llvm dev - Jul 2019 - Linker errors after installing/compiling LLVM/CLANG

I don’t personally develop on Mac (i use Windows), but I have an analogous
setup there where i use ninja to build and Visual Studio for editing,
debugging, etc.

What i do, and I assume it will be the same or very similar for Xcode, is
to run cmake twice, once with Ninja, and once with VS (Xcode for you), from
separate directories.  I build with the ninja one (“ninja clang” on command
line), and I change  the debugger target from the default to point directly
into my ninja directory , so VS is debugging the thing that was built with
ninja.

Hopefully that makes sense

On Sun, Jul 7, 2019 at 11:59 AM Joan Lluch <joan.lluch at icloud.com>
wrote:
> Hi zturner
>
> Please, would you describe me step by step how do I get both a Xcode
> project and a Ninja setup for compiling the same?
>
> I have downloaded the Ninja-mac binary from here
> https://github.com/ninja-build/ninja/releases and have setup system path
> to it.  What’s next?
>
> Thanks
>
>
>
>
> On 7 Jul 2019, at 19:23, Zachary Turner <zturner at roblox.com>
wrote:
>
> I’m not saying you can’t use Xcode, I’m just saying that instead of
> *building* in Xcode, just type “ninja” on the command line to do your build
> and then use Xcode as you normally would.
>
> I don’t think it’s the case that LLVM does not intend to support Xcode,
> just that its a community driven project, so unless someone is sufficiently
> motivated to fix whatever this problem is, it might stay this way for some
> time.  On that note, patches are certainly welcome, but if you just want to
> unblock yourself, the easiest way is going to be to type a command on the
> command line to do your build instead of pressing a button in the UI (and
> you could still use the UI for everything else)
>
> On Sun, Jul 7, 2019 at 9:40 AM Joan Lluch <joan.lluch at icloud.com>
wrote:
>
>>
>> Hi zturner,
>>
>> I understand what you say and I have been suggested this a couple of
>> times, but I really don’t want to make the switch to ninja. I’m a
retired
>> senior software developer and I just use LLVM for a custom backend that
I
>> have already almost completed in LLVM 7.0. I’m not really into
LLVM-project
>> development, and Xcode is both familiar and fast enough for incremental
>> builds of ‘llc’ or ‘clang’ alone including my target backend, (or it
used
>> to be in 7.0). It’s just the right tool for me.
>>
>> On the other hand I think that in case there’s no intention to fully
>> support Xcode in the future, then it should be removed from de doc
>> descriptions to prevent deceptive information. Otherwise, at least
major
>> issues like this one, should be taken care of.
>>
>> John
>>
>>
>>
>> On 7 Jul 2019, at 17:08, Zachary Turner <zturner at roblox.com>
wrote:
>>
>> Try using ninja generator, most people do not use Xcode for building,
so
>> since it lesser-used, it also lesser tested.  Note that it’s perfectly
>> possible to use Xcode for code browsing, debugging, editing while using
>> ninja for building, which is what I think most people do
>>
>> On Sun, Jul 7, 2019 at 4:20 AM Joan Lluch via llvm-dev <
>> llvm-dev at lists.llvm.org> wrote:
>>
>>> I also filled a bug report. I think this is actually a bug
>>>
>>> https://bugs.llvm.org/show_bug.cgi?id=42528
>>>
>>> John
>>>
>>>
>>> On 7 Jul 2019, at 09:27, Joan Lluch via llvm-dev <
>>> llvm-dev at lists.llvm.org> wrote:
>>>
>>> I understand that a difference between ninja and xcode is they use
a
>>> different way to determine code dependencies. So to my
understanding xcode
>>> needs dependencies to be properly created whereas ninja just
doesn’t care.
>>> Maybe this is why ninja is able to find what it needs for the
compilation
>>> to succeed, but not xcode.
>>>
>>> So I have now looked at the CMakeLists.txt files and found that all
the
>>> missing libraries are defined in files under the ‘clang’ directory.
>>>
>>> The llvm_project clone has the following structure:
>>>
>>> llvm-project
>>> llvm
>>> clang
>>> (others)
>>>
>>> Everything  under ‘llvm’ is properly compiled with no issues,
however
>>> what is under ‘clang’ fails to compile (with linker errors) even if
>>> -DLLVM_ENABLE_PROJECTS=“clang” is specified.
>>>
>>> I suspect now that there may be some kind of bug in the llvm
project
>>> that prevents this to work properly, or maybe something else needs
to be
>>> done to get clang compiled on xcode. I also suspect that this may
pass
>>> unnoticed when using ninja because it simply uses it’s own way to
find
>>> dependencies (but I don’t really know anything about ninja).
