[PATCH bpf-next v3] samples/bpf: Update build procedure for manually compiling LLVM and Clang

[PATCH bpf-next v3] samples/bpf: Update build procedure for manually compiling LLVM and Clang

[Tiezhu Yang]

The current LLVM and Clang build procedure in samples/bpf/README.rst is
out of date. See below that the links are not accessible any more.

$ git clone http://llvm.org/git/llvm.git
Cloning into 'llvm'...
fatal: unable to access 'http://llvm.org/git/llvm.git/': Maximum (20) redirects followed
$ git clone --depth 1 http://llvm.org/git/clang.git
Cloning into 'clang'...
fatal: unable to access 'http://llvm.org/git/clang.git/': Maximum (20) redirects followed

The LLVM community has adopted new ways to build the compiler. There are
different ways to build LLVM and Clang, the Clang Getting Started page [1]
has one way. As Yonghong said, it is better to copy the build procedure
in Documentation/bpf/bpf_devel_QA.rst to keep consistent.

I verified the procedure and it is proved to be feasible, so we should
update README.rst to reflect the reality. At the same time, update the
related comment in Makefile.

Additionally, as Fangrui said, the dir llvm-project/llvm/build/install is
not used, BUILD_SHARED_LIBS=OFF is the default option [2], so also change
Documentation/bpf/bpf_devel_QA.rst together.

[1] https://clang.llvm.org/get_started.html
[2] https://www.llvm.org/docs/CMake.html

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Yonghong Song <yhs@fb.com>
---

v2: Update the commit message suggested by Yonghong,
    thank you very much.

v3: Remove the default option BUILD_SHARED_LIBS=OFF
    and just mkdir llvm-project/llvm/build suggested
    by Fangrui.

 Documentation/bpf/bpf_devel_QA.rst |  3 +--
 samples/bpf/Makefile               |  2 +-
 samples/bpf/README.rst             | 16 +++++++++-------
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst
index 5b613d2..18788bb 100644
--- a/Documentation/bpf/bpf_devel_QA.rst
+++ b/Documentation/bpf/bpf_devel_QA.rst
@@ -506,11 +506,10 @@ that set up, proceed with building the latest LLVM and clang version
 from the git repositories::
 
      $ git clone https://github.com/llvm/llvm-project.git
-     $ mkdir -p llvm-project/llvm/build/install
+     $ mkdir -p llvm-project/llvm/build
      $ cd llvm-project/llvm/build
      $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
                 -DLLVM_ENABLE_PROJECTS="clang"    \
-                -DBUILD_SHARED_LIBS=OFF           \
                 -DCMAKE_BUILD_TYPE=Release        \
                 -DLLVM_BUILD_RUNTIME=OFF
      $ ninja
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 26fc96c..d061446 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -208,7 +208,7 @@ TPROGLDLIBS_xdpsock		+= -pthread -lcap
 TPROGLDLIBS_xsk_fwd		+= -pthread
 
 # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
-#  make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
+# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
 LLC ?= llc
 CLANG ?= clang
 OPT ?= opt
diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
index dd34b2d..23006cb 100644
--- a/samples/bpf/README.rst
+++ b/samples/bpf/README.rst
@@ -65,17 +65,19 @@ To generate a smaller llc binary one can use::
 Quick sniplet for manually compiling LLVM and clang
 (build dependencies are cmake and gcc-c++)::
 
- $ git clone http://llvm.org/git/llvm.git
- $ cd llvm/tools
- $ git clone --depth 1 http://llvm.org/git/clang.git
- $ cd ..; mkdir build; cd build
- $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86"
- $ make -j $(getconf _NPROCESSORS_ONLN)
+ $ git clone https://github.com/llvm/llvm-project.git
+ $ mkdir -p llvm-project/llvm/build
+ $ cd llvm-project/llvm/build
+ $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
+            -DLLVM_ENABLE_PROJECTS="clang"    \
+            -DCMAKE_BUILD_TYPE=Release        \
+            -DLLVM_BUILD_RUNTIME=OFF
+ $ ninja
 
 It is also possible to point make to the newly compiled 'llc' or
 'clang' command via redefining LLC or CLANG on the make command line::
 
- make M=samples/bpf LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
+ make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
 
 Cross compiling samples
 -----------------------
-- 
2.1.0

Re: [PATCH bpf-next v3] samples/bpf: Update build procedure for manually compiling LLVM and Clang

[Nathan Chancellor]

