Beispiel #1
0
// TestLineComments, using a simple test case, checks that consequtive line
// comments are properly terminated with a newline even if the AST position
// information is incorrect.
//
func TestLineComments(t *testing.T) {
	const src = `// comment 1
	// comment 2
	// comment 3
	package main
	`

	fset := token.NewFileSet()
	ast1, err1 := parser.ParseFile(fset, "", src, parser.ParseComments)
	if err1 != nil {
		panic(err1)
	}

	var buf bytes.Buffer
	fset = token.NewFileSet() // use the wrong file set
	Fprint(&buf, fset, ast1)

	nlines := 0
	for _, ch := range buf.Bytes() {
		if ch == '\n' {
			nlines++
		}
	}

	const expected = 3
	if nlines < expected {
		t.Errorf("got %d, expected %d\n", nlines, expected)
	}
}
// cannot initialize in init because (printer) Fprint launches goroutines.
func initialize() {
	const filename = "testdata/parser.go"

	src, err := ioutil.ReadFile(filename)
	if err != nil {
		log.Fatalf("%s", err)
	}

	file, err := parser.ParseFile(fset, filename, src, parser.ParseComments)
	if err != nil {
		log.Fatalf("%s", err)
	}

	var buf bytes.Buffer
	testprint(&buf, file)
	if !bytes.Equal(buf.Bytes(), src) {
		log.Fatalf("print error: %s not idempotent", filename)
	}

	testfile = file
}
func TestParse3(t *testing.T) {
	dbg.InitLogging(0)
	relish.InitRuntime("relish.db")
	builtin.InitBuiltinFunctions()
	var g *Generator
	for _, filename := range validFiles {
		fileNode, err := parser.ParseFile(fset, filename, nil, parser.DeclarationErrors|parser.Trace)
		if err != nil {
			t.Errorf("ParseFile(%s): %v", filename, err)
		}
		ast.Print(fset, fileNode)

		fileNameRoot := filename[:len(filename)-4]

		g = NewGenerator(fileNode, fileNameRoot)
		g.GenerateCode()
		//g.TestWalk()
	}

	g.Interp.RunMain()
}
// TODO(gri) Need to revisit parser interface. We should be able to use parser.ParseFiles
//           or a similar function instead.
func parseFiles(t *testing.T, testname string, filenames []string) (map[string]*ast.File, error) {
	files := make(map[string]*ast.File)
	var errors scanner.ErrorList
	for _, filename := range filenames {
		if _, exists := files[filename]; exists {
			t.Fatalf("%s: duplicate file %s", testname, filename)
		}
		file, err := parser.ParseFile(fset, filename, nil, parser.DeclarationErrors)
		if file == nil {
			t.Fatalf("%s: could not parse file %s", testname, filename)
		}
		files[filename] = file
		if err != nil {
			// if the parser returns a non-scanner.ErrorList error
			// the file couldn't be read in the first place and
			// file == nil; in that case we shouldn't reach here
			errors = append(errors, err.(scanner.ErrorList)...)
		}

	}
	return files, errors
}
Beispiel #5
0
func runcheck(t *testing.T, source, golden string, mode checkMode) {
	// parse source
	prog, err := parser.ParseFile(fset, source, nil, parser.ParseComments)
	if err != nil {
		t.Error(err)
		return
	}

	// filter exports if necessary
	if mode&export != 0 {
		ast.FileExports(prog) // ignore result
		prog.Comments = nil   // don't print comments that are not in AST
	}

	// determine printer configuration
	cfg := Config{Tabwidth: tabwidth}
	if mode&rawFormat != 0 {
		cfg.Mode |= RawFormat
	}

	// format source
	var buf bytes.Buffer
	if _, err := cfg.Fprint(&buf, fset, prog); err != nil {
		t.Error(err)
	}
	res := buf.Bytes()

	// update golden files if necessary
	if *update {
		if err := ioutil.WriteFile(golden, res, 0644); err != nil {
			t.Error(err)
		}
		return
	}

	// get golden
	gld, err := ioutil.ReadFile(golden)
	if err != nil {
		t.Error(err)
		return
	}

	// compare lengths
	if len(res) != len(gld) {
		t.Errorf("len = %d, expected %d (= len(%s))", len(res), len(gld), golden)
	}

	// compare contents
	for i, line, offs := 0, 1, 0; i < len(res) && i < len(gld); i++ {
		ch := res[i]
		if ch != gld[i] {
			t.Errorf("%s:%d:%d: %s", source, line, i-offs+1, lineString(res, offs))
			t.Errorf("%s:%d:%d: %s", golden, line, i-offs+1, lineString(gld, offs))
			t.Error()
			return
		}
		if ch == '\n' {
			line++
			offs = i + 1
		}
	}
}
Beispiel #6
0
/*
Loads the code from the specified package into the runtime.