>>>
>>> Maybe this may help somebody to figure out what could be happening
and
>>> hopefully help me to narrow the issue? I honestly am totally lost
on what
>>> to try next. This is kind of ridiculous.
>>>
>>> Thanks
>>>
>>>
>>> On 6 Jul 2019, at 23:49, Neil Nelson <nnelson at
infowest.com> wrote:
>>>
>>> Joan,
>>>
>>> Just completed a good clang compile built from a mostly vanilla
Xubuntu
>>> 19.04 VM, installed the llvm-needed Ubuntu packages, downloaded a
new copy
>>> of llvm using the noted llvm install page, configured using
>>>
>>> cmake -G Ninja -DLLVM_ENABLE_PROJECTS="clang"
-DLLVM_USE_LINKER=lld
>>> -DCMAKE_BUILD_TYPE="Release"
>>> -DCMAKE_INSTALL_PREFIX=/home/nnelson/Documents/llvm/install ../llvm
&>
>>> cmake.log
>>>
>>> which is primarily different from yours where I am using a
'Release'
>>> build to avoid the much larger memory and disk usage of a
'Debug' build.
>>> The 'ninja install' command put everything in llvm/install
as expected
>>> including clang. I look through cmake.log to see if there are
errors
>>> that need to be corrected.
>>>
>>> My differences appear to be Xubuntu, the packages, ninja, and the
cmake
>>> line.
>>>
>>> On Linux I can use
>>>
>>> ninja &> ninja_compile.log
>>>
>>> to look at the compile history and see if something went wrong.
>>>
>>> Neil
>>> On 7/6/19 12:00 AM, Joan Lluch wrote:
>>>
>>> Hi Nelson,
>>>
>>> Thanks for your reply.
>>>
>>> The “build/Debug/lib” and "build/Release/lib” directories is
where all
>>> the libraries go. Similarly, the executables go to
“build/Debug/bin” and
>>> “build/Release/bin” before they are moved to the install directory.
This is
>>> expected and normal. However, the problem is that a small number of
>>> libraries (exactly 20 in total) are not created at all for the LLVM
9.0
>>> version that I cloned from gitHub. These libraries are in fact not
created
>>> anywhere!.
>>>
>>> I still have LLVM 7.0 installed in my computer and the libraries
for
>>> that version are all there in the right places under the LLMV 7.0
>>> directory, but in that case I installed it all in a different way
as I
>>> said, loosing the benefits of git.
>>>
>>> I forgot to mention that “llc” alone compiles and links correctly
>>> without any issue. The problem is only when I try to get ‘clang’
compiled.
>>>
>>> You mention that you enabled a lot of projects:
>>> 
"clang;clang-tools-extra;compiler-rt;debuginfo-tests;libclc;libcxx;libcxxabi;libunwind;lld;lldb;llvm;openmp;parallel-libs;polly;pstl”.
>>> I only really need the basic installation of “clang”, and I do not
need any
>>> testing tools because all I want is to add my custom target to it.
I also
>>> tried "clang;libclc;libcxx” but the problem with the missing
libraries is
>>> exactly the same.
>>>
>>> Just as a matter of information: I successfully implemented a
custom
>>> target backend, and have it almost finished and running perfectly
on LLVM
>>> 7.0. Now, I just want to move it to LLVM 9.0, but got stuck in what
is
>>> supposed to be the easiest part which is just compiling it (??),
but I do
>>> not understand why it doesn’t compile!
>>>
>>> Any ideas?
>>>
>>> Joan
>>>
>>> John, I compiled and installed to /usr/local all the projects under
llvm
>>> except llgo yesterday. The three files you noted are in
>>> ../llvm-project/build/lib
>>> I do not have a llvm-project/build/Debug directory.
>>> Xubuntu 19.04. llvm downloaded from github on 6/18 using
instructions
>>> from the page you note.
>>> cmake -G Ninja
>>>
-DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra;compiler-rt;debuginfo-tests;libclc;libcxx;libcxxabi;libunwind;lld;lldb;llvm;openmp;parallel-libs;polly;pstl"
>>> -DLLVM_USE_LINKER=lld -DCMAKE_BUILD_TYPE="Release"
../llvm
>>> Installed additional packages as needed.
>>> Neil
>>> On 7/5/19 6:46 AM, Joan Lluch via llvm-dev wrote:
>>>
>>> Hi All,
>>>
>>> I am looking for the best way to install LLVM+clang,  but I do not
seem
>>> to find a way that works for me.
