clang/test/Analysis/errno.c

   1 // RUN: %clang_analyze_cc1 -verify %s \
   2 // RUN:   -analyzer-checker=core \
   3 // RUN:   -analyzer-checker=apiModeling.Errno \
   4 // RUN:   -analyzer-checker=debug.ExprInspection \
   5 // RUN:   -analyzer-checker=debug.ErrnoTest \
   6 // RUN:   -analyzer-checker=unix.Errno \
   7 // RUN:   -DERRNO_VAR
   8
   9 // RUN: %clang_analyze_cc1 -verify %s \
  10 // RUN:   -analyzer-checker=core \
  11 // RUN:   -analyzer-checker=apiModeling.Errno \
  12 // RUN:   -analyzer-checker=debug.ExprInspection \
  13 // RUN:   -analyzer-checker=debug.ErrnoTest \
  14 // RUN:   -analyzer-checker=unix.Errno \
  15 // RUN:   -DERRNO_FUNC
  16
  17 #include "Inputs/system-header-simulator.h"
  18 #ifdef ERRNO_VAR
  19 #include "Inputs/errno_var.h"
  20 #endif
  21 #ifdef ERRNO_FUNC
  22 #include "Inputs/errno_func.h"
  23 #endif
  24
  25 void clang_analyzer_eval(int);
  26 void ErrnoTesterChecker_setErrno(int);
  27 int ErrnoTesterChecker_getErrno();
  28 int ErrnoTesterChecker_setErrnoIfError();
  29 int ErrnoTesterChecker_setErrnoIfErrorRange();
  30 int ErrnoTesterChecker_setErrnoCheckState();
  31
  32 void something();
  33
  34 void test() {
  35   // Test if errno is initialized.
  36   clang_analyzer_eval(errno == 0); // expected-warning{{TRUE}}
  37
  38   ErrnoTesterChecker_setErrno(1);
  39   // Test if errno was recognized and changed.
  40   clang_analyzer_eval(errno == 1);                         // expected-warning{{TRUE}}
  41   clang_analyzer_eval(ErrnoTesterChecker_getErrno() == 1); // expected-warning{{TRUE}}
  42
  43   something();
  44
  45   // Test if errno was invalidated.
  46   clang_analyzer_eval(errno);                         // expected-warning{{UNKNOWN}}
  47   clang_analyzer_eval(ErrnoTesterChecker_getErrno()); // expected-warning{{UNKNOWN}}
  48 }
  49
  50 void testRange(int X) {
  51   if (X > 0) {
  52     ErrnoTesterChecker_setErrno(X);
  53     clang_analyzer_eval(errno > 0); // expected-warning{{TRUE}}
  54   }
  55 }
  56
  57 void testIfError() {
  58   if (ErrnoTesterChecker_setErrnoIfError())
  59     clang_analyzer_eval(errno == 11); // expected-warning{{TRUE}}
  60 }
  61
  62 void testIfErrorRange() {
  63   if (ErrnoTesterChecker_setErrnoIfErrorRange()) {
  64     clang_analyzer_eval(errno != 0); // expected-warning{{TRUE}}
  65     clang_analyzer_eval(errno == 1); // expected-warning{{FALSE}} expected-warning{{TRUE}}
  66   }
  67 }
  68
  69 void testErrnoCheck0() {
  70   // If the function returns a success result code, value of 'errno'
  71   // is unspecified and it is unsafe to make any decision with it.
  72   // The function did not promise to not change 'errno' if no failure happens.
  73   int X = ErrnoTesterChecker_setErrnoCheckState();
  74   if (X == 0) {
  75     if (errno) { // expected-warning{{An undefined value may be read from 'errno' [unix.Errno]}}
  76     }
  77     if (errno) { // no warning for second time (analysis stops at the first warning)
  78     }
  79   }
  80   X = ErrnoTesterChecker_setErrnoCheckState();
  81   if (X == 0) {
  82     if (errno) { // expected-warning{{An undefined value may be read from 'errno' [unix.Errno]}}
  83     }
  84     errno = 0;
  85   }
  86   X = ErrnoTesterChecker_setErrnoCheckState();
  87   if (X == 0) {
  88     errno = 0;
  89     if (errno) { // no warning after overwritten 'errno'
  90     }
  91   }
  92 }
  93
  94 void testErrnoCheck1() {
  95   // If the function returns error result code that is out-of-band (not a valid
  96   // non-error return value) the value of 'errno' can be checked but it is not
  97   // required to do so.
  98   int X = ErrnoTesterChecker_setErrnoCheckState();
  99   if (X == 1) {
 100     if (errno) { // no warning
 101     }
 102   }
 103   X = ErrnoTesterChecker_setErrnoCheckState();
 104   if (X == 1) {
 105     errno = 0; // no warning
 106   }
 107 }
 108
 109 void testErrnoCheck2() {
 110   // If the function returns an in-band error result the value of 'errno' is
 111   // required to be checked to verify if error happened.
 112   // The same applies to other functions that can indicate failure only by
 113   // change of 'errno'.
