nnocr/scripts/build-tesseract.js

Native Node.js bindings for the Tesseract OCR project.

const fs = require('fs');
const path = require('path');
const shell = require('shelljs');
const process = require("process");

const requiredCMakeVersion = '3.15';
const cmakeBuildType = 'Release';

shell.config.fatal = true; // thrown an exception on any error

let commonEnvVariables = {
  CMAKE_BUILD_TYPE: cmakeBuildType,
  CMAKE_INSTALL_PREFIX: '${PWD}/bin',
  BUILD_SHARED_LIBS: 'OFF',
  CMAKE_POSITION_INDEPENDENT_CODE: 'ON',
  CMAKE_MSVC_RUNTIME_LIBRARY: 'MultiThreaded',
  CMAKE_POLICY_DEFAULT_CMP0091: 'NEW',
  CMAKE_OSX_DEPLOYMENT_TARGET: '10.9'
}

const buildForArch = process.env["BUILD_FOR_ARCH"] || process.arch;
shell.echo('buildForArch', buildForArch);

if (buildForArch === 'arm64') {
  shell.echo('arm64 build');
  commonEnvVariables = {
    ...commonEnvVariables,
    CMAKE_OSX_ARCHITECTURES: '\"arm64\"'
  }
} else if (buildForArch === 'x64') {
  shell.echo('x64 build');
  commonEnvVariables = {
    ...commonEnvVariables,
    CMAKE_OSX_ARCHITECTURES: '\"x86_64\"'
  }
}

// ------ startup ------
shell.echo('build-tesseract script start.');

if (!shell.which('git')) {
  shell.echo('This script requires Git.');
  shell.exit(1);
}

checkCMakeVersion();

const homeDir = path.resolve(__dirname,'..');
shell.cd(homeDir);
shell.echo(`Working directory: ${homeDir}`);

// ------ libraries ------
buildLibjpeg ('libjpeg');
buildLeptonica ('leptonica');
buildTesseract ('tesseract');

shell.echo('build-tesseract script end.');

function checkCMakeVersion() {
  let versionOK = false;
  shell.echo(`This script requires CMake version ${requiredCMakeVersion} or later.`);
  if (!shell.which('cmake')) {
    shell.echo('CMake not found on this system.');
  } else {
    const reply = shell.exec('cmake --version', {silent: true});
    foundVersion = (/\d+.\d+.\d+/mg).exec(reply)[0];
    versionOK = checkVersion(foundVersion, requiredCMakeVersion) >= 0;
    if (versionOK) {
      shell.echo(`CMake ${foundVersion} found on this system.`);
    } else {
      shell.echo(`CMake ${foundVersion} found on this system is too old.`);
    }
  }

  if (!versionOK) shell.exit(1);
}

// https://codereview.stackexchange.com/questions/236647/comparing-version-numbers-with-javascript
function checkVersion (a, b) {
  const x = a.split('.').map(e => parseInt(e, 10));
  const y = b.split('.').map(e => parseInt(e, 10));

  for (const i in x) {
      y[i] = y[i] || 0;
      if (x[i] === y[i]) {
          continue;
      } else if (x[i] > y[i]) {
          return 1;
      } else {
          return -1;
      }
  }
  return y.length > x.length ? -1 : 0;
}

function buildLibjpeg (dirName) {
  shell.echo('Building libjpeg.');

  if (shell.test('-e', dirName)) {
    shell.echo(`The ${dirName} directory already exists.`);
  } else {
    shell.exec(`git clone https://github.com/tamaskenez/libjpeg-cmake.git ${dirName}`);
  }

  runCMakeBuild (dirName, cmakeBuildType);
}

function buildLeptonica (dirName) {
  shell.echo('Building Leptonica.');

  runCMakeBuild (dirName, cmakeBuildType, 
    {
      SW_BUILD: 'OFF',
      CMAKE_FIND_USE_CMAKE_SYSTEM_PATH: 'FALSE',
      CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH: process.platform === 'darwin' ? 'FALSE' : 'TRUE',
      CMAKE_PREFIX_PATH: '${PWD}/../../libjpeg/build',
      CMAKE_INCLUDE_PATH: '${PWD}/../../libjpeg/build/bin/include',
      CMAKE_LIBRARY_PATH: '${PWD}/../../libjpeg/build/bin/lib'
    },     
    (dirName, cmakeConfig, envVars) => { // patch config_auto.h between config and build
      if (process.platform === 'darwin') {
        const filePath = path.resolve(__dirname,'..',dirName,'build','src','config_auto.h');
        shell.echo(`Patching ${filePath} for Mac.`);
        let autoConfig = fs.readFileSync(filePath, 'utf8');
        const searchText = /^#define\s+HAVE_FMEMOPEN\s+1/gm;
        const replacementText = '#define HAVE_FMEMOPEN 0';
        const foundText = autoConfig.match(searchText);
        if (foundText) {
          const updatedConfig = autoConfig.replace(searchText, replacementText);
          fs.writeFileSync(filePath, updatedConfig, 'utf8');
          shell.echo(`The '${foundText}' directive was replaced with '${replacementText}'.`);
        } else {
          shell.echo(`The '#define HAVE_FMEMOPEN 1' directive was not found.`);
          shell.echo('This may lead to a build that does not run on all macOS machines.');
        }
      }
    }
  );
}

function buildTesseract (dirName) {
  shell.echo('Building Tesseract.');

  runCMakeBuild (dirName, cmakeBuildType, 
    {
      STATIC: 'ON',
      CPPAN_BUILD: 'OFF',
      BUILD_TRAINING_TOOLS: 'OFF',
      AUTO_OPTIMIZE: 'OFF',
      Leptonica_DIR: '../leptonica/build'
    }
  );
}

function runCMakeBuild (dirName, cmakeBuildType, envVars, patchConfig) {
  createAndEnterBuildDir(dirName);

  let cmakeCmd = 'cmake';
  cmakeCmd += formatEnvVars (envVars);
  cmakeCmd += formatEnvVars (commonEnvVariables);
  cmakeCmd += ' ..';

  shell.echo(`Configuring a ${cmakeBuildType} build.`)
  shell.echo(cmakeCmd);
  shell.exec(cmakeCmd);

  if (patchConfig) patchConfig(dirName, cmakeBuildType, envVars);

  shell.echo(`Creating a ${cmakeBuildType} build.`)
  shell.exec(`cmake --build . --config ${cmakeBuildType}`);

  shell.echo(`Installing a ${cmakeBuildType} build.`)
  shell.exec('cmake --install .');

  leaveBuildDir();
}

function createAndEnterBuildDir (dirName) {
  shell.pushd('-q', dirName);
  if (!shell.test('-e', 'build')) shell.mkdir('build');
  shell.pushd('-q', 'build');
}

function leaveBuildDir() {
  shell.popd('-q');
  shell.popd('-q');
}

function formatEnvVars (envVars) {
  const continuation = process.platform === 'win32' ? '' : ' \\\n';
  let args = '';
  for (key in envVars) {
    args += ` -D${key}=${envVars[key]}${continuation}`;
  }
  return args;
}