fix(pset): fix nested invalidation inside *(*this).value

Author: qqiangwu

integration_test/safety/contract_return.cpp

@@ -32,4 +32,40 @@ int* get2()
     static int x;
     static int* y = &x;
     return y;
+}
+
+struct Dummy {
+    int m;
+};
+
+const int* get3();
+const int* get4(const Dummy& d);
+const int* get5(const Owner<int>& d);
+const int* get6(const Owner<Dummy>& d);
+const int* get7(const Owner<Pair<int, int>>& d);
+
+void test_contract_return()
+{
+    __lifetime_contracts(&get3);
+    // expected-warning@-1 {{pset(Post((return value))) = ((global), (null))}}
+
+    __lifetime_contracts(&get4);
+    // expected-warning@-1 {{pset(Pre(d)) = (*d)}}
+    // expected-warning@-2 {{pset(Pre((*d).m)) = (*d)}}
+    // expected-warning@-3 {{pset(Post((return value))) = ((null), *d)}}
+
+    __lifetime_contracts(&get5);
+    // expected-warning@-1 {{pset(Pre(d)) = (*d)}}
+    // expected-warning@-2 {{pset(Pre(*d)) = (**d)}}
+    // expected-warning@-3 {{pset(Post((return value))) = ((null), **d)}}
+
+    __lifetime_contracts(&get6);
+    // expected-warning@-1 {{pset(Pre(d)) = (*d)}}
+    // expected-warning@-2 {{pset(Pre(*d)) = (**d)}}
+    // expected-warning@-3 {{pset(Post((return value))) = ((null), **d)}}
+
+    __lifetime_contracts(&get7);
+    // expected-warning@-1 {{pset(Pre(d)) = (*d)}}
+    // expected-warning@-2 {{pset(Pre(*d)) = (**d)}}
+    // expected-warning@-3 {{pset(Post((return value))) = ((null), **d)}}
 }

lib/lifetime/LifetimePsetBuilder.cpp

@@ -841,7 +841,7 @@ class PSetsBuilder final : public ConstStmtVisitor<PSetsBuilder, void>, public P
             }
 
             if (PS.containsParent(V)) {
-                // WORKAROUND: https://github.com/qqiangwu/cppsafe/issues/82
+                // BADCASE: https://github.com/qqiangwu/cppsafe/issues/82
                 //
                 // when move var with pset {*container}, only invalidate the var itself,
                 // containers and iterators are not invalidated.
@@ -851,7 +851,6 @@ class PSetsBuilder final : public ConstStmtVisitor<PSetsBuilder, void>, public P
                 //    for (auto& x : cont) {
                 //      p = std::move(x);
                 //}
-
                 //    for (auto& x: cont) {
                 //      use(x);
                 //}
@@ -879,6 +878,20 @@ class PSetsBuilder final : public ConstStmtVisitor<PSetsBuilder, void>, public P
 
             auto DerefV = V;
             DerefV.deref();
+            if (Var == DerefV) {
+                // WORKAROUND
+                //<code>
+                // inline void PinnableWideColumns::MoveValue(std::string&& value) {
+                // std::string* const buf = value_.GetSelf();
+                // assert(buf);
+                //
+                // *buf = std::move(value);  // PMap[(*(*this).value_)] = (**(*this).value_)
+                //
+                // value_.PinSelf();
+                //}
+                //</code>
+                continue;
+            }
             if (PS.containsParent(DerefV)) {
                 setPSet(PSet::singleton(Var), PSet::invalid(Reason), Reason.getRange());
             }