[Clang] fix range calculation for conditionals with throw expressions

clang/docs/ReleaseNotes.rst

@@ -517,6 +517,7 @@ Bug Fixes to C++ Support
   certain situations. (#GH47400), (#GH90896)
 - Fix erroneous templated array size calculation leading to crashes in generated code. (#GH41441)
 - During the lookup for a base class name, non-type names are ignored. (#GH16855)
+- Fixed assertion failure in range calculations for conditional throw expressions (#GH111854)
 
 Bug Fixes to AST Handling
 ^^^^^^^^^^^^^^^^^^^^^^^^^

clang/lib/Sema/SemaChecking.cpp

@@ -9827,6 +9827,9 @@ static IntRange GetExprRange(ASTContext &C, const Expr *E, unsigned MaxWidth,
     return IntRange(BitField->getBitWidthValue(C),
                     BitField->getType()->isUnsignedIntegerOrEnumerationType());
 
+  if (GetExprType(E)->isVoidType())
+    return IntRange{0, true};
+
   return IntRange::forValueOfType(C, GetExprType(E));
 }
 

clang/test/SemaCXX/conditional-expr.cpp

@@ -429,3 +429,10 @@ void g() {
   long e = a = b ? throw 0 : throw 1;
 }
 } // namespace PR46484
+
+namespace GH111854 {
+void f() {
+  (true ? throw 0 : 0) <= 0;  // expected-warning {{relational comparison result unused}}
+  (false ? 0 : throw 0) <= 0; // expected-warning {{relational comparison result unused}}
+}
+}