qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PULL 1/3] makefile: merge GENERATED_HEADERS & GENERATE


From: Eric Blake
Subject: Re: [Qemu-devel] [PULL 1/3] makefile: merge GENERATED_HEADERS & GENERATED_SOURCES variables
Date: Tue, 21 Mar 2017 08:48:24 -0500
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0

On 03/16/2017 04:08 AM, Markus Armbruster wrote:
> Sorry for chiming in late, I had missed this change.
> 
> Stefan Hajnoczi <address@hidden> writes:
> 
>> From: "Daniel P. Berrange" <address@hidden>
>>
>> The only functional difference between the GENERATED_HEADERS
>> and GENERATED_SOURCES variables is that 'Makefile' has a
>> dependancy on GENERATED_HEADERS, causing generated header files
>> to be created immediatey at the start of the build process.
>> There is no reason why this early creation should be restricted
>> to the .h files, and not include .c files too.
> 
> Actually, there is.
> 
> Any prerequisites of Makefile are made even by make -n.  Restricting
> them to the ones make -n absolutely needs is good practice.

In fact, this is part of what tripped me up in trying to get to a root
cause in why modifying scripts/tracetool/format/h.py didn't cause
trace.h to be regenerated.  When trace.h is treated as a prerequisite of
Makefile, it's rules get run automatically and don't show up in 'make
--debug' output (you have to resort to the noisier 'make -d' to see that
the rule was run).

> 
> Generated headers must be prerequisites of Makefile, because automatic
> dependency generation may fail without them.
> 
> There is no such reason for generated non-headers.
> 
>>                                                Merge both of
>> the variables into a single GENERATED_FILES variable to make
>> it clear it is for any type of generated file.
> 
> I don't hate this quite enough for an outright NAK at this late stage.
> I do hate it enough to ask you to think about it once more.
> 
> 

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

Attachment: signature.asc
Description: OpenPGP digital signature


reply via email to

[Prev in Thread] Current Thread [Next in Thread]