Recurses to load packages which the argument package depends on.

TODO artifact version preferences are NOT being handled correctly yet.
What should happen is that all artifacts whose versions "ARE" recursively preferred should have their version preferences
consulted and respected first (closer to top of load-tree has preference priority) and then and only then should
a single no-version-preferred artifact be loaded by asking what its latest version is, then re-visit if that constrains other
formerly no-version-preferred ones, then load newly preferred versions, then load the next no-version-preferred artifact.
Currently, an artifact version may be loaded in a no-version-preferred way, because the current load-tree descent path does
not prefer a version, but it could be that a subsequently loaded artifact somewhere else in the load-tree COULD express
a preference for a different version of the artifact, but its preference is consulted too late, after the artifact is already loaded.

Handles searching first in a local (private) artifacts repository (directory tree) then a shared artifacts repository,
but only if a directive is not in effect to load from shared only, and only if another package from
the same artifact has not already been loaded, because in that case, the local (private) or shared decision has already
been made and must apply to subsequent packages loaded from the same artifact.

If not found locally, tries to load from the Internet (at several standard locations).

TODO signed-code integrity checks
*/
func (ldr *Loader) LoadPackage(originAndArtifactPath string, version string, packagePath string, mustBeFromShared bool) (gen *generator.Generator, err error) {

	if Logging(PARSE_) {
		parserDebugMode |= parser.Trace
	}

	// First, see if the package is already loaded. If so, return

	packageIdentifier := originAndArtifactPath + "/pkg/" + packagePath

	beingLoaded := ldr.PackagesBeingLoaded[packageIdentifier]
	if beingLoaded {
		err = fmt.Errorf("Package dependency loop. Package '%s' is also present in the tree of packages it imports.", packageIdentifier)
		return
	}

	loadedVersion, found := ldr.LoadedPackages[packageIdentifier]
	if found {
		if loadedVersion != version && version != "" {
			err = fmt.Errorf("Can't load version %s of '%s' since version %s is already loaded into runtime.", version, packageIdentifier, loadedVersion)
		}
		return
	}

	localArtifactMetadataFilePath := ldr.RelishRuntimeLocation + "/artifacts/" + originAndArtifactPath + "/metadata.txt"

	sharedArtifactMetadataFilePath := ldr.RelishRuntimeLocation + "/shared/relish/artifacts/" + originAndArtifactPath + "/metadata.txt"

	sharedReplicaMetadataFilePath := ldr.RelishRuntimeLocation + "/shared/relish/replicas/" + originAndArtifactPath + "/metadata.txt"

	// Current version of artifact according to shared artifact metadata found in this relish directory tree.
	sharedCurrentVersion := ""

	// Date of the artifact metadata that is being relied on for the package load.
	metadataDate := ""

	ldr.PackagesBeingLoaded[packageIdentifier] = true

	if !ldr.quiet {
		Log(ALWAYS_, "Loading package %s\n", packageIdentifier)
	}

	Log(LOAD2_, "LoadPackage: ldr.RelishRuntimeLocation=%s\n", ldr.RelishRuntimeLocation)
	Log(LOAD2_, "LoadPackage: originAndArtifactPath=%s\n", originAndArtifactPath)
	Log(LOAD2_, "LoadPackage: version=%s\n", version)
	Log(LOAD2_, "LoadPackage: packagePath=%s\n", packagePath)

	mustBeFromShared = mustBeFromShared || ldr.SharedCodeOnly // Set whether will consider local code for this package.
	var mustBeFromLocal bool                                  // We may end up constrained to load from local artifact.

