Re: [Qemu-devel] [PATCH] roms/edk2-build.sh: Allow to run edk2-build.sh from command line

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 6/14/19 3:29 PM, Eric Blake wrote:
> On 6/14/19 5:16 AM, Philippe Mathieu-Daudé wrote:
>> Cc'ing Eric :)
>>
> 
>>> When running this script out of 'make', we get:
>>>
>>>   $ cd roms
>>>   $ ./edk2-build.sh aarch64 --arch=AARCH64 --platform=ArmVirtPkg/ArmVirtQemu.dsc > /dev/null
>>>   ./edk2-build.sh: line 46: MAKEFLAGS: unbound variable
>>>
>>> Fix this by checking the variable is defined before using it,
>>> else use a default value.
>>>
>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>> ---
>>>  roms/edk2-build.sh | 8 +++++++-
>>>  1 file changed, 7 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/roms/edk2-build.sh b/roms/edk2-build.sh
>>> index 4f46f8a6a2..5390228b4e 100755
>>> --- a/roms/edk2-build.sh
>>> +++ b/roms/edk2-build.sh
> 
> This is running under /bin/bash (hmm - not '/bin/env bash' like other
> scripts in qemu?), so...
> 
>>> @@ -43,7 +43,13 @@ fi
>>>  # any), for the edk2 "build" utility.
>>>  source ../edk2-funcs.sh
>>>  edk2_toolchain=$(qemu_edk2_get_toolchain "$emulation_target")
>>> -edk2_thread_count=$(qemu_edk2_get_thread_count "$MAKEFLAGS")
>>> +if [ -v MAKEFLAGS ]; then
> 
> the non-portable bashism '[ -v' works. However, it's just as easy to

Ah, OK.

> work around this problem portably for all POSIX shells without needing 'if':
> 
>>> +  edk2_thread_count=$(qemu_edk2_get_thread_count "$MAKEFLAGS")
>>> +else
>>> +  # We are not running within 'make', let the edk2 "build" utility to fetch
>>> +  # the logical CPU count with Python's multiprocessing.cpu_count() method.
>>> +  edk2_thread_count=0
>>> +fi
> 
> edk2_thread_count=$(qemu_edk2_get_thread_count "${MAKEFLAGS:-0}")

Argh I'm confuse, this is what I wanted to do first but I couldn't get
it working, maybe I forget the '-'.

Thanks a lot for your help, the result is way more elegant :)

> 
> at which point the really long comment needs a bit of a tweak.
>