On Thu, Jan 21, 2021 at 01:27:35PM +0800, Tiezhu Yang wrote:
> The current LLVM and Clang build procedure in samples/bpf/README.rst is
> out of date. See below that the links are not accessible any more.
> 
> $ git clone http://llvm.org/git/llvm.git
> Cloning into 'llvm'...
> fatal: unable to access 'http://llvm.org/git/llvm.git/': Maximum (20) redirects followed
> $ git clone --depth 1 http://llvm.org/git/clang.git
> Cloning into 'clang'...
> fatal: unable to access 'http://llvm.org/git/clang.git/': Maximum (20) redirects followed
> 
> The LLVM community has adopted new ways to build the compiler. There are
> different ways to build LLVM and Clang, the Clang Getting Started page [1]
> has one way. As Yonghong said, it is better to copy the build procedure
> in Documentation/bpf/bpf_devel_QA.rst to keep consistent.
> 
> I verified the procedure and it is proved to be feasible, so we should
> update README.rst to reflect the reality. At the same time, update the
> related comment in Makefile.
> 
> Additionally, as Fangrui said, the dir llvm-project/llvm/build/install is
> not used, BUILD_SHARED_LIBS=OFF is the default option [2], so also change
> Documentation/bpf/bpf_devel_QA.rst together.
> 
> [1] https://clang.llvm.org/get_started.html
> [2] https://www.llvm.org/docs/CMake.html
> 
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> Acked-by: Yonghong Song <yhs@fb.com>

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>

Small comment below.

> ---
> 
> v2: Update the commit message suggested by Yonghong,
>     thank you very much.
> 
> v3: Remove the default option BUILD_SHARED_LIBS=OFF
>     and just mkdir llvm-project/llvm/build suggested
>     by Fangrui.
> 
>  Documentation/bpf/bpf_devel_QA.rst |  3 +--
>  samples/bpf/Makefile               |  2 +-
>  samples/bpf/README.rst             | 16 +++++++++-------
>  3 files changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst
> index 5b613d2..18788bb 100644
> --- a/Documentation/bpf/bpf_devel_QA.rst
> +++ b/Documentation/bpf/bpf_devel_QA.rst
> @@ -506,11 +506,10 @@ that set up, proceed with building the latest LLVM and clang version
>  from the git repositories::
>  
>       $ git clone https://github.com/llvm/llvm-project.git
> -     $ mkdir -p llvm-project/llvm/build/install
> +     $ mkdir -p llvm-project/llvm/build
>       $ cd llvm-project/llvm/build
>       $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
>                  -DLLVM_ENABLE_PROJECTS="clang"    \
> -                -DBUILD_SHARED_LIBS=OFF           \
>                  -DCMAKE_BUILD_TYPE=Release        \
>                  -DLLVM_BUILD_RUNTIME=OFF
>       $ ninja
> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> index 26fc96c..d061446 100644
> --- a/samples/bpf/Makefile
> +++ b/samples/bpf/Makefile
> @@ -208,7 +208,7 @@ TPROGLDLIBS_xdpsock		+= -pthread -lcap
>  TPROGLDLIBS_xsk_fwd		+= -pthread
>  
>  # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
> -#  make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> +# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
>  LLC ?= llc
>  CLANG ?= clang
>  OPT ?= opt
> diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
> index dd34b2d..23006cb 100644
> --- a/samples/bpf/README.rst
> +++ b/samples/bpf/README.rst
> @@ -65,17 +65,19 @@ To generate a smaller llc binary one can use::
>  Quick sniplet for manually compiling LLVM and clang
>  (build dependencies are cmake and gcc-c++)::

Technically, ninja is now a build dependency as well, it might be worth
mentioning that here (usually the package is ninja or ninja-build).

Regardless of whether that is addressed or not (because it is small),
feel free to carry forward my tag in any future revisions unless they
drastically change.

> - $ git clone http://llvm.org/git/llvm.git
> - $ cd llvm/tools
> - $ git clone --depth 1 http://llvm.org/git/clang.git
> - $ cd ..; mkdir build; cd build
> - $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86"
> - $ make -j $(getconf _NPROCESSORS_ONLN)
> + $ git clone https://github.com/llvm/llvm-project.git
> + $ mkdir -p llvm-project/llvm/build
> + $ cd llvm-project/llvm/build
> + $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
> +            -DLLVM_ENABLE_PROJECTS="clang"    \
> +            -DCMAKE_BUILD_TYPE=Release        \
> +            -DLLVM_BUILD_RUNTIME=OFF
> + $ ninja
>  
>  It is also possible to point make to the newly compiled 'llc' or
>  'clang' command via redefining LLC or CLANG on the make command line::
>  
> - make M=samples/bpf LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> + make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
>  
>  Cross compiling samples
>  -----------------------
> -- 
> 2.1.0
> 

Re: [PATCH bpf-next v3] samples/bpf: Update build procedure for manually compiling LLVM and Clang

[Andrii Nakryiko]

