clang/test/Analysis/conversion.c

   1 // RUN: %clang_analyze_cc1 %s \
   2 // RUN:   -Wno-conversion -Wno-tautological-constant-compare \
   3 // RUN:   -analyzer-checker=core,apiModeling,unix.StdCLibraryFunctions,alpha.core.Conversion \
   4 // RUN:   -verify
   5
   6 unsigned char U8;
   7 signed char S8;
   8
   9 void assign(unsigned U, signed S) {
  10   if (S < -10)
  11     U8 = S; // expected-warning {{Loss of sign in implicit conversion}}
  12   if (U > 300)
  13     S8 = U; // expected-warning {{Loss of precision in implicit conversion}}
  14   if (S > 10)
  15     U8 = S; // no-warning
  16   if (U < 200)
  17     S8 = U; // no-warning
  18 }
  19
  20 void addAssign(void) {
  21   unsigned long L = 1000;
  22   int I = -100;
  23   U8 += L; // expected-warning {{Loss of precision in implicit conversion}}
  24   L += I; // no-warning
  25 }
  26
  27 void subAssign(void) {
  28   unsigned long L = 1000;
  29   int I = -100;
  30   U8 -= L; // expected-warning {{Loss of precision in implicit conversion}}
  31   L -= I; // no-warning
  32 }
  33
  34 void mulAssign(void) {
  35   unsigned long L = 1000;
  36   int I = -1;
  37   U8 *= L; // expected-warning {{Loss of precision in implicit conversion}}
  38   L *= I;  // expected-warning {{Loss of sign in implicit conversion}}
  39   I = 10;
  40   L *= I; // no-warning
  41 }
  42
  43 void divAssign(void) {
  44   unsigned long L = 1000;
  45   int I = -1;
  46   U8 /= L; // no-warning
  47   L /= I; // expected-warning {{Loss of sign in implicit conversion}}
  48 }
  49
  50 void remAssign(void) {
  51   unsigned long L = 1000;
  52   int I = -1;
  53   U8 %= L; // no-warning
  54   L %= I; // expected-warning {{Loss of sign in implicit conversion}}
  55 }
  56
  57 void andAssign(void) {
  58   unsigned long L = 1000;
  59   int I = -1;
  60   U8 &= L; // no-warning
  61   L &= I; // expected-warning {{Loss of sign in implicit conversion}}
  62 }
  63
  64 void orAssign(void) {
  65   unsigned long L = 1000;
  66   int I = -1;
  67   U8 |= L; // expected-warning {{Loss of precision in implicit conversion}}
  68   L |= I;  // expected-warning {{Loss of sign in implicit conversion}}
  69 }
  70
  71 void xorAssign(void) {
  72   unsigned long L = 1000;
  73   int I = -1;
  74   U8 ^= L; // expected-warning {{Loss of precision in implicit conversion}}
  75   L ^= I;  // expected-warning {{Loss of sign in implicit conversion}}
  76 }
  77
  78 void init1(void) {
  79   long long A = 1LL << 60;
  80   short X = A; // expected-warning {{Loss of precision in implicit conversion}}
  81 }
  82
  83 void relational(unsigned U, signed S) {
  84   if (S > 10) {
  85     if (U < S) { // no-warning
  86     }
  87   }
  88   if (S < -10) {
  89     if (U < S) { // expected-warning {{Loss of sign in implicit conversion}}
  90     }
  91   }
  92 }
  93
  94 void multiplication(unsigned U, signed S) {
  95   if (S > 5)
  96     S = U * S; // no-warning
  97   if (S < -10)
  98     S = U * S; // expected-warning {{Loss of sign}}
  99 }
 100
 101 void division(unsigned U, signed S) {
 102   if (S > 5)
 103     S = U / S; // no-warning
 104   if (S < -10)
 105     S = U / S; // expected-warning {{Loss of sign}}
 106 }
 107
 108 void f(unsigned x) {}
 109 void g(unsigned x) {}
 110
 111 void functioncall1(void) {
 112   long x = -1;
 113   int y = 0;
 114   f(x); // expected-warning {{Loss of sign in implicit conversion}}
 115   f(y);
 116 }
 117
 118 void functioncall2(int x, int y) {
 119   if (x < 0)
 120     f(x); // expected-warning {{Loss of sign in implicit conversion}}
 121   f(y);
 122   f(x); // expected-warning {{Loss of sign in implicit conversion}}
 123 }
 124
 125 void dontwarn1(unsigned U, signed S) {
 126   U8 = S; // It might be known that S is always 0x00-0xff.
 127   S8 = U; // It might be known that U is always 0x00-0xff.
 128
 129   U8 = -1;  // Explicit conversion.
 130   S8 = ~0U; // Explicit conversion.
 131   if (U > 300)
 132     U8 &= U; // No loss of precision since there is &=.
 133 }
 134
 135 void dontwarn2(unsigned int U) {
 136   if (U <= 4294967295) {
 137   }
 138   if (U <= (2147483647 * 2U + 1U)) {
 139   }
 140 }
 141
 142 void dontwarn3(int X) {
 143   S8 = X ? 'a' : 'b';
 144 }
 145
 146 // don't warn for macros
 147 #define DOSTUFF ({ unsigned X = 1000; U8 = X; })
 148 void dontwarn4(void) {
 149   DOSTUFF;
 150 }
 151
 152 void dontwarn5(void) {
 153   unsigned char c1 = 'A';
 154   c1 = (c1 >= 'A' && c1 <= 'Z') ? c1 - 'A' + 'a' : c1;
 155   unsigned char c2 = 0;
 156   c2 = (c2 >= 'A' && c2 <= 'Z') ? c2 - 'A' + 'a' : c2;
 157   unsigned char c3 = 'Z';
 158   c3 = (c3 >= 'A' && c3 <= 'Z') ? c3 - 'A' + 'a' : c3;
 159   unsigned char c4 = 'a';
 160   c4 = (c4 >= 'A' && c4 <= 'Z') ? c4 - 'A' + 'a' : c4;
 161   unsigned char c5 = '@';
 162   c5 = (c5 >= 'A' && c5 <= 'Z') ? c5 - 'A' + 'a' : c5;
 163 }
 164
 165 void dontwarn6(void) {
 166   int x = ~0;
 167   unsigned y = ~0;
 168 }
 169
 170 void dontwarn7(unsigned x) {
 171   if (x == (unsigned)-1) {
 172   }
 173 }
 174
 175 void dontwarn8(void) {
 176   unsigned x = (unsigned)-1;
 177 }
 178
 179 unsigned dontwarn9(void) {
 180   return ~0;
 181 }
 182
 183 char dontwarn10(long long x) {
 184   long long y = 42;
 185   y += x;
 186   return y == 42;
 187 }
 188
 189
 190 // C library functions, handled via unix.StdCLibraryFunctions
 191
 192 int isascii(int c);
 193 void libraryFunction1(void) {
 194   char kb2[5];
 195   int X = 1000;
 196   if (isascii(X)) {
 197     kb2[0] = X; // no-warning
 198   }
 199 }
 200
 201
 202 typedef struct FILE {} FILE; int getc(FILE *stream);
 203 # define EOF (-1)
 204 char reply_string[8192];
 205 FILE *cin;
 206 extern int dostuff(void);
 207 int libraryFunction2(void) {
 208   int c, n;
 209   int dig;
 210   char *cp = reply_string;
 211   int pflag = 0;
 212   int code;
 213
 214   for (;;) {
 215     dig = n = code = 0;
 216     while ((c = getc(cin)) != '\n') {
 217       if (dig < 4 && dostuff())
 218         code = code * 10 + (c - '0');
 219       if (!pflag && code == 227)
 220         pflag = 1;
 221       if (n == 0)
 222         n = c;
 223       if (c == EOF)
 224         return(4);
 225       if (cp < &reply_string[sizeof(reply_string) - 1])
 226         *cp++ = c; // no-warning
 227     }
 228   }
 229 }
 230
 231 double floating_point(long long a, int b) {
 232   if (a > 1LL << 55) {
 233     double r = a; // expected-warning {{Loss of precision}}
 234     return r;
 235   } else if (b > 1 << 25) {
 236     float f = b; // expected-warning {{Loss of precision}}
 237     return f;
 238   }
 239   return 137;
 240 }
 241
 242 double floating_point2(void) {
 243   int a = 1 << 24;
 244   long long b = 1LL << 53;
 245   float f = a; // no-warning
 246   double d = b; // no-warning
 247   return d - f;
 248 }
 249
 250 int floating_point_3(unsigned long long a) {
 251   double b = a; // no-warning
 252   return 42;
 253 }