clang/test/Sema/format-strings-scanf.c

   1 // RUN: %clang_cc1 -std=c11 -fsyntax-only -verify -Wformat-nonliteral %s
   2
   3 // Test that -Wformat=0 works:
   4 // RUN: %clang_cc1 -std=c11 -fsyntax-only -Werror -Wformat=0 %s
   5
   6 #include <stdarg.h>
   7 typedef __SIZE_TYPE__ size_t;
   8 #define __SSIZE_TYPE__                                                         \
   9   __typeof__(_Generic((__SIZE_TYPE__)0,                                        \
  10                       unsigned long long int : (long long int)0,               \
  11                       unsigned long int : (long int)0,                         \
  12                       unsigned int : (int)0,                                   \
  13                       unsigned short : (short)0,                               \
  14                       unsigned char : (signed char)0))
  15 typedef __SSIZE_TYPE__ ssize_t;
  16
  17 typedef __PTRDIFF_TYPE__ ptrdiff_t;
  18 #define __UNSIGNED_PTRDIFF_TYPE__                                              \
  19   __typeof__(_Generic((__PTRDIFF_TYPE__)0,                                     \
  20                       long long int : (unsigned long long int)0,               \
  21                       long int : (unsigned long int)0,                         \
  22                       int : (unsigned int)0,                                   \
  23                       short : (unsigned short)0,                               \
  24                       signed char : (unsigned char)0))
  25
  26 typedef struct _FILE FILE;
  27 typedef __WCHAR_TYPE__ wchar_t;
  28
  29 int fscanf(FILE * restrict, const char * restrict, ...) ;
  30 int scanf(const char * restrict, ...) ;
  31 int sscanf(const char * restrict, const char * restrict, ...) ;
  32 int my_scanf(const char * restrict, ...) __attribute__((__format__(__scanf__, 1, 2)));
  33
  34 int vscanf(const char * restrict, va_list);
  35 int vfscanf(FILE * restrict, const char * restrict, va_list);
  36 int vsscanf(const char * restrict, const char * restrict, va_list);
  37
  38 void test(const char *s, int *i) {
  39   scanf(s, i); // expected-warning{{format string is not a string literal}}
  40   scanf("%0d", i); // expected-warning{{zero field width in scanf format string is unused}}
  41   scanf("%00d", i); // expected-warning{{zero field width in scanf format string is unused}}
  42   scanf("%d%[asdfasdfd", i, s); // expected-warning{{no closing ']' for '%[' in scanf format string}}
  43   scanf("%B", i); // expected-warning{{invalid conversion specifier 'B'}}
  44
  45   unsigned short s_x;
  46   scanf ("%" "hu" "\n", &s_x); // no-warning
  47   scanf("%hb", &s_x);
  48   scanf("%y", i); // expected-warning{{invalid conversion specifier 'y'}}
  49   scanf("%%"); // no-warning
  50   scanf("%%%1$d", i); // no-warning
  51   scanf("%1$d%%", i); // no-warning
  52   scanf("%d", i, i); // expected-warning{{data argument not used by format string}}
  53   scanf("%*d", i); // // expected-warning{{data argument not used by format string}}
  54   scanf("%*d", i); // // expected-warning{{data argument not used by format string}}
  55   scanf("%*d%1$d", i); // no-warning
  56
  57   scanf("%s", (char*)0); // no-warning
  58   scanf("%s", (volatile char*)0); // no-warning
  59   scanf("%s", (signed char*)0); // no-warning
  60   scanf("%s", (unsigned char*)0); // no-warning
  61   scanf("%hhu", (signed char*)0); // no-warning
  62   scanf("%hhb", (signed char*)0); // no-warning
  63 }
  64
  65 void bad_length_modifiers(char *s, void *p, wchar_t *ws, long double *ld) {
  66   scanf("%hhs", "foo"); // expected-warning{{length modifier 'hh' results in undefined behavior or no effect with 's' conversion specifier}}
  67   scanf("%1$zp", &p); // expected-warning{{length modifier 'z' results in undefined behavior or no effect with 'p' conversion specifier}}
  68   scanf("%ls", ws); // no-warning
  69   scanf("%#.2Lf", ld); // expected-warning{{invalid conversion specifier '#'}}
  70 }
  71
  72 void missing_argument_with_length_modifier() {
  73   char buf[30];
  74   scanf("%s:%900s", buf); // expected-warning{{more '%' conversions than data arguments}}
  75 }
  76
  77 // Test that the scanf call site is where the warning is attached.  If the
  78 // format string is somewhere else, point to it in a note.
