Files
clang-p2996/clang/test/Analysis/NewDelete-checker-test.cpp
Kristóf Umann efd1a8e66e [analyzer][MallocChecker] Make NewDeleteLeaks depend on DynamicMemoryModeling rather than NewDelete
If you remember the mail [1] I sent out about how I envision the future of the
already existing checkers to look dependencywise, one my main points was that no
checker that emits diagnostics should be a dependency. This is more problematic
for some checkers (ahem, RetainCount [2]) more than for others, like this one.

The MallocChecker family is a mostly big monolithic modeling class some small
reporting checkers that only come to action when we are constructing a warning
message, after the actual bug was detected. The implication of this is that
NewDeleteChecker doesn't really do anything to depend on, so this change was
relatively simple.

The only thing that complicates this change is that FreeMemAux (MallocCheckers
method that models general memory deallocation) returns after calling a bug
reporting method, regardless whether the report was ever emitted (which may not
always happen, for instance, if the checker responsible for the report isn't
enabled). This return unfortunately happens before cleaning up the maps in the
GDM keeping track of the state of symbols (whether they are released, whether
that release was successful, etc). What this means is that upon disabling some
checkers, we would never clean up the map and that could've lead to false
positives, e.g.:

error: 'warning' diagnostics seen but not expected:
  File clang/test/Analysis/NewDelete-intersections.mm Line 66: Potential leak of memory pointed to by 'p'
  File clang/test/Analysis/NewDelete-intersections.mm Line 73: Potential leak of memory pointed to by 'p'
  File clang/test/Analysis/NewDelete-intersections.mm Line 77: Potential leak of memory pointed to by 'p'

error: 'warning' diagnostics seen but not expected:
  File clang/test/Analysis/NewDelete-checker-test.cpp Line 111: Undefined or garbage value returned to caller
  File clang/test/Analysis/NewDelete-checker-test.cpp Line 200: Potential leak of memory pointed to by 'p'

error: 'warning' diagnostics seen but not expected:
  File clang/test/Analysis/new.cpp Line 137: Potential leak of memory pointed to by 'x'
There two possible approaches I had in mind:

Make bug reporting methods of MallocChecker returns whether they succeeded, and
proceed with the rest of FreeMemAux if not,
Halt execution with a sink node upon failure. I decided to go with this, as
described in the code.
As you can see from the removed/changed test files, before the big checker
dependency effort landed, there were tests to check for all the weird
configurations of enabled/disabled checkers and their messy interactions, I
largely repurposed these.

[1] http://lists.llvm.org/pipermail/cfe-dev/2019-August/063070.html
[2] http://lists.llvm.org/pipermail/cfe-dev/2019-August/063205.html

Differential Revision: https://reviews.llvm.org/D77474
2020-05-27 00:03:53 +02:00