On Wed, Jan 20, 2021 at 9:36 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> On Thu, Jan 21, 2021 at 01:27:35PM +0800, Tiezhu Yang wrote:
> > The current LLVM and Clang build procedure in samples/bpf/README.rst is
> > out of date. See below that the links are not accessible any more.
> >
> > $ git clone http://llvm.org/git/llvm.git
> > Cloning into 'llvm'...
> > fatal: unable to access 'http://llvm.org/git/llvm.git/': Maximum (20) redirects followed
> > $ git clone --depth 1 http://llvm.org/git/clang.git
> > Cloning into 'clang'...
> > fatal: unable to access 'http://llvm.org/git/clang.git/': Maximum (20) redirects followed
> >
> > The LLVM community has adopted new ways to build the compiler. There are
> > different ways to build LLVM and Clang, the Clang Getting Started page [1]
> > has one way. As Yonghong said, it is better to copy the build procedure
> > in Documentation/bpf/bpf_devel_QA.rst to keep consistent.
> >
> > I verified the procedure and it is proved to be feasible, so we should
> > update README.rst to reflect the reality. At the same time, update the
> > related comment in Makefile.
> >
> > Additionally, as Fangrui said, the dir llvm-project/llvm/build/install is
> > not used, BUILD_SHARED_LIBS=OFF is the default option [2], so also change
> > Documentation/bpf/bpf_devel_QA.rst together.
> >
> > [1] https://clang.llvm.org/get_started.html
> > [2] https://www.llvm.org/docs/CMake.html
> >
> > Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> > Acked-by: Yonghong Song <yhs@fb.com>
>
> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
>
> Small comment below.
>
> > ---
> >
> > v2: Update the commit message suggested by Yonghong,
> >     thank you very much.
> >
> > v3: Remove the default option BUILD_SHARED_LIBS=OFF
> >     and just mkdir llvm-project/llvm/build suggested
> >     by Fangrui.
> >
> >  Documentation/bpf/bpf_devel_QA.rst |  3 +--
> >  samples/bpf/Makefile               |  2 +-
> >  samples/bpf/README.rst             | 16 +++++++++-------
> >  3 files changed, 11 insertions(+), 10 deletions(-)
> >
> > diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst
> > index 5b613d2..18788bb 100644
> > --- a/Documentation/bpf/bpf_devel_QA.rst
> > +++ b/Documentation/bpf/bpf_devel_QA.rst
> > @@ -506,11 +506,10 @@ that set up, proceed with building the latest LLVM and clang version
> >  from the git repositories::
> >
> >       $ git clone https://github.com/llvm/llvm-project.git
> > -     $ mkdir -p llvm-project/llvm/build/install
> > +     $ mkdir -p llvm-project/llvm/build
> >       $ cd llvm-project/llvm/build
> >       $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
> >                  -DLLVM_ENABLE_PROJECTS="clang"    \
> > -                -DBUILD_SHARED_LIBS=OFF           \
> >                  -DCMAKE_BUILD_TYPE=Release        \
> >                  -DLLVM_BUILD_RUNTIME=OFF
> >       $ ninja
> > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> > index 26fc96c..d061446 100644
> > --- a/samples/bpf/Makefile
> > +++ b/samples/bpf/Makefile
> > @@ -208,7 +208,7 @@ TPROGLDLIBS_xdpsock               += -pthread -lcap
> >  TPROGLDLIBS_xsk_fwd          += -pthread
> >
> >  # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
> > -#  make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> > +# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
> >  LLC ?= llc
> >  CLANG ?= clang
> >  OPT ?= opt
> > diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
> > index dd34b2d..23006cb 100644
> > --- a/samples/bpf/README.rst
> > +++ b/samples/bpf/README.rst
> > @@ -65,17 +65,19 @@ To generate a smaller llc binary one can use::
> >  Quick sniplet for manually compiling LLVM and clang
> >  (build dependencies are cmake and gcc-c++)::
>
> Technically, ninja is now a build dependency as well, it might be worth
> mentioning that here (usually the package is ninja or ninja-build).

it's possible to generate Makefile by passing `-g "Unix Makefiles"`,
which would avoid dependency on ninja, no?

>
> Regardless of whether that is addressed or not (because it is small),
> feel free to carry forward my tag in any future revisions unless they
> drastically change.
>
> > - $ git clone http://llvm.org/git/llvm.git
> > - $ cd llvm/tools
> > - $ git clone --depth 1 http://llvm.org/git/clang.git
> > - $ cd ..; mkdir build; cd build
> > - $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86"
> > - $ make -j $(getconf _NPROCESSORS_ONLN)
> > + $ git clone https://github.com/llvm/llvm-project.git
> > + $ mkdir -p llvm-project/llvm/build
> > + $ cd llvm-project/llvm/build
> > + $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
> > +            -DLLVM_ENABLE_PROJECTS="clang"    \
> > +            -DCMAKE_BUILD_TYPE=Release        \
> > +            -DLLVM_BUILD_RUNTIME=OFF
> > + $ ninja
> >
> >  It is also possible to point make to the newly compiled 'llc' or
> >  'clang' command via redefining LLC or CLANG on the make command line::
> >
> > - make M=samples/bpf LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> > + make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
> >
> >  Cross compiling samples
> >  -----------------------
> > --
> > 2.1.0
> >

Re: [PATCH bpf-next v3] samples/bpf: Update build procedure for manually compiling LLVM and Clang

[Sedat Dilek]

