clang/test/Analysis/retain-count-alloc.cpp

   1 // RUN: %clang_analyze_cc1 \
   2 // RUN:  -analyzer-checker=core,unix.Malloc \
   3 // RUN:  -verify %s
   4
   5 // expected-no-diagnostics: We do not model Integer Set Library's retain-count
   6 //                          based allocation. If any of the parameters has an
   7 //                          '__isl_' prefixed macro definition we escape every
   8 //                          of them when we are about to 'free()' something.
   9
  10 #define __isl_take
  11 #define __isl_keep
  12
  13 struct Object { int Ref; };
  14 void free(void *);
  15
  16 Object *copyObj(__isl_keep Object *O) {
  17   O->Ref++;
  18   return O;
  19 }
  20
  21 void freeObj(__isl_take Object *O) {
  22   if (--O->Ref > 0)
  23     return;
  24
  25   free(O); // Here we notice that the parameter contains '__isl_', escape it.
  26 }
  27
  28 void useAfterFree(__isl_take Object *A) {
  29   if (!A)
  30     return;
  31
  32   Object *B = copyObj(A);
  33   freeObj(B);
  34
  35   A->Ref = 13;
  36   // no-warning: 'Use of memory after it is freed' was here.
  37 }