406 lines
9.5 KiB
C++

// RUN: %clang_analyze_cc1 -std=c++11 -fblocks %s \
// RUN: -verify=expected,newdelete \
// RUN: -analyzer-checker=core \
// RUN: -analyzer-checker=cplusplus.NewDelete
//
// RUN: %clang_analyze_cc1 -DLEAKS -std=c++11 -fblocks %s \
// RUN: -verify=expected,newdelete,leak \
// RUN: -analyzer-checker=core \
// RUN: -analyzer-checker=cplusplus.NewDelete \
// RUN: -analyzer-checker=cplusplus.NewDeleteLeaks
//
// RUN: %clang_analyze_cc1 -std=c++11 -fblocks %s \
// RUN: -verify=expected,newdelete \
// RUN: -analyzer-checker=core \
// RUN: -analyzer-checker=cplusplus.NewDelete \
// RUN: -analyzer-config c++-allocator-inlining=true
//
// RUN: %clang_analyze_cc1 -std=c++11 -fblocks -verify %s \
// RUN: -verify=expected,newdelete,leak \
// RUN: -analyzer-checker=core \
// RUN: -analyzer-checker=cplusplus.NewDelete \
// RUN: -analyzer-checker=cplusplus.NewDeleteLeaks \
// RUN: -analyzer-config c++-allocator-inlining=true
//
// RUN: %clang_analyze_cc1 -std=c++11 -fblocks -verify %s \
// RUN: -verify=expected,leak \
// RUN: -analyzer-checker=core \
// RUN: -analyzer-checker=cplusplus.NewDeleteLeaks
#include "Inputs/system-header-simulator-cxx.h"
typedef __typeof__(sizeof(int)) size_t;
extern "C" void *malloc(size_t);
extern "C" void free (void* ptr);
int *global;
//------------------
// check for leaks
//------------------
//----- Standard non-placement operators
void testGlobalOpNew() {
void *p = operator new(0);
} // leak-warning{{Potential leak of memory pointed to by 'p'}}
void testGlobalOpNewArray() {
void *p = operator new[](0);
} // leak-warning{{Potential leak of memory pointed to by 'p'}}
void testGlobalNewExpr() {
int *p = new int;
} // leak-warning{{Potential leak of memory pointed to by 'p'}}
void testGlobalNewExprArray() {
int *p = new int[0];
} // leak-warning{{Potential leak of memory pointed to by 'p'}}
//----- Standard nothrow placement operators
void testGlobalNoThrowPlacementOpNewBeforeOverload() {
void *p = operator new(0, std::nothrow);
} // leak-warning{{Potential leak of memory pointed to by 'p'}}
void testGlobalNoThrowPlacementExprNewBeforeOverload() {
int *p = new(std::nothrow) int;
} // leak-warning{{Potential leak of memory pointed to by 'p'}}
//----- Standard pointer placement operators
void testGlobalPointerPlacementNew() {
int i;
void *p1 = operator new(0, &i); // no warn
void *p2 = operator new[](0, &i); // no warn
int *p3 = new(&i) int; // no warn
int *p4 = new(&i) int[0]; // no warn
}
//----- Other cases
void testNewMemoryIsInHeap() {
int *p = new int;
if (global != p) // condition is always true as 'p' wraps a heap region that
// is different from a region wrapped by 'global'
global = p; // pointer escapes
}
struct PtrWrapper {
int *x;
PtrWrapper(int *input) : x(input) {}
};
void testNewInvalidationPlacement(PtrWrapper *w) {
// Ensure that we don't consider this a leak.
new (w) PtrWrapper(new int); // no warn
}
//-----------------------------------------
// check for usage of zero-allocated memory
//-----------------------------------------
void testUseZeroAlloc1() {
int *p = (int *)operator new(0);
*p = 1; // newdelete-warning {{Use of zero-allocated memory}}
delete p;
}
int testUseZeroAlloc2() {
int *p = (int *)operator new[](0);
return p[0]; // newdelete-warning {{Use of zero-allocated memory}}
delete[] p;
}
void f(int);
void testUseZeroAlloc3() {
int *p = new int[0];
f(*p); // newdelete-warning {{Use of zero-allocated memory}}
delete[] p;
}
//---------------
// other checks
//---------------
class SomeClass {
public:
void f(int *p);
};
void f(int *p1, int *p2 = 0, int *p3 = 0);
void g(SomeClass &c, ...);
void testUseFirstArgAfterDelete() {
int *p = new int;
delete p;
f(p); // newdelete-warning{{Use of memory after it is freed}}
}
void testUseMiddleArgAfterDelete(int *p) {
delete p;
f(0, p); // newdelete-warning{{Use of memory after it is freed}}
}
void testUseLastArgAfterDelete(int *p) {
delete p;
f(0, 0, p); // newdelete-warning{{Use of memory after it is freed}}
}
void testUseSeveralArgsAfterDelete(int *p) {
delete p;
f(p, p, p); // newdelete-warning{{Use of memory after it is freed}}
}
void testUseRefArgAfterDelete(SomeClass &c) {
delete &c;
g(c); // newdelete-warning{{Use of memory after it is freed}}
}
void testVariadicArgAfterDelete() {
SomeClass c;
int *p = new int;
delete p;
g(c, 0, p); // newdelete-warning{{Use of memory after it is freed}}
}
void testUseMethodArgAfterDelete(int *p) {
SomeClass *c = new SomeClass;
delete p;
c->f(p); // newdelete-warning{{Use of memory after it is freed}}
}
void testUseThisAfterDelete() {
