io.joern.c2cpg.parser.CdtParser.scala Maven / Gradle / Ivy

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c2cpg
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package io.joern.c2cpg.parser

import better.files.File
import io.joern.c2cpg.Config
import io.shiftleft.utils.IOUtils
import org.eclipse.cdt.core.dom.ast.gnu.c.GCCLanguage
import org.eclipse.cdt.core.dom.ast.gnu.cpp.GPPLanguage
import org.eclipse.cdt.core.dom.ast.{IASTPreprocessorStatement, IASTTranslationUnit}
import org.eclipse.cdt.core.model.ILanguage
import org.eclipse.cdt.core.parser.{DefaultLogService, ScannerInfo}
import org.eclipse.cdt.core.parser.FileContent
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPVisitor
import org.eclipse.cdt.internal.core.parser.scanner.InternalFileContent
import org.slf4j.LoggerFactory

import java.nio.file.{NoSuchFileException, Path}
import scala.jdk.CollectionConverters.*
import scala.util.Failure
import scala.util.Success
import scala.util.Try

object CdtParser {

  private val logger = LoggerFactory.getLogger(classOf[CdtParser])

  private case class ParseResult(
    translationUnit: Option[IASTTranslationUnit],
    preprocessorErrorCount: Int = 0,
    problems: Int = 0,
    failure: Option[Throwable] = None
  )

  def readFileAsFileContent(path: Path): FileContent = {
    val lines = IOUtils.readLinesInFile(path).mkString("\n").toArray
    FileContent.create(path.toString, true, lines)
  }

}

class CdtParser(config: Config) extends ParseProblemsLogger with PreprocessorStatementsLogger {

  import io.joern.c2cpg.parser.CdtParser._

  private val headerFileFinder = new HeaderFileFinder(config.inputPath)
  private val parserConfig     = ParserConfig.fromConfig(config)
  private val definedSymbols   = parserConfig.definedSymbols.asJava
  private val includePaths     = parserConfig.userIncludePaths
  private val log              = new DefaultLogService

  // enables parsing of code behind disabled preprocessor defines:
  private var opts: Int = ILanguage.OPTION_PARSE_INACTIVE_CODE
  // instructs the parser to skip function and method bodies
  if (config.skipFunctionBodies) opts |= ILanguage.OPTION_SKIP_FUNCTION_BODIES
  // performance optimization, allows the parser not to create image-locations
  if (config.noImageLocations) opts |= ILanguage.OPTION_NO_IMAGE_LOCATIONS

  private def preprocessedFileIsFromCPPFile(file: Path, code: String): Boolean = {
    if (config.withPreprocessedFiles && file.toString.endsWith(FileDefaults.PREPROCESSED_EXT)) {
      val fileWithoutExt  = file.toString.stripSuffix(FileDefaults.PREPROCESSED_EXT)
      val filesWithCPPExt = FileDefaults.CPP_FILE_EXTENSIONS.map(ext => File(s"$fileWithoutExt$ext").name)
      code.linesIterator.exists(line => filesWithCPPExt.exists(f => line.contains(s"\"$f\"")))
    } else {
      false
    }
  }

  private def createParseLanguage(file: Path, code: String): ILanguage = {
    if (FileDefaults.isCPPFile(file.toString) || preprocessedFileIsFromCPPFile(file, code)) {
      GPPLanguage.getDefault
    } else {
      GCCLanguage.getDefault
    }
  }

  private def createScannerInfo(file: Path): ScannerInfo = {
    val additionalIncludes =
      if (FileDefaults.isCPPFile(file.toString)) parserConfig.systemIncludePathsCPP
      else parserConfig.systemIncludePathsC
    new ScannerInfo(definedSymbols, (includePaths ++ additionalIncludes).map(_.toString).toArray)
  }

  private def parseInternal(code: String, inFile: File): IASTTranslationUnit = {
    val fileContent         = FileContent.create(inFile.toString, true, code.toCharArray)
    val fileContentProvider = new CustomFileContentProvider(headerFileFinder)
    val lang                = createParseLanguage(inFile.path, code)
    val scannerInfo         = createScannerInfo(inFile.path)
    val translationUnit     = lang.getASTTranslationUnit(fileContent, scannerInfo, fileContentProvider, null, opts, log)
    val problems            = CPPVisitor.getProblems(translationUnit)
    if (parserConfig.logProblems) logProblems(problems.toList)
    if (parserConfig.logPreprocessor) logPreprocessorStatements(translationUnit)
    translationUnit
  }

  private def parseInternal(file: Path): ParseResult = {
    val realPath = File(file)
    if (realPath.isRegularFile) { // handling potentially broken symlinks
      try {
        val fileContent         = readFileAsFileContent(realPath.path)
        val fileContentProvider = new CustomFileContentProvider(headerFileFinder)
        val lang            = createParseLanguage(realPath.path, fileContent.asInstanceOf[InternalFileContent].toString)
        val scannerInfo     = createScannerInfo(realPath.path)
        val translationUnit = lang.getASTTranslationUnit(fileContent, scannerInfo, fileContentProvider, null, opts, log)
        val problems        = CPPVisitor.getProblems(translationUnit)
        if (parserConfig.logProblems) logProblems(problems.toList)
        if (parserConfig.logPreprocessor) logPreprocessorStatements(translationUnit)
        ParseResult(
          Option(translationUnit),
          preprocessorErrorCount = translationUnit.getPreprocessorProblemsCount,
          problems = problems.length
        )
      } catch {
        case u: UnsupportedClassVersionError =>
          logger.error("c2cpg requires at least JRE-17 to run. Please check your Java Runtime Environment!", u)
          System.exit(1)
          ParseResult(None, failure = Option(u)) // return value to make the compiler happy
        case e: Throwable =>
          ParseResult(None, failure = Option(e))
      }
    } else {
      ParseResult(
        None,
        failure = Option(new NoSuchFileException(s"File '$realPath' does not exist. Check for broken symlinks!"))
      )
    }
  }

  def preprocessorStatements(file: Path): Iterable[IASTPreprocessorStatement] = {
    parse(file).map(t => preprocessorStatements(t)).getOrElse(Iterable.empty)
  }

  def parse(code: String, inFile: Path): Option[IASTTranslationUnit] = {
    Try(parseInternal(code, inFile)) match {
      case Failure(exception) =>
        logger.warn(s"Failed to parse '$code' in file '$inFile': ${extractParseException(exception)}")
        None
      case Success(translationUnit) =>
        Some(translationUnit)
    }
  }

  def parse(file: Path): Option[IASTTranslationUnit] = {
    val parseResult = parseInternal(file)
    parseResult match {
      case ParseResult(Some(t), c, p, _) =>
        logger.info(s"Parsed '${t.getFilePath}' ($c preprocessor error(s), $p problems)")
        Option(t)
      case ParseResult(_, _, _, maybeThrowable) =>
        logger.warn(
          s"Failed to parse '$file': ${maybeThrowable.map(extractParseException).getOrElse("Unknown parse error!")}"
        )
        None
    }
  }

}