pkgtree

Documentation

Index

• type LocalImportsError
  • func (e *LocalImportsError) Error() string
• type Package
• type PackageOrErr
• type PackageTree
  • func ListPackages(fileRoot, importRoot string) (PackageTree, error)
  • func (t PackageTree) Copy() PackageTree
  • func (t PackageTree) ToReachMap(main, tests, backprop bool, ignore map[string]bool) (ReachMap, map[string]*ProblemImportError)
• type ProblemImportError
  • func (e *ProblemImportError) Error() string
• type ReachMap
  • func (rm ReachMap) FlattenFn(exclude func(string) bool) []string

Types

type LocalImportsError

type LocalImportsError struct {
	ImportPath   string
	Dir          string
	LocalImports []string
}

LocalImportsError indicates that a package contains at least one relative import that will prevent it from compiling.

TODO(sdboyer) add a Files property once we're doing our own per-file parsing

func (*LocalImportsError) Error

func (e *LocalImportsError) Error() string

type Package

type Package struct {
	Name        string   // Package name, as declared in the package statement
	ImportPath  string   // Full import path, including the prefix provided to ListPackages()
	CommentPath string   // Import path given in the comment on the package statement
	Imports     []string // Imports from all go and cgo files
	TestImports []string // Imports from all go test files (in go/build parlance: both TestImports and XTestImports)
}

Package represents a Go package. It contains a subset of the information go/build.Package does.

type PackageOrErr

type PackageOrErr struct {
	P   Package
	Err error
}

PackageOrErr stores the results of attempting to parse a single directory for Go source code.

type PackageTree

type PackageTree struct {
	ImportRoot string
	Packages   map[string]PackageOrErr
}

A PackageTree represents the results of recursively parsing a tree of packages, starting at the ImportRoot. The results of parsing the files in the directory identified by each import path - a Package or an error - are stored in the Packages map, keyed by that import path.

func ListPackages

func ListPackages(fileRoot, importRoot string) (PackageTree, error)

ListPackages reports Go package information about all directories in the tree at or below the provided fileRoot.

The importRoot parameter is prepended to the relative path when determining the import path for each package. The obvious case is for something typical, like:

fileRoot = "/home/user/go/src/github.com/foo/bar"
importRoot = "github.com/foo/bar"

where the fileRoot and importRoot align. However, if you provide:

fileRoot = "/home/user/workspace/path/to/repo"
importRoot = "github.com/foo/bar"

then the root package at path/to/repo will be ascribed import path "github.com/foo/bar", and the package at "/home/user/workspace/path/to/repo/baz" will be "github.com/foo/bar/baz".

A PackageTree is returned, which contains the ImportRoot and map of import path to PackageOrErr - each path under the root that exists will have either a Package, or an error describing why the directory is not a valid package.

func (PackageTree) Copy

func (t PackageTree) Copy() PackageTree

Copy copies the PackageTree.

This is really only useful as a defensive measure to prevent external state mutations.

func (PackageTree) ToReachMap

func (t PackageTree) ToReachMap(main, tests, backprop bool, ignore map[string]bool) (ReachMap, map[string]*ProblemImportError)

ToReachMap looks through a PackageTree and computes the list of external import statements (that is, import statements pointing to packages that are not logical children of PackageTree.ImportRoot) that are transitively imported by the internal packages in the tree.

main indicates whether (true) or not (false) to include main packages in the analysis. When utilized by gps' solver, main packages are generally excluded from analyzing anything other than the root project, as they necessarily can't be imported.

tests indicates whether (true) or not (false) to include imports from test files in packages when computing the reach map.

backprop indicates whether errors (an actual PackageOrErr.Err, or an import to a nonexistent internal package) should be backpropagated, transitively "poisoning" all corresponding importers to all importers.

ignore is a map of import paths that, if encountered, should be excluded from analysis. This exclusion applies to both internal and external packages. If an external import path is ignored, it is simply omitted from the results.

If an internal path is ignored, then it not only does not appear in the final map, but it is also excluded from the transitive calculations of other internal packages. That is, if you ignore A/foo, then the external package list for all internal packages that import A/foo will not include external packages that are only reachable through A/foo.

Visually, this means that, given a PackageTree with root A and packages at A, A/foo, and A/bar, and the following import chain:

A -> A/foo -> A/bar -> B/baz

In this configuration, all of A's packages transitively import B/baz, so the returned map would be:

 map[string][]string{
	"A": []string{"B/baz"},
	"A/foo": []string{"B/baz"}
	"A/bar": []string{"B/baz"},
 }

However, if you ignore A/foo, then A's path to B/baz is broken, and A/foo is omitted entirely. Thus, the returned map would be:

 map[string][]string{
	"A": []string{},
	"A/bar": []string{"B/baz"},
 }

If there are no packages to ignore, it is safe to pass a nil map.

Finally, if an internal PackageOrErr contains an error, it is always omitted from the result set. If backprop is true, then the error from that internal package will be transitively propagated back to any other internal PackageOrErrs that import it, causing them to also be omitted. So, with the same import chain:

A -> A/foo -> A/bar -> B/baz

If A/foo has an error, then it would backpropagate to A, causing both to be omitted, and the returned map to contain only A/bar:

 map[string][]string{
	"A/bar": []string{"B/baz"},
 }

If backprop is false, then errors will not backpropagate to internal importers. So, with an error in A/foo, this would be the result map:

 map[string][]string{
	"A": []string{},
	"A/bar": []string{"B/baz"},
 }

type ProblemImportError

type ProblemImportError struct {
	// The import path of the package with some problem rendering it
	// unimportable.
	ImportPath string
	// The path to the internal package the problem package imports that is the
	// original cause of this issue. If empty, the package itself is the
	// problem.
	Cause []string
	// The actual error from ListPackages that is undermining importability for
	// this package.
	Err error
}

ProblemImportError describes the reason that a particular import path is not safely importable.

func (*ProblemImportError) Error

func (e *ProblemImportError) Error() string

Error formats the ProblemImportError as a string, reflecting whether the error represents a direct or transitive problem.

type ReachMap

type ReachMap map[string]struct {
	Internal, External []string
}

ReachMap maps a set of import paths (keys) to the sets of transitively reachable tree-internal packages, and all the tree-external packages reachable through those internal packages.

See PackageTree.ToReachMap() for more information.

func (ReachMap) FlattenFn

func (rm ReachMap) FlattenFn(exclude func(string) bool) []string

FlattenFn flattens a reachmap into a sorted, deduplicated list of all the external imports named by its contained packages, but excludes imports coming from packages with disallowed patterns in their names: any path element with a leading dot, a leading underscore, with the name "testdata".

Imports for which exclude returns true will be left out.