	// Package is not loaded. But see if any other packages from the same artifact are loaded.
	// If so, make sure they don't have an incompatible version.

	var artifactAlreadyLoaded bool // if true, at least one package from the currently-being-loaded artifact has already been loade.
	// This means the needed version of the artifact and the artifacts it depends on have already
	// been loaded from built.txt into LoadedArtifacts map.

	var artifactKnownToBeLocal bool     // if artifact is loaded or being loaded, is it loaded from local
	var artifactKnownToBePublished bool // if artifact is loaded or being loaded, is it loaded from shared
	var artifactKnownToBeReplica bool   // if artifact is loaded or being loaded, is it downloaded and loaded from shared/replicas

	loadedVersion, artifactAlreadyLoaded = ldr.LoadedArtifacts[originAndArtifactPath]
	if artifactAlreadyLoaded {
		if loadedVersion != version && version != "" {
			err = fmt.Errorf("Can't load package '%s' from version %s of '%s'. Another package from version %s of the artifact is already loaded into runtime.", packagePath, version, originAndArtifactPath, loadedVersion)
			return
		}

		artifactKnownToBeLocal = ldr.LoadedArtifactKnownToBeLocal[originAndArtifactPath]
		artifactKnownToBePublished = ldr.LoadedArtifactKnownToBePublished[originAndArtifactPath]
		artifactKnownToBeReplica = ldr.LoadedArtifactKnownToBeReplica[originAndArtifactPath]
		mustBeFromShared = mustBeFromShared || artifactKnownToBePublished || artifactKnownToBeReplica // Set whether will consider local code for this package.

		Log(LOAD2_, "%s %s mustBeFromShared=%v\n", originAndArtifactPath, packagePath, mustBeFromShared)
		if artifactKnownToBeLocal {
			if mustBeFromShared {
				// This should never happen I think. Check anyway.
				err = fmt.Errorf("Can't load package '%s' from shared artifact '%s'. Another package from the local copy of the artifact is already loaded into runtime.", packagePath, originAndArtifactPath)
				return
			} else {
				mustBeFromLocal = true
			}
		}
	}

	// Now try to load the package from local file system.

	// If allowed, need to try twice, trying to read from
	// local artifacts dir tree, then if not found from shared artifacts dir tree.

	//// If no version has been specified, but some version of the artifact exists in local disk,
	//// the first thing to do is to read the metadata.txt of the local artifact, and set the version number desired
	//// to the current version as specified by the local artifact copy. Note this could be out of date, but we need a
	//// different command to go check if there is a later version of the artifact out there and download it.

	//// If we can find a metadata.txt file for the artifact locally, set the version with it.

	if version == "" {

		if !mustBeFromShared {

			version, metadataDate, err = ldr.readMetadataFile(localArtifactMetadataFilePath)
			if err != nil {
				return
			}
		}

		if version == "" {

			if mustBeFromLocal {
				// We already loaded a package from the local artifact, but somehow the local artifact is no longer there on filesystem.
				// This should never happen if everything is being loaded at once at beginning of run. Check anyway.
				err = fmt.Errorf("Can't load package '%s' from local artifact '%s'. Local artifact not found.", packagePath, originAndArtifactPath)
				return
			}

			version, metadataDate, err = ldr.readMetadataFile(sharedArtifactMetadataFilePath)
			if err != nil {
				return
			}
			if version == "" {
				version, metadataDate, err = ldr.readMetadataFile(sharedReplicaMetadataFilePath)
				if err != nil {
					return
				}
				if version != "" {
					artifactKnownToBeReplica = true
				}
			} else {
				artifactKnownToBePublished = true
			}
			sharedCurrentVersion = version
		}
	}

	// stat the artifact version dir to see if the version of the artifact exists in the filesystem.
	//
	// try local then shared artifacts and replicas dir trees as allowed by constraints so far

	artifactVersionDirFound := false
	var artifactVersionDir string

	if version != "" {
		versionStr := "/v" + version

		if !mustBeFromShared {

			// try local artifacts dir tree
			artifactVersionDir = ldr.RelishRuntimeLocation + "/artifacts/" + originAndArtifactPath + versionStr

