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
7 #include <stddef.h> // For wint_t and wchar_t
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}}
21 int vscanf(const char *restrict format, va_list arg);
25 void check_string_literal( FILE* fp, const char* s, char *buf, ... ) {
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}}
47 vscanf(s, ap); // expected-warning {{format string is not a string literal}}
51 "%*d", 1, 1); // no-warning
54 "%*d", 1, 1); // no-warning
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
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, ... ) {
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
81 vscanf(s, ap); // expected-warning {{format string is not a string literal}}
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}}
91 void check_writeback_specifier()
95 printf("%n", b); // expected-warning{{format specifies type 'int *' but the argument has type 'char *'}}
96 printf("%n", &x); // no-warning
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 *'}}
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 *'}}
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 *'}}
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 *'}}
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 *'}}
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 *'}}
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'?}}
127 void check_invalid_specifier(FILE* fp, char *buf)
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 ';'}}
135 void check_null_char_string(char* b)
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'}}
142 void check_empty_format_string(char* buf, ...)
146 vprintf("",ap); // expected-warning {{format string is empty}}
147 sprintf(buf, "", 1); // expected-warning {{format string is empty}}
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
152 sprintf(buf, ""); // no-warning
155 void check_wide_string(char* b, ...)
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}}
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 *'}}
172 void __attribute__((format(printf,1,3))) myprintf(const char*, int blah, ...);
174 void test_myprintf() {
175 myprintf("%d", 17, 18); // okay
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[];
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}}
193 // Test what happens when -Wformat-security only.
194 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
195 #pragma GCC diagnostic warning "-Wformat-security"
197 void test9(char *P) {
199 printf(P); // expected-warning {{format string is not a string literal (potentially insecure)}}
203 void torture(va_list v8) {
204 vprintf ("%*.*d", v8); // no-warning
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\n", x, x); // expected-warning{{invalid conversion specifier 'W'}}
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 '!'}}
242 typedef unsigned char uint8_t;
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'}}
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}}
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]'}}
268 // Verify that we are checking asprintf
269 asprintf(&b, "%d", "asprintf"); // expected-warning{{format specifies type 'int' but the argument has type 'char *'}}
272 void test13(short x) {
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'}}
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'}}
287 // <rdar://problem/7595366>
288 typedef enum { A } int_t;
289 void f0(int_t x) { printf("%d\n", x); }
291 // Unicode test cases. These are possibly specific to Mac OS X. If so, they should
292 // eventually be moved into a separate test.
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
299 // FIXME: This test reports inconsistent results. On Windows, '%C' expects
302 printf("%S", "hello"); // expected-warning{{but the argument has type 'char *'}}
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$d%%", (int) 2); // no-warning
321 // PR 6697 - Handle format strings where the data argument is not adjacent to the format string
322 void myprintf_PR_6697(const char *format, int x, ...) __attribute__((__format__(printf,1, 3)));
323 void test_pr_6697() {
324 myprintf_PR_6697("%s\n", 1, "foo"); // no-warning
325 myprintf_PR_6697("%s\n", 1, (int)0); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}}
326 // FIXME: Not everything should clearly support positional arguments,
327 // but we need a way to identify those cases.
328 myprintf_PR_6697("%1$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$s\n", 1, (int) 0); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}}
334 void rdar8026030(FILE *fp) {
335 fprintf(fp, "\%"); // expected-warning{{incomplete format specifier}}
338 void bug7377_bad_length_mod_usage() {
339 // Bad length modifiers
340 printf("%hhs", "foo"); // expected-warning{{length modifier 'hh' results in undefined behavior or no effect with 's' conversion specifier}}
341 printf("%1$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
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
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}}
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
365 // PR 7981 - handle '%lc' (wint_t)
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
380 // <rdar://problem/8269537> -Wformat-security says NULL is not a string literal
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
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)));
392 void rdar8332221(va_list ap, int *x, long *y) {
393 rdar8332221_vprintf_scanf("%", ap, "%d", x); // expected-warning{{incomplete format specifier}}
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}}
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"
418 printf("%s", 1); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}}
422 // Don't warn about string literals that are PreDefinedExprs, e.g. __func__.
424 printf(__PRETTY_FUNCTION__); // no-warning
425 printf(__func__); // no-warning
428 int printf(const char * restrict, ...) __attribute__((__format__ (__printf__, 1, 2)));
430 void rdar9612060(void) {
431 printf("%s", 2); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}}
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
443 // Test suppression of individual warnings.
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
452 // Make sure warnings are on for next test.
453 #pragma GCC diagnostic warning "-Wformat"
454 #pragma GCC diagnostic warning "-Wformat-security"
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.
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}}
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)}}
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'}}
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}}
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'}}
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)}}
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}}
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}}
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}}
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}}
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'}}
503 const char kFormat13[] = "%.3p"; // expected-note{{format string is defined here}}
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}}
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}}
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}}
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}}
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}}
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}}
527 printf("%a", (long double)0); // expected-warning{{format specifies type 'double' but the argument has type 'long double'}}
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}}
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}}
536 0.0); // expected-warning{{format specifies}}
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}}
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}}
554 void __attribute__((format(strfmon,1,2))) monformat(const char *fmt, ...);
555 void __attribute__((format(strftime,1,0))) dateformat(const char *fmt);
558 void test_other_formats() {
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)
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}}
573 void pr12761(char c) {
574 // This should not warn even with -fno-signed-char.
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)));
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)));
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}}
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 *'}}
600 printf("%n", vip); // No warning.
601 printf("%p", cip); // No warning.
602 printf("%p", cvip); // No warning.
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 *')}}
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)}}
619 #pragma GCC diagnostic warning "-Wformat-nonliteral"