llvm-project/clang/test/Analysis/dead-stores.cpp

103 lines
3.2 KiB
C++

// RUN: %clang_cc1 -analyze -analyzer-experimental-internal-checks -analyzer-check-dead-stores -verify -Wno-unreachable-code %s
// RUN: %clang_cc1 -analyze -analyzer-experimental-internal-checks -analyzer-check-objc-mem -analyzer-store=basic -analyzer-constraints=basic -analyzer-check-dead-stores -verify -Wno-unreachable-code %s
// RUN: %clang_cc1 -analyze -analyzer-experimental-internal-checks -analyzer-check-objc-mem -analyzer-store=basic -analyzer-constraints=range -analyzer-check-dead-stores -verify -Wno-unreachable-code %s
// RUN: %clang_cc1 -analyze -analyzer-experimental-internal-checks -analyzer-check-objc-mem -analyzer-store=region -analyzer-constraints=basic -analyzer-check-dead-stores -verify -Wno-unreachable-code %s
// RUN: %clang_cc1 -analyze -analyzer-experimental-internal-checks -analyzer-check-objc-mem -analyzer-store=region -analyzer-constraints=range -analyzer-check-dead-stores -verify -Wno-unreachable-code %s
//===----------------------------------------------------------------------===//
// Basic dead store checking (but in C++ mode).
//===----------------------------------------------------------------------===//
int j;
void test1() {
int x = 4;
++x; // expected-warning{{never read}}
switch (j) {
case 1:
throw 1;
(void)x;
break;
}
}
//===----------------------------------------------------------------------===//
// Dead store checking involving constructors.
//===----------------------------------------------------------------------===//
class Test2 {
int &x;
public:
Test2(int &y) : x(y) {}
~Test2() { ++x; }
};
int test2(int x) {
{ Test2 a(x); } // no-warning
return x;
}
//===----------------------------------------------------------------------===//
// Dead store checking involving CXXTemporaryExprs
//===----------------------------------------------------------------------===//
namespace TestTemp {
template<typename _Tp>
class pencil {
public:
~pencil() throw() {}
};
template<typename _Tp, typename _Number2> struct _Row_base {
_Row_base(const pencil<_Tp>& x) {}
};
template<typename _Tp, typename _Number2 = TestTemp::pencil<_Tp> >
class row : protected _Row_base<_Tp, _Number2> {
typedef _Row_base<_Tp, _Number2> _Base;
typedef _Number2 pencil_type;
public:
explicit row(const pencil_type& __a = pencil_type()) : _Base(__a) {}
};
}
void test2_b() {
TestTemp::row<const char*> x; // no-warning
}
//===----------------------------------------------------------------------===//
// Test references.
//===----------------------------------------------------------------------===//
void test3_a(int x) {
++x; // expected-warning{{never read}}
}
void test3_b(int &x) {
++x; // no-warninge
}
void test3_c(int x) {
int &y = x;
// Shows the limitation of dead stores tracking. The write is really
// dead since the value cannot escape the function.
++y; // no-warning
}
void test3_d(int &x) {
int &y = x;
++y; // no-warning
}
void test3_e(int &x) {
int &y = x;
}
//===----------------------------------------------------------------------===//
// Dead stores involving 'new'
//===----------------------------------------------------------------------===//
static void test_new(unsigned n) {
char **p = new char* [n]; // expected-warning{{never read}}
}