On Thu, Jan 21, 2021 at 9:08 AM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Wed, Jan 20, 2021 at 9:36 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > On Thu, Jan 21, 2021 at 01:27:35PM +0800, Tiezhu Yang wrote:
> > > The current LLVM and Clang build procedure in samples/bpf/README.rst is
> > > out of date. See below that the links are not accessible any more.
> > >
> > > $ git clone http://llvm.org/git/llvm.git
> > > Cloning into 'llvm'...
> > > fatal: unable to access 'http://llvm.org/git/llvm.git/': Maximum (20) redirects followed
> > > $ git clone --depth 1 http://llvm.org/git/clang.git
> > > Cloning into 'clang'...
> > > fatal: unable to access 'http://llvm.org/git/clang.git/': Maximum (20) redirects followed
> > >
> > > The LLVM community has adopted new ways to build the compiler. There are
> > > different ways to build LLVM and Clang, the Clang Getting Started page [1]
> > > has one way. As Yonghong said, it is better to copy the build procedure
> > > in Documentation/bpf/bpf_devel_QA.rst to keep consistent.
> > >
> > > I verified the procedure and it is proved to be feasible, so we should
> > > update README.rst to reflect the reality. At the same time, update the
> > > related comment in Makefile.
> > >
> > > Additionally, as Fangrui said, the dir llvm-project/llvm/build/install is
> > > not used, BUILD_SHARED_LIBS=OFF is the default option [2], so also change
> > > Documentation/bpf/bpf_devel_QA.rst together.
> > >
> > > [1] https://clang.llvm.org/get_started.html
> > > [2] https://www.llvm.org/docs/CMake.html
> > >
> > > Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> > > Acked-by: Yonghong Song <yhs@fb.com>
> >
> > Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> >
> > Small comment below.
> >
> > > ---
> > >
> > > v2: Update the commit message suggested by Yonghong,
> > >     thank you very much.
> > >
> > > v3: Remove the default option BUILD_SHARED_LIBS=OFF
> > >     and just mkdir llvm-project/llvm/build suggested
> > >     by Fangrui.
> > >
> > >  Documentation/bpf/bpf_devel_QA.rst |  3 +--
> > >  samples/bpf/Makefile               |  2 +-
> > >  samples/bpf/README.rst             | 16 +++++++++-------
> > >  3 files changed, 11 insertions(+), 10 deletions(-)
> > >
> > > diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst
> > > index 5b613d2..18788bb 100644
> > > --- a/Documentation/bpf/bpf_devel_QA.rst
> > > +++ b/Documentation/bpf/bpf_devel_QA.rst
> > > @@ -506,11 +506,10 @@ that set up, proceed with building the latest LLVM and clang version
> > >  from the git repositories::
> > >
> > >       $ git clone https://github.com/llvm/llvm-project.git
> > > -     $ mkdir -p llvm-project/llvm/build/install
> > > +     $ mkdir -p llvm-project/llvm/build
> > >       $ cd llvm-project/llvm/build
> > >       $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
> > >                  -DLLVM_ENABLE_PROJECTS="clang"    \
> > > -                -DBUILD_SHARED_LIBS=OFF           \
> > >                  -DCMAKE_BUILD_TYPE=Release        \
> > >                  -DLLVM_BUILD_RUNTIME=OFF
> > >       $ ninja
> > > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> > > index 26fc96c..d061446 100644
> > > --- a/samples/bpf/Makefile
> > > +++ b/samples/bpf/Makefile
> > > @@ -208,7 +208,7 @@ TPROGLDLIBS_xdpsock               += -pthread -lcap
> > >  TPROGLDLIBS_xsk_fwd          += -pthread
> > >
> > >  # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
> > > -#  make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> > > +# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
> > >  LLC ?= llc
> > >  CLANG ?= clang
> > >  OPT ?= opt
> > > diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
> > > index dd34b2d..23006cb 100644
> > > --- a/samples/bpf/README.rst
> > > +++ b/samples/bpf/README.rst
> > > @@ -65,17 +65,19 @@ To generate a smaller llc binary one can use::
> > >  Quick sniplet for manually compiling LLVM and clang
> > >  (build dependencies are cmake and gcc-c++)::
> >
> > Technically, ninja is now a build dependency as well, it might be worth
> > mentioning that here (usually the package is ninja or ninja-build).
>
> it's possible to generate Makefile by passing `-g "Unix Makefiles"`,
> which would avoid dependency on ninja, no?
>

AFAICS, cmake is now the default and "Unix Makefiles" deprecated with
newer versions of LLVM/Clang.

