5337efc69c
Throw away MallocChecker warnings that occur after releasing a pointer within a destructor (or its callees) after performing C11 atomic fetch_add or fetch_sub within that destructor (or its callees). This is an indication that the destructor's class is likely a reference-counting pointer. The analyzer is not able to understand that the original reference count is usually large enough to avoid most use-after-frees. Even when the smart pointer is a local variable, we still have these false positives that this patch suppresses, because the analyzer doesn't currently support atomics well enough. Differential Revision: https://reviews.llvm.org/D43791 llvm-svn: 326249
75 lines
1.9 KiB
C++
75 lines
1.9 KiB
C++
// RUN: %clang_analyze_cc1 -analyzer-checker=core,cplusplus.NewDelete -std=c++11 -verify %s
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// RUN: %clang_analyze_cc1 -analyzer-checker=core,cplusplus.NewDeleteLeaks -DLEAKS -std=c++11 -verify %s
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// RUN: %clang_analyze_cc1 -analyzer-checker=core,cplusplus.NewDelete -std=c++11 -DTEST_INLINABLE_ALLOCATORS -verify %s
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// RUN: %clang_analyze_cc1 -analyzer-checker=core,cplusplus.NewDeleteLeaks -DLEAKS -std=c++11 -DTEST_INLINABLE_ALLOCATORS -verify %s
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// expected-no-diagnostics
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#include "Inputs/system-header-simulator-cxx.h"
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typedef enum memory_order {
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memory_order_relaxed = __ATOMIC_RELAXED,
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memory_order_consume = __ATOMIC_CONSUME,
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memory_order_acquire = __ATOMIC_ACQUIRE,
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memory_order_release = __ATOMIC_RELEASE,
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memory_order_acq_rel = __ATOMIC_ACQ_REL,
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memory_order_seq_cst = __ATOMIC_SEQ_CST
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} memory_order;
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class Obj {
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int RefCnt;
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public:
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int incRef() {
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return __c11_atomic_fetch_add((volatile _Atomic(int) *)&RefCnt, 1,
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memory_order_relaxed);
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}
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int decRef() {
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return __c11_atomic_fetch_sub((volatile _Atomic(int) *)&RefCnt, 1,
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memory_order_relaxed);
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}
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void foo();
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};
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class IntrusivePtr {
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Obj *Ptr;
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public:
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IntrusivePtr(Obj *Ptr) : Ptr(Ptr) {
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Ptr->incRef();
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}
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IntrusivePtr(const IntrusivePtr &Other) : Ptr(Other.Ptr) {
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Ptr->incRef();
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}
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~IntrusivePtr() {
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// We should not take the path on which the object is deleted.
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if (Ptr->decRef() == 1)
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delete Ptr;
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}
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Obj *getPtr() const { return Ptr; }
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};
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void testDestroyLocalRefPtr() {
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IntrusivePtr p1(new Obj());
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{
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IntrusivePtr p2(p1);
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}
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// p1 still maintains ownership. The object is not deleted.
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p1.getPtr()->foo(); // no-warning
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}
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void testDestroySymbolicRefPtr(const IntrusivePtr &p1) {
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{
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IntrusivePtr p2(p1);
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}
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// p1 still maintains ownership. The object is not deleted.
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p1.getPtr()->foo(); // no-warning
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}
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