Re: [PATCH] make function_args_iterator a proper iterator

[Martin Sebor <msebor@gmail.com>]

On 11/19/2018 03:32 AM, Richard Biener wrote:
> On Sat, Nov 17, 2018 at 12:05 AM Martin Sebor <msebor@gmail.com> wrote:
>>
>> To encourage and simplify the adoption of iterator classes in
>> GCC the attached patch turns the function_args_iterator struct
>> into an (almost) proper C++ iterator class that can be used
>> the same way as traditional forward iterators.
>>
>> The patch also replaces all of the 26 uses of the legacy
>> FOREACH_FUNCTION_ARGS macro with ordinary for loops that use
>> function_args_iterator directly, and also poisons both
>> FOREACH_FUNCTION_ARGS and the unused FOREACH_FUNCTION_ARGS_PTR
>> macros.
>>
>> The few dozen (hundred?) existing uses of for loops that iterate
>> over function parameter types using the TREE_CHAIN() macro can
>> be relatively easily modified to adopt the iterator approach over
>> time.  (The patch stops of short of making this change.)
>>
>> Eventually, when GCC moves to more a recent C++ revision, it will
>> become possible to simplify the for loops to make use of the range
>> based for loop syntax along the lines of:
>>
>>    for (auto argtype: function_args (functype))
>>      {
>>        ...
>>      }
>>
>> Tested on x86_64-linux, and (lightly) on powerpc64le-linux using
>> a cross-compiler.  I'll test the changes to the other back ends
>> before committing.
>
> This isn't stage3 material.

In the response referenced below Jeff requested I make use of
iterators in my patch.  This simply does what he asked for,
except throughout all of GCC.

Martin

>
> Richard.
>
>>
>> Martin
>>
>> PS For some additional background on this change see:
>>    https://gcc.gnu.org/ml/gcc-patches/2018-11/msg00493.html