Tag: archLinux

Build gRPC on ArchLinux

Today, I followed Build from Source to compile gRPC on ArchLinux:

 $ git clone -b $(curl -L https://grpc.io/release) https://github.com/grpc/grpc
 $ cd grpc
 $ git submodule update --init
 $ make

Current gRPC‘s release version is v1.4.x:

$ curl -L https://grpc.io/release
v1.4.x

The build flow will generate the errors like this:

......
src/core/lib/support/murmur_hash.c: In function ‘gpr_murmur_hash3’:
src/core/lib/support/murmur_hash.c:79:10: error: this statement may fall through [-Werror=implicit-fallthrough=]
       k1 ^= ((uint32_t)tail[2]) << 16;
       ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/core/lib/support/murmur_hash.c:80:5: note: here
     case 2:
     ^~~~
src/core/lib/support/murmur_hash.c:81:10: error: this statement may fall through [-Werror=implicit-fallthrough=]
       k1 ^= ((uint32_t)tail[1]) << 8;
       ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
src/core/lib/support/murmur_hash.c:82:5: note: here
     case 1:
     ^~~~
cc1: all warnings being treated as errors
......

After referring Fix warnings with GCC 7, I finally make the compilation successful. To facilitate others to build gRPC v1.4.x source code on ArchLinux, I create a patch, and hope it can help others.

P.S.
(1) You should fallback to OpenSSL 1.0. Please refer here:

PKG_CONFIG_PATH=/usr/lib/openssl-1.0/pkgconfig make

Otherwise you may encounter following errors:

src/core/tsi/ssl_transport_security.c: In function ‘tsi_create_ssl_client_handshaker_factory’:
src/core/tsi/ssl_transport_security.c:1281:3: error: ‘TLSv1_2_method’ is deprecated [-Werror=deprecated-declarations]
   ssl_context = SSL_CTX_new(TLSv1_2_method());
   ^~~~~~~~~~~
In file included from /usr/include/openssl/ct.h:13:0,
                 from /usr/include/openssl/ssl.h:61,
                 from src/core/tsi/ssl_transport_security.c:45:
/usr/include/openssl/ssl.h:1624:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_2_method(void)) /* TLSv1.2 */
 ^
src/core/tsi/ssl_transport_security.c: In function ‘tsi_create_ssl_server_handshaker_factory_ex’:
src/core/tsi/ssl_transport_security.c:1389:7: error: ‘TLSv1_2_method’ is deprecated [-Werror=deprecated-declarations]
       impl->ssl_contexts[i] = SSL_CTX_new(TLSv1_2_method());
       ^~~~
In file included from /usr/include/openssl/ct.h:13:0,
                 from /usr/include/openssl/ssl.h:61,
                 from src/core/tsi/ssl_transport_security.c:45:
/usr/include/openssl/ssl.h:1624:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur const SSL_METHOD *TLSv1_2_method(void)) /* TLSv1.2 */
 ^
At top level:
src/core/tsi/ssl_transport_security.c:118:22: error: ‘openssl_thread_id_cb’ defined but not used [-Werror=unused-functio ]
 static unsigned long openssl_thread_id_cb(void) {
                      ^~~~~~~~~~~~~~~~~~~~
src/core/tsi/ssl_transport_security.c:110:13: error: ‘openssl_locking_cb’ defined but not used [-Werror=unused-function]
 static void openssl_locking_cb(int mode, int type, const char *file, int line) {
             ^~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors

(2) You may need to change installation directory from /usr/local to /usr:

make prefix=/usr install

This lets you process pkg-config path easily.

gcc’s enable “–enable-default-pie” option make you stuck at “relocation R_X86_64_32S against …” error

Recently, after I upgrade gcc on my Arch Linux, I find it has enabled “--enable-default-pie” option by default:

$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-pc-linux-gnu/7.1.1/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /build/gcc/src/gcc/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared --enable-threads=posix --enable-libmpx --with-system-zlib --with-isl --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-gnu-indirect-function --disable-multilib --disable-werror --enable-checking=release --enable-default-pie --enable-default-ssp
Thread model: posix
gcc version 7.1.1 20170630 (GCC)

One consequence of this enhancement is you should rebuild the static libraries which you projects depend on, otherwise you may counter totally confused link errors like this:

relocation R_X86_64_32S against `.text’ can not be used when making a shared object; recompile with -fPIC

A caveat you must pay attention to is if your static library has assembly code object which is not position independent, you must specify “-no-pie” option during link stage of generating final executable binary. This issue let me spend half day to debug, so it is a really good habit to check critical packages’ change log, such as your compiler.

Reference:
PIE.

Install bcc on ArchLinux

To install bcc on ArchLinux, firstly you need to setup yaourt from AUR:

$ git clone https://aur.archlinux.org/yaourt.git
$ cd yaourt
$ makepkg -si

Then execute yaourt bcc command:

# yaourt bcc
1 aur/bcc 0.3.0-1 [installed] (17) (2.51)
    BPF Compiler Collection - C library and examples
2 aur/bcc-git v0.1.8.r330.52cd371-1 (2) (0.06)
    BPF Compiler Collection - C library and examples
3 aur/bcc-tools 0.3.0-1 [installed] (17) (2.51)
    BPF Compiler Collection - Tools
4 aur/bcc-tools-git v0.1.8.r330.52cd371-1 (2) (0.06)
    BPF Compiler Collection - Tools
......

Select the order number of bcc, bcc-tools, python-bcc and python2-bcc, and install them.

Once finished, the bcc would be installed in the directory of /usr/share/bcc:

# ls
examples  man  tools

To facilitate your daily work, you can add man pages and tools in your .bashrc file:

MANPATH=/usr/share/bcc/man:$MANPATH
PATH=/usr/share/bcc/tools:$PATH

You can also install from source code:

git clone https://github.com/iovisor/bcc.git
mkdir bcc/build; cd bcc/build
cmake .. -DCMAKE_INSTALL_PREFIX=/usr
make
sudo make install

P.S. To run tools shipped in bcc, you need to install kernel header files:

sudo pacman -S linux-headers

Update on 28/10/2020：
Currently, bcc is the official package and split to 3 pieces: bcc, bcc-tools and python-bcc. Please install all 3 packages. If you forgot to install python-bcc, when running commands from bcc-tools, you will come across following errors:

# /usr/share/bcc/tools/execsnoop
Traceback (most recent call last):
  File "/usr/share/bcc/tools/execsnoop", line 21, in <module>
    from bcc import BPF
ModuleNotFoundError: No module named 'bcc'

Clang may be a better choice than gcc in developing OpenMP program

As referred in The first gcc bug I ever meet, I upgraded gcc to the newest 7.1.0 version to conquer building OpenMP errors. But unfortunately, when using taskloop clause, weird issue happened again. My application utilizes HElib, and I just added following statement in a source file:

#pragma omp taskloop

Then the strange link error reported:

In function `EncryptedArray::EncryptedArray(EncryptedArray const&)':
/root/Project/../../HElib/src/EncryptedArray.h:539: undefined reference to `cloned_ptr<EncryptedArrayBase, deep_clone<EncryptedArrayBase> >::cloned_ptr(cloned_ptr<EncryptedArrayBase, deep_clone<EncryptedArrayBase> > const&)'
collect2: error: ld returned 1 exit status

I tried to debug it, nevertheless, nothing valuable was found.

So I attempted to use clang. Install it on ArchLinux like this:

# pacman -S clang
resolving dependencies...
looking for conflicting packages...

Packages (2) llvm-libs-4.0.0-3  clang-4.0.0-3

Total Download Size:53.24 MiB
Total Installed Size:  275.24 MiB

:: Proceed with installation? [Y/n] y
......
checking available disk space  [#########################################] 100%
:: Processing package changes...
(1/2) installing llvm-libs   [#########################################] 100%
(2/2) installing clang   [#########################################] 100%
Optional dependencies for clang
openmp: OpenMP support in clang with -fopenmp
python2: for scan-view and git-clang-format [installed]
:: Running post-transaction hooks...
(1/1) Arming ConditionNeedsUpdate...

Unlike gcc, to enable OpenMP feature in clang, we need to install an additional openmp package:

# pacman -S openmp

Write a simple program:

# cat parallel.cpp
#include <stdio.h>
#include <omp.h>

int main(void) {
    omp_set_num_threads(5);

    #pragma omp parallel for
    for (int i = 0; i < 5; i++) {

        #pragma omp taskloop
        for (int j = 0; j < 3; j++) {
            printf("%d\n", omp_get_thread_num());
        }

    }   
}

Compile and run it:

# clang++ -fopenmp parallel.cpp
# ./a.out
0
0
0
0
0
1
1
2
4
4
4
4
3
0
1

Clang OpenMP works as I expected. Build my project again, no eccentric errors! Work like a charm!

So according to my testing experience, clang may be a better choice than gcc in developing OpenMP program, especially for some new OpenMP features.