[PATCH] D86027: [analyzer] Add bool operator modeling for unque_ptr

[Artem Dergachev via Phabricator via cfe-commits]

NoQ added inline comments.


================
Comment at: clang/lib/StaticAnalyzer/Checkers/SmartPtrModeling.cpp:315-318
+    SVal Val = I->second;
+    for (auto si = Val.symbol_begin(), se = Val.symbol_end(); si != se; ++si) {
+      SR.markLive(*si);
+    }
----------------
Yes, this looks correct, thanks!

In the ideal world we'd have checked that `I->first` is live before marking `I->second` live. Unfortunately, currently `checkLiveSymbols` is invoked before RegionStore's live symbols detection, so we can't rely on that and it's a bug; in order to be correct, RegionStore's live symbols detection and checker's live symbols callback should engage in fixpoint iteration.


================
Comment at: clang/lib/StaticAnalyzer/Checkers/SmartPtrModeling.cpp:494-496
+      OS << "Smart pointer";
+      checkAndPrettyPrintRegion(OS, ThisRegion);
+      OS << " is non-null";
----------------
Because these note tags aren't specific to the bug report at hand, they have to be marked as //prunable// (i.e., the optional `getNoteTag()`'s parameter "`IsPrunable`" should be set to true). That'd reduce bug report clutter by not bringing in stack frames that aren't otherwise interesting for the bug report.

Something like this may act as a test (i didn't try):
```lang=c++
struct S {
  std::unique_ptr<int> P;

  void foo() {
    if (!P) { // no-note because foo() is pruned
      return;
    }
  }

  int bar() {
    P = new int(0);
    foo();
    return 1 / *P; // warning: division by zero
  }

}

```


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D86027/new/

https://reviews.llvm.org/D86027