>>>
>>> I followed the steps in this document Getting Started with the LLVM
>>> System — LLVM 9 documentation
>>> <https://llvm.org/docs/GettingStarted.html> except that I
created the
>>> following folder structure as I do not want clang and llc to go to
>>> /usr/local
>>>
>>> LLVM-9
>>>    llvm-project  (cloned from github)
>>>    install
>>>
>>> I ran the following command line from the build directory in
>>> llvm-project as described in the doc, but added the
>>> DLLVM_OPTIMIZED_TABLEGEN=On variable :
>>>
>>> cmake -G Xcode -DLLVM_ENABLE_PROJECTS=clang
>>> -DCMAKE_INSTALL_PREFIX=/Users/joan/LLVM-9/install
>>> -DLLVM_OPTIMIZED_TABLEGEN=On ../llvm
>>>
>>> The cmake command above seems to work ok, but after that, when I
compile
>>> the “install” or “build_all” schemes I get a lot of linker errors.
Such as
>>> these ones and more:
>>>
>>> clang: error: no such file or directory:
>>>
'/Users/joan/LLVM-9/llvm-project/build/Debug/lib/libclangAST.a'
>>> clang: error: no such file or directory:
>>>
'/Users/joan/LLVM-9/llvm-project/build/Debug/lib/libclangLex.a'
>>> clang: error: no such file or directory:
>>>
'/Users/joan/LLVM-9/llvm-project/build/Debug/lib/libclangBasic.a'
>>>
>>> Up until recently, I have worked with LLVM 7.0 and all what I did
was
>>> downloading both llvm and clang from llvm.org, copied clang into
>>> llvm/tools, and ran the cmake application (not command line).  That
kind of
>>> worked except for some minor glitches but of course I didn’t get
the
>>> benefits of git.
>>>
>>> So what am I doing wrong now? Why I’m getting such linker errors?
>>>
>>> It seems that a few required libraries are not created, but I do
not
>>> understand why. Any ideas?
>>>
>>> Thanks,
>>>
>>> John
>>>
>>>
>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>>>
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>>
>>
>
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Hey Joan,

I looked into the Xcode build issue that you're experiencing, and it relates
to a limitation in Xcode which was surfaced by a CMake change I made a few
months back. The issue is that Xcode can't handle library targets that
don't have any sources associated with them, and I made a change to how we
build clang so that we generate object libraries for every target then build a
static library from the object target.

Long story short, I actually think I have a fix for it.

I should have a patch up for review today.

-Chris
> On Jul 7, 2019, at 3:25 PM, Zachary Turner via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> I don’t personally develop on Mac (i use Windows), but I have an analogous
setup there where i use ninja to build and Visual Studio for editing, debugging,
etc.
> 
> What i do, and I assume it will be the same or very similar for Xcode, is
to run cmake twice, once with Ninja, and once with VS (Xcode for you), from
separate directories.  I build with the ninja one (“ninja clang” on command
line), and I change  the debugger target from the default to point directly into
my ninja directory , so VS is debugging the thing that was built with ninja.
> 
> Hopefully that makes sense
> 
> On Sun, Jul 7, 2019 at 11:59 AM Joan Lluch <joan.lluch at icloud.com
<mailto:joan.lluch at icloud.com>> wrote:
> Hi zturner
> 
> Please, would you describe me step by step how do I get both a Xcode
project and a Ninja setup for compiling the same?
> 
> I have downloaded the Ninja-mac binary from here
https://github.com/ninja-build/ninja/releases
<https://github.com/ninja-build/ninja/releases> and have setup system path
to it.  What’s next?
> 
> Thanks
> 
> 
> 
> 
>> On 7 Jul 2019, at 19:23, Zachary Turner <zturner at roblox.com
<mailto:zturner at roblox.com>> wrote:
>> 
>> I’m not saying you can’t use Xcode, I’m just saying that instead of
*building* in Xcode, just type “ninja” on the command line to do your build and
then use Xcode as you normally would.
>> 
>> I don’t think it’s the case that LLVM does not intend to support Xcode,
just that its a community driven project, so unless someone is sufficiently
motivated to fix whatever this problem is, it might stay this way for some time.
On that note, patches are certainly welcome, but if you just want to unblock
yourself, the easiest way is going to be to type a command on the command line
to do your build instead of pressing a button in the UI (and you could still use
the UI for everything else)
>> 
>> On Sun, Jul 7, 2019 at 9:40 AM Joan Lluch <joan.lluch at icloud.com
<mailto:joan.lluch at icloud.com>> wrote:
>> 
>> Hi zturner,
>> 
>> I understand what you say and I have been suggested this a couple of
times, but I really don’t want to make the switch to ninja. I’m a retired senior
software developer and I just use LLVM for a custom backend that I have already
almost completed in LLVM 7.0. I’m not really into LLVM-project development, and
Xcode is both familiar and fast enough for incremental builds of ‘llc’ or
‘clang’ alone including my target backend, (or it used to be in 7.0). It’s just
the right tool for me.