			_, statErr := gos.Stat(artifactVersionDir)
			if statErr != nil {
				if !os.IsNotExist(statErr) {
					err = fmt.Errorf("Can't stat relish artifact version directory '%s': %v\n", artifactVersionDir, statErr)
					return
				}
			} else {
				artifactVersionDirFound = true
				mustBeFromLocal = true // locked to local (private) artifact now
				artifactKnownToBeLocal = true
			}
		}

		if !artifactVersionDirFound {

			// this version not found in local artifacts dir tree
			// try published shared artifacts dir tree
			artifactVersionDir = ldr.RelishRuntimeLocation + "/shared/relish/artifacts/" + originAndArtifactPath + versionStr

			_, statErr := gos.Stat(artifactVersionDir)
			if statErr != nil {
				if !os.IsNotExist(statErr) {
					err = fmt.Errorf("Can't stat relish artifact version directory '%s': %v\n", artifactVersionDir, statErr)
					return
				}
			} else {
				artifactVersionDirFound = true
				mustBeFromShared = true // locked to shared artifact now
				artifactKnownToBePublished = true
			}
		}

		if !artifactVersionDirFound {

			// this version not found in local artifacts dir tree or published shared artifacts dir tree
			// try downloaded shared replicas dir tree
			artifactVersionDir = ldr.RelishRuntimeLocation + "/shared/relish/replicas/" + originAndArtifactPath + versionStr

			_, statErr := gos.Stat(artifactVersionDir)
			if statErr != nil {
				if !os.IsNotExist(statErr) {
					err = fmt.Errorf("Can't stat relish artifact version directory '%s': %v\n", artifactVersionDir, statErr)
					return
				}
			} else {
				artifactVersionDirFound = true
				mustBeFromShared = true // locked to shared artifact now
				artifactKnownToBeReplica = true
			}
		}

	}

	if !artifactVersionDirFound {

		// Have not found the artifact version locally. Fetch it from the Internet.

		Log(LOAD2_, "artifact version |%s| not found locally\n", version)
		Log(LOAD2_, "localArtifactMetadataFilePath=%s\n", localArtifactMetadataFilePath)

		// TODO Need this path in order to install or update the artifact metadata file from remote, if there is none locally
		// or if the remote one is more recent.
		//
		// artifactMetadataFilePath := ldr.RelishRuntimeLocation + "/shared/relish/artifacts/" + originAndArtifactPath + "/metadata.txt"

		// Note: We will always be fetching into the shared artifacts directory tree.
		// If programmer wants to copy an artifact version into the local artifacts directory tree to develop/modify it,
		// they must currently do that copy separately manually.

		var zipFileContents []byte

		if sharedCurrentVersion == "" {
			sharedCurrentVersion, metadataDate, err = ldr.readMetadataFile(sharedReplicaMetadataFilePath)
		}

		// replaced by stuff below
		// defaultHostURL := ldr.DefaultCodeHost(originAndArtifactPath)
		// hostURL := defaultHostURL
		//
		// REVIEW THIS COMMENT
		// Note: TODO The correct order to do things is to load the metadata.txt file from the default host
		// (if possible) then to search for secondary hosts to get the version zip file, selecting
		// one AT RANDOM,
		// then if all of those (some number of) mirrors fail, get it from the default host
		// Also, use port 80 then 8421.

		// TODO: RE: SERVER SEARCH ORDER
		// We really ought to consider using a different order of servers tried
		// for fetching artifact source-code zip files than the order we use for trying to find
		// the smaller artifact metadata.txt files. Specifically, it is better to find
		// metadata.txt files at servers owned or controlled by the origin, because the metadata.txt
		// file will be up to date. shared.relish.pl is next best for that consideration.
		// However, from a performance (load sharing when scaled) perspective, it is better to
		// download the actual source code zip files from randomly found replica servers or
		// secondary general repositories.

		hostURLs := ldr.NonSearchedCodeHostURLs(originAndArtifactPath, "") // NEW

		// If we did not have the metadata file on filesystem before, or if remote metadata file is newer,
		// we should download and cache the metadata.txt file from the remote repository.
		//
		// Then, if we do not have a specified version yet, we should set version # from that,

		var currentVersion string

		var usingCentralRepo bool = false // whether getting code from http://shared.relish.pl

		var hostURL string

		for _, hostURL = range hostURLs {

			// Read remote metadata file. Store it locally if its date is >= the local shared artifact metadata date.
			currentVersion, err = fetchArtifactMetadata(hostURL, originAndArtifactPath, metadataDate, sharedCurrentVersion, sharedReplicaMetadataFilePath)
			if err == nil {
				break
			} else if currentVersion != "" {
				return // Inability to create or write local metadata file. Bad error.
			}
		}
		if currentVersion == "" {

