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

   1 // RUN: %clang_analyze_cc1 -verify %s \
   2 // RUN:     -analyzer-checker=core,unix.StdCLibraryFunctions \
   3 // RUN:     -analyzer-config unix.StdCLibraryFunctions:ModelPOSIX=true \
   4 // RUN:     -analyzer-output=text
   5
   6 #include "Inputs/std-c-library-functions-POSIX.h"
   7 #define NULL ((void *)0)
   8
   9 char *getenv(const char *);
  10 int isalpha(int);
  11 int isdigit(int);
  12 int islower(int);
  13
  14 char test_getenv() {
  15   char *env = getenv("VAR"); // \
  16   // expected-note{{Assuming the environment variable does not exist}} \
  17   // expected-note{{'env' initialized here}}
  18
  19   return env[0]; // \
  20   // expected-warning{{Array access (from variable 'env') results in a null pointer dereference}} \
  21   // expected-note   {{Array access (from variable 'env') results in a null pointer dereference}}
  22 }
  23
  24 int test_isalpha(int *x, char c, char d) {
  25   int iad = isalpha(d);
  26   if (isalpha(c)) {// \
  27     // expected-note{{Taking true branch}}
  28     x = NULL; // \
  29     // expected-note{{Null pointer value stored to 'x'}}
  30   }
  31
  32   return *x; // \
  33   // expected-warning{{Dereference of null pointer (loaded from variable 'x')}} \
  34   // expected-note   {{Dereference of null pointer (loaded from variable 'x')}}
  35 }
  36
  37 int test_isdigit(int *x, char c) {
  38   if (!isdigit(c)) {// \
  39   // expected-note{{Taking true branch}}
  40     x = NULL; // \
  41     // expected-note{{Null pointer value stored to 'x'}}
  42   }
  43
  44   return *x; // \
  45   // expected-warning{{Dereference of null pointer (loaded from variable 'x')}} \
  46   // expected-note   {{Dereference of null pointer (loaded from variable 'x')}}
  47 }
  48
  49 int test_islower(int *x) {
  50   char c = 'c';
  51   // No "Assuming..." note. We aren't assuming anything. We *know*.
  52   if (islower(c)) { // \
  53     // expected-note{{Taking true branch}}
  54     x = NULL; // \
  55     // expected-note{{Null pointer value stored to 'x'}}
  56   }
  57
  58   return *x; // \
  59   // expected-warning{{Dereference of null pointer (loaded from variable 'x')}} \
  60   // expected-note   {{Dereference of null pointer (loaded from variable 'x')}}
  61 }
  62
  63 int test_bugpath_notes(FILE *f1, char c, FILE *f2) {
  64   // This test has the purpose of checking that notes appear at correct place.
  65   long a = ftell(f2); // no note
  66   if (a == -1) // \
  67     // expected-note{{Taking false branch}}
  68     return -1;
  69   int l = islower(c); // no note
  70   a = ftell(f1); // \
  71   // expected-note{{Value assigned to 'a'}} \
  72   // expected-note{{Assuming that 'ftell' fails}}
  73   return dup(a); // \
  74   // expected-warning{{The 1st argument to 'dup' is -1 but should be >= 0}} \
  75   // expected-note{{The 1st argument to 'dup' is -1 but should be >= 0}}
  76 }
  77
  78 int test_fileno_arg_note(FILE *f1) {
  79   return dup(fileno(f1)); // no warning
  80 }
  81
  82 int test_readlink_bufsize_zero(char *Buf, size_t Bufsize) {
  83   ssize_t Ret = readlink("path", Buf, Bufsize); // \
  84   // expected-note{{Assuming that argument 'bufsize' is 0}} \
  85   // expected-note{{'Ret' initialized here}}
  86   return 1 / Ret; // \
  87   // expected-warning{{Division by zero}} \
  88   // expected-note{{Division by zero}}
  89 }