- Sedat -

> >
> > Regardless of whether that is addressed or not (because it is small),
> > feel free to carry forward my tag in any future revisions unless they
> > drastically change.
> >
> > > - $ git clone http://llvm.org/git/llvm.git
> > > - $ cd llvm/tools
> > > - $ git clone --depth 1 http://llvm.org/git/clang.git
> > > - $ cd ..; mkdir build; cd build
> > > - $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86"
> > > - $ make -j $(getconf _NPROCESSORS_ONLN)
> > > + $ git clone https://github.com/llvm/llvm-project.git
> > > + $ mkdir -p llvm-project/llvm/build
> > > + $ cd llvm-project/llvm/build
> > > + $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
> > > +            -DLLVM_ENABLE_PROJECTS="clang"    \
> > > +            -DCMAKE_BUILD_TYPE=Release        \
> > > +            -DLLVM_BUILD_RUNTIME=OFF
> > > + $ ninja
> > >
> > >  It is also possible to point make to the newly compiled 'llc' or
> > >  'clang' command via redefining LLC or CLANG on the make command line::
> > >
> > > - make M=samples/bpf LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> > > + make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
> > >
> > >  Cross compiling samples
> > >  -----------------------
> > > --
> > > 2.1.0
> > >
>
> --
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Re: [PATCH bpf-next v3] samples/bpf: Update build procedure for manually compiling LLVM and Clang

[Sedat Dilek]

On Thu, Jan 21, 2021 at 9:55 AM Sedat Dilek <sedat.dilek@gmail.com> wrote:
>
> On Thu, Jan 21, 2021 at 9:08 AM Andrii Nakryiko
> <andrii.nakryiko@gmail.com> wrote:
> >
> > On Wed, Jan 20, 2021 at 9:36 PM Nathan Chancellor
> > <natechancellor@gmail.com> wrote:
> > >
> > > On Thu, Jan 21, 2021 at 01:27:35PM +0800, Tiezhu Yang wrote:
> > > > The current LLVM and Clang build procedure in samples/bpf/README.rst is
> > > > out of date. See below that the links are not accessible any more.
> > > >
> > > > $ git clone http://llvm.org/git/llvm.git
> > > > Cloning into 'llvm'...
> > > > fatal: unable to access 'http://llvm.org/git/llvm.git/': Maximum (20) redirects followed
> > > > $ git clone --depth 1 http://llvm.org/git/clang.git
> > > > Cloning into 'clang'...
> > > > fatal: unable to access 'http://llvm.org/git/clang.git/': Maximum (20) redirects followed
> > > >
> > > > The LLVM community has adopted new ways to build the compiler. There are
> > > > different ways to build LLVM and Clang, the Clang Getting Started page [1]
> > > > has one way. As Yonghong said, it is better to copy the build procedure
> > > > in Documentation/bpf/bpf_devel_QA.rst to keep consistent.
> > > >
> > > > I verified the procedure and it is proved to be feasible, so we should
> > > > update README.rst to reflect the reality. At the same time, update the
> > > > related comment in Makefile.
> > > >
> > > > Additionally, as Fangrui said, the dir llvm-project/llvm/build/install is
> > > > not used, BUILD_SHARED_LIBS=OFF is the default option [2], so also change
> > > > Documentation/bpf/bpf_devel_QA.rst together.
> > > >
> > > > [1] https://clang.llvm.org/get_started.html
> > > > [2] https://www.llvm.org/docs/CMake.html
> > > >
> > > > Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> > > > Acked-by: Yonghong Song <yhs@fb.com>
> > >
> > > Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> > >
> > > Small comment below.
> > >
> > > > ---
> > > >
> > > > v2: Update the commit message suggested by Yonghong,
> > > >     thank you very much.
> > > >
> > > > v3: Remove the default option BUILD_SHARED_LIBS=OFF
> > > >     and just mkdir llvm-project/llvm/build suggested
> > > >     by Fangrui.
> > > >
> > > >  Documentation/bpf/bpf_devel_QA.rst |  3 +--
> > > >  samples/bpf/Makefile               |  2 +-
> > > >  samples/bpf/README.rst             | 16 +++++++++-------
> > > >  3 files changed, 11 insertions(+), 10 deletions(-)
> > > >
> > > > diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst
> > > > index 5b613d2..18788bb 100644
> > > > --- a/Documentation/bpf/bpf_devel_QA.rst
> > > > +++ b/Documentation/bpf/bpf_devel_QA.rst
> > > > @@ -506,11 +506,10 @@ that set up, proceed with building the latest LLVM and clang version
> > > >  from the git repositories::
> > > >
> > > >       $ git clone https://github.com/llvm/llvm-project.git
> > > > -     $ mkdir -p llvm-project/llvm/build/install
> > > > +     $ mkdir -p llvm-project/llvm/build
> > > >       $ cd llvm-project/llvm/build
> > > >       $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
> > > >                  -DLLVM_ENABLE_PROJECTS="clang"    \
> > > > -                -DBUILD_SHARED_LIBS=OFF           \
> > > >                  -DCMAKE_BUILD_TYPE=Release        \
> > > >                  -DLLVM_BUILD_RUNTIME=OFF
> > > >       $ ninja
> > > > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> > > > index 26fc96c..d061446 100644
> > > > --- a/samples/bpf/Makefile
> > > > +++ b/samples/bpf/Makefile
> > > > @@ -208,7 +208,7 @@ TPROGLDLIBS_xdpsock               += -pthread -lcap
> > > >  TPROGLDLIBS_xsk_fwd          += -pthread
> > > >
> > > >  # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
> > > > -#  make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> > > > +# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
> > > >  LLC ?= llc
> > > >  CLANG ?= clang
> > > >  OPT ?= opt
> > > > diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
> > > > index dd34b2d..23006cb 100644
> > > > --- a/samples/bpf/README.rst
> > > > +++ b/samples/bpf/README.rst
> > > > @@ -65,17 +65,19 @@ To generate a smaller llc binary one can use::
> > > >  Quick sniplet for manually compiling LLVM and clang
> > > >  (build dependencies are cmake and gcc-c++)::
> > >
> > > Technically, ninja is now a build dependency as well, it might be worth
> > > mentioning that here (usually the package is ninja or ninja-build).
> >
> > it's possible to generate Makefile by passing `-g "Unix Makefiles"`,
> > which would avoid dependency on ninja, no?
> >
>
> AFAICS, cmake is now the default and "Unix Makefiles" deprecated with
> newer versions of LLVM/Clang.
>

