[analyzer] PR41269: Add a bit of C++ smart pointer modeling.

Implement cplusplus.SmartPtrModeling, a new checker that doesn't
emit any warnings but models methods of smart pointers more precisely.

For now the only thing it does is make `(bool) P` return false when `P`
is a freshly moved pointer. This addresses a false positive in the
use-after-move-checker.

Differential Revision: https://reviews.llvm.org/D60796

llvm-svn: 358944

1 files changed, 12 insertions, 0 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/MoveChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MoveChecker.cpp
index 545f310a51b..891a350ff23 100644
--- a/clang/lib/StaticAnalyzer/Checkers/MoveChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MoveChecker.cpp
@@ -227,6 +227,18 @@ private:
 
 REGISTER_MAP_WITH_PROGRAMSTATE(TrackedRegionMap, const MemRegion *, RegionState)
 
+// Define the inter-checker API.
+namespace clang {
+namespace ento {
+namespace move {
+bool isMovedFrom(ProgramStateRef State, const MemRegion *Region) {
+  const RegionState *RS = State->get<TrackedRegionMap>(Region);
+  return RS && (RS->isMoved() || RS->isReported());
+}
+} // namespace move
+} // namespace ento
+} // namespace clang
+
 // If a region is removed all of the subregions needs to be removed too.
 static ProgramStateRef removeFromState(ProgramStateRef State,
                                        const MemRegion *Region) {