			// TODO Now try google search

			// Should really do a Google search for metadata found anywhere (except shared.relish.pl) now,
			// so as to limit load and single point of failure on shared.relish.pl.
			/*
					    hostURLs,err = ldr.FindSecondaryCodeHosts(originAndArtifactPath, hostURLs)
					    if err != nil {
						   return
					    }
				        for _,hostURL = range hostURLs {

					       // Read remote metadata file. Store it locally if its date is >= the local shared artifact metadata date.
					       currentVersion, err = fetchArtifactMetadata(hostURL, originAndArtifactPath, metadataDate, sharedCurrentVersion, sharedReplicaMetadataFilePath)
					       if err == nil {
				               break
				           } else if currentVersion != "" {
				               return  // Inability to create or write local metadata file. Bad error.
				           }
				        }
			*/
			//
			// Only if trying other replica sites fails should shared.relish.pl be tried.
			//
			// However, for now, we're going straight to trying shared.relish.pl, because Google searching and
			// signed-metadata verification and signed-code verification aren't implemented yet.
		}

		if currentVersion == "" {

			// Now try shared.relish.pl

			usingCentralRepo = true
			hostURL = "http://shared.relish.pl"

			// Read remote metadata file. Store it locally if its date is >= the local shared artifact metadata date.
			currentVersion, err = fetchArtifactMetadata(hostURL, originAndArtifactPath, metadataDate, sharedCurrentVersion, sharedReplicaMetadataFilePath)
			if err != nil {
				return // We really couldn't find and download metadata for this artifact anywhere we looked. Too bad.
			}
		}

		// metadataHostURL := hostURL  // If we need to keep track of where we got the metadata from.

		if usingCentralRepo {
			hostURLs = []string{hostURL}
		} else {
			hostURLs = ldr.NonSearchedCodeHostURLs(originAndArtifactPath, hostURL) // NEW
		}

		if version == "" {
			version = currentVersion
		}

		// Version must now be a proper version number string, not ""

		var zipFileName string

		for _, hostURL = range hostURLs {
			zipFileContents, zipFileName, err = fetchArtifactZipFile(hostURL, originAndArtifactPath, version)
			if err == nil {
				break
			}
			// TODO consider logging the missed fetch and or developing a bad reputation for the host.
		}

		if zipFileContents == nil {
			err = fmt.Errorf("Search of Internet did not find relish software artifact '%s'", originAndArtifactPath)
			return
		}

		artifactKnownToBeReplica = true

		// Unzip the artifact into the proper local directory tree

		// TODO TODO Really don't know the artifact version here in some case, (in case there was nothing
		// not even a metadata.txt file locally, and no version was specified on command line) so
		// we don't have the correct path for artifactVersionDir known yet in that case !!!
		// WE DO KNOW IT HAS TO BE A SHARED REPLICASE DIR PATH however.

		versionStr := "/v" + version
		artifactVersionDir = ldr.RelishRuntimeLocation + "/shared/relish/replicas/" + originAndArtifactPath + versionStr

		//gos.MkdirAll(name string, perm FileMode) error
		var perm os.FileMode = 0777
		err = gos.MkdirAll(artifactVersionDir, perm)
		if err != nil {
			return
		}

		zipFilePath := ldr.RelishRuntimeLocation + "/shared/relish/replicas/" + originAndArtifactPath + "/" + zipFileName
		err = gos.WriteFile(zipFilePath, zipFileContents, perm)
		if err != nil {
			return
		}

		// Open an artifact version zip archive for reading.

		var srcZipFileContents []byte
		srcZipFileContents, err = zip_util.ExtractFileFromZipFileContents(zipFileContents, "artifactVersionContents.zip")
		if err != nil {
			return
		}

		/////////////////////////////////////////////////////////////////////////////////////
		// Verify the signed contents using digital signature verification.

