// return the same package.
	ImportFrom(path, dir string, mode ImportMode) (*Package, error)
}

// A Config specifies the configuration for type checking.
// The zero value for Config is a ready-to-use default configuration.
type Config struct {
	// Context is the context used for resolving global identifiers. If nil, the
	// type checker will initialize this field with a newly created context.
	Context *Context

	objdirSeq int // counter for NewObjdir
	pkgSeq    int

	backgroundSh *Shell // Shell that per-Action Shells are derived from

	exec      sync.Mutex
	readySema chan bool
	ready     actionQueue

	id           sync.Mutex
	toolIDCache  map[string]string // tool name -> tool ID
	buildIDCache map[string]string // file name -> build ID
}

	// "linux_386_race" instead of the usual "linux_386".
	InstallSuffix string

	// By default, Import uses the operating system's file system calls
	// to read directories and files. To read from other sources,
	// callers can set the following functions. They all have default
	// behaviors that use the local file system, so clients need only set
	// the functions whose behaviors they wish to change.

	"strings"
	"sync"
)

// A Scope maintains a set of objects and links to its containing
// (parent) and contained (children) scopes. Objects may be inserted
// and looked up by name. The zero value for Scope is a ready-to-use
// empty scope.
type Scope struct {
	parent   *Scope
	children []*Scope
	number   int               // parent.children[number-1] is this scope; 0 if there is no parent
	elems    map[string]Object // lazily allocated

		if rmErr := os.RemoveAll(dir); err == nil {
			err = rmErr
		}
	}()

	localGitRepo = filepath.Join(dir, "gitrepo2")

	// Redirect the module cache to a fresh directory to avoid crosstalk, and make
	// it read/write so that the test can still clean it up easily when done.
	cfg.GOMODCACHE = filepath.Join(dir, "modcache")
	cfg.ModCacheRW = true

	m.Run()
	return nil
}

		// Assignments can only alias with direct uses of this variable.
		assigned.Add(name)
	}

	early.Append(late.Take()...)
	return early
}

// readsMemory reports whether the evaluation n directly reads from
// memory that might be written to indirectly.
func readsMemory(n ir.Node) bool {
	switch n.Op() {
	case ir.ONAME:
		n := n.(*ir.Name)
		if n.Class == ir.PFUNC {
			return false
		}

// symbol names.
func (s *SymABIs) canonicalize(linksym string) string {
	