Backport [analyzer] Fix cast evaluation on scoped enums in ExprEngine

clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h

@@ -95,11 +95,15 @@ class SValBuilder {
   }
 
   bool haveSameType(QualType Ty1, QualType Ty2) {
+    const bool BothHaveSameCanonicalTypes =
+        Context.getCanonicalType(Ty1) == Context.getCanonicalType(Ty2);
+    const bool BothHaveIntegralOrUnscopedEnumerationType =
+        Ty1->isIntegralOrUnscopedEnumerationType() &&
+        Ty2->isIntegralOrUnscopedEnumerationType();
     // FIXME: Remove the second disjunct when we support symbolic
     // truncation/extension.
-    return (Context.getCanonicalType(Ty1) == Context.getCanonicalType(Ty2) ||
-            (Ty1->isIntegralOrEnumerationType() &&
-             Ty2->isIntegralOrEnumerationType()));
+    return BothHaveSameCanonicalTypes ||
+           BothHaveIntegralOrUnscopedEnumerationType;
   }
 
   SVal evalCast(SVal val, QualType castTy, QualType originalType);

clang/test/Analysis/z3-refute-enum-crash.cpp

@@ -0,0 +1,37 @@
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection \
+// RUN:   -analyzer-config crosscheck-with-z3=true -verify %s
+//
+// RUN: %clang_analyze_cc1 -analyzer-checker=core,debug.ExprInspection \
+// RUN:   -verify %s
+//
+// REQUIRES: z3
+//
+// Requires z3 only for refutation. Works with both constraint managers.
+
+void clang_analyzer_dump(int);
+
+using sugar_t = unsigned char;
+
+// Enum types
+enum class ScopedSugared : sugar_t {};
+enum class ScopedPrimitive : unsigned char {};
+enum UnscopedSugared : sugar_t {};
+enum UnscopedPrimitive : unsigned char {};
+
+template <typename T>
+T conjure();
+
+void test_enum_types() {
+  int sym1 = static_cast<unsigned char>(conjure<ScopedSugared>()) & 0x0F;
+  int sym2 = static_cast<unsigned char>(conjure<ScopedPrimitive>()) & 0x0F;
+  int sym3 = static_cast<unsigned char>(conjure<UnscopedSugared>()) & 0x0F;
+  int sym4 = static_cast<unsigned char>(conjure<UnscopedPrimitive>()) & 0x0F;
+
+  if (sym1 && sym2 && sym3 && sym4) {
+    // no-crash on these dumps
+    clang_analyzer_dump(sym1); // expected-warning{{((unsigned char) (conj_}}
+    clang_analyzer_dump(sym2); // expected-warning{{((unsigned char) (conj_}}
+    clang_analyzer_dump(sym3); // expected-warning{{(conj_}}
+    clang_analyzer_dump(sym4); // expected-warning{{(conj_}}
+  }
+}