[cfe-commits] r55299 - in /cfe/trunk/lib: AST/Expr.cpp CodeGen/CGExprConstant.cpp

[Daniel Dunbar]

Nice, thanks! A few notes:


  return builtinID == Builtin::BI__builtin___CFStringMakeConstantString ||
> -         builtinID == Builtin::BI__builtin_classify_type;
> +         builtinID == Builtin::BI__builtin_classify_type ||
> +         builtinID == Builtin::BI__builtin_huge_valf;
>

Quite a few builtins are treated as constant exprs. We should probably add
another parameter to BUILTIN in Builtins.def to handle this instead of
building a big disjunction here.

+  llvm::Constant *VisitCallExpr(const CallExpr *E) {
> +    if (const ImplicitCastExpr *IcExpr =
> +        dyn_cast<const ImplicitCastExpr>(E->getCallee()))
> +      if (const DeclRefExpr *DRExpr =
> +          dyn_cast<const DeclRefExpr>(IcExpr->getSubExpr()))
> +        if (const FunctionDecl *FDecl =
> +            dyn_cast<const FunctionDecl>(DRExpr->getDecl()))
> +          if (unsigned builtinID = FDecl->getIdentifier()->getBuiltinID())
> +            return EmitBuiltinExpr(builtinID, E);
> +
> +    CGM.ErrorUnsupported(E, "constant call expression");
> +    return llvm::Constant::getNullValue(ConvertType(E->getType()));
> +  }


This seems rather fragile and possibly broken. Two immediates issues:
(1) The cast is being ignored, which probably means we may end up emitting
the wrong type.
(2) We also should handle the case when there is no ImplicitCastExpr of a
builtin.

 - Daniel
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