 114   int X = ErrnoTesterChecker_setErrnoCheckState();
 115   if (X == 2) {
 116     errno = 0; // expected-warning{{Value of 'errno' was not checked and is overwritten here [unix.Errno]}}
 117     errno = 0;
 118   }
 119   X = ErrnoTesterChecker_setErrnoCheckState();
 120   if (X == 2) {
 121     errno = 0; // expected-warning{{Value of 'errno' was not checked and is overwritten here [unix.Errno]}}
 122     if (errno) {
 123     }
 124   }
 125 }
 126
 127 void testErrnoCheck3() {
 128   int X = ErrnoTesterChecker_setErrnoCheckState();
 129   if (X == 2) {
 130     if (errno) {
 131     }
 132     errno = 0; // no warning after 'errno' was read
 133   }
 134   X = ErrnoTesterChecker_setErrnoCheckState();
 135   if (X == 2) {
 136     int A = errno;
 137     errno = 0; // no warning after 'errno' was read
 138   }
 139 }
 140
 141 void testErrnoCheckUndefinedLoad() {
 142   int X = ErrnoTesterChecker_setErrnoCheckState();
 143   if (X == 0) {
 144     if (errno) { // expected-warning{{An undefined value may be read from 'errno' [unix.Errno]}}
 145     }
 146   }
 147 }
 148
 149 void testErrnoNotCheckedAtSystemCall() {
 150   int X = ErrnoTesterChecker_setErrnoCheckState();
 151   if (X == 2) {
 152     printf("%i", 1); // expected-warning{{Value of 'errno' was not checked and may be overwritten by function 'printf' [unix.Errno]}}
 153     printf("%i", 1); // no warning ('printf' does not change errno state)
 154   }
 155 }
 156
 157 void testErrnoCheckStateInvalidate() {
 158   int X = ErrnoTesterChecker_setErrnoCheckState();
 159   if (X == 0) {
 160     something();
 161     if (errno) { // no warning after an invalidating function call
 162     }
 163   }
 164   X = ErrnoTesterChecker_setErrnoCheckState();
 165   if (X == 0) {
 166     printf("%i", 1);
 167     if (errno) { // no warning after an invalidating standard function call
 168     }
 169   }
 170 }
 171
 172 void testErrnoCheckStateInvalidate1() {
 173   int X = ErrnoTesterChecker_setErrnoCheckState();
 174   if (X == 2) {
 175     clang_analyzer_eval(errno); // expected-warning{{TRUE}}
 176     something();
 177     clang_analyzer_eval(errno); // expected-warning{{UNKNOWN}}
 178     errno = 0;                  // no warning after invalidation
 179   }
 180 }
 181
 182 void test_if_cond_in_expr() {
 183   ErrnoTesterChecker_setErrnoIfError();
 184   if (errno + 10 > 2) {
 185     // expected-warning@-1{{An undefined value may be read from 'errno'}}
 186   }
 187 }
 188
 189 void test_for_cond() {
 190   ErrnoTesterChecker_setErrnoIfError();
 191   for (; errno != 0;) {
 192   // expected-warning@-1{{An undefined value may be read from 'errno'}}
 193   }
 194 }
 195
 196 void test_do_cond() {
 197   ErrnoTesterChecker_setErrnoIfError();
 198   do {
 199   } while (errno != 0);
 200   // expected-warning@-1{{An undefined value may be read from 'errno'}}
 201 }
 202
 203 void test_while_cond() {
 204   ErrnoTesterChecker_setErrnoIfError();
 205   while (errno != 0) {
 206   // expected-warning@-1{{An undefined value may be read from 'errno'}}
 207   }
 208 }
 209
 210 void test_switch_cond() {
 211   ErrnoTesterChecker_setErrnoIfError();
 212   switch (errno) {}
 213   // expected-warning@-1{{An undefined value may be read from 'errno'}}
 214 }
 215
 216 void test_conditional_cond() {
 217   ErrnoTesterChecker_setErrnoIfError();
 218   int A = errno ? 1 : 2;
 219   // expected-warning@-1{{An undefined value may be read from 'errno'}}
 220 }
 221
 222 void test_binary_conditional_cond() {
 223   ErrnoTesterChecker_setErrnoIfError();
 224   int A = errno ?: 2;
 225   // expected-warning@-1{{An undefined value may be read from 'errno'}}
 226 }
 227
 228 void test_errno_store_into_variable() {
 229   ErrnoTesterChecker_setErrnoIfError();
 230   int a = errno; // AllowNonConditionErrnoRead is on by default, no warning
 231 }
 232
 233 void test_errno_store_into_variable_in_expr() {
 234   ErrnoTesterChecker_setErrnoIfError();
 235   int a = errno > 1; // AllowNonConditionErrnoRead is on by default, no warning
 236 }
 237
 238 int test_errno_return() {
 239   ErrnoTesterChecker_setErrnoIfError();
 240   return errno;
 241 }
 242
 243 void test_errno_pointer1() {
 244   ErrnoTesterChecker_setErrnoIfError();
 245   int *ErrnoP = &errno;
 246   int A = errno ? 1 : 2;
 247   // expected-warning@-1{{An undefined value may be read from 'errno'}}
 248 }
 249
 250 void test_errno_pointer2() {
 251   ErrnoTesterChecker_setErrnoIfError();
 252   int *ErrnoP = &errno;
 253   int A = (*ErrnoP) ? 1 : 2;
 254   // expected-warning@-1{{An undefined value may be read from 'errno'}}
 255 }
 256
 257 int f(int);
 258
 259 void test_errno_in_condition_in_function_call() {
 260   ErrnoTesterChecker_setErrnoIfError();
 261   if (f(errno) != 0) {
 262   }
 263 }