Re: [PATCH] ArmPkg/CompilerIntrinsicsLib: fix GCC8 warning for __aeabi_memcpy aliases

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 7 June 2018 at 19:02, Michael Zimmermann <sigmaepsilon92@gmail.com> wrote:
> Hi Ard,
>
> yes that fixes the problem too and looks much better, thx!

Pushed as a683ceca800e9

Thanks!

> On Thu, Jun 7, 2018 at 9:05 AM Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
>>
>> On 7 June 2018 at 07:47, Michael Zimmermann <sigmaepsilon92@gmail.com> wrote:
>> > This was the warning(shown for __aeabi_memcpy, __aeabi_memcpy4 and __aeabi_memcpy8):
>> > ArmPkg/Library/CompilerIntrinsicsLib/memcpy.c:42:6: error: '__aeabi_memcpy8' alias between functions of incompatible types 'void(void
>> > *, const void *, size_t)' {aka 'void(void *, const void *, unsigned int)'} and 'void *(void *, const void *, size_t)' {aka 'void
>> > *(void *, const void *, unsigned int)'} [-Werror=attribute-alias]
>> > void __aeabi_memcpy8(void *dest, const void *src, size_t n);
>> > ^~~~~~~~~~~~~~~
>> > ArmPkg/Library/CompilerIntrinsicsLib/memcpy.c:19:7: note: aliased declaration here
>> > void *__memcpy(void *dest, const void *src, size_t n)
>> >
>> > The problem is the different return type(void vs void*).
>> > This commit adds a wrapper '__aeabi___memcpy' with a void return value.
>> >
>> > Contributed-under: TianoCore Contribution Agreement 1.1
>> > Signed-off-by: Michael Zimmermann <sigmaepsilon92@gmail.com>
>> > ---
>> >  ArmPkg/Library/CompilerIntrinsicsLib/memcpy.c | 11 ++++++++---
>> >  1 file changed, 8 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/ArmPkg/Library/CompilerIntrinsicsLib/memcpy.c b/ArmPkg/Library/CompilerIntrinsicsLib/memcpy.c
>> > index a944e00b89e1..507234186fa9 100644
>> > --- a/ArmPkg/Library/CompilerIntrinsicsLib/memcpy.c
>> > +++ b/ArmPkg/Library/CompilerIntrinsicsLib/memcpy.c
>> > @@ -31,14 +31,19 @@ __attribute__((__alias__("__memcpy")))
>> >  void *memcpy(void *dest, const void *src, size_t n);
>> >
>> >  #ifdef __arm__
>> > +static __attribute__((__used__))
>> > +void __aeabi___memcpy(void *dest, const void *src, size_t n)
>> > +{
>> > +  __memcpy(dest, src, n);
>> > +}
>> >
>> > -__attribute__((__alias__("__memcpy")))
>> > +__attribute__((__alias__("__aeabi___memcpy")))
>> >  void __aeabi_memcpy(void *dest, const void *src, size_t n);
>> >
>> > -__attribute__((__alias__("__memcpy")))
>> > +__attribute__((__alias__("__aeabi___memcpy")))
>> >  void __aeabi_memcpy4(void *dest, const void *src, size_t n);
>> >
>> > -__attribute__((__alias__("__memcpy")))
>> > +__attribute__((__alias__("__aeabi___memcpy")))
>> >  void __aeabi_memcpy8(void *dest, const void *src, size_t n);
>> >
>> >  #endif
>>
>> Thanks Michael.
>>
>> Would this fix the problem as well?
>>
>> --- a/ArmPkg/Library/CompilerIntrinsicsLib/memcpy.c
>> +++ b/ArmPkg/Library/CompilerIntrinsicsLib/memcpy.c
>> @@ -16,20 +16,21 @@
>>  typedef __SIZE_TYPE__ size_t;
>>
>>  static __attribute__((__used__))
>> -void *__memcpy(void *dest, const void *src, size_t n)
>> +void __memcpy(void *dest, const void *src, size_t n)
>>  {
>>    unsigned char *d = dest;
>>    unsigned char const *s = src;
>>
>>    while (n--)
>>      *d++ = *s++;
>> +}
>>
>> +void *memcpy(void *dest, const void *src, size_t n)
>> +{
>> +  __memcpy(dest, src, n);
>>    return dest;
>>  }
>>
>> -__attribute__((__alias__("__memcpy")))
>> -void *memcpy(void *dest, const void *src, size_t n);
>> -
>>  #ifdef __arm__
>>
>>  __attribute__((__alias__("__memcpy")))