clang/test/Analysis/std-c-library-functions-path-notes.c

   1 // RUN: %clang_analyze_cc1 -verify %s \
   2 // RUN:     -analyzer-checker=core,apiModeling \
   3 // RUN:     -analyzer-output=text
   4
   5 #define NULL ((void *)0)
   6
   7 char *getenv(const char *);
   8 int isalpha(int);
   9 int isdigit(int);
  10 int islower(int);
  11
  12 char test_getenv() {
  13   char *env = getenv("VAR"); // \
  14   // expected-note{{Assuming the environment variable does not exist}} \
  15   // expected-note{{'env' initialized here}}
  16
  17   return env[0]; // \
  18   // expected-warning{{Array access (from variable 'env') results in a null pointer dereference}} \
  19   // expected-note   {{Array access (from variable 'env') results in a null pointer dereference}}
  20 }
  21
  22 int test_isalpha(int *x, char c) {
  23   if (isalpha(c)) {// \
  24     // expected-note{{Assuming the character is alphabetical}} \
  25     // expected-note{{Taking true branch}}
  26     x = NULL; // \
  27     // expected-note{{Null pointer value stored to 'x'}}
  28   }
  29
  30   return *x; // \
  31   // expected-warning{{Dereference of null pointer (loaded from variable 'x')}} \
  32   // expected-note   {{Dereference of null pointer (loaded from variable 'x')}}
  33 }
  34
  35 int test_isdigit(int *x, char c) {
  36   if (!isdigit(c)) {// \
  37     // expected-note{{Assuming the character is not a digit}} \
  38     // expected-note{{Taking true branch}}
  39     x = NULL; // \
  40     // expected-note{{Null pointer value stored to 'x'}}
  41   }
  42
  43   return *x; // \
  44   // expected-warning{{Dereference of null pointer (loaded from variable 'x')}} \
  45   // expected-note   {{Dereference of null pointer (loaded from variable 'x')}}
  46 }
  47
  48 int test_islower(int *x) {
  49   char c = 'c';
  50   // No "Assuming..." note. We aren't assuming anything. We *know*.
  51   if (islower(c)) { // \
  52     // expected-note{{Taking true branch}}
  53     x = NULL; // \
  54     // expected-note{{Null pointer value stored to 'x'}}
  55   }
  56
  57   return *x; // \
  58   // expected-warning{{Dereference of null pointer (loaded from variable 'x')}} \
  59   // expected-note   {{Dereference of null pointer (loaded from variable 'x')}}
  60 }