  79 void pr9751(void) {
  80   int *i;
  81   char str[100];
  82   const char kFormat1[] = "%00d"; // expected-note{{format string is defined here}}}
  83   scanf(kFormat1, i); // expected-warning{{zero field width in scanf format string is unused}}
  84   scanf("%00d", i); // expected-warning{{zero field width in scanf format string is unused}}
  85   const char kFormat2[] = "%["; // expected-note{{format string is defined here}}}
  86   scanf(kFormat2, str); // expected-warning{{no closing ']' for '%[' in scanf format string}}
  87   scanf("%[", str); // expected-warning{{no closing ']' for '%[' in scanf format string}}
  88   const char kFormat3[] = "%hu"; // expected-note{{format string is defined here}}}
  89   scanf(kFormat3, &i); // expected-warning {{format specifies type 'unsigned short *' but the argument}}
  90   const char kFormat4[] = "%lp"; // expected-note{{format string is defined here}}}
  91   scanf(kFormat4, &i); // expected-warning {{length modifier 'l' results in undefined behavior or no effect with 'p' conversion specifier}}
  92 }
  93
  94 void test_variants(int *i, const char *s, ...) {
  95   FILE *f = 0;
  96   char buf[100];
  97
  98   fscanf(f, "%ld", i); // expected-warning{{format specifies type 'long *' but the argument has type 'int *'}}
  99   sscanf(buf, "%ld", i); // expected-warning{{format specifies type 'long *' but the argument has type 'int *'}}
 100   my_scanf("%ld", i); // expected-warning{{format specifies type 'long *' but the argument has type 'int *'}}
 101
 102   va_list ap;
 103   va_start(ap, s);
 104
 105   vscanf("%[abc", ap); // expected-warning{{no closing ']' for '%[' in scanf format string}}
 106   vfscanf(f, "%[abc", ap); // expected-warning{{no closing ']' for '%[' in scanf format string}}
 107   vsscanf(buf, "%[abc", ap); // expected-warning{{no closing ']' for '%[' in scanf format string}}
 108 }
 109
 110 void test_scanlist(int *ip, char *sp, wchar_t *ls) {
 111   scanf("%[abc]", ip); // expected-warning{{format specifies type 'char *' but the argument has type 'int *'}}
 112   scanf("%h[abc]", sp); // expected-warning{{length modifier 'h' results in undefined behavior or no effect with '[' conversion specifier}}
 113   scanf("%l[xyx]", ls); // no-warning
 114   scanf("%ll[xyx]", ls); // expected-warning {{length modifier 'll' results in undefined behavior or no effect with '[' conversion specifier}}
 115
 116   // PR19559
 117   scanf("%[]% ]", sp); // no-warning
 118   scanf("%[^]% ]", sp); // no-warning
 119   scanf("%[a^]% ]", sp); // expected-warning {{invalid conversion specifier ' '}}
 120 }
 121
 122 void test_alloc_extension(char **sp, wchar_t **lsp, float *fp) {
 123   /* Make sure "%a" gets parsed as a conversion specifier for float,
 124    * even when followed by an 's', 'S' or '[', which would cause it to be
 125    * parsed as a length modifier in C90. */
 126   scanf("%as", sp); // expected-warning{{format specifies type 'float *' but the argument has type 'char **'}}
 127   scanf("%aS", lsp); // expected-warning{{format specifies type 'float *' but the argument has type 'wchar_t **'}}
 128   scanf("%a[bcd]", sp); // expected-warning{{format specifies type 'float *' but the argument has type 'char **'}}
 129
 130   // Test that the 'm' length modifier is only allowed with s, S, c, C or [.
 131   // TODO: Warn that 'm' is an extension.
 132   scanf("%ms", sp); // No warning.
 133   scanf("%mS", lsp); // No warning.
 134   scanf("%mc", sp); // No warning.
 135   scanf("%mC", lsp); // No warning.
 136   scanf("%m[abc]", sp); // No warning.
 137   scanf("%md", sp); // expected-warning{{length modifier 'm' results in undefined behavior or no effect with 'd' conversion specifier}}
 138
 139   // Test argument type check for the 'm' length modifier.
