[clang][dataflow] fix assert in Environment::getResultObjectLocation

[paulsemel]

When calling Environment::getResultObjectLocation with a CXXOperatorCallExpr that is a prvalue, we just hit an assert because no record was ever created.

[llvmbot]

@llvm/pr-subscribers-clang-analysis

@llvm/pr-subscribers-clang

Author: Paul Semel (paulsemel)

Changes

When calling Environment::getResultObjectLocation with a CXXOperatorCallExpr that is a prvalue, we just hit an assert because no record was ever created.

---

Full diff: https://github.com/llvm/llvm-project/pull/79608.diff

1 Files Affected:

• (modified) clang/lib/Analysis/FlowSensitive/Transfer.cpp (+5)

diff --git a/clang/lib/Analysis/FlowSensitive/Transfer.cpp b/clang/lib/Analysis/FlowSensitive/Transfer.cpp
index 2271a75fbcaf709..3b028a3200b72b2 100644
--- a/clang/lib/Analysis/FlowSensitive/Transfer.cpp
+++ b/clang/lib/Analysis/FlowSensitive/Transfer.cpp
@@ -536,6 +536,11 @@ class TransferVisitor : public ConstStmtVisitor<TransferVisitor> {
 
       copyRecord(*LocSrc, *LocDst, Env);
       Env.setStorageLocation(*S, *LocDst);
+    } else {
+      // CXXOperatorCallExpr can be prvalues, in which case we must create a
+      // record for them in order for `Environment::getResultObjectLocation()`
+      // to be able to return a value.
+      VisitCallExpr(S);
     }
   }
 

[martinboehme]

Thanks for catching this!

Can you add a test that fails without the fix? See the existing test ResultObjectLocation in TransferTest.cpp -- you should be able to create a new test based on this that has a CXXOperatorCallExpr returning a record by value.

[paulsemel]

The added test aborts (assert fails) without this patch.