Add CompilationDatabase and CompileCommand.

.travis.yml

@@ -10,6 +10,7 @@ matrix:
     - export PATH=/usr/local/opt/llvm/bin:"${PATH}"
     - brew install llvm
     - sudo swift utils/make-pkgconfig.swift
+    - swift utils/make-compile_commands.swift
     script:
     - swift test
 notifications:

Sources/Clang/CompilationDatabase.swift

@@ -0,0 +1,130 @@
+#if SWIFT_PACKAGE
+import cclang
+#endif
+
+import Foundation
+
+/// Error code for Compilation Database
+///
+/// - noError: no error.
+/// - canNotLoadDatabase: failed to load database.
+public enum CompilationDatabaseError: Error {
+
+  case canNotLoadDatabase
+
+  init?(clang: CXCompilationDatabase_Error) {
+    switch clang {
+    case CXCompilationDatabase_CanNotLoadDatabase:
+      self = .canNotLoadDatabase
+    default:
+      return nil
+    }
+  }
+}
+
+/// Contains the results of a search in the compilation database.
+public struct CompileCommand: Equatable {
+
+  // the working directory where the CompileCommand was executed from.
+  public let directory: String
+
+  // the filename associated with the CompileCommand.
+  public let filename: String
+
+  // the array of argument value in the compiler invocations.
+  public let arguments: [String]
+
+  fileprivate init(command: CXCompileCommand) {
+    // get directory and filename
+    self.directory = clang_CompileCommand_getDirectory(command).asSwift()
+    self.filename = clang_CompileCommand_getFilename(command).asSwift()
+
+    // get arguments
+    let args = clang_CompileCommand_getNumArgs(command)
+    self.arguments = (0 ..< args).map { i in
+      return clang_CompileCommand_getArg(command, i).asSwift()
+    }
+
+    // MARK: - unsupported api by cclang yet?
+    //    let mappedSourcesCount = clang_CompileCommand_getNumMappedSources(command)
+    //    (0 ..< mappedSourcesCount).forEach { i in
+    //      let path = clang_CompileCommand_getMappedSourcePath(command, UInt32(i)).asSwift()
+    //      let content = clang_CompileCommand_getMappedSourceContent(command, UInt32(i)).asSwift()
+    //    }
+  }
+}
+
+/// A compilation database holds all information used to compile files in a project.
+public class CompilationDatabase {
+  let db: CXCompilationDatabase
+  private let owned: Bool
+
+  public init(directory: String) throws {
+    var err = CXCompilationDatabase_NoError
+
+    // check `compile_commands.json` file existence in directory folder.
+    let cmdFile = URL(fileURLWithPath: directory, isDirectory: true)
+        .appendingPathComponent("compile_commands.json").path
+    guard FileManager.default.fileExists(atPath: cmdFile) else {
+        throw CompilationDatabaseError.canNotLoadDatabase
+    }
+
+    // initialize compilation db
+    self.db = clang_CompilationDatabase_fromDirectory(directory, &err)
+    if let error = CompilationDatabaseError(clang: err) {
+      throw error
+    }
+
+    self.owned = true
+  }
+
+  /// the array of all compile command in the compilation database.
+  public lazy private(set) var compileCommands: [CompileCommand] = {
+    guard let commands = clang_CompilationDatabase_getAllCompileCommands(self.db) else {
+      return []
+    }
+    // the compileCommands needs to be disposed.
+    defer {
+      clang_CompileCommands_dispose(commands)
+    }
+
+    let count = clang_CompileCommands_getSize(commands)
+    return (0 ..< count).map { i in
+      // get compile command
+      guard let cmd = clang_CompileCommands_getCommand(commands, UInt32(i)) else {
+        fatalError("Failed to get compile command for an index \(i)")
+      }
+      return CompileCommand(command: cmd)
+    }
+  }()
+
+
+  /// Returns the array of compile command for a file.
+  ///
+  /// - Parameter filename: a filename containing directory.
+  /// - Returns: the array of compile command.
+  public func compileCommands(forFile filename: String) -> [CompileCommand] {
+    guard let commands = clang_CompilationDatabase_getCompileCommands(self.db, filename) else {
+      fatalError("failed to load compileCommands for \(filename).")
+    }
+    // the compileCommands needs to be disposed.
+    defer {
+      clang_CompileCommands_dispose(commands)
+    }
+
+    let size = clang_CompileCommands_getSize(commands)
+
+    return (0 ..< size).map { i in
+      guard let cmd = clang_CompileCommands_getCommand(commands, UInt32(i)) else {
+        fatalError("Failed to get compile command for an index \(i)")
+      }
+      return CompileCommand(command: cmd)
+    }
+  }
+
+  deinit {
+    if self.owned {
+      clang_CompilationDatabase_dispose(self.db)
+    }
+  }
+}