 140   scanf("%ms", fp); // expected-warning{{format specifies type 'char **' but the argument has type 'float *'}}
 141   scanf("%mS", fp); // expected-warning-re{{format specifies type 'wchar_t **' (aka '{{[^']+}}') but the argument has type 'float *'}}
 142   scanf("%mc", fp); // expected-warning{{format specifies type 'char **' but the argument has type 'float *'}}
 143   scanf("%mC", fp); // expected-warning-re{{format specifies type 'wchar_t **' (aka '{{[^']+}}') but the argument has type 'float *'}}
 144   scanf("%m[abc]", fp); // expected-warning{{format specifies type 'char **' but the argument has type 'float *'}}
 145 }
 146
 147 void test_quad(int *x, long long *llx) {
 148   scanf("%qd", x); // expected-warning{{format specifies type 'long long *' but the argument has type 'int *'}}
 149   scanf("%qd", llx); // no-warning
 150 }
 151
 152 void test_writeback(int *x) {
 153   scanf("%n", (void*)0); // expected-warning{{format specifies type 'int *' but the argument has type 'void *'}}
 154   scanf("%n %c", x, x); // expected-warning{{format specifies type 'char *' but the argument has type 'int *'}}
 155
 156   scanf("%hhn", (signed char*)0); // no-warning
 157   scanf("%hhn", (char*)0); // no-warning
 158   scanf("%hhn", (unsigned char*)0); // no-warning
 159   scanf("%hhn", (int*)0); // expected-warning{{format specifies type 'signed char *' but the argument has type 'int *'}}
 160
 161   scanf("%hn", (short*)0); // no-warning
 162   scanf("%hn", (unsigned short*)0); // no-warning
 163   scanf("%hn", (int*)0); // expected-warning{{format specifies type 'short *' but the argument has type 'int *'}}
 164
 165   scanf("%n", (int*)0); // no-warning
 166   scanf("%n", (unsigned int*)0); // no-warning
 167   scanf("%n", (char*)0); // expected-warning{{format specifies type 'int *' but the argument has type 'char *'}}
 168
 169   scanf("%ln", (long*)0); // no-warning
 170   scanf("%ln", (unsigned long*)0); // no-warning
 171   scanf("%ln", (int*)0); // expected-warning{{format specifies type 'long *' but the argument has type 'int *'}}
 172
 173   scanf("%lln", (long long*)0); // no-warning
 174   scanf("%lln", (unsigned long long*)0); // no-warning
 175   scanf("%lln", (int*)0); // expected-warning{{format specifies type 'long long *' but the argument has type 'int *'}}
 176
 177   scanf("%qn", (long long*)0); // no-warning
 178   scanf("%qn", (unsigned long long*)0); // no-warning
 179   scanf("%qn", (int*)0); // expected-warning{{format specifies type 'long long *' but the argument has type 'int *'}}
 180
 181 }
 182
 183 void test_qualifiers(const int *cip, volatile int* vip,
 184                      const char *ccp, volatile char* vcp,
 185                      const volatile int *cvip) {
 186   scanf("%d", cip); // expected-warning{{format specifies type 'int *' but the argument has type 'const int *'}}
 187   scanf("%n", cip); // expected-warning{{format specifies type 'int *' but the argument has type 'const int *'}}
 188   scanf("%s", ccp); // expected-warning{{format specifies type 'char *' but the argument has type 'const char *'}}
 189   scanf("%d", cvip); // expected-warning{{format specifies type 'int *' but the argument has type 'const volatile int *'}}
 190
 191   scanf("%d", vip); // No warning.
 192   scanf("%n", vip); // No warning.
 193   scanf("%c", vcp); // No warning.
 194
 195   typedef int* ip_t;
 196   typedef const int* cip_t;
 197   scanf("%d", (ip_t)0); // No warning.
 198   scanf("%d", (cip_t)0); // expected-warning{{format specifies type 'int *' but the argument has type 'cip_t' (aka 'const int *')}}
 199 }
 200
 201 void test_size_types(void) {
 202   size_t s = 0;
 203   scanf("%zu", &s); // No warning.
 204   scanf("%zb", &s);
 205
 206   double d1 = 0.;
 207   scanf("%zu", &d1); // expected-warning-re{{format specifies type 'size_t *' (aka '{{.+}}') but the argument has type 'double *'}}
 208
 209   ssize_t ss = 0;
 210   scanf("%zd", &s); // No warning.
 211
 212   double d2 = 0.;
 213   scanf("%zd", &d2); // expected-warning-re{{format specifies type 'ssize_t *' (aka '{{.+}}') but the argument has type 'double *'}}
 214
 215   ssize_t sn = 0;
 216   scanf("%zn", &sn); // No warning.
 217
 218   double d3 = 0.;
 219   scanf("%zn", &d3); // expected-warning-re{{format specifies type 'ssize_t *' (aka '{{.+}}') but the argument has type 'double *'}}
 220 }
 221
 222 void test_ptrdiff_t_types(void) {
 223   __UNSIGNED_PTRDIFF_TYPE__ p1 = 0;
 224   scanf("%tu", &p1); // No warning.
 225   scanf("%tb", &p1);
 226
 227   double d1 = 0.;
 228   scanf("%tu", &d1); // expected-warning-re{{format specifies type 'unsigned ptrdiff_t *' (aka '{{.+}}') but the argument has type 'double *'}}
 229
 230   ptrdiff_t p2 = 0;
 231   scanf("%td", &p2); // No warning.
