[PATCH 5/6]AArch64: Fix Armv9-a warnings that get emitted whenever a ACLE header is used.

[Richard Sandiford]

Tamar Christina <tamar.christina@arm.com> writes:
> Hi All,
>
> At the moment, trying to use -march=armv9-a with any ACLE header such as
> arm_neon.h results in rows and rows of warnings saying:
>
> <built-in>: warning: "__ARM_ARCH" redefined
> <built-in>: note: this is the location of the previous definition
>
> This is obviously not useful and happens because the header was defined at
> __ARM_ARCH == 8 and the commandline changes it.
>
> The Arm port solves this by undef the macro during argument processing and we do
> the same on AArch64 for the majority of macros.  However we define this macro
> using a different helper which requires the manual undef.
>
> Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
>
> Ok for master?
>
> Thanks,
> Tamar
>
> gcc/ChangeLog:
>
> 	* config/aarch64/aarch64-c.cc (aarch64_update_cpp_builtins): Add undef.

OK!  Thanks for fixing this.

Richard.

>
> gcc/testsuite/ChangeLog:
>
> 	* gcc.target/aarch64/armv9_warning.c: New test.
>
> --- inline copy of patch -- 
> diff --git a/gcc/config/aarch64/aarch64-c.cc b/gcc/config/aarch64/aarch64-c.cc
> index 578ec6f45b06347d90f951b37064006786baf10f..ab8844f6049dc95b97648b651bfcd3a4ccd3ca0b 100644
> --- a/gcc/config/aarch64/aarch64-c.cc
> +++ b/gcc/config/aarch64/aarch64-c.cc
> @@ -82,6 +82,7 @@ aarch64_update_cpp_builtins (cpp_reader *pfile)
>  {
>    aarch64_def_or_undef (flag_unsafe_math_optimizations, "__ARM_FP_FAST", pfile);
>  
> +  cpp_undef (pfile, "__ARM_ARCH");
>    builtin_define_with_int_value ("__ARM_ARCH", AARCH64_ISA_V9A ? 9 : 8);
>  
>    builtin_define_with_int_value ("__ARM_SIZEOF_MINIMAL_ENUM",
> diff --git a/gcc/testsuite/gcc.target/aarch64/armv9_warning.c b/gcc/testsuite/gcc.target/aarch64/armv9_warning.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..35690d5bce790e11331788aacef00f3f35cdf216
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/aarch64/armv9_warning.c
> @@ -0,0 +1,5 @@
> +/* { dg-do compile } */
> +/* { dg-additional-options "-march=armv9-a -Wpedantic -Werror" } */
> +
> +#include <arm_neon.h>
> +