PrecompilingCommandLineCompiler.java

/*
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 * Native ARchive plugin for Maven
 * %%
 * Copyright (C) 2002 - 2014 NAR Maven Plugin developers.
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
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package com.github.maven_nar.cpptasks.compiler;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.types.Environment;

import com.github.maven_nar.cpptasks.parser.Parser;

/**
 * A command line C compiler that can utilize precompilation of header files
 *
 * @author Curt Arnold
 */
public abstract class PrecompilingCommandLineCompiler extends CommandLineCompiler implements PrecompilingCompiler {
  protected PrecompilingCommandLineCompiler(final String command, final String identifierArg,
      final String[] sourceExtensions, final String[] headerExtensions, final String outputSuffix,
      final boolean libtool, final PrecompilingCommandLineCompiler libtoolCompiler, final boolean newEnvironment,
      final Environment env) {
    super(command, identifierArg, sourceExtensions, headerExtensions, outputSuffix, libtool, libtoolCompiler,
        newEnvironment, env);
  }

  /**
   * 
   * This method may be used to get two distinct compiler configurations, one
   * for compiling the specified file and producing a precompiled header
   * file, and a second for compiling other files using the precompiled
   * header file.
   * 
   * The last (preferrably only) include directive in the prototype file will
   * be used to mark the boundary between pre-compiled and normally compiled
   * headers.
   * 
   * @param config
   *          base configuration
   * @param prototype
   *          A source file (for example, stdafx.cpp) that is used to build
   *          the precompiled header file. @returns null if precompiled
   *          headers are not supported or a two element array containing
   *          the precompiled header generation configuration and the
   *          consuming configuration
   * 
   */
  @Override
  public CompilerConfiguration[] createPrecompileConfigurations(final CompilerConfiguration config,
      final File prototype, final String[] exceptFiles) {
    //
    // cast should success or someone is passing us a configuration
    // that was prepared by another processor
    //
    final CommandLineCompilerConfiguration cmdLineConfig = (CommandLineCompilerConfiguration) config;
    //
    // parse prototype file to determine last header
    //
    final Parser parser = createParser(prototype);
    String[] includes;
    try {
      final Reader reader = new BufferedReader(new FileReader(prototype));
      parser.parse(reader);
      includes = parser.getIncludes();
    } catch (final IOException ex) {
      throw new BuildException("Error parsing precompiled header protoype: " + prototype.toString() + ":"
          + ex.toString());
    }
    if (includes.length == 0) {
      throw new BuildException("Precompiled header prototype: " + prototype.toString()
          + " does not contain any include directives.");
    }
    final CompilerConfiguration[] configs = new CompilerConfiguration[2];
    configs[0] = createPrecompileGeneratingConfig(cmdLineConfig, prototype, includes[0]);
    configs[1] = createPrecompileUsingConfig(cmdLineConfig, prototype, includes[0], exceptFiles);
    return configs;
  }

  abstract protected CompilerConfiguration createPrecompileGeneratingConfig(
      CommandLineCompilerConfiguration baseConfig, File prototype, String lastInclude);

  abstract protected CompilerConfiguration createPrecompileUsingConfig(CommandLineCompilerConfiguration baseConfig,
      File prototype, String lastInclude, String[] exceptFiles);
}