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Date: Sat, 14 Apr 2012 02:41:00 -0000
Message-ID: <CAPOVtOvNW6+Lrxn6Tob=rBS0m1Pnh490_nR=-hvnn2p8nrDLfg@mail.gmail.com>
Subject: Re: Switching to C++ by default in 4.8
From: Chiheng Xu <chiheng.xu@gmail.com>
To: Richard Guenther <richard.guenther@gmail.com>
Cc: Bernd Schmidt <bernds@codesourcery.com>, 	Gabriel Dos Reis <gdr@integrable-solutions.net>, David Edelsohn <dje.gcc@gmail.com>, 	Diego Novillo <dnovillo@google.com>, gcc <gcc@gcc.gnu.org>
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On Wed, Apr 4, 2012 at 8:04 PM, Richard Guenther
<richard.guenther@gmail.com> wrote:
>
> I agree for the idea of converting all of GCC to C++ (whatever that means=
).
> I disagree for the part making the internal infrastructure easier to use,
> understand and maintain. =C2=A0Which means targeting mostly isolated sub-=
systems,
> like vec.h (and other various containers), double-int.[ch] (and other var=
ious
> way of representing and working with constants). =C2=A0Making tree or gim=
ple a
> C++ class with inheritance and whatever is indeed a huge waste of time
> and existing developer ressources (that, if only because they have to ada=
pt
> and maintain two completely different code-bases over some time).
>
> I expect the GCC core to maintain written in C, compiled by C++.
>

Making tree or gimple or even rtl a C++ class with inheritance should be ea=
sy.

Current functions and accessor macros can be preserved.

for example:

C:

typedef struct base_type_tag {
     int m_data_1;
} base_type;

typedef struct derived_type_tag {
     struct base_type base;
     int m_data_2;
} derived_type;

#define BASE_TYPE_ACCESSOR_MACRO_1(a)   ...
#define DERIVED_TYPE_ACCESSOR_MACRO_2(a)   ...

int base_type _func_1(base_type * p_base, ...)
{
}

int derived_type_func_2(derived_type * p_derived, ...)
{
}


C++:

class base_type {
     int m_data_1;
     getter_1();
     setter_1();
     method_1();
};

class derived_type : public base_type {
     int m_data_2;
     getter_2();
     setter_2();
     method_2();
};


#define BASE_TYPE_ACCESSOR_MACRO_1(a)   ...
#define DERIVED_TYPE_ACCESSOR_MACRO_2(a)   ...

int base_type _func_1(base_type * p_base, ...)
{
}

int derived_type_func_2(derived_type * p_derived, ...)
{
}

base_type::getter_1()
{
}

base_type::setter_1()
{
}

base_type::method_1()
{
}

derived_type::getter_2()
{
}

derived_type::setter_2()
{
}

derived_type::method_2()
{
}


--=20
Chiheng Xu