ArmPkg: add prebuilt glue binaries for GCC5 LTO support

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GCC in LTO mode interoperates poorly with non-standard libraries that
provide implementations of compiler intrinsics such as memcpy/memset
or the stack protector entry points. Such libraries need to be built
in non-LTO mode, and then referenced explicitly on the linker command
line using a -plugin-opt=-pass-through=-lxxx linker option.

However, if these intrinsics are also referenced directly, the LTO
version of the code will be pulled in, and will happily satisfy all
other references to the same symbol.

So add a pair of glue libraries, for ARM and AARCH64, that reference
the known intrinsics. Since the binaries live under ArmPkg directly,
we can reference them in tools_def.txt. Under LD garbage collection,
the object itself will be pruned, and so will the intrinsics that end
up unused by the module.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

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This commit is contained in:

Ard Biesheuvel

2016-07-18 12:19:34 +02:00

parent a1b8baccc3

commit e1458aaded

4 changed files with 88 additions and 0 deletions

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