 232
 233   double d2 = 0.;
 234   scanf("%td", &d2); // expected-warning-re{{format specifies type 'ptrdiff_t *' (aka '{{.+}}') but the argument has type 'double *'}}
 235
 236   ptrdiff_t p3 = 0;
 237   scanf("%tn", &p3); // No warning.
 238
 239   double d3 = 0.;
 240   scanf("%tn", &d3); // expected-warning-re{{format specifies type 'ptrdiff_t *' (aka '{{.+}}') but the argument has type 'double *'}}
 241 }
 242
 243 void check_conditional_literal(char *s, int *i) {
 244   scanf(0 ? "%s" : "%d", i); // no warning
 245   scanf(1 ? "%s" : "%d", i); // expected-warning{{format specifies type 'char *'}}
 246   scanf(0 ? "%d %d" : "%d", i); // no warning
 247   scanf(1 ? "%d %d" : "%d", i); // expected-warning{{more '%' conversions than data arguments}}
 248   scanf(0 ? "%d %d" : "%d", i, s); // expected-warning{{data argument not used}}
 249   scanf(1 ? "%d %s" : "%d", i, s); // no warning
 250   scanf(i ? "%d %s" : "%d", i, s); // no warning
 251   scanf(i ? "%d" : "%d", i, s); // expected-warning{{data argument not used}}
 252   scanf(i ? "%s" : "%d", s); // expected-warning{{format specifies type 'int *'}}
 253 }
 254
 255 void test_promotion(void) {
 256   // No promotions for *scanf pointers clarified in N2562
 257   // https://github.com/llvm/llvm-project/issues/57102
 258   // N2562: https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2562.pdf
 259   int i;
 260   signed char sc;
 261   unsigned char uc;
 262   short ss;
 263   unsigned short us;
 264
 265   // pointers could not be "promoted"
 266   scanf("%hhd", &i); // expected-warning{{format specifies type 'char *' but the argument has type 'int *'}}
 267   scanf("%hd", &i); // expected-warning{{format specifies type 'short *' but the argument has type 'int *'}}
 268   scanf("%d", &i); // no-warning
 269   // char & uchar
 270   scanf("%hhd", &sc); // no-warning
 271   scanf("%hhd", &uc); // no-warning
 272   scanf("%hd", &sc); // expected-warning{{format specifies type 'short *' but the argument has type 'signed char *'}}
 273   scanf("%hd", &uc); // expected-warning{{format specifies type 'short *' but the argument has type 'unsigned char *'}}
 274   scanf("%d", &sc); // expected-warning{{format specifies type 'int *' but the argument has type 'signed char *'}}
 275   scanf("%d", &uc); // expected-warning{{format specifies type 'int *' but the argument has type 'unsigned char *'}}
 276   // short & ushort
 277   scanf("%hhd", &ss); // expected-warning{{format specifies type 'char *' but the argument has type 'short *'}}
 278   scanf("%hhd", &us); // expected-warning{{format specifies type 'char *' but the argument has type 'unsigned short *'}}
 279   scanf("%hd", &ss); // no-warning
 280   scanf("%hd", &us); // no-warning
 281   scanf("%d", &ss); // expected-warning{{format specifies type 'int *' but the argument has type 'short *'}}
 282   scanf("%d", &us); // expected-warning{{format specifies type 'int *' but the argument has type 'unsigned short *'}}
 283
 284   // long types
 285   scanf("%ld", &i); // expected-warning{{format specifies type 'long *' but the argument has type 'int *'}}
 286   scanf("%lld", &i); // expected-warning{{format specifies type 'long long *' but the argument has type 'int *'}}
 287   scanf("%ld", &sc); // expected-warning{{format specifies type 'long *' but the argument has type 'signed char *'}}
 288   scanf("%lld", &sc); // expected-warning{{format specifies type 'long long *' but the argument has type 'signed char *'}}
 289   scanf("%ld", &uc); // expected-warning{{format specifies type 'long *' but the argument has type 'unsigned char *'}}
 290   scanf("%lld", &uc); // expected-warning{{format specifies type 'long long *' but the argument has type 'unsigned char *'}}
 291   scanf("%llx", &i); // expected-warning{{format specifies type 'unsigned long long *' but the argument has type 'int *'}}
 292
 293   // ill-formed floats
 294   scanf("%hf", // expected-warning{{length modifier 'h' results in undefined behavior or no effect with 'f' conversion specifier}}
 295   &sc);
 296
 297   // pointers in scanf
 298   scanf("%s", i); // expected-warning{{format specifies type 'char *' but the argument has type 'int'}}
 299
 300   // FIXME: does this match what the C committee allows or should it be pedantically warned on?
 301   char c;
 302   void *vp;
 303   scanf("%hhd", &c); // Pedantic warning?
 304   scanf("%hhd", vp); // expected-warning{{format specifies type 'char *' but the argument has type 'void *'}}
 305 }