Sources/Clang/TranslationUnit.swift

@@ -219,6 +219,35 @@ public class TranslationUnit {
                   index: index,
                   commandLineArgs: args,
                   options: options)
+    }
+
+  /// Creates a `TranslationUnit` using the CompileCommand.
+  /// the name of the source file is expected to reside in the command line arguments.
+  ///
+  /// - Parameters:
+  ///   - command: The compile command initialized by the CompilationDatabase.
+  ///              (load data from the `compile_commands.json` file generated by CMake.)
+  ///   - index: The index (optional, will use a default index if not
+  ///            provided)
+  ///   - options: Options for how to handle the parsed file
+  /// - throws: `ClangError` if the translation unit could not be created
+  ///           successfully.
+  public init(compileCommand command: CompileCommand,
+              index: Index = Index(),
+              options: TranslationUnitOptions = [],
+              unsavedFiles: [UnsavedFile] = []) throws {
+    self.clang = try command.arguments.withUnsafeCStringBuffer { argC in
+      var cxUnsavedFiles = unsavedFiles.map { $0.clang }
+      let unit: CXTranslationUnit? = clang_createTranslationUnitFromSourceFile(index.clang,
+                                                                               nil,
+                                                                               Int32(argC.count), argC.baseAddress,
+                                                                               UInt32(cxUnsavedFiles.count), &cxUnsavedFiles)
+      guard unit != nil else {
+        throw ClangError.astRead
+      }
+      return unit!
+    }
+    self.owned = true
   }
 
   /// Creates a `TranslationUnit` from an AST file generated by `-emit-ast`.

