[cfe-commits] [Patch] Enabling/disabling support for wchar_t type.

[John McCall]

On Sep 5, 2012, at 1:59 AM, Enea Zaffanella wrote:

> On 09/04/2012 07:47 PM, John McCall wrote:
>> On Sep 2, 2012, at 11:02 PM, Enea Zaffanella wrote:
>>> Resending to cfe-commit.
>>> 
>>> On 08/31/2012 12:09 PM, Enea Zaffanella wrote:
>>>> Hello.
>>>> 
>>>> According to language standards, the wchar_t type is
>>>>   - a library provided type in C
>>>>   - a native type in C++.
>>>> 
>>>> There are C++ compilers allowing users to enable/disable the native
>>>> support. For instance, MSVC has option /Zc:wchar_t. Even though the
>>>> default in newer versions of MSVC is to enable wchar_t support, there is
>>>> much code in the real world that will only work if this is disabled
>>>> (e.g., Qt X.Y.Z with X < 5).
>>>> 
>>>> The attached simple patch adds flag WChar to LangOptions.
>>>> The flag is similar to Bool: if set, the native wchar_t type is
>>>> supported (i.e., wchar_t will be lexed as a keyword), otherwise it won't
>>>> be supported (i.e., it will be a normal identifier). Currently, the flag
>>>> is initialized the same as CPlusPlus, so that the addition should cause
>>>> no visible change.
>>>> 
>>>> The addition of this flag will be enough for people using clang as a set
>>>> of libraries. For more "conventional" uses, it might be worth
>>>> considering the addition of a suitable command line option to toggle the
>>>> flag.
>>>> 
>>>> Opinions?
>> 
>> Please add a -cc1 option to suppress native wchar_t;  I think -fno-wchar
>> would be sufficient.
>> 
>> John.
> 
> Here is the revised patch, including a testcase.
> 
> OK to commit?

Looks great, thanks.

John.