Hmm, I mixed it up...
This is about the cmake-generator (GNU/make was deprecated/abandoned).
Cannot say I use "ninja" - it's fast.

Just as a hint for a fast build of LLVM/Clang:
Use tc-build together with stage1-only (build and install) options.

- Sedat -

[1] https://github.com/ClangBuiltLinux/tc-build

>
> > >
> > > Regardless of whether that is addressed or not (because it is small),
> > > feel free to carry forward my tag in any future revisions unless they
> > > drastically change.
> > >
> > > > - $ git clone http://llvm.org/git/llvm.git
> > > > - $ cd llvm/tools
> > > > - $ git clone --depth 1 http://llvm.org/git/clang.git
> > > > - $ cd ..; mkdir build; cd build
> > > > - $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86"
> > > > - $ make -j $(getconf _NPROCESSORS_ONLN)
> > > > + $ git clone https://github.com/llvm/llvm-project.git
> > > > + $ mkdir -p llvm-project/llvm/build
> > > > + $ cd llvm-project/llvm/build
> > > > + $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
> > > > +            -DLLVM_ENABLE_PROJECTS="clang"    \
> > > > +            -DCMAKE_BUILD_TYPE=Release        \
> > > > +            -DLLVM_BUILD_RUNTIME=OFF
> > > > + $ ninja
> > > >
> > > >  It is also possible to point make to the newly compiled 'llc' or
> > > >  'clang' command via redefining LLC or CLANG on the make command line::
> > > >
> > > > - make M=samples/bpf LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> > > > + make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
> > > >
> > > >  Cross compiling samples
> > > >  -----------------------
> > > > --
> > > > 2.1.0
> > > >
> >
> > --
> > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
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Re: [PATCH bpf-next v3] samples/bpf: Update build procedure for manually compiling LLVM and Clang

[Nathan Chancellor]

On Thu, Jan 21, 2021 at 12:08:31AM -0800, Andrii Nakryiko wrote:
> On Wed, Jan 20, 2021 at 9:36 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > On Thu, Jan 21, 2021 at 01:27:35PM +0800, Tiezhu Yang wrote:
> > > The current LLVM and Clang build procedure in samples/bpf/README.rst is
> > > out of date. See below that the links are not accessible any more.
> > >
> > > $ git clone http://llvm.org/git/llvm.git
> > > Cloning into 'llvm'...
> > > fatal: unable to access 'http://llvm.org/git/llvm.git/': Maximum (20) redirects followed
> > > $ git clone --depth 1 http://llvm.org/git/clang.git
> > > Cloning into 'clang'...
> > > fatal: unable to access 'http://llvm.org/git/clang.git/': Maximum (20) redirects followed
> > >
> > > The LLVM community has adopted new ways to build the compiler. There are
> > > different ways to build LLVM and Clang, the Clang Getting Started page [1]
> > > has one way. As Yonghong said, it is better to copy the build procedure
> > > in Documentation/bpf/bpf_devel_QA.rst to keep consistent.
> > >
> > > I verified the procedure and it is proved to be feasible, so we should
> > > update README.rst to reflect the reality. At the same time, update the
> > > related comment in Makefile.
> > >
> > > Additionally, as Fangrui said, the dir llvm-project/llvm/build/install is
> > > not used, BUILD_SHARED_LIBS=OFF is the default option [2], so also change
> > > Documentation/bpf/bpf_devel_QA.rst together.
> > >
> > > [1] https://clang.llvm.org/get_started.html
> > > [2] https://www.llvm.org/docs/CMake.html
> > >
> > > Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> > > Acked-by: Yonghong Song <yhs@fb.com>
> >
> > Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
> >
> > Small comment below.
> >
> > > ---
> > >
> > > v2: Update the commit message suggested by Yonghong,
> > >     thank you very much.
> > >
> > > v3: Remove the default option BUILD_SHARED_LIBS=OFF
> > >     and just mkdir llvm-project/llvm/build suggested
> > >     by Fangrui.
> > >
> > >  Documentation/bpf/bpf_devel_QA.rst |  3 +--
> > >  samples/bpf/Makefile               |  2 +-
> > >  samples/bpf/README.rst             | 16 +++++++++-------
> > >  3 files changed, 11 insertions(+), 10 deletions(-)
> > >
> > > diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst
> > > index 5b613d2..18788bb 100644
> > > --- a/Documentation/bpf/bpf_devel_QA.rst
> > > +++ b/Documentation/bpf/bpf_devel_QA.rst
> > > @@ -506,11 +506,10 @@ that set up, proceed with building the latest LLVM and clang version
> > >  from the git repositories::
> > >
> > >       $ git clone https://github.com/llvm/llvm-project.git
> > > -     $ mkdir -p llvm-project/llvm/build/install
> > > +     $ mkdir -p llvm-project/llvm/build
> > >       $ cd llvm-project/llvm/build
> > >       $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
> > >                  -DLLVM_ENABLE_PROJECTS="clang"    \
> > > -                -DBUILD_SHARED_LIBS=OFF           \
> > >                  -DCMAKE_BUILD_TYPE=Release        \
> > >                  -DLLVM_BUILD_RUNTIME=OFF
> > >       $ ninja
> > > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> > > index 26fc96c..d061446 100644
> > > --- a/samples/bpf/Makefile
> > > +++ b/samples/bpf/Makefile
> > > @@ -208,7 +208,7 @@ TPROGLDLIBS_xdpsock               += -pthread -lcap
> > >  TPROGLDLIBS_xsk_fwd          += -pthread
> > >
> > >  # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
> > > -#  make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> > > +# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
> > >  LLC ?= llc
> > >  CLANG ?= clang
> > >  OPT ?= opt
> > > diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
> > > index dd34b2d..23006cb 100644
> > > --- a/samples/bpf/README.rst
> > > +++ b/samples/bpf/README.rst
> > > @@ -65,17 +65,19 @@ To generate a smaller llc binary one can use::
> > >  Quick sniplet for manually compiling LLVM and clang
> > >  (build dependencies are cmake and gcc-c++)::
> >
> > Technically, ninja is now a build dependency as well, it might be worth
> > mentioning that here (usually the package is ninja or ninja-build).
> 
> it's possible to generate Makefile by passing `-g "Unix Makefiles"`,
> which would avoid dependency on ninja, no?