		var sharedRelishPublicKeyCertificateBytes []byte
		var sharedRelishPublicKeyCertificate string
		var installationSharedRelishPublicKeyCert string
		var originPublicKeyCertificateBytes []byte
		var originPublicKeyCertificate string
		var signatureBytes []byte
		var signature string

		sharedRelishPublicKeyCertificateBytes, err = zip_util.ExtractFileFromZipFileContents(zipFileContents, "sharedRelishPublicKeyCertificate.pem")
		if err != nil {
			return
		}

		sharedRelishPublicKeyCertificate = strings.TrimSpace(string(sharedRelishPublicKeyCertificateBytes))

		originPublicKeyCertificateBytes, err = zip_util.ExtractFileFromZipFileContents(zipFileContents, "originPublicKeyCertificate.pem")
		if err != nil {
			return
		}

		originPublicKeyCertificate = strings.TrimSpace(string(originPublicKeyCertificateBytes))

		signatureBytes, err = zip_util.ExtractFileFromZipFileContents(zipFileContents, "signatureOfArtifactVersionContents.pem")
		if err != nil {
			return
		}

		signature = strings.TrimSpace(string(signatureBytes))

		installationSharedRelishPublicKeyCert, err = crypto_util.GetPublicKeyCert("origin", "shared.relish.pl2012")
		if err != nil {
			// Could not find shared relish pl public key cert in keys/public directory of this relish project directory.
			// Try downloading the public key from http://shared.relish.pl and installing it in the project directory.
			var cert string
			cert, err = FetchSharedRelishPublicKeyCert()
			if err != nil {
				return
			}
			err = crypto_util.StorePublicKeyCert("origin", "shared.relish.pl2012", cert)
			if err != nil {
				return
			}
			installationSharedRelishPublicKeyCert, err = crypto_util.GetPublicKeyCert("origin", "shared.relish.pl2012")
			if err != nil {
				return
			}
		}
		installationSharedRelishPublicKeyCert = strings.TrimSpace(installationSharedRelishPublicKeyCert)
		if err != nil {
			return
		}

		//   Is the shared relish public key cert in the artifact zip file identical to the cert that came with my
		//   relish distribution? If not, panic.

		if sharedRelishPublicKeyCertificate != installationSharedRelishPublicKeyCert {
			err = fmt.Errorf("Did not install downloaded artifact because shared.relish.pl2012 public key certificate\n"+
				"in artifact %s (v%s) downloaded from %s\n"+
				"is different than shared.relish.pl2012 public key certificate in this relish installation.\n",
				originAndArtifactPath, version, hostURL)
			return
		}

		// Validate that shared.relish.pl2012 public key is signed properly, obtaining the shared.relish.pl2012 publicKeyPEM.

		sharedRelishPublicKey := crypto_util.VerifiedPublicKey("", sharedRelishPublicKeyCertificate, "origin", "shared.relish.pl2012")

		if sharedRelishPublicKey == "" {
			err = errors.New("Invalid shared.relish.pl2012 public key certificate.")
			return
		}

		// Validate the artifact-publishing origin's public key cert

		slashPos := strings.Index(originAndArtifactPath, "/")
		originId := originAndArtifactPath[:slashPos]

		originPublicKey := crypto_util.VerifiedPublicKey(sharedRelishPublicKey, originPublicKeyCertificate, "origin", originId)

		if originPublicKey == "" {
			err = fmt.Errorf("Did not install downloaded artifact because %s public key certificate\n"+
				"in artifact %s (v%s) downloaded from %s\n"+
				"is invalid.\n",
				originId, originAndArtifactPath, version, hostURL)
			return
		}

		signedContent := zipFileName + "_|_" + string(srcZipFileContents)
		if !crypto_util.Verify(originPublicKey, signature, signedContent) {
			err = fmt.Errorf("Did not install downloaded artifact because artifact version content\n"+
				"in artifact %s (v%s) downloaded from %s\n"+
				"does not match (was not verified by) its digital signature.\n",
				originAndArtifactPath, version, hostURL)
			return
		}

		// Woohoo! Contents are verified.
		//
		/////////////////////////////////////////////////////////////////////////////////////
		//
		// Write them to relish installation shared code directory tree.

