[cfe-dev] Should DiffTemplate be able to handle Integral args?

[Matthew Curtis]

Hello all,

I'm seeing an assert when compiling code like this:

    template <int i> struct X { };
    void f(X<8> x) {
       X<7> y;
       y = x;
    }


DiffTemplate/GetExpr (in ASTDiagnostic.cpp) assumes that the non-type 
args are expressions:

    void DiffTemplate() {

       // Handle Expressions
       if (NonTypeTemplateParmDecl *DefaultNTTPD =
           dyn_cast<NonTypeTemplateParmDecl>(ParamND)) {
         Expr *FromExpr, *ToExpr;
         GetExpr(FromIter, DefaultNTTPD, FromExpr);
         GetExpr(ToIter, DefaultNTTPD, ToExpr);
       }

    }

    void GetExpr(const TSTiterator &Iter, ) {

       if (!Iter.isEnd())
         ArgExpr = Iter->getAsExpr();

    }


But in some cases they are integral values (e.g. Iter->getKind() == 
TemplateArgument::Integral). As a result, an assertion inside 
Iter->getAsExpr() fails.

Is DiffTemplate broken or should the integral arg never have found it's 
way to it?

BTW, I modified GetExpr to create an Expr from the Integral arg and that 
seemed to work, but I'm not sure if that's the right thing to do.

Cheers,
Matthew C.


-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

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