[PATCH] D140753: [clang][dataflow] Check both operand's type in mergeDistinctValues

[Jun Zhang via Phabricator via cfe-commits]

junaire updated this revision to Diff 485654.
junaire added a comment.

Update patch according to @ymandel 's suggestion. Thanks!


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D140753/new/

https://reviews.llvm.org/D140753

Files:
  clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
  clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp


Index: clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp
===================================================================
--- clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp
+++ clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp
@@ -2970,6 +2970,23 @@
       cxxConstructorDecl(ofClass(hasName("Target"))));
 }
 
+// This is regression test, it shouldn't crash.
+TEST_P(UncheckedOptionalAccessTest, Bitfield) {
+  using namespace ast_matchers;
+  ExpectDiagnosticsFor(
+      R"(
+    #include "unchecked_optional_access_test.h"
+    struct Dst {
+      unsigned int n : 1;
+    };
+    void target() {
+      $ns::$optional<bool> v;
+      Dst d;
+      if (v.has_value())
+        d.n = v.value();
+    }
+  )");
+}
 // FIXME: Add support for:
 // - constructors (copy, move)
 // - assignment operators (default, copy, move)
Index: clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
===================================================================
--- clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
+++ clang/lib/Analysis/FlowSensitive/DataflowEnvironment.cpp
@@ -93,7 +93,18 @@
                                   Environment::ValueModel &Model) {
   // Join distinct boolean values preserving information about the constraints
   // in the respective path conditions.
-  if (auto *Expr1 = dyn_cast<BoolValue>(&Val1)) {
+  if (Type->isBooleanType()) {
+    // FIXME: This is sort of workaound. Since now we just ignore all (implicit)
+    // integral casts, treating the resulting value as same as the underling
+    // value, it could cause inconsistency between values after `Join` if in
+    // some paths the type doesn't strictly match.
+    // Eg:
+    // std::optional<bool> o;
+    // int x;
+    // if (o.has_value()) {
+    //   x = o.value();
+    // }
+    auto *Expr1 = cast<BoolValue>(&Val1);
     auto *Expr2 = cast<BoolValue>(&Val2);
     auto &MergedVal = MergedEnv.makeAtomicBoolValue();
     MergedEnv.addToFlowCondition(MergedEnv.makeOr(


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