NoQ created this revision.
NoQ added reviewers: dcoughlin, xazax.hun, a_sidorin, george.karpenkov, szepet,
rnkovacs, Szelethus.
Herald added subscribers: cfe-commits, dkrupp, donat.nagy, mikhail.ramalho,
a.sidorin, baloghadamsoftware.
If a moved-from object is passed into a conservatively evaluated function by
pointer or by reference, we assume that the function may reset its state.
Make sure it doesn't apply to const pointers and const references. Add a test
that demonstrates that it does apply to rvalue references.
Additionally, make sure that the object is invalidated when its contents change
for reasons other than invalidation caused by evaluating a call conservatively.
In particular, when the object's fields are manipulated directly, we should
assume that some sort of reset may be happening.
Repository:
rC Clang
https://reviews.llvm.org/D55289
Files:
lib/StaticAnalyzer/Checkers/MoveChecker.cpp
test/Analysis/use-after-move.cpp
Index: test/Analysis/use-after-move.cpp
===================================================================
--- test/Analysis/use-after-move.cpp
+++ test/Analysis/use-after-move.cpp
@@ -116,6 +116,19 @@
bool empty() const;
bool isEmpty() const;
operator bool() const;
+
+ void testUpdateField() {
+ A a;
+ A b = std::move(a);
+ a.i = 1;
+ a.foo(); // no-warning
+ }
+ void testUpdateFieldDouble() {
+ A a;
+ A b = std::move(a);
+ a.d = 1.0;
+ a.foo(); // no-warning
+ }
};
int bignum();
@@ -594,24 +607,50 @@
foobar(a.getI(), std::move(a)); //no-warning
}
-void not_known(A &a);
-void not_known(A *a);
+void not_known_pass_by_ref(A &a);
+void not_known_pass_by_const_ref(const A &a);
+void not_known_pass_by_rvalue_ref(A &&a);
+void not_known_pass_by_ptr(A *a);
+void not_known_pass_by_const_ptr(const A *a);
void regionAndPointerEscapeTest() {
{
A a;
A b;
b = std::move(a);
- not_known(a);
- a.foo(); //no-warning
+ not_known_pass_by_ref(a);
+ a.foo(); // no-warning
+ }
+ {
+ A a;
+ A b;
+ b = std::move(a); // expected-note{{Object 'a' is moved}}
+ not_known_pass_by_const_ref(a);
+ a.foo(); // expected-warning{{Method called on moved-from object 'a'}}
+ // expected-note@-1{{Method called on moved-from object 'a'}}
+ }
+ {
+ A a;
+ A b;
+ b = std::move(a);
+ not_known_pass_by_rvalue_ref(std::move(a));
+ a.foo(); // no-warning
}
{
A a;
A b;
b = std::move(a);
- not_known(&a);
+ not_known_pass_by_ptr(&a);
a.foo(); // no-warning
}
+ {
+ A a;
+ A b;
+ b = std::move(a); // expected-note{{Object 'a' is moved}}
+ not_known_pass_by_const_ptr(&a);
+ a.foo(); // expected-warning{{Method called on moved-from object 'a'}}
+ // expected-note@-1{{Method called on moved-from object 'a'}}
+ }
}
// A declaration statement containing multiple declarations sequences the
Index: lib/StaticAnalyzer/Checkers/MoveChecker.cpp
===================================================================
--- lib/StaticAnalyzer/Checkers/MoveChecker.cpp
+++ lib/StaticAnalyzer/Checkers/MoveChecker.cpp
@@ -527,16 +527,28 @@
ArrayRef<const MemRegion *> ExplicitRegions,
ArrayRef<const MemRegion *> Regions, const LocationContext *LCtx,
const CallEvent *Call) const {
- // In case of an InstanceCall don't remove the ThisRegion from the GDM since
- // it is handled in checkPreCall and checkPostCall.
- const MemRegion *ThisRegion = nullptr;
- if (const auto *IC = dyn_cast_or_null<CXXInstanceCall>(Call)) {
- ThisRegion = IC->getCXXThisVal().getAsRegion();
- }
-
- for (const auto *Region : ExplicitRegions) {
- if (ThisRegion != Region)
- State = removeFromState(State, Region);
+ if (Call) {
+ // Relax invalidation upon function calls: only invalidate parameters
+ // that are passed directly via non-const pointers or non-const references
+ // or rvalue references.
+ // In case of an InstanceCall don't invalidate the this-region since
+ // it is fully handled in checkPreCall and checkPostCall.
+ const MemRegion *ThisRegion = nullptr;
+ if (const auto *IC = dyn_cast_or_null<CXXInstanceCall>(Call))
+ ThisRegion = IC->getCXXThisVal().getAsRegion();
+
+ // Explicit regions are the regions passed into the call directly, but
+ // not all of them end up being invalidated. The ones that do appear in
+ // the Regions array as well.
+ for (const auto *Region : ExplicitRegions)
+ if (ThisRegion != Region)
+ if (std::find(Regions.begin(), Regions.end(), Region) != Regions.end())
+ State = removeFromState(State, Region);
+ } else {
+ // For invalidations that aren't caused by calls, assume nothing. In
+ // particular, direct write into an object's field invalidates the status.
+ for (const auto *Region : Regions)
+ State = removeFromState(State, Region->getBaseRegion());
}
return State;
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