>> 
>> On the other hand I think that in case there’s no intention to fully
support Xcode in the future, then it should be removed from de doc descriptions
to prevent deceptive information. Otherwise, at least major issues like this
one, should be taken care of.
>> 
>> John
>> 
>> 
>> 
>> On 7 Jul 2019, at 17:08, Zachary Turner <zturner at roblox.com
<mailto:zturner at roblox.com>> wrote:
>> 
>>> Try using ninja generator, most people do not use Xcode for
building, so since it lesser-used, it also lesser tested.  Note that it’s
perfectly possible to use Xcode for code browsing, debugging, editing while
using ninja for building, which is what I think most people do
>>> 
>>> On Sun, Jul 7, 2019 at 4:20 AM Joan Lluch via llvm-dev <llvm-dev
at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
>>> I also filled a bug report. I think this is actually a bug
>>> 
>>> https://bugs.llvm.org/show_bug.cgi?id=42528
<https://bugs.llvm.org/show_bug.cgi?id=42528>
>>> 
>>> John
>>> 
>>> 
>>>> On 7 Jul 2019, at 09:27, Joan Lluch via llvm-dev <llvm-dev
at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
>>>> 
>>>> I understand that a difference between ninja and xcode is they
use a different way to determine code dependencies. So to my understanding xcode
needs dependencies to be properly created whereas ninja just doesn’t care. Maybe
this is why ninja is able to find what it needs for the compilation to succeed,
but not xcode.
>>>> 
>>>> So I have now looked at the CMakeLists.txt files and found that
all the missing libraries are defined in files under the ‘clang’ directory.
>>>> 
>>>> The llvm_project clone has the following structure:
>>>> 
>>>> llvm-project
>>>> 	llvm
>>>> 	clang
>>>> 	(others)
>>>> 
>>>> Everything  under ‘llvm’ is properly compiled with no issues,
however what is under ‘clang’ fails to compile (with linker errors) even if
-DLLVM_ENABLE_PROJECTS=“clang” is specified.
>>>> 
>>>> I suspect now that there may be some kind of bug in the llvm
project that prevents this to work properly, or maybe something else needs to be
done to get clang compiled on xcode. I also suspect that this may pass unnoticed
when using ninja because it simply uses it’s own way to find dependencies (but I
don’t really know anything about ninja).
>>>> 
>>>> Maybe this may help somebody to figure out what could be
happening and hopefully help me to narrow the issue? I honestly am totally lost
on what to try next. This is kind of ridiculous.
>>>> 
>>>> Thanks
>>>> 
>>>> 
>>>>> On 6 Jul 2019, at 23:49, Neil Nelson <nnelson at
infowest.com <mailto:nnelson at infowest.com>> wrote:
>>>>> 
>>>>> Joan,
>>>>> 
>>>>> Just completed a good clang compile built from a mostly
vanilla Xubuntu 19.04 VM, installed the llvm-needed Ubuntu packages, downloaded
a new copy of llvm using the noted llvm install page, configured using
>>>>> 
>>>>> cmake -G Ninja -DLLVM_ENABLE_PROJECTS="clang"
-DLLVM_USE_LINKER=lld -DCMAKE_BUILD_TYPE="Release"
-DCMAKE_INSTALL_PREFIX=/home/nnelson/Documents/llvm/install         ../llvm
&> cmake.log
>>>>> 
>>>>> which is primarily different from yours where I am using a
'Release' build to avoid the much larger memory and disk usage of a
'Debug' build. The 'ninja install' command put everything in
llvm/install as expected including clang. I look through cmake.log to see if
there are errors that need to be corrected.
>>>>> 
>>>>> My differences appear to be Xubuntu, the packages, ninja,
and the cmake line.
>>>>> 
>>>>> On Linux I can use
>>>>> 
>>>>> ninja &> ninja_compile.log
>>>>> 
>>>>> to look at the compile history and see if something went
wrong.
>>>>> 
>>>>> Neil
>>>>> 
>>>>> On 7/6/19 12:00 AM, Joan Lluch wrote:
>>>>>> Hi Nelson,
>>>>>> 
>>>>>> Thanks for your reply. 
>>>>>> 
>>>>>> The “build/Debug/lib” and "build/Release/lib”
directories is where all the libraries go. Similarly, the executables go to
“build/Debug/bin” and “build/Release/bin” before they are moved to the install
directory. This is expected and normal. However, the problem is that a small
number of libraries (exactly 20 in total) are not created at all for the LLVM
9.0 version that I cloned from gitHub. These libraries are in fact not created
anywhere!.