Yes, although I am fairly certain that building with ninja is quicker so
I would recommend keeping it. One small extra dependency never killed
anyone plus ninja is becoming more common nowadays :)

> > Regardless of whether that is addressed or not (because it is small),
> > feel free to carry forward my tag in any future revisions unless they
> > drastically change.
> >
> > > - $ git clone http://llvm.org/git/llvm.git
> > > - $ cd llvm/tools
> > > - $ git clone --depth 1 http://llvm.org/git/clang.git
> > > - $ cd ..; mkdir build; cd build
> > > - $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86"
> > > - $ make -j $(getconf _NPROCESSORS_ONLN)
> > > + $ git clone https://github.com/llvm/llvm-project.git
> > > + $ mkdir -p llvm-project/llvm/build
> > > + $ cd llvm-project/llvm/build
> > > + $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
> > > +            -DLLVM_ENABLE_PROJECTS="clang"    \
> > > +            -DCMAKE_BUILD_TYPE=Release        \
> > > +            -DLLVM_BUILD_RUNTIME=OFF
> > > + $ ninja
> > >
> > >  It is also possible to point make to the newly compiled 'llc' or
> > >  'clang' command via redefining LLC or CLANG on the make command line::
> > >
> > > - make M=samples/bpf LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
> > > + make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
> > >
> > >  Cross compiling samples
> > >  -----------------------
> > > --
> > > 2.1.0
> > >

Re: [PATCH bpf-next v3] samples/bpf: Update build procedure for manually compiling LLVM and Clang

[Yonghong Song]

