clang/test/Analysis/malloc-static-storage.cpp

   1 // RUN: %clang_analyze_cc1 -analyzer-checker=core,unix.Malloc -verify %s
   2
   3 typedef __typeof(sizeof(int)) size_t;
   4 void* malloc(size_t size);
   5 void *calloc(size_t num, size_t size);
   6 void free(void * ptr);
   7
   8 void escape(void *);
   9 void next_statement();
  10
  11 void conditional_malloc(bool coin) {
  12   static int *p;
  13
  14   if (coin) {
  15     p = (int *)malloc(sizeof(int));
  16   }
  17   p = 0; // Pointee of 'p' dies, which is recognized at the next statement.
  18   next_statement(); // expected-warning {{Potential memory leak}}
  19 }
  20
  21 void malloc_twice() {
  22   static int *p;
  23   p = (int *)malloc(sizeof(int));
  24   next_statement();
  25   p = (int *)malloc(sizeof(int));
  26   next_statement(); // expected-warning {{Potential memory leak}}
  27   p = 0;
  28   next_statement(); // expected-warning {{Potential memory leak}}
  29 }
  30
  31 void malloc_escape() {
  32   static int *p;
  33   p = (int *)malloc(sizeof(int));
  34   escape(p); // no-leak
  35   p = 0; // no-leak
  36 }
  37
  38 void free_whatever_escaped();
  39 void malloc_escape_reversed() {
  40   static int *p;
  41   escape(&p);
  42   p = (int *)malloc(sizeof(int));
  43   free_whatever_escaped();
  44   p = 0; // FIXME: We should not report a leak here.
  45   next_statement(); // expected-warning {{Potential memory leak}}
  46 }
  47
  48 int *malloc_return_static() {
  49   static int *p = (int *)malloc(sizeof(int));
  50   return p; // no-leak
  51 }
  52
  53 int malloc_unreachable(int rng) {
  54   // 'p' does not escape and never freed :(
  55   static int *p;
  56
  57   // For the second invocation of this function, we leak the previous pointer.
  58   // FIXME: We should catch this at some point.
  59   p = (int *)malloc(sizeof(int));
  60   *p = 0;
  61
  62   if (rng > 0)
  63     *p = rng;
  64
  65   return *p; // FIXME: We just leaked 'p'. We should warn about this.
  66 }
  67
  68 void malloc_cond(bool cond) {
  69   static int *p;
  70   if (cond) {
  71     p = (int*)malloc(sizeof(int));
  72     free_whatever_escaped();
  73     p = 0; // FIXME: We should not report a leak here.
  74     next_statement(); // expected-warning {{Potential memory leak}}
  75   }
  76   escape(&p);
  77 }