>>>>>> 
>>>>>> I still have LLVM 7.0 installed in my computer and the
libraries for that version are all there in the right places under the LLMV 7.0
directory, but in that case I installed it all in a different way as I said,
loosing the benefits of git.
>>>>>> 
>>>>>> I forgot to mention that “llc” alone compiles and links
correctly without any issue. The problem is only when I try to get ‘clang’
compiled.
>>>>>> 
>>>>>> You mention that you enabled a lot of projects: 
"clang;clang-tools-extra;compiler-rt;debuginfo-tests;libclc;libcxx;libcxxabi;libunwind;lld;lldb;llvm;openmp;parallel-libs;polly;pstl”.
I only really need the basic installation of “clang”, and I do not need any
testing tools because all I want is to add my custom target to it. I also tried
"clang;libclc;libcxx” but the problem with the missing libraries is exactly
the same.
>>>>>> 
>>>>>> Just as a matter of information: I successfully
implemented a custom target backend, and have it almost finished and running
perfectly on LLVM 7.0. Now, I just want to move it to LLVM 9.0, but got stuck in
what is supposed to be the easiest part which is just compiling it (??), but I
do not understand why it doesn’t compile!
>>>>>> 
>>>>>> Any ideas?
>>>>>> 
>>>>>> Joan
>>>>>> 
>>>>>>> John, I compiled and installed to /usr/local all
the projects under llvm except llgo yesterday. The three files you noted are in
>>>>>>> ../llvm-project/build/lib
>>>>>>> I do not have a llvm-project/build/Debug directory.
>>>>>>> Xubuntu 19.04. llvm downloaded from github on 6/18
using instructions from the page you note.
>>>>>>> cmake -G Ninja
-DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra;compiler-rt;debuginfo-tests;libclc;libcxx;libcxxabi;libunwind;lld;lldb;llvm;openmp;parallel-libs;polly;pstl"
-DLLVM_USE_LINKER=lld -DCMAKE_BUILD_TYPE="Release" ../llvm
>>>>>>> Installed additional packages as needed.
>>>>>>> Neil
>>>>>>> On 7/5/19 6:46 AM, Joan Lluch via llvm-dev wrote:
>>>>>>>> Hi All,
>>>>>>>> 
>>>>>>>> I am looking for the best way to install
LLVM+clang,  but I do not seem to find a way that works for me.
>>>>>>>> 
>>>>>>>> I followed the steps in this document Getting
Started with the LLVM System — LLVM 9 documentation
<https://llvm.org/docs/GettingStarted.html> except that I created the
following folder structure as I do not want clang and llc to go to /usr/local
>>>>>>>> 
>>>>>>>> LLVM-9
>>>>>>>>    llvm-project  (cloned from github)
>>>>>>>>    install
>>>>>>>> 
>>>>>>>> I ran the following command line from the build
directory in llvm-project as described in the doc, but added the
DLLVM_OPTIMIZED_TABLEGEN=On variable :
>>>>>>>> 
>>>>>>>> cmake -G Xcode -DLLVM_ENABLE_PROJECTS=clang
-DCMAKE_INSTALL_PREFIX=/Users/joan/LLVM-9/install -DLLVM_OPTIMIZED_TABLEGEN=On
../llvm
>>>>>>>> 
>>>>>>>> The cmake command above seems to work ok, but
after that, when I compile the “install” or “build_all” schemes I get a lot of
linker errors. Such as these ones and more:
>>>>>>>> 
>>>>>>>> clang: error: no such file or directory:
'/Users/joan/LLVM-9/llvm-project/build/Debug/lib/libclangAST.a'
>>>>>>>> clang: error: no such file or directory:
'/Users/joan/LLVM-9/llvm-project/build/Debug/lib/libclangLex.a'
>>>>>>>> clang: error: no such file or directory:
'/Users/joan/LLVM-9/llvm-project/build/Debug/lib/libclangBasic.a'
>>>>>>>> 
>>>>>>>> Up until recently, I have worked with LLVM 7.0
and all what I did was downloading both llvm and clang from llvm.org
<http://llvm.org/>, copied clang into llvm/tools, and ran the cmake
application (not command line).  That kind of worked except for some minor
glitches but of course I didn’t get the benefits of git.
>>>>>>>> 
>>>>>>>> So what am I doing wrong now? Why I’m getting
such linker errors?
>>>>>>>> 
>>>>>>>> It seems that a few required libraries are not
created, but I do not understand why. Any ideas?
>>>>>>>> 
>>>>>>>> Thanks,
>>>>>>>> 
>>>>>>>> John
>>>>>> 
>>>> 
>>>> _______________________________________________
>>>> LLVM Developers mailing list
>>>> llvm-dev at lists.llvm.org <mailto:llvm-dev at
lists.llvm.org>
>>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
<https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
>>> 
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org <mailto:llvm-dev at
lists.llvm.org>
>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
<https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
> 
> _______________________________________________
> LLVM Developers mailing list
> llvm-dev at lists.llvm.org
> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
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Hey Joan,

Take a look at this patch, and see if it resolves your issue:
https://reviews.llvm.org/D64300 <https://reviews.llvm.org/D64300>

Thanks,
-Chris
> On Jul 7, 2019, at 3:54 PM, Chris Bieneman via llvm-dev <llvm-dev at
lists.llvm.org> wrote:
> 
> Hey Joan,
> 
> I looked into the Xcode build issue that you're experiencing, and it
relates to a limitation in Xcode which was surfaced by a CMake change I made a
few months back. The issue is that Xcode can't handle library targets that
don't have any sources associated with them, and I made a change to how we
build clang so that we generate object libraries for every target then build a
static library from the object target.
> 
> Long story short, I actually think I have a fix for it.
> 
> I should have a patch up for review today.
> 
> -Chris
> 
>> On Jul 7, 2019, at 3:25 PM, Zachary Turner via llvm-dev <llvm-dev at
lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote:
>> 
>> I don’t personally develop on Mac (i use Windows), but I have an
analogous setup there where i use ninja to build and Visual Studio for editing,
debugging, etc.
>> 
>> What i do, and I assume it will be the same or very similar for Xcode,
is to run cmake twice, once with Ninja, and once with VS (Xcode for you), from
separate directories.  I build with the ninja one (“ninja clang” on command
line), and I change  the debugger target from the default to point directly into
my ninja directory , so VS is debugging the thing that was built with ninja.
>> 
>> Hopefully that makes sense
>> 
>> On Sun, Jul 7, 2019 at 11:59 AM Joan Lluch <joan.lluch at icloud.com
<mailto:joan.lluch at icloud.com>> wrote:
>> Hi zturner
>> 
>> Please, would you describe me step by step how do I get both a Xcode
project and a Ninja setup for compiling the same?
>> 
>> I have downloaded the Ninja-mac binary from here
https://github.com/ninja-build/ninja/releases
<https://github.com/ninja-build/ninja/releases> and have setup system path
to it.  What’s next?
>> 
>> Thanks
>> 
>> 
>> 
>> 
>>> On 7 Jul 2019, at 19:23, Zachary Turner <zturner at roblox.com
<mailto:zturner at roblox.com>> wrote:
>>> 
>>> I’m not saying you can’t use Xcode, I’m just saying that instead of
*building* in Xcode, just type “ninja” on the command line to do your build and
then use Xcode as you normally would.
>>> 
>>> I don’t think it’s the case that LLVM does not intend to support
Xcode, just that its a community driven project, so unless someone is
sufficiently motivated to fix whatever this problem is, it might stay this way
for some time.  On that note, patches are certainly welcome, but if you just
want to unblock yourself, the easiest way is going to be to type a command on
the command line to do your build instead of pressing a button in the UI (and
you could still use the UI for everything else)
>>> 
>>> On Sun, Jul 7, 2019 at 9:40 AM Joan Lluch <joan.lluch at
icloud.com <mailto:joan.lluch at icloud.com>> wrote:
>>> 
>>> Hi zturner,
>>> 
>>> I understand what you say and I have been suggested this a couple
of times, but I really don’t want to make the switch to ninja. I’m a retired
senior software developer and I just use LLVM for a custom backend that I have
already almost completed in LLVM 7.0. I’m not really into LLVM-project
development, and Xcode is both familiar and fast enough for incremental builds
of ‘llc’ or ‘clang’ alone including my target backend, (or it used to be in
7.0). It’s just the right tool for me.
>>> 
>>> On the other hand I think that in case there’s no intention to
fully support Xcode in the future, then it should be removed from de doc
descriptions to prevent deceptive information. Otherwise, at least major issues
like this one, should be taken care of.
