================
@@ -3300,6 +3300,73 @@ remove the const qualifier from the original declaration
or use a mutable copy.
### alpha.cplusplus
+(alpha-cplusplus-danglingptrderef)=
+
+#### alpha.cplusplus.DanglingPtrDeref (C++)
+
+Check for dereferences of pointers that refer to an object whose
+lifetime has already ended. Such a pointer is dangling. The checker
+reports it when it is dereferenced and when it is passed to a function.
+This includes a dereference in a return statement. A return statement that
+does not dereference the pointer does not lead to a report. Such a case is
+reported by the {ref}`core-StackAddressEscape` checker.
+
+Each object is reported at most once on an execution path. If the same dangling
+pointer is used several times then only the first use is reported.
+
+```cpp
+void test_deref() {
+ int *ptr = 0;
+ {
+ int num = 5;
+ ptr = #
+ } // note: 'num' is destroyed here
+ *ptr = 6; // warn: use of 'num' after its lifetime ended
+}
+
+int test_deref_in_return() {
+ int *ptr = 0;
+ {
+ int num = 5;
+ ptr = #
+ } // note: 'num' is destroyed here
+ return *ptr; // warn: use of 'num' after its lifetime ended
+}
+
+void test_in_scope() {
+ int num = 5;
+ int *ptr = #
+ {
+ *ptr = 6; // no warning, 'num' is still in scope
+ }
+}
+```
+
+The `-analyzer-config cfg-lifetime=true` option is a prerequisite for these
+reports. Without it the checker does not report anything and no error is
emitted
+by the analyzer.
+
+**Limitations**
+
+If the analyzer cannot analyze the body of the called function, for example
because
+its definition is not available in the given translation unit, then a dangling
+pointer passed to it is reported even if the function would never dereference
+it. This can lead to false positives.
----------------
benedekaibas wrote:
Applied changes here:
[0181e05](https://github.com/llvm/llvm-project/pull/216688/commits/0181e057fbd2e3fe44f3a20be311a14390761ced)
https://github.com/llvm/llvm-project/pull/216688
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