[Mesa-dev] [PATCH] Android: Fix LLVM duplicated symbols linking for N and M

[Rob Herring]

On Sun, Aug 20, 2017 at 2:57 PM, Rob Herring <robh at kernel.org> wrote:
> On Fri, Aug 18, 2017 at 8:53 PM, Chih-Wei Huang <cwhuang at android-x86.org> wrote:
>> 2017-08-19 8:27 GMT+08:00 Emil Velikov <emil.l.velikov at gmail.com>:
>>> On 18 August 2017 at 20:46, Rob Herring <robh at kernel.org> wrote:
>>>> Both statically linking libLLVMCore and dynamically linking libLLVM causes
>>>> duplicated symbols in gallium_dri.so and it fails to dlopen. We don't
>>>> really need to link libLLVMCore, but just need generated headers to be
>>>> built first. Dynamically linking to libLLVM instead is enough to do
>>>> that. Thanks to Qiang Yu for finding the root cause.

[...]

>>>>    $(if $(filter 7,$(MESA_ANDROID_MAJOR_VERSION)), \
>>>> -    $(eval LOCAL_CFLAGS += -DHAVE_LLVM=0x0308 -DMESA_LLVM_VERSION_PATCH=0) \
>>>> -    $(eval LOCAL_STATIC_LIBRARIES += libLLVMCore) \
>>>> -    $(eval LOCAL_C_INCLUDES += external/llvm/include external/llvm/device/include),) \
>>>> +    $(eval LOCAL_CFLAGS += -DHAVE_LLVM=0x0308 -DMESA_LLVM_VERSION_PATCH=0),) \
>>>>    $(if $(filter O,$(MESA_ANDROID_MAJOR_VERSION)), \
>>>> -    $(eval LOCAL_CFLAGS += -DHAVE_LLVM=0x0309 -DMESA_LLVM_VERSION_PATCH=0) \
>>>> -    $(eval LOCAL_HEADER_LIBRARIES += llvm-headers),)
>>>> +    $(eval LOCAL_CFLAGS += -DHAVE_LLVM=0x0309 -DMESA_LLVM_VERSION_PATCH=0),) \
>>>> +  $(eval LOCAL_SHARED_LIBRARIES += libLLVM)
>>> Am I the only person getting tad confused by amount of brackets?
>>> As mentioned by Chih-Wei - a shell switch is not possible, but how
>>> about a test vague like the following?
>>>
>>> test "x$(MESA_ANDROID_MAJOR_VERSION)" = "xO" &&
>>>    $(eval LOCAL_CFLAGS += -DHAVE_LLVM=0x0309 -DMESA_LLVM_VERSION_PATCH=0)
>>
>> Only possible if you put it into $(shell ...)
>> That gives me an idea. Maybe we ca do like
>>
>> $(shell case "$(MESA_ANDROID_MAJOR_VERSION)" in \
>>             6) echo ... ;; \
>>             7) echo ... ;; \
>>             *)  echo ... ;; \
>>             esac)
>>
>> I haven't really try it yet.
>
> What does either really buy us? It's really just bike shedding and
> unrelated to fixing the problem at hand.
>
> I have another idea which is to use llvm-config and avoid the
> conditionals altogether. I haven't looked into that closely though.

Well, the build is broken again because the version changed from O to
8 (and I'm not sure if master is going to change to P or 9 at some
point). So I went ahead and have this all coded up like this (I don't
see a simple way to build and run llvm-config):

  $(eval $(shell sed -n -e
's/.*\(LLVM_VERSION_MAJOR\).*\([0-9].*\)/\1:=\2/p'
external/llvm/device/include/llvm/Config/llvm-config.h)) \
  $(eval $(shell sed -n -e
's/.*\(LLVM_VERSION_MINOR\).*\([0-9].*\)/\1:=\2/p'
external/llvm/device/include/llvm/Config/llvm-config.h)) \
  $(eval LOCAL_CFLAGS +=
-DHAVE_LLVM=0x$(LLVM_VERSION_MAJOR)0$(LLVM_VERSION_MINOR))

Only one slight problem in that for master/O it reports 3.8 as the
version is 3.8.275480 which I think is the SVN version number. Not
sure what to do with that...

Rob