misc-misplaced-widening-cast: fix assertion

[AndersRonnholm]

Summary

Fixes assert reported in https://bugs.llvm.org/show_bug.cgi?id=33660

[danielmarjamaki]

LGTM. I let others approve this.

[xazax.hun]

LGTM!

[xazax.hun]

test/clang-tidy/misc-misplaced-widening-cast-explicit-only.cpp

63

Isn't this testcase a bit overcomplicated to demonstrate the issue?

[alexfh]

LG. Thank you for the fix!

test/clang-tidy/misc-misplaced-widening-cast-explicit-only.cpp

63

It's what creduce spat out a few hours after I had run it on a pretty large preprocessed source. I wouldn't spend more time simplifying the case ;)

clang-tidy/misc/MisplacedWideningCastCheck.cpp

if (!CheckImplicitCasts && isa<ImplicitCastExpr>(Cast))
     return;
   if (Cast->getLocStart().isMacroID())
     return;
 
   const auto *Calc = Result.Nodes.getNodeAs<Expr>("Calc");
   if (Calc->getLocStart().isMacroID())
     return;
 
+  if (Cast->isTypeDependent() || Cast->isValueDependent() ||
+      Calc->isTypeDependent() || Calc->isValueDependent())
+    return;
+
   ASTContext &Context = *Result.Context;
 
   QualType CastType = Cast->getType();
   QualType CalcType = Calc->getType();
 
   // Explicit truncation using cast.
   if (Context.getIntWidth(CastType) < Context.getIntWidth(CalcType))
     return;

test/clang-tidy/misc-misplaced-widening-cast-explicit-only.cpp

if (a < 0) {
     return a * 1000;
   } else if (a > 0) {
     return (long)(a * 1000);
     // CHECK-MESSAGES: :[[@LINE-1]]:12: warning: either cast from 'int' to 'long'
   } else {
     return (long)a * 1000;
   }
 }
+
+// Shall not generate an assert. https://bugs.llvm.org/show_bug.cgi?id=33660
+template <class> class A {
+  enum Type {};
+  static char *m_fn1() { char p = (Type)(&p - m_fn1()); }
+};