Re: [PATCH-for-8.1 4/5] bulk: Do not declare function prototypes using extern keyword

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 20/3/23 14:48, Daniel P. Berrangé wrote:
> On Mon, Mar 20, 2023 at 02:42:18PM +0100, Philippe Mathieu-Daudé wrote:
>> By default, C function prototypes declared in headers are visible,
>> so there is no need to declare them as 'extern' functions.
>> Remove this redundancy in a single bulk commit; do not modify:
>>
>>    - meson.build (used to check function availability at runtime)
>>    - pc-bios
>>    - libdecnumber
>>    - *.c
>>
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>>   block/dmg.h                    |  8 +++----
>>   bsd-user/bsd-file.h            |  6 ++---
>>   crypto/hmacpriv.h              | 13 +++++------
>>   hw/xen/xen_pt.h                |  8 +++----
>>   include/crypto/secret_common.h | 14 +++++-------
>>   include/exec/page-vary.h       |  4 ++--
>>   include/hw/misc/aspeed_scu.h   |  2 +-
>>   include/hw/nvram/npcm7xx_otp.h |  4 ++--
>>   include/hw/qdev-core.h         |  4 ++--
>>   include/qemu/crc-ccitt.h       |  4 ++--
>>   include/qemu/osdep.h           |  2 +-
>>   include/qemu/rcu.h             | 14 ++++++------
>>   include/qemu/sys_membarrier.h  |  4 ++--
>>   include/qemu/uri.h             |  6 ++---
>>   include/sysemu/accel-blocker.h | 14 ++++++------
>>   include/sysemu/os-win32.h      |  4 ++--
>>   include/user/safe-syscall.h    |  4 ++--
>>   target/i386/sev.h              |  6 ++---
>>   target/mips/cpu.h              |  4 ++--
>>   tcg/tcg-internal.h             |  4 ++--
>>   tests/tcg/minilib/minilib.h    |  2 +-
>>   include/exec/memory_ldst.h.inc | 42 +++++++++++++++++-----------------
>>   roms/seabios                   |  2 +-
> 
> Accidental submodule commit.,
> 
>>   23 files changed, 84 insertions(+), 91 deletions(-)
>>
>> diff --git a/block/dmg.h b/block/dmg.h
>> index e488601b62..ed209b5dec 100644
>> --- a/block/dmg.h
>> +++ b/block/dmg.h
>> @@ -51,10 +51,10 @@ typedef struct BDRVDMGState {
>>       z_stream zstream;
>>   } BDRVDMGState;
>>   
>> -extern int (*dmg_uncompress_bz2)(char *next_in, unsigned int avail_in,
>> -                                 char *next_out, unsigned int avail_out);
>> +int (*dmg_uncompress_bz2)(char *next_in, unsigned int avail_in,
>> +                          char *next_out, unsigned int avail_out);
>>   
>> -extern int (*dmg_uncompress_lzfse)(char *next_in, unsigned int avail_in,
>> -                                   char *next_out, unsigned int avail_out);
>> +int (*dmg_uncompress_lzfse)(char *next_in, unsigned int avail_in,
>> +                            char *next_out, unsigned int avail_out);
> 
> These are variable declarations, so with this change you'll get multiple
> copies of the variable if this header is included from multiple source
> files. IOW, the 'extern' usage is correct.

Doh indeed, good catch, thanks.

>> diff --git a/roms/seabios b/roms/seabios
>> index ea1b7a0733..3208b098f5 160000
>> --- a/roms/seabios
>> +++ b/roms/seabios
>> @@ -1 +1 @@
>> -Subproject commit ea1b7a0733906b8425d948ae94fba63c32b1d425
>> +Subproject commit 3208b098f51a9ef96d0dfa71d5ec3a3eaec88f0a
> 
> Nope !

Oops...