On 1/21/21 6:23 AM, Nathan Chancellor wrote:
> On Thu, Jan 21, 2021 at 12:08:31AM -0800, Andrii Nakryiko wrote:
>> On Wed, Jan 20, 2021 at 9:36 PM Nathan Chancellor
>> <natechancellor@gmail.com> wrote:
>>>
>>> On Thu, Jan 21, 2021 at 01:27:35PM +0800, Tiezhu Yang wrote:
>>>> The current LLVM and Clang build procedure in samples/bpf/README.rst is
>>>> out of date. See below that the links are not accessible any more.
>>>>
>>>> $ git clone http://llvm.org/git/llvm.git
>>>> Cloning into 'llvm'...
>>>> fatal: unable to access 'http://llvm.org/git/llvm.git/ ': Maximum (20) redirects followed
>>>> $ git clone --depth 1 http://llvm.org/git/clang.git
>>>> Cloning into 'clang'...
>>>> fatal: unable to access 'http://llvm.org/git/clang.git/ ': Maximum (20) redirects followed
>>>>
>>>> The LLVM community has adopted new ways to build the compiler. There are
>>>> different ways to build LLVM and Clang, the Clang Getting Started page [1]
>>>> has one way. As Yonghong said, it is better to copy the build procedure
>>>> in Documentation/bpf/bpf_devel_QA.rst to keep consistent.
>>>>
>>>> I verified the procedure and it is proved to be feasible, so we should
>>>> update README.rst to reflect the reality. At the same time, update the
>>>> related comment in Makefile.
>>>>
>>>> Additionally, as Fangrui said, the dir llvm-project/llvm/build/install is
>>>> not used, BUILD_SHARED_LIBS=OFF is the default option [2], so also change
>>>> Documentation/bpf/bpf_devel_QA.rst together.
>>>>
>>>> [1] https://clang.llvm.org/get_started.html
>>>> [2] https://www.llvm.org/docs/CMake.html
>>>>
>>>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
>>>> Acked-by: Yonghong Song <yhs@fb.com>
>>>
>>> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
>>>
>>> Small comment below.
>>>
>>>> ---
>>>>
>>>> v2: Update the commit message suggested by Yonghong,
>>>>      thank you very much.
>>>>
>>>> v3: Remove the default option BUILD_SHARED_LIBS=OFF
>>>>      and just mkdir llvm-project/llvm/build suggested
>>>>      by Fangrui.
>>>>
>>>>   Documentation/bpf/bpf_devel_QA.rst |  3 +--
>>>>   samples/bpf/Makefile               |  2 +-
>>>>   samples/bpf/README.rst             | 16 +++++++++-------
>>>>   3 files changed, 11 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst
>>>> index 5b613d2..18788bb 100644
>>>> --- a/Documentation/bpf/bpf_devel_QA.rst
>>>> +++ b/Documentation/bpf/bpf_devel_QA.rst
>>>> @@ -506,11 +506,10 @@ that set up, proceed with building the latest LLVM and clang version
>>>>   from the git repositories::
>>>>
>>>>        $ git clone https://github.com/llvm/llvm-project.git
>>>> -     $ mkdir -p llvm-project/llvm/build/install
>>>> +     $ mkdir -p llvm-project/llvm/build
>>>>        $ cd llvm-project/llvm/build
>>>>        $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
>>>>                   -DLLVM_ENABLE_PROJECTS="clang"    \
>>>> -                -DBUILD_SHARED_LIBS=OFF           \
>>>>                   -DCMAKE_BUILD_TYPE=Release        \
>>>>                   -DLLVM_BUILD_RUNTIME=OFF
>>>>        $ ninja
>>>> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
>>>> index 26fc96c..d061446 100644
>>>> --- a/samples/bpf/Makefile
>>>> +++ b/samples/bpf/Makefile
>>>> @@ -208,7 +208,7 @@ TPROGLDLIBS_xdpsock               += -pthread -lcap
>>>>   TPROGLDLIBS_xsk_fwd          += -pthread
>>>>
>>>>   # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
>>>> -#  make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
>>>> +# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
>>>>   LLC ?= llc
>>>>   CLANG ?= clang
>>>>   OPT ?= opt
>>>> diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
>>>> index dd34b2d..23006cb 100644
>>>> --- a/samples/bpf/README.rst
>>>> +++ b/samples/bpf/README.rst
>>>> @@ -65,17 +65,19 @@ To generate a smaller llc binary one can use::
>>>>   Quick sniplet for manually compiling LLVM and clang
>>>>   (build dependencies are cmake and gcc-c++)::
>>>
>>> Technically, ninja is now a build dependency as well, it might be worth
>>> mentioning that here (usually the package is ninja or ninja-build).
>>
>> it's possible to generate Makefile by passing `-g "Unix Makefiles"`,
>> which would avoid dependency on ninja, no?
> 
> Yes, although I am fairly certain that building with ninja is quicker so
> I would recommend keeping it. One small extra dependency never killed
> anyone plus ninja is becoming more common nowadays :)

Agree. Let us use 'ninja' here, which is widely used in llvm community
for llvm-project build compared to other alternatives.

> 
>>> Regardless of whether that is addressed or not (because it is small),
>>> feel free to carry forward my tag in any future revisions unless they
>>> drastically change.
>>>
>>>> - $ git clone http://llvm.org/git/llvm.git
>>>> - $ cd llvm/tools
>>>> - $ git clone --depth 1 http://llvm.org/git/clang.git
>>>> - $ cd ..; mkdir build; cd build
>>>> - $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86"
>>>> - $ make -j $(getconf _NPROCESSORS_ONLN)
>>>> + $ git clone https://github.com/llvm/llvm-project.git
>>>> + $ mkdir -p llvm-project/llvm/build
>>>> + $ cd llvm-project/llvm/build
>>>> + $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
>>>> +            -DLLVM_ENABLE_PROJECTS="clang"    \
>>>> +            -DCMAKE_BUILD_TYPE=Release        \
>>>> +            -DLLVM_BUILD_RUNTIME=OFF
>>>> + $ ninja
>>>>
>>>>   It is also possible to point make to the newly compiled 'llc' or
>>>>   'clang' command via redefining LLC or CLANG on the make command line::
>>>>
>>>> - make M=samples/bpf LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
>>>> + make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
>>>>
>>>>   Cross compiling samples
>>>>   -----------------------
>>>> --
>>>> 2.1.0
>>>>