		// Note: Assuming the artifactVersionContents.zip file starts with src/ pkg/ doc/ etc not with v0002/

		err = zip_util.ExtractZipFileContents(srcZipFileContents, artifactVersionDir)
		if err != nil {
			return
		}

		Log(ALWAYS_, "Downloaded %s (v%s) from %s\n", originAndArtifactPath, version, hostURL)

	}

	if !artifactAlreadyLoaded { // Read built.txt from the artifact version directory
		builtFilePath := artifactVersionDir + "/built.txt"
		var builtFileContents []byte

		_, statErr := gos.Stat(builtFilePath)

		if statErr == nil {

			builtFileContents, err = gos.ReadFile(builtFilePath)
			if err != nil {
				return
			}

			artifactsVersionsStrs := strings.Fields(string(builtFileContents))
			n := len(artifactsVersionsStrs)
			for i := 0; i < n; i += 2 {
				artifactPath := artifactsVersionsStrs[i]
				artifactVersion := artifactsVersionsStrs[i+1]

				alreadyDesiredVersion, versionFound := ldr.LoadedArtifacts[artifactPath]
				if versionFound {
					if artifactVersion != alreadyDesiredVersion {
						Log(ALWAYS_, "Using v%s of %s. %s (v%s) may prefer v%s of %s.\n", alreadyDesiredVersion, artifactPath, originAndArtifactPath, version, artifactVersion, artifactPath)
					}
				} else {
					// Tell the loader to prefer the version of the other artifact
					// that the being-loaded artifact built.txt file specifies.
					ldr.LoadedArtifacts[artifactPath] = artifactVersion
				}
			}

		} else if !os.IsNotExist(statErr) {
			err = fmt.Errorf("Can't stat '%s': %v\n", builtFilePath, statErr)
			return
		}
		// else there is no built.txt file. Accept that for now
		// and subsequently load the current versions of artifacts where no other version is preferred.
	}

	////////////////////////////////////////////////////////////////////////

	// TODO
	// Load all the code files in the package of the artifact.
	// compile files if necessary?
	//
	// record the version of the artifact and package in the loader's registry of loaded packages and artifacts.

	packageSourcePath := artifactVersionDir + "/src/" + packagePath
	packageCompiledPath := artifactVersionDir + "/pkg/" + packagePath

	// Read the filenames of source files etc. in the /src/... package directory

	var sourceDirFile *os.File
	sourceDirFile, err = gos.Open(packageSourcePath)
	if err != nil {
		return
	}
	defer sourceDirFile.Close()

	var filenames []string
	filenames, err = sourceDirFile.Readdirnames(-1)
	if err != nil {
		return
	}

	// Create /pkg/ dir tree if does not exist already
	_, statErr := gos.Stat(packageCompiledPath)
	if statErr != nil {
		if !os.IsNotExist(statErr) {
			err = fmt.Errorf("Can't stat relish intermediate-code directory '%s': %v\n", packageCompiledPath, statErr)
			return
		}
		var perm os.FileMode = 0777
		err = gos.MkdirAll(packageCompiledPath, perm)
		if err != nil {
			return
		}
	}

	ldr.LoadedArtifacts[originAndArtifactPath] = version

	ldr.LoadedArtifactKnownToBePublished[originAndArtifactPath] = strings.Contains(artifactVersionDir, "/shared/relish/artifacts/")
	ldr.LoadedArtifactKnownToBeReplica[originAndArtifactPath] = artifactKnownToBeReplica

	Log(LOAD2_, "ldr.LoadedArtifactKnownToBePublished[%s]=%v\n", originAndArtifactPath, ldr.LoadedArtifactKnownToBePublished[originAndArtifactPath])
	Log(LOAD2_, "ldr.LoadedArtifactKnownToBeReplica[%s]=%v\n", originAndArtifactPath, ldr.LoadedArtifactKnownToBeReplica[originAndArtifactPath])
	Logln(LOAD_, "artifactVersionDir="+artifactVersionDir)

	ldr.LoadedArtifactKnownToBeLocal[originAndArtifactPath] = !(ldr.LoadedArtifactKnownToBePublished[originAndArtifactPath] || artifactKnownToBeReplica)

	if relish.DatabaseURI() == "" {
		dbDirPath := ldr.databaseDirPath(originAndArtifactPath)

		var perm os.FileMode = 0777
		err = gos.MkdirAll(dbDirPath, perm)
		if err != nil {
			return
		}

		dbFilePath := dbDirPath + "/" + ldr.DatabaseName
		relish.SetDatabaseURI(dbFilePath) // TODO NOT TRUE AT ALL YET
		// This can be overridden with a statement in the program, as long as a persistence op has not been used first.
	}