SomeClass *c = new SomeClass;
delete c;
c->f(0); // newdelete-warning{{Use of memory after it is freed}}
}
void testDoubleDelete() {
int *p = new int;
delete p;
delete p; // newdelete-warning{{Attempt to free released memory}}
}
void testExprDeleteArg() {
int i;
delete &i; // newdelete-warning{{Argument to 'delete' is the address of the local variable 'i', which is not memory allocated by 'new'}}
}
void testExprDeleteArrArg() {
int i;
delete[] & i; // newdelete-warning{{Argument to 'delete[]' is the address of the local variable 'i', which is not memory allocated by 'new[]'}}
}
void testAllocDeallocNames() {
int *p = new(std::nothrow) int[1];
delete[] (++p);
// newdelete-warning@-1{{Argument to 'delete[]' is offset by 4 bytes from the start of memory allocated by 'new[]'}}
}
//--------------------------------
// Test escape of newed const pointer. Note, a const pointer can be deleted.
//--------------------------------
struct StWithConstPtr {
const int *memp;
};
void escape(const int &x);
void escapeStruct(const StWithConstPtr &x);
void escapePtr(const StWithConstPtr *x);
void escapeVoidPtr(const void *x);
void testConstEscape() {
int *p = new int(1);
escape(*p);
} // no-warning
void testConstEscapeStruct() {
StWithConstPtr *St = new StWithConstPtr();
escapeStruct(*St);
} // no-warning
void testConstEscapeStructPtr() {
StWithConstPtr *St = new StWithConstPtr();
escapePtr(St);
} // no-warning
void testConstEscapeMember() {
StWithConstPtr St;
St.memp = new int(2);
escapeVoidPtr(St.memp);
} // no-warning
void testConstEscapePlacementNew() {
int *x = (int *)malloc(sizeof(int));
void *y = new (x) int;
escapeVoidPtr(y);
} // no-warning
//============== Test Uninitialized delete delete[]========================
void testUninitDelete() {
int *x;
int * y = new int;
delete y;
delete x; // expected-warning{{Argument to 'delete' is uninitialized}}
}
void testUninitDeleteArray() {
int *x;
int * y = new int[5];
delete[] y;
delete[] x; // expected-warning{{Argument to 'delete[]' is uninitialized}}
}
void testUninitFree() {
int *x;
free(x); // expected-warning{{1st function call argument is an uninitialized value}}
}
void testUninitDeleteSink() {
int *x;
delete x; // expected-warning{{Argument to 'delete' is uninitialized}}
(*(volatile int *)0 = 1); // no warn
}
void testUninitDeleteArraySink() {
int *x;
delete[] x; // expected-warning{{Argument to 'delete[]' is uninitialized}}
(*(volatile int *)0 = 1); // no warn
}
namespace reference_count {
class control_block {
unsigned count;
public:
control_block() : count(0) {}
void retain() { ++count; }
int release() { return --count; }
};
template <typename T>
class shared_ptr {
T *p;
control_block *control;
public:
shared_ptr() : p(0), control(0) {}
explicit shared_ptr(T *p) : p(p), control(new control_block) {
control->retain();
}
shared_ptr(shared_ptr &other) : p(other.p), control(other.control) {
if (control)
control->retain();
}
~shared_ptr() {
if (control && control->release() == 0) {
delete p;
delete control;
}
};
T &operator *() {
return *p;
};
void swap(shared_ptr &other) {
T *tmp = p;
p = other.p;
other.p = tmp;
control_block *ctrlTmp = control;
control = other.control;
other.control = ctrlTmp;
}
};
void testSingle() {
shared_ptr<int> a(new int);
*a = 1;
}
void testDouble() {
shared_ptr<int> a(new int);
shared_ptr<int> b = a;
*a = 1;
}
void testInvalidated() {
shared_ptr<int> a(new int);
shared_ptr<int> b = a;
*a = 1;
extern void use(shared_ptr<int> &);
use(b);
}
void testNestedScope() {
shared_ptr<int> a(new int);
{
shared_ptr<int> b = a;
}
*a = 1;
}
void testSwap() {
shared_ptr<int> a(new int);
shared_ptr<int> b;
shared_ptr<int> c = a;
shared_ptr<int>(c).swap(b);
}
void testUseAfterFree() {
int *p = new int;
{
shared_ptr<int> a(p);
shared_ptr<int> b = a;
}
// FIXME: We should get a warning here, but we don't because we've
// conservatively modeled ~shared_ptr.
*p = 1;
}
}
// Test double delete
class DerefClass{
public:
int *x;
DerefClass() {}
~DerefClass() {*x = 1;}
};
void testDoubleDeleteClassInstance() {
DerefClass *foo = new DerefClass();
delete foo;
delete foo; // newdelete-warning {{Attempt to delete released memory}}
}
class EmptyClass{
public:
EmptyClass() {}
~EmptyClass() {}
};
void testDoubleDeleteEmptyClass() {
EmptyClass *foo = new EmptyClass();
delete foo;
delete foo; // newdelete-warning {{Attempt to delete released memory}}
}
struct Base {
virtual ~Base() {}
};
struct Derived : Base {
};
Base *allocate() {
return new Derived;
}
void shouldNotReportLeak() {
Derived *p = (Derived *)allocate();
delete p;
}