clang/test/Analysis/symbol-reaper.cpp

   1 // RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection -verify %s
   2
   3 void clang_analyzer_eval(int);
   4 void clang_analyzer_warnOnDeadSymbol(int);
   5
   6 namespace test_dead_region_with_live_subregion_in_environment {
   7 int glob;
   8
   9 struct A {
  10   int x;
  11
  12   void foo() {
  13     // FIXME: Maybe just let clang_analyzer_eval() work within callees already?
  14     // The glob variable shouldn't keep our symbol alive because
  15     // 'x != 0' is concrete 'true'.
  16     glob = (x != 0);
  17   }
  18 };
  19
  20 void test_A(A a) {
  21   if (a.x == 0)
  22     return;
  23
  24   clang_analyzer_warnOnDeadSymbol(a.x);
  25
  26   // What we're testing is that a.x is alive until foo() exits.
  27   a.foo(); // no-warning // (i.e., no 'SYMBOL DEAD' yet)
  28
  29   // Let's see if constraints on a.x were known within foo().
  30   clang_analyzer_eval(glob); // expected-warning{{TRUE}}
  31                              // expected-warning@-1{{SYMBOL DEAD}}
  32 }
  33
  34 struct B {
  35   A a;
  36   int y;
  37 };
  38
  39 A &noop(A &a) {
  40   // This function ensures that the 'b' expression within its argument
  41   // would be cleaned up before its call, so that only 'b.a' remains
  42   // in the Environment.
  43   return a;
  44 }
  45
  46
  47 void test_B(B b) {
  48   if (b.a.x == 0)
  49     return;
  50
  51   clang_analyzer_warnOnDeadSymbol(b.a.x);
  52
  53   // What we're testing is that b.a.x is alive until foo() exits.
  54   noop(b.a).foo(); // no-warning // (i.e., no 'SYMBOL DEAD' yet)
  55
  56   // Let's see if constraints on a.x were known within foo().
  57   clang_analyzer_eval(glob); // expected-warning{{TRUE}}
  58                              // expected-warning@-1{{SYMBOL DEAD}}
  59 }
  60 } // namespace test_dead_region_with_live_subregion_in_environment