	// Collect a map of file nodes to the root of the filename. We will be passing this to the generator to generate runtime
	// code for the whole package all at once.
	//
	astFileNodes := make(map[*ast.File]string)

	for _, filename := range filenames {
		var sourceFound bool
		var pickledFound bool
		if strings.HasSuffix(filename, ".rel") { // consider only the relish source files in the dir.
			// This is actually quite controversial, since it means that source code MUST be present
			// or we won't bother looking for the compiled file to load.
			// This is a somewhat political opinionated decision. Will have to be seriously mulled if not pondered.

			// TODO add in here the on-demand compilation as found in relish.go
			// Doing it NOW!!
			sourceFilePath := packageSourcePath + "/" + filename

			fileNameRoot := filename[:len(filename)-4]

			pickleFilePath := packageCompiledPath + "/" + fileNameRoot + ".rlc"

			sourceFileInfo, statErr := gos.Stat(sourceFilePath)
			if statErr != nil {
				if !os.IsNotExist(statErr) {
					err = fmt.Errorf("Can't stat relish source file '%s': %v\n", sourceFilePath, statErr)
					return
				}
			} else {
				sourceFound = true
			}

			pickleFileInfo, statErr := gos.Stat(pickleFilePath)
			if statErr != nil {
				if !os.IsNotExist(statErr) {
					err = fmt.Errorf("Can't stat relish intermediate-code file '%s': %v\n", pickleFilePath, statErr)
					return
				}
			} else {
				pickledFound = true
			}

			var parseNeeded bool
			if sourceFound {
				if pickledFound {
					if sourceFileInfo.ModTime().After(pickleFileInfo.ModTime()) {
						parseNeeded = true
					}
				} else {
					parseNeeded = true
				}
			} else if !pickledFound {
				err = fmt.Errorf("Error: Found neither relish source file '%s' nor intermediate-code file '%s'.\n", sourceFilePath, pickleFilePath)
				return
			}

			var fileNode *ast.File
			if parseNeeded {
				var fset = token.NewFileSet()
				fileNode, err = parser.ParseFile(fset, sourceFilePath, nil, parserDebugMode)
				if err != nil {
					err = fmt.Errorf("Error parsing file '%s': %v\n", sourceFilePath, err)
					return
				}

				err = ast.Pickle(fileNode, pickleFilePath)
				if err != nil {
					err = fmt.Errorf("Error pickling file '%s': %v\n", sourceFilePath, err)
					return
				}
			} else { // read the pickled (intermediate-code) file

				fileNode, err = ast.Unpickle(pickleFilePath)
				if err != nil {
					err = fmt.Errorf("Error unpickling file '%s': %v\n", pickleFilePath, err)
					return
				}
			}

			err = ldr.ensureImportsAreLoaded(fileNode)
			if err != nil {
				return
			}

			astFileNodes[fileNode] = fileNameRoot
			//         gen = generator.NewGenerator(fileNode, fileNameRoot) // TODO NOW add a isLocal =ldr.LoadedArtifactKnownToBeLocal[originAndArtifactPath]
			// argument so that we can flag the RPackage object as local or shared.
			//         gen.GenerateCode()

			if packageIdentifier != fileNode.Name.Name {
				err = fmt.Errorf("\nThe origin, artifact, or package metadata at top of source code file\n'%s'\ndoes not match the package directory path where the file resides.\n", sourceFilePath)
				return
			}

			if parseNeeded {
				if !ldr.quiet {
					Log(ALWAYS_, "Compiled %s\n", sourceFilePath)
				}
			}

		} // end of if it is a code file.
	} // end of loop over each file in the package.

	if len(astFileNodes) > 0 {
		gen = generator.NewGenerator(astFileNodes)
		gen.GenerateCode()
	}

	native_methods.WrapNativeMethods(packageIdentifier) // Check if package has native methods, if so, make RMethod wrappers.

	ldr.LoadedPackages[packageIdentifier] = version

	delete(ldr.PackagesBeingLoaded, packageIdentifier)

	if !ldr.quiet {
		Log(ALWAYS_, "Loaded %s\n", packageCompiledPath)
	}

	return
}