[dpdk-dev] build failure with MinGW GCC 10.2

[Dmitry Kozlyuk]

On Tue, 01 Dec 2020 14:18:53 +0100, Thomas Monjalon wrote:
> Hi,
> 
> I'm hitting an issue with x86_64-w64-mingw32-gcc (GCC) 10.2.0:
> 	lib/librte_eal/windows/eal_memory.c:30:14: error:
> 	redeclaration of ‘enum MEM_EXTENDED_PARAMETER_TYPE’
> and others:
> 	redeclaration of enumerator ‘MemExtendedParameterInvalidType’
> 	redeclaration of enumerator ‘MemExtendedParameterAddressRequirements’
> 	redeclaration of enumerator ‘MemExtendedParameterNumaNode’
> 	redeclaration of enumerator ‘MemExtendedParameterPartitionHandle’
> 	redeclaration of enumerator ‘MemExtendedParameterUserPhysicalHandle’
> 	redeclaration of enumerator ‘MemExtendedParameterAttributeFlags’
> 	redeclaration of enumerator ‘MemExtendedParameterMax’
> 	redefinition of ‘struct MEM_EXTENDED_PARAMETER’
> 	"MEM_EXTENDED_PARAMETER_TYPE_BITS" redefined
> 
> I see in the code it should be avoided:
> 
> /* MinGW-w64 headers lack VirtualAlloc2() in some distributions.
>  * Provide a copy of definitions and code to load it dynamically.
>  * Note: definitions are copied verbatim from Microsoft documentation
>  * and don't follow DPDK code style.
>  *
>  * MEM_RESERVE_PLACEHOLDER being defined means VirtualAlloc2() is present too.
>  */
> #ifndef MEM_PRESERVE_PLACEHOLDER
> 
> Does it mean using this flag is not true anymore in recent MinGW?

I think the #ifndef test is incorrect, maybe MEM_PRESERVE_PLACEHOLDER is not
a macro in MinGW headers as it is in Windows SDK.

What's your environment?

I can't reproduce this with the latest MinGW-w64 8.0.0 for Windows from
https://sourceforge.net/projects/mingw-w64/files/, x86_64-win32-seh flavour
(GCC 8.1.0), and neither with MinGW-w64 6.0.0 (9.3.0) on NixOS.