>>> 
>>> John
>>> 
>>> 
>>> 
>>> On 7 Jul 2019, at 17:08, Zachary Turner <zturner at roblox.com
<mailto:zturner at roblox.com>> wrote:
>>> 
>>>> Try using ninja generator, most people do not use Xcode for
building, so since it lesser-used, it also lesser tested.  Note that it’s
perfectly possible to use Xcode for code browsing, debugging, editing while
using ninja for building, which is what I think most people do
>>>> 
>>>> On Sun, Jul 7, 2019 at 4:20 AM Joan Lluch via llvm-dev
<llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>>
wrote:
>>>> I also filled a bug report. I think this is actually a bug
>>>> 
>>>> https://bugs.llvm.org/show_bug.cgi?id=42528
<https://bugs.llvm.org/show_bug.cgi?id=42528>
>>>> 
>>>> John
>>>> 
>>>> 
>>>>> On 7 Jul 2019, at 09:27, Joan Lluch via llvm-dev
<llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>>
wrote:
>>>>> 
>>>>> I understand that a difference between ninja and xcode is
they use a different way to determine code dependencies. So to my understanding
xcode needs dependencies to be properly created whereas ninja just doesn’t care.
Maybe this is why ninja is able to find what it needs for the compilation to
succeed, but not xcode.
>>>>> 
>>>>> So I have now looked at the CMakeLists.txt files and found
that all the missing libraries are defined in files under the ‘clang’ directory.
>>>>> 
>>>>> The llvm_project clone has the following structure:
>>>>> 
>>>>> llvm-project
>>>>> 	llvm
>>>>> 	clang
>>>>> 	(others)
>>>>> 
>>>>> Everything  under ‘llvm’ is properly compiled with no
issues, however what is under ‘clang’ fails to compile (with linker errors) even
if -DLLVM_ENABLE_PROJECTS=“clang” is specified.
>>>>> 
>>>>> I suspect now that there may be some kind of bug in the
llvm project that prevents this to work properly, or maybe something else needs
to be done to get clang compiled on xcode. I also suspect that this may pass
unnoticed when using ninja because it simply uses it’s own way to find
dependencies (but I don’t really know anything about ninja).
>>>>> 
>>>>> Maybe this may help somebody to figure out what could be
happening and hopefully help me to narrow the issue? I honestly am totally lost
on what to try next. This is kind of ridiculous.
>>>>> 
>>>>> Thanks
>>>>> 
>>>>> 
>>>>>> On 6 Jul 2019, at 23:49, Neil Nelson <nnelson at
infowest.com <mailto:nnelson at infowest.com>> wrote:
>>>>>> 
>>>>>> Joan,
>>>>>> 
>>>>>> Just completed a good clang compile built from a mostly
vanilla Xubuntu 19.04 VM, installed the llvm-needed Ubuntu packages, downloaded
a new copy of llvm using the noted llvm install page, configured using
>>>>>> 
>>>>>> cmake -G Ninja -DLLVM_ENABLE_PROJECTS="clang"
-DLLVM_USE_LINKER=lld -DCMAKE_BUILD_TYPE="Release"
-DCMAKE_INSTALL_PREFIX=/home/nnelson/Documents/llvm/install ../llvm &>
cmake.log
>>>>>> 
>>>>>> which is primarily different from yours where I am
using a 'Release' build to avoid the much larger memory and disk usage
of a 'Debug' build. The 'ninja install' command put everything
in llvm/install as expected including clang. I look through cmake.log to see if
there are errors that need to be corrected.
>>>>>> 
>>>>>> My differences appear to be Xubuntu, the packages,
ninja, and the cmake line.
>>>>>> 
>>>>>> On Linux I can use
>>>>>> 
>>>>>> ninja &> ninja_compile.log
>>>>>> 
>>>>>> to look at the compile history and see if something
went wrong.
>>>>>> 
>>>>>> Neil
>>>>>> 
>>>>>> On 7/6/19 12:00 AM, Joan Lluch wrote:
>>>>>>> Hi Nelson,
>>>>>>> 
>>>>>>> Thanks for your reply. 
>>>>>>> 
>>>>>>> The “build/Debug/lib” and "build/Release/lib”
directories is where all the libraries go. Similarly, the executables go to
“build/Debug/bin” and “build/Release/bin” before they are moved to the install
directory. This is expected and normal. However, the problem is that a small
number of libraries (exactly 20 in total) are not created at all for the LLVM
9.0 version that I cloned from gitHub. These libraries are in fact not created
anywhere!.
>>>>>>> 
>>>>>>> I still have LLVM 7.0 installed in my computer and
the libraries for that version are all there in the right places under the LLMV
7.0 directory, but in that case I installed it all in a different way as I said,
loosing           the benefits of git.
>>>>>>> 
>>>>>>> I forgot to mention that “llc” alone compiles and
links correctly without any issue. The problem is only when I try to get ‘clang’
compiled.
>>>>>>> 
>>>>>>> You mention that you enabled a lot of projects: 
"clang;clang-tools-extra;compiler-rt;debuginfo-tests;libclc;libcxx;libcxxabi;libunwind;lld;lldb;llvm;openmp;parallel-libs;polly;pstl”.
I only really need the basic installation of “clang”, and I do not need any
testing tools because all I want is to add my custom target to it. I also tried
"clang;libclc;libcxx” but the problem with the missing libraries is exactly
the same.
>>>>>>> 
>>>>>>> Just as a matter of information: I successfully
implemented a custom target backend, and have it almost finished and running
perfectly on LLVM 7.0. Now, I just want to move it to LLVM 9.0, but got stuck in
what is supposed to be the easiest part which is just compiling it (??), but I
do not understand why it doesn’t compile!
>>>>>>> 
>>>>>>> Any ideas?
>>>>>>> 
>>>>>>> Joan
>>>>>>> 
>>>>>>>> John, I compiled and installed to /usr/local
all the projects under llvm except llgo yesterday. The three files you noted are
in
>>>>>>>> ../llvm-project/build/lib
>>>>>>>> I do not have a llvm-project/build/Debug
directory.
>>>>>>>> Xubuntu 19.04. llvm downloaded from github on
6/18 using instructions from the page you note.
>>>>>>>> cmake -G Ninja
-DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra;compiler-rt;debuginfo-tests;libclc;libcxx;libcxxabi;libunwind;lld;lldb;llvm;openmp;parallel-libs;polly;pstl"
-DLLVM_USE_LINKER=lld -DCMAKE_BUILD_TYPE="Release" ../llvm
>>>>>>>> Installed additional packages as needed.
>>>>>>>> Neil
>>>>>>>> On 7/5/19 6:46 AM, Joan Lluch via llvm-dev
wrote:
>>>>>>>>> Hi All,
>>>>>>>>> 
>>>>>>>>> I am looking for the best way to install
LLVM+clang,  but I do not seem to find a way that works for me.
>>>>>>>>> 
>>>>>>>>> I followed the steps in this document
Getting Started with the LLVM System — LLVM 9 documentation
<https://llvm.org/docs/GettingStarted.html> except that I created the
following folder structure as I do not want clang and llc to go to /usr/local
>>>>>>>>> 
>>>>>>>>> LLVM-9
>>>>>>>>>    llvm-project  (cloned from github)
>>>>>>>>>    install
>>>>>>>>> 
>>>>>>>>> I ran the following command line from the
build directory in llvm-project as described in the doc, but added the
DLLVM_OPTIMIZED_TABLEGEN=On variable :
>>>>>>>>> 
>>>>>>>>> cmake -G Xcode -DLLVM_ENABLE_PROJECTS=clang
-DCMAKE_INSTALL_PREFIX=/Users/joan/LLVM-9/install -DLLVM_OPTIMIZED_TABLEGEN=On
../llvm
>>>>>>>>> 
>>>>>>>>> The cmake command above seems to work ok,
but after that, when I compile the “install” or “build_all” schemes I get a lot
of linker errors. Such as these ones and more:
>>>>>>>>> 
>>>>>>>>> clang: error: no such file or directory:
'/Users/joan/LLVM-9/llvm-project/build/Debug/lib/libclangAST.a'
>>>>>>>>> clang: error: no such file or directory:
'/Users/joan/LLVM-9/llvm-project/build/Debug/lib/libclangLex.a'
>>>>>>>>> clang: error: no such file or directory:
'/Users/joan/LLVM-9/llvm-project/build/Debug/lib/libclangBasic.a'
>>>>>>>>> 
>>>>>>>>> Up until recently, I have worked with LLVM
7.0 and all what I did was downloading both llvm and clang from llvm.org
<http://llvm.org/>, copied clang into llvm/tools, and ran the cmake
application (not command line).  That kind of worked except for some minor
glitches but of course I didn’t get the benefits of git.
>>>>>>>>> 
>>>>>>>>> So what am I doing wrong now? Why I’m
getting such linker errors?
>>>>>>>>> 
>>>>>>>>> It seems that a few required libraries are
not created, but I do not understand why. Any ideas?
>>>>>>>>> 
>>>>>>>>> Thanks,
>>>>>>>>> 
>>>>>>>>> John
>>>>>>> 
>>>>> 
>>>>> _______________________________________________
>>>>> LLVM Developers mailing list
>>>>> llvm-dev at lists.llvm.org <mailto:llvm-dev at
lists.llvm.org>
>>>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
<https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
>>>> 
>>>> _______________________________________________
>>>> LLVM Developers mailing list
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lists.llvm.org>
>>>> https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
<https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev>
>> 
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