Re: [PATCH v5 0/8] BaseTools: add support for GCC5 in LTO mode

[Laszlo Ersek <lersek@redhat.com>]

On 08/02/16 11:03, Ard Biesheuvel wrote:
> On 1 August 2016 at 10:01, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
>> This v5 to introduce GCC5 is now a 8 piece series, including some
>> preparatory cleanup patches that allow all GCC4x and CLANG35 toolchains
>> to switch to using 'gcc' as the linker. This allows us to get rid of
>> the wrapper script to marshall ld arguments in order to make them
>> understandable by gcc, which is fragile and likely to cause problems in
>> the future.
>>
>> Since there appears to be a natural split between the 'legacy' GCC
>> toolchains UNIXGCC, ELFGCC, and CYGGCC[xASL], both in term of supported
>> architectures [IA32, X64, IPF] vs [IA32, X64, ARM, AARCH64], and in
>> terms of maintenance, these toolchains are not moved to using 'gcc' as
>> the linker, and instead, a new BUILDRULEFAMILY is introduced called GCCLD
>> that will retain the old behavior.
>>
>> The result is that GCC5 can align much more closely with its predecessors,
>> making the expected maintenance burden of supporting GCC back to v4.4
>> much lower.
>>
>> Changes since v4:
>> - added patch to use 'protected' visibility only for the libraries that
>>   define the module entry points (_ModuleEntryPoint), to prevent them from
>>   being optimized away by the LTO routines
>> - added Jordan's ack/RBs
>> - add some extra comments to tools_def.template (#8)
>>
> 
> Thanks all. Committed as
> 
> 1c63516075b3 BaseTools CLANG35: drop problematic use-movt and save-temps options
> ff54bcdf2e4e ArmVirtPkg/ArmVirtPrePiUniCoreRelocatable: ignore .hash
> and .note sections
> befb3ba51502 BaseTools UNIXGCC ELFGCC CYGGCC: clone GCC build rule
> family into GCCLD
> a1b8baccc30b BaseTools GCC: use 'gcc' as the linker command for GCC44 and later
> e1458aaded8e ArmPkg: add prebuilt glue binaries for GCC5 LTO support
> 7fd5d619806d BaseTools GCC: drop GNU notes section from EFI image
> 4a8466d4baba BaseTools GCC: introduce GCC5 toolchain to support GCC
> v5.x in LTO mode
> 
> with Leif and Liming's R-b. I dropped patch #7, and instead made the
> visibility pragma conditional on whether LTO is disabled.

Re gcc-5, do we need a patch for "OvmfPkg/build.sh" now? See also
<https://tianocore.acgmultimedia.com/show_bug.cgi?id=62>.

Thanks
Laszlo