Re: [PATCH] MdeModulePkg:disable wraning to pass gcc4.8 build

[Laszlo Ersek <lersek@redhat.com>]

Wait a sec:

On 10/01/18 19:48, Laszlo Ersek wrote:

> However, this (edk2) commit message seems to suggest that the warnings
> are only present with gcc-4.8 (and no later gcc releases). This in turn
> suggests that the warnings are spurious (presumably, later gcc releases
> recognize that none of the affected variables are actually read without
> a prior initialization or assignment.)
> 
> Hence, upstream Oniguruma might argue that we should fix our compiler --
> they might consider gcc-4.8 too old to care -- rather than litter their
> code with superfluous assignments, just to pacify gcc-4.8.

[...]

> So, I think I agree with this patch, but the commit message should be a
> *lot* more detailed. (Basically, include the analysis from above.)

In fact, another improvement is possible: if the issue only affects
gcc-4.8, then:

>> On 29/09/18 02:55, Dongao Guo wrote:
>>> Change-Id: I782962e4994a8edf14beb7ede8b1aabe233dc3a8
>>> Contributed-under: TianoCore Contribution Agreement 1.1
>>> ---
>>>  MdeModulePkg/Universal/RegularExpressionDxe/RegularExpressionDxe.inf | 3 +++
>>>  1 file changed, 3 insertions(+)
>>>
>>> diff --git a/MdeModulePkg/Universal/RegularExpressionDxe/RegularExpressionDxe.inf b/MdeModulePkg/Universal/RegularExpressionDxe/RegularExpressionDxe.inf
>>> index 16e91bd..07bc02e 100644
>>> --- a/MdeModulePkg/Universal/RegularExpressionDxe/RegularExpressionDxe.inf
>>> +++ b/MdeModulePkg/Universal/RegularExpressionDxe/RegularExpressionDxe.inf
>>> @@ -109,3 +109,6 @@
>>>
>>>    # Oniguruma: error: variable 'fp' set but not used
>>>    GCC:*_*_*_CC_FLAGS = -Wno-error=unused-but-set-variable
>>> +
>>> +  # Oniguruma: tag_end in parse_callout_of_name
>>> +  GCC:*_*_*_CC_FLAGS = -Wno-error=maybe-uninitialized

this toolchain glob pattern is too general. It should be:

  GCC:*_GCC48_*_CC_FLAGS

(or maybe spell it out for all GCC versions up to and including 4.8,
from the earliest we support, 4.4.)

Thanks
Laszlo