ChuanqiXu added inline comments.
================ Comment at: clang/lib/Sema/SemaTemplate.cpp:2658-2682 + Expr::EvalResult EVRX, EVRY; + if (!DefaultArgumentX->EvaluateAsConstantExpr(EVRX, C) || + !DefaultArgumentY->EvaluateAsConstantExpr(EVRY, C)) + return false; + + APValue VX = EVRX.Val, VY = EVRY.Val; + if (VX.getKind() != VY.getKind()) ---------------- urnathan wrote: > ChuanqiXu wrote: > > urnathan wrote: > > > I'm kind of surprised how complex this check is. Isn't there an AST > > > comparator available somewhere? > > I found ODRHash. I think it is much better now. > hm that suggests there there must be a comparator too -- this isn't a > cryptographically strong hash is it? How would the compiler currently make > use of 'definitely different' and 'probably the same' without such a > comparator? Yeah, I am sure there is not an such comparator. Or it has some methods like: `ASTContext::hasSameType` for type and `ASTContext::isSameEntity()` for Decl. But it lacks such methods now for Stmt and Expr. > How would the compiler currently make use of 'definitely different' and > 'probably the same' without such a comparator? Now it uses the two methods I listed above and ODRHash to compare. I think the two methods works for 'definitely different' and ODRHash works for 'probably the same'. So it's the reason why my previous implementation looks lengthy. Since I want to handle it by hand. (The previous method only works for simple Expr. I think it would be large work to implement comparator for whole Expr or Stmt). CHANGES SINCE LAST ACTION https://reviews.llvm.org/D118034/new/ https://reviews.llvm.org/D118034 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
