("%.9n", (int *) 0); // expected-warning{{precision used with 'n' conversion specifier, resulting in undefined behavior}} 356 357 // Ignored flags 358 printf("% +f", 1.23); // expected-warning{{flag ' ' is ignored when flag '+' is present}} 359 printf("%+ f", 1.23); // expected-warning{{flag ' ' is ignored when flag '+' is present}} 360 printf("%0-f", 1.23); // expected-warning{{flag '0' is ignored when flag '-' is present}} 361 printf("%-0f", 1.23); // expected-warning{{flag '0' is ignored when flag '-' is present}} 362 printf("%-+f", 1.23); // no-warning 363 } 364 365 // PR 7981 - handle '%lc' (wint_t) 366 367 void pr7981(wint_t c, wchar_t c2) { 368 printf("%lc", c); // no-warning 369 printf("%lc", 1.0); // expected-warning{{the argument has type 'double'}} 370 printf("%lc", (char) 1); // no-warning 371 printf("%lc", &c); // expected-warning{{the argument has type 'wint_t *'}} 372 // If wint_t and wchar_t are the same width and wint_t is signed where 373 // wchar_t is unsigned, an implicit conversion isn't possible. 374 #if defined(__WINT_UNSIGNED__) || !defined(__WCHAR_UNSIGNED__) || \ 375 __WINT_WIDTH__ > __WCHAR_WIDTH__ 376 printf("%lc", c2); // no-warning 377 #endif 378 } 379 380 // <rdar://problem/8269537> -Wformat-security says NULL is not a string literal 381 void rdar8269537() { 382 // This is likely to crash in most cases, but -Wformat-nonliteral technically 383 // doesn't warn in this case. 384 printf(0); // no-warning 385 } 386 387 // Handle functions with multiple format attributes. 388 extern void rdar8332221_vprintf_scanf(const char *, va_list, const char *, ...) 389 __attribute__((__format__(__printf__, 1, 0))) 390 __attribute__((__format__(__scanf__, 3, 4))); 391 392 void rdar8332221(va_list ap, int *x, long *y) { 393 rdar8332221_vprintf_scanf("%", ap, "%d", x); // expected-warning{{incomplete format specifier}} 394 } 395 396 // PR8641 397 void pr8641() { 398 printf("%#x\n", 10); 399 printf("%#X\n", 10); 400 } 401 402 void posix_extensions() { 403 // Test %'d, "thousands grouping". 404 // <rdar://problem/8816343> 405 printf("%'d\n", 123456789); // no-warning 406 printf("%'i\n", 123456789); // no-warning 407 printf("%'f\n", (float) 1.0); // no-warning 408 printf("%'p\n", (void*) 0); // expected-warning{{results in undefined behavior with 'p' conversion specifier}} 409 } 410 411 // PR8486 412 // 413 // Test what happens when -Wformat is on, but -Wformat-security is off. 414 #pragma GCC diagnostic warning "-Wformat" 415 #pragma GCC diagnostic ignored "-Wformat-security" 416 417 void pr8486() { 418 printf("%s", 1); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 419 } 420 421 // PR9314 422 // Don't warn about string literals that are PreDefinedExprs, e.g. __func__. 423 void pr9314() { 424 printf(__PRETTY_FUNCTION__); // no-warning 425 printf(__func__); // no-warning 426 } 427 428 int printf(const char * restrict, ...) __attribute__((__format__ (__printf__, 1, 2))); 429 430 void rdar9612060(void) { 431 printf("%s", 2); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 432 } 433 434 void check_char(unsigned char x, signed char y) { 435 printf("%c", y); // no-warning 436 printf("%hhu", x); // no-warning 437 printf("%hhi", y); // no-warning 438 printf("%hhi", x); // no-warning 439 printf("%c", x); // no-warning 440 printf("%hhu", y); // no-warning 441 } 442 443 // Test suppression of individual warnings. 444 445 void test_suppress_invalid_specifier() { 446 #pragma clang diagnostic push 447 #pragma clang diagnostic ignored "-Wformat-invalid-specifier" 448 printf("%@", 12); // no-warning 449 #pragma clang diagnostic pop 450 } 451 452 // Make sure warnings are on for next test. 453 #pragma GCC diagnostic warning "-Wformat" 454 #pragma GCC diagnostic warning "-Wformat-security" 455 456 // Test that the printf call site is where the warning is attached. If the 457 // format string is somewhere else, point to it in a note. 458 void pr9751() { 459 const char kFormat1[] = "%d %d \n"; // expected-note{{format string is defined here}}} 460 printf(kFormat1, 0); // expected-warning{{more '%' conversions than data arguments}} 461 printf("%d %s\n", 0); // expected-warning{{more '%' conversions than data arguments}} 462 463 const char kFormat2[] = "%18$s\n"; // expected-note{{format string is defined here}} 464 printf(kFormat2, 1, "foo"); // expected-warning{{data argument position '18' exceeds the number of data arguments (2)}} 465 printf("%18$s\n", 1, "foo"); // expected-warning{{data argument position '18' exceeds the number of data arguments (2)}} 466 467 const char kFormat4[] = "%y"; // expected-note{{format string is defined here}} 468 printf(kFormat4, 5); // expected-warning{{invalid conversion specifier 'y'}} 469 printf("%y", 5); // expected-warning{{invalid conversion specifier 'y'}} 470 471 const char kFormat5[] = "%."; // expected-note{{format string is defined here}} 472 printf(kFormat5, 5); // expected-warning{{incomplete format specifier}} 473 printf("%.", 5); // expected-warning{{incomplete format specifier}} 474 475 const char kFormat6[] = "%s"; // expected-note{{format string is defined here}} 476 printf(kFormat6, 5); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 477 printf("%s", 5); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}} 478 479 const char kFormat7[] = "%0$"; // expected-note{{format string is defined here}} 480 printf(kFormat7, 5); // expected-warning{{position arguments in format strings start counting at 1 (not 0)}} 481 printf("%0$", 5); // expected-warning{{position arguments in format strings start counting at 1 (not 0)}} 482 483 const char kFormat8[] = "%1$d %d"; // expected-note{{format string is defined here}} 484 printf(kFormat8, 4, 4); // expected-warning{{cannot mix positional and non-positional arguments in format string}} 485 printf("%1$d %d", 4, 4); // expected-warning{{cannot mix positional and non-positional arguments in format string}} 486 487 const char kFormat9[] = ""; // expected-note{{format string is defined here}} 488 printf(kFormat9, 4, 4); // expected-warning{{format string is empty}} 489 printf("", 4, 4); // expected-warning{{format string is empty}} 490 491 const char kFormat10[] = "\0%d"; // expected-note{{format string is defined here}} 492 printf(kFormat10, 4); // expected-warning{{format string contains '\0' within the string body}} 493 printf("\0%d", 4); // expected-warning{{format string contains '\0' within the string body}} 494 495 const char kFormat11[] = "%*d"; // expected-note{{format string is defined here}} 496 printf(kFormat11); // expected-warning{{'*' specified field width is missing a matching 'int' argument}} 497 printf("%*d"); // expected-warning{{'*' specified field width is missing a matching 'int' argument}} 498 499 const char kFormat12[] = "%*d"; // expected-note{{format string is defined here}} 500 printf(kFormat12, 4.4); // expected-warning{{field width should have type 'int', but argument has type 'double'}} 501 printf("%*d", 4.4); // expected-warning{{field width should have type 'int', but argument has type 'double'}} 502 503 const char kFormat13[] = "%.3p"; // expected-note{{format string is defined here}} 504 void *p; 505 printf(kFormat13, p); // expected-warning{{precision used with 'p' conversion specifier, resulting in undefined behavior}} 506 printf("%.3p", p); // expected-warning{{precision used with 'p' conversion specifier, resulting in undefined behavior}} 507 508 const char kFormat14[] = "%0s"; // expected-note{{format string is defined here}} 509 printf(kFormat14, "a"); // expected-warning{{flag '0' results in undefined behavior with 's' conversion specifier}} 510 printf("%0s", "a"); // expected-warning{{flag '0' results in undefined behavior with 's' conversion specifier}} 511 512 const char kFormat15[] = "%hhs"; // expected-note{{format string is defined here}} 513 printf(kFormat15, "a"); // expected-warning{{length modifier 'hh' results in undefined behavior or no effect with 's' conversion specifier}} 514 printf("%hhs", "a"); // expected-warning{{length modifier 'hh' results in undefined behavior or no effect with 's' conversion specifier}} 515 516 const char kFormat16[] = "%-0d"; // expected-note{{format string is defined here}} 517 printf(kFormat16, 5); // expected-warning{{flag '0' is ignored when flag '-' is present}} 518 printf("%-0d", 5); // expected-warning{{flag '0' is ignored when flag '-' is present}} 519 520 // Make sure that the "format string is defined here" note is not emitted 521 // when the original string is within the argument expression. 522 printf(1 ? "yes %d" : "no %d"); // expected-warning 2{{more '%' conversions than data arguments}} 523 524 const char kFormat17[] = "%hu"; // expected-note{{format string is defined here}}} 525 printf(kFormat17, (int[]){0}); // expected-warning{{format specifies type 'unsigned short' but the argument}} 526 527 printf("%a", (long double)0); // expected-warning{{format specifies type 'double' but the argument has type 'long double'}} 528 529 // Test braced char[] initializers. 530 const char kFormat18[] = { "%lld" }; // expected-note{{format string is defined here}} 531 printf(kFormat18, 0); // expected-warning{{format specifies type}} 532 533 // Make sure we point at the offending argument rather than the format string. 534 const char kFormat19[] = "%d"; // expected-note{{format string is defined here}} 535 printf(kFormat19, 536 0.0); // expected-warning{{format specifies}} 537 } 538 539 void pr18905() { 540 const char s1[] = "s\0%s"; // expected-note{{format string is defined here}} 541 const char s2[1] = "s"; // expected-note{{format string is defined here}} 542 const char s3[2] = "s\0%s"; // expected-warning{{initializer-string for char array is too long}} 543 const char s4[10] = "s"; 544 const char s5[0] = "%s"; // expected-warning{{initializer-string for char array is too long}} 545 // expected-note@-1{{format string is defined here}} 546 547 printf(s1); // expected-warning{{format string contains '\0' within the string body}} 548 printf(s2); // expected-warning{{format string is not null-terminated}} 549 printf(s3); // no-warning 550 printf(s4); // no-warning 551 printf(s5); // expected-warning{{format string is not null-terminated}} 552 } 553 554 void __attribute__((format(strfmon,1,2))) monformat(const char *fmt, ...); 555 void __attribute__((format(strftime,1,0))) dateformat(const char *fmt); 556 557 // Other formats 558 void test_other_formats() { 559 char *str = ""; 560 monformat("", 1); // expected-warning{{format string is empty}} 561 monformat(str); // expected-warning{{format string is not a string literal (potentially insecure)}} 562 dateformat(""); // expected-warning{{format string is empty}} 563 dateformat(str); // no-warning (using strftime non-literal is not unsafe) 564 } 565 566 // Do not warn about unused arguments coming from system headers. 567 // <rdar://problem/11317765> 568 #include <format-unused-system-args.h> 569 void test_unused_system_args(int x) { 570 PRINT1("%d\n", x); // no-warning{{extra argument is system header is OK}} 571 } 572 573 void pr12761(char c) { 574 // This should not warn even with -fno-signed-char. 575 printf("%hhx", c); 576 } 577 578 579 // Test that we correctly merge the format in both orders. 580 extern void test14_foo(const char *, const char *, ...) 581 __attribute__((__format__(__printf__, 1, 3))); 582 extern void test14_foo(const char *, const char *, ...) 583 __attribute__((__format__(__scanf__, 2, 3))); 584 585 extern void test14_bar(const char *, const char *, ...) 586 __attribute__((__format__(__scanf__, 2, 3))); 587 extern void test14_bar(const char *, const char *, ...) 588 __attribute__((__format__(__printf__, 1, 3))); 589 590 void test14_zed(int *p) { 591 test14_foo("%", "%d", p); // expected-warning{{incomplete format specifier}} 592 test14_bar("%", "%d", p); // expected-warning{{incomplete format specifier}} 593 } 594 595 void test_qualifiers(volatile int *vip, const int *cip, 596 const volatile int *cvip) { 597 printf("%n", cip); // expected-warning{{format specifies type 'int *' but the argument has type 'const int *'}} 598 printf("%n", cvip); // expected-warning{{format specifies type 'int *' but the argument has type 'const volatile int *'}} 599 600 printf("%n", vip); // No warning. 601 printf("%p", cip); // No warning. 602 printf("%p", cvip); // No warning. 603 604 605 typedef int* ip_t; 606 typedef const int* cip_t; 607 printf("%n", (ip_t)0); // No warning. 608 printf("%n", (cip_t)0); // expected-warning{{format specifies type 'int *' but the argument has type 'cip_t' (aka 'const int *')}} 609 } 610 611 #pragma GCC diagnostic ignored "-Wformat-nonliteral" 612 #pragma GCC diagnostic warning "-Wformat-security" 613 // <rdar://problem/14178260> 614 extern void test_format_security_extra_args(const char*, int, ...) 615 __attribute__((__format__(__printf__, 1, 3))); 616 void test_format_security_pos(char* string) { 617 test_format_security_extra_args(string, 5); // expected-warning {{format string is not a string literal (potentially insecure)}} 618 } 619 #pragma GCC diagnostic warning "-Wformat-nonliteral" 620
