Remove early-exit for non-ptr-to-ptr casts

This looks like an attempted optimization, but all tests pass without it
if we just ignore the cast kinds that cast between pointers and values
and vice versa.

This simplifies the flow for more advanced cast expressions.

1 files changed, 2 insertions, 24 deletions

diff --git a/iwyu.cc b/iwyu.cc
index 20308a5..1c3f29e 100644
--- a/iwyu.cc
+++ b/iwyu.cc
@@ -2011,21 +2011,6 @@ class IwyuBaseAstVisitor : public BaseAstVisitor<Derived> {
     const Type* const deref_from_type = RemovePointersAndReferences(from_type);
     const Type* const deref_to_type = RemovePointersAndReferences(to_type);
 
-    // For all those casts that don't result in function calls
-    // (everything except a user-defined cast or a constructor cast),
-    // we only care about the need for full types when casting either
-    // a pointer to a pointer, or any type to a reference.
-    // Unfortunately, when casting to a reference, clang seems to
-    // strip the reference off of to_type, so we need a separate
-    // function call to tell.
-    if (expr->getCastKind() != clang::CK_UserDefinedConversion &&
-        expr->getCastKind() != clang::CK_ConstructorConversion) {
-      if (!((from_type->hasPointerRepresentation() &&   // pointer or reference
-             to_type->hasPointerRepresentation()) ||
-            IsCastToReferenceType(expr)))
-        return true;    // we only care about ptr-to-ptr casts for this check
-    }
-
     bool need_full_deref_from_type = false;
     bool need_full_deref_to_type = false;
     // The list of kinds: http://clang.llvm.org/doxygen/namespaceclang.html
@@ -2047,7 +2032,7 @@ class IwyuBaseAstVisitor : public BaseAstVisitor<Derived> {
                                               // the full type.
         break;
 
-      // We shouldn't be seeing any of these kinds.
+      // Ignore non-ptr-to-ptr casts.
       case clang::CK_ArrayToPointerDecay:
       case clang::CK_BooleanToSignedIntegral:
       case clang::CK_FixedPointCast:
@@ -2077,15 +2062,8 @@ class IwyuBaseAstVisitor : public BaseAstVisitor<Derived> {
       case clang::CK_PointerToIntegral:
       case clang::CK_ToUnion:
       case clang::CK_ToVoid:
-        // Due to a bug in clang, we sometimes get IntegralToPointer
-        // kinds for a cast that should be a NoOp kind:
-        //    http://llvm.org/bugs/show_bug.cgi?id=8543
-        // It's possible clang mis-categorizes in other cases too.  So
-        // I just log here, rather than asserting and possibly
-        // crashing iwyu.
-        VERRS(3) << "WARNING: Unexpected cast that involves a non-pointer: "
-                 << expr->getCastKindName() << "\n";
         break;
+
       case clang::CK_AnyPointerToBlockPointerCast:
       case clang::CK_ARCConsumeObject:
       case clang::CK_ARCExtendBlockObject: