C++

Cython – Integração entre Python e C/C++ – Segunda Parte

Neste segundo artigo, iremos criar um projeto em C, em seguida desenvolver um projeto Hello World em Python, que iremos chamar no C e compilar.

GITHUB

https://github.com/marcelomaurin/cython

Primeiramente vamos criar nosso projeto em C.

Primeiramente criamos um arquivo Makefile

CC= gcc
SAMPLE=sample.pyx
LIBS= `pkg-config --cflags --libs python3`
TARGET=hello
SOURCE= \
hello.c \
sample.c



all: clean compile install

clean:
	rm ./sample.c
	rm ./sample.h


compile:
	cython ./$(SAMPLE)
	$(CC) $(SOURCE) $(LIBS) -o ./$(TARGET)

install:
	cp ./$(TARGET) /usr/local/bin/

No exemplo acima, temos dois pontos chaves no nosso código.

A inclusão do sample.pyx que irá ser convertido em um sample.c e um sample.h, conforme script do compile.

Agora iremos mostrar o código do C, que chamará o python, nosso código: hello.c

#include <stdio.h>
#include "sample.h"

int main()
{
	call_hello();
}

Neste código vemos uma chamada para a lib sample.h, que será criada pelo cython a partir do script.

A função Call_hello é declarada já no python, e a seguir vemos como ela é apresentada.

Fonte: hello.pyx

from sam import sam

cdef public void call_hello():
	sam.hello()

Agora iremos escrever o sam.py, que será chamado:


def hello():
    print("Hello World")

Por fim, compilamos o script:

make compile

E rodamos o mesmo

./hello

Documentação de Apoio

https://riptutorial.com/Download/cython.pdf

Fóruns e Artigos coligados

Montagem de código em C com Ninja

Definição

Ninja é um pequeno conjunto de ferramentas, desenvolvido por Evan Martin, um empregado da Google. Ninja foi usado em diversas construções de aplicações.

Entre suas vantagens estão a facilidade de montagem de aplicação, a velocidade e rapidez.

Outra vantagem é a capacidade de construir aplicações em multiplos SOs. (Windows, Linux, MacOS).

Referência:

https://en.wikipedia.org/wiki/Ninja_(build_system)

Construção

Iremos apresentar um pequeno projeto construído com NINJA.

O srvOuve é um projeto que visa integrar o CMU sphinx, estaremos construindo uma build com ninja.

Primeiramente precisamos criar o arquivo CMakeLists.txt , que fará a magica acontecer.

Criamos o arquivo conforme aparece no fragmento abaixo:

cmake_minimum_required (VERSION 3.8)

#Define o projeto
project(srvOuve VERSION 1.0)

#Diretorios de Include
include_directories(	   "/usr/local/include/pocketsphinx"
						   "/usr/local/include/sphinxbase"
                          )

set(CMAKE_CXX_STANDARD 14)

add_executable(srvOuve ouve.cpp)

Agora precisaremos dizer ao sistema para gerar os arquivos do ninja, para tanto chamamos o cmake, conforme a sintaxe abaixo:

$ cmake -G Ninja
Execução na console

Com este passo o cmake criará dois arquivos:

build.ninja – Este arquivo contem as configurações de compilação (build)

O build.ninja conterá as regras de construção da aplicação.

# CMAKE generated file: DO NOT EDIT!
# Generated by "Ninja" Generator, CMake Version 3.10

# This file contains all the build statements describing the
# compilation DAG.

# =============================================================================
# Write statements declared in CMakeLists.txt:
#
# Which is the root file.
# =============================================================================

# =============================================================================
# Project: srvOuve
# Configuration:
# =============================================================================

#############################################
# Minimal version of Ninja required by this file

ninja_required_version = 1.5

# =============================================================================
# Include auxiliary files.


#############################################
# Include rules file.

include rules.ninja


#############################################
# Utility command for rebuild_cache

build CMakeFiles/rebuild_cache.util: CUSTOM_COMMAND
  COMMAND = cd /home/maurinsoft/projetos/srvOuve/srv && /usr/bin/cmake -H/home/maurinsoft/projetos/srvOuve/srv -B/home/maurinsoft/projetos/srvOuve/srv
  DESC = Running CMake to regenerate build system...
  pool = console
  restat = 1
build rebuild_cache: phony CMakeFiles/rebuild_cache.util
# =============================================================================
# Object build statements for EXECUTABLE target srvOuve


#############################################
# Order-only phony target for srvOuve

build cmake_object_order_depends_target_srvOuve: phony
build CMakeFiles/srvOuve.dir/ouve.cpp.o: CXX_COMPILER__srvOuve ouve.cpp || cmake_object_order_depends_target_srvOuve
  DEP_FILE = CMakeFiles/srvOuve.dir/ouve.cpp.o.d
  FLAGS = -std=gnu++14
  INCLUDES = -I/usr/local/include/pocketsphinx -I/usr/local/include/sphinxbase
  OBJECT_DIR = CMakeFiles/srvOuve.dir
  OBJECT_FILE_DIR = CMakeFiles/srvOuve.dir

# =============================================================================
# Link build statements for EXECUTABLE target srvOuve


#############################################
# Link the executable srvOuve

build srvOuve: CXX_EXECUTABLE_LINKER__srvOuve CMakeFiles/srvOuve.dir/ouve.cpp.o
  OBJECT_DIR = CMakeFiles/srvOuve.dir
  POST_BUILD = :
  PRE_LINK = :
  TARGET_FILE = srvOuve
  TARGET_PDB = srvOuve.dbg

#############################################
# Utility command for edit_cache

build CMakeFiles/edit_cache.util: CUSTOM_COMMAND
  COMMAND = cd /home/maurinsoft/projetos/srvOuve/srv && /usr/bin/cmake-gui -H/home/maurinsoft/projetos/srvOuve/srv -B/home/maurinsoft/projetos/srvOuve/srv
  DESC = Running CMake cache editor...
  pool = console
  restat = 1
build edit_cache: phony CMakeFiles/edit_cache.util
# =============================================================================
# Target aliases.

# =============================================================================
# Folder targets.

# =============================================================================
# =============================================================================
# Built-in targets


#############################################
# The main all target.

build all: phony srvOuve

#############################################
# Make the all target the default.

default all

#############################################
# Re-run CMake if any of its inputs changed.

build build.ninja: RERUN_CMAKE | /usr/share/cmake-3.10/Modules/CMakeCInformation.cmake /usr/share/cmake-3.10/Modules/CMakeCXXInformation.cmake /usr/share/cmake-3.10/Modules/CMakeCommonLanguageInclude.cmake /usr/share/cmake-3.10/Modules/CMakeGenericSystem.cmake /usr/share/cmake-3.10/Modules/CMakeLanguageInformation.cmake /usr/share/cmake-3.10/Modules/CMakeSystemSpecificInformation.cmake /usr/share/cmake-3.10/Modules/CMakeSystemSpecificInitialize.cmake /usr/share/cmake-3.10/Modules/Compiler/CMakeCommonCompilerMacros.cmake /usr/share/cmake-3.10/Modules/Compiler/GNU-C.cmake /usr/share/cmake-3.10/Modules/Compiler/GNU-CXX.cmake /usr/share/cmake-3.10/Modules/Compiler/GNU.cmake /usr/share/cmake-3.10/Modules/Platform/Linux-GNU-C.cmake /usr/share/cmake-3.10/Modules/Platform/Linux-GNU-CXX.cmake /usr/share/cmake-3.10/Modules/Platform/Linux-GNU.cmake /usr/share/cmake-3.10/Modules/Platform/Linux.cmake /usr/share/cmake-3.10/Modules/Platform/UnixPaths.cmake CMakeCache.txt CMakeFiles/3.10.2/CMakeCCompiler.cmake CMakeFiles/3.10.2/CMakeCXXCompiler.cmake CMakeFiles/3.10.2/CMakeSystem.cmake CMakeLists.txt
  pool = console

#############################################
# A missing CMake input file is not an error.

build /usr/share/cmake-3.10/Modules/CMakeCInformation.cmake /usr/share/cmake-3.10/Modules/CMakeCXXInformation.cmake /usr/share/cmake-3.10/Modules/CMakeCommonLanguageInclude.cmake /usr/share/cmake-3.10/Modules/CMakeGenericSystem.cmake /usr/share/cmake-3.10/Modules/CMakeLanguageInformation.cmake /usr/share/cmake-3.10/Modules/CMakeSystemSpecificInformation.cmake /usr/share/cmake-3.10/Modules/CMakeSystemSpecificInitialize.cmake /usr/share/cmake-3.10/Modules/Compiler/CMakeCommonCompilerMacros.cmake /usr/share/cmake-3.10/Modules/Compiler/GNU-C.cmake /usr/share/cmake-3.10/Modules/Compiler/GNU-CXX.cmake /usr/share/cmake-3.10/Modules/Compiler/GNU.cmake /usr/share/cmake-3.10/Modules/Platform/Linux-GNU-C.cmake /usr/share/cmake-3.10/Modules/Platform/Linux-GNU-CXX.cmake /usr/share/cmake-3.10/Modules/Platform/Linux-GNU.cmake /usr/share/cmake-3.10/Modules/Platform/Linux.cmake /usr/share/cmake-3.10/Modules/Platform/UnixPaths.cmake CMakeCache.txt CMakeFiles/3.10.2/CMakeCCompiler.cmake CMakeFiles/3.10.2/CMakeCXXCompiler.cmake CMakeFiles/3.10.2/CMakeSystem.cmake CMakeLists.txt: phony

#############################################
# Clean all the built files.

build clean: CLEAN

#############################################
# Print all primary targets available.

build help: HELP

O cmake tambem cria o arquivo rules.ninja, responsável pelas regras de compilação.

# CMAKE generated file: DO NOT EDIT!
# Generated by "Ninja" Generator, CMake Version 3.10

# This file contains all the rules used to get the outputs files
# built from the input files.
# It is included in the main 'build.ninja'.

# =============================================================================
# Project: srvOuve
# Configuration:
# =============================================================================
# =============================================================================

#############################################
# Rule for running custom commands.

rule CUSTOM_COMMAND
  command = $COMMAND
  description = $DESC


#############################################
# Rule for compiling CXX files.

rule CXX_COMPILER__srvOuve
  depfile = $DEP_FILE
  deps = gcc
  command = /usr/bin/c++  $DEFINES $INCLUDES $FLAGS -MD -MT $out -MF $DEP_FILE -o $out -c $in
  description = Building CXX object $out


#############################################
# Rule for linking CXX executable.

rule CXX_EXECUTABLE_LINKER__srvOuve
  command = $PRE_LINK && /usr/bin/c++  $FLAGS  $LINK_FLAGS $in  -o $TARGET_FILE $LINK_PATH $LINK_LIBRARIES && $POST_BUILD
  description = Linking CXX executable $TARGET_FILE
  restat = $RESTAT


#############################################
# Rule for re-running cmake.

rule RERUN_CMAKE
  command = /usr/bin/cmake -H/home/maurinsoft/projetos/srvOuve/srv -B/home/maurinsoft/projetos/srvOuve/srv
  description = Re-running CMake...
  generator = 1


#############################################
# Rule for cleaning all built files.

rule CLEAN
  command = /usr/bin/ninja -t clean
  description = Cleaning all built files...


#############################################
# Rule for printing all primary targets available.

rule HELP
  command = /usr/bin/ninja -t targets
  description = All primary targets available:

Para processar o ninja precisamos fazer uma pequena mudança, alterar as extensões de .c para .cpp, para que o sistema identifique que se trata de compilador C.

Incluindo dependências

Para incluir diretorios para Include, basta incluir a linha

Diretórios de Include

include_directories( “/usr/local/include/pocketsphinx”
“/usr/local/include/sphinxbase”
)
Include adicional

Gerando binário

Por fim precisaremos dar o comando ninja para compilar os scripts.

$ ninja

Pronto você montou um Montador em Ninja! Parabéns!