Tests/ClangTests/ClangTests.swift

@@ -168,7 +168,7 @@ class ClangTests: XCTestCase {
       XCTFail("\(error)")
     }
   }
-      
+
   func testParsingWithUnsavedFile() {
     do {
       let filename = "input_tests/unsaved-file.c"
@@ -248,6 +248,106 @@ class ClangTests: XCTestCase {
       XCTFail("\(error)")
     }
   }
+
+  // ${projectRoot}/ folder URL.
+  var projectRoot: URL {
+    return URL(fileURLWithPath: #file).appendingPathComponent("../../../", isDirectory: true).standardized
+  }
+
+  // ${projectRoot}/input_tests folder URL.
+  var inputTestUrl: URL {
+    return projectRoot.appendingPathComponent("input_tests", isDirectory: true)
+  }
+
+  // ${projectRoot}/.build/build.input_tests folder URL
+  var buildUrl: URL {
+    return projectRoot.appendingPathComponent(".build/build.input_tests", isDirectory: true)
+  }
+
+  func testInitCompilationDB() {
+    do {
+      let db = try CompilationDatabase(directory: buildUrl.path)
+      XCTAssertNotNil(db)
+      XCTAssertEqual(db.compileCommands.count, 7)
+
+    } catch {
+      XCTFail("\(error)")
+    }
+  }
+
+  func testCompileCommand() {
+    do {
+      // intialize CompilationDatabase.
+      let db = try CompilationDatabase(directory: buildUrl.path)
+      XCTAssertNotNil(db)
+
+      // test first compileCommand
+      let cmd = db.compileCommands[0]
+      XCTAssertEqual(cmd.directory, buildUrl.path)
+      XCTAssertGreaterThan(cmd.arguments.count, 0)
+
+      // test all compileCommands
+      let filenames = db.compileCommands.map { URL(fileURLWithPath: $0.filename) }
+
+      let expectation: Set<URL> = [
+        inputTestUrl.appendingPathComponent("inclusion.c"),
+        inputTestUrl.appendingPathComponent("index-action.c"),
+        inputTestUrl.appendingPathComponent("init-ast.c"),
+        inputTestUrl.appendingPathComponent("is-from-main-file.c"),
+        inputTestUrl.appendingPathComponent("locations.c"),
+        inputTestUrl.appendingPathComponent("reparse.c"),
+        inputTestUrl.appendingPathComponent("unsaved-file.c"),
+      ]
+      XCTAssertEqual(Set(filenames), expectation)
+    } catch {
+      XCTFail("\(error)")
+    }
+  }
+
+  func testCompileCommandForFile() {
+    do {
+      // intialize CompilationDatabase.
+      let db = try CompilationDatabase(directory: buildUrl.path)
+      XCTAssertNotNil(db)
+
+      let inclusionFile = inputTestUrl.appendingPathComponent("inclusion.c")
+
+      // test compileCommand for file `inclusion.c`
+      let cmds = db.compileCommands(forFile: inclusionFile.path)
+      XCTAssertEqual(cmds.count, 1)
+      XCTAssertEqual(cmds[0].filename, inclusionFile.path)
+      XCTAssertEqual(cmds[0].directory, buildUrl.path)
+      XCTAssertGreaterThan(cmds[0].arguments.count, 0)
+    } catch {
+      XCTFail("\(error)")
+    }
+  }
+
+  func testInitTranslationUnitUsingCompileCommand() {
+    do {
+      // intialize CompilationDatabase.
+      let filename = inputTestUrl.path + "/locations.c"
+      let db = try CompilationDatabase(directory: buildUrl.path)
+
+      // get first compile command and initialize TranslationUnit using it.
+      let cmd = db.compileCommands(forFile: filename).first!
+      let unit = try TranslationUnit(compileCommand: cmd)
+
+      // verify.
+      let file = unit.getFile(for: unit.spelling)!
+      let start = SourceLocation(translationUnit: unit, file: file, offset: 19)
+      let end = SourceLocation(translationUnit: unit, file: file, offset: 59)
+      let range = SourceRange(start: start, end: end)
+
+      XCTAssertEqual(
+        unit.tokens(in: range).map { $0.spelling(in: unit) },
+        ["int", "a", "=", "1", ";", "int", "b", "=", "1", ";", "int", "c", "=",
+         "a", "+", "b", ";"]
+      )
+    } catch {
+        XCTFail("\(error)")
+    }
+  }
 
   static var allTests : [(String, (ClangTests) -> () throws -> Void)] {
     return [
@@ -262,6 +362,10 @@ class ClangTests: XCTestCase {
       ("testIsFromMainFile", testIsFromMainFile),
       ("testVisitInclusion", testVisitInclusion),
       ("testGetFile", testGetFile),
+      ("testInitCompilationDB", testInitCompilationDB),
+      ("testCompileCommand", testCompileCommand),
+      ("testCompileCommandForFile", testCompileCommandForFile),
+      ("testInitTranslationUnitUsingCompileCommand", testInitTranslationUnitUsingCompileCommand)
     ]
   }
 }

input_tests/CMakeLists.txt

@@ -0,0 +1,24 @@
+project(InputTests)
+cmake_minimum_required(VERSION 3.3)
+
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+add_library(InputTests 
+  inclusion.c index-action.c init-ast.c is-from-main-file.c locations.c reparse.c unsaved-file.c
+  inclusion-header.h
+)
+
+target_include_directories(InputTests
+PUBLIC
+  ${CMAKE_CURRENT_SOURCE_DIR}
+PRIVATE
+)
+
+# target_compile_features(InputTests
+# PUBLIC
+# PRIVATE
+# )
+# target_link_libraries(InputTests
+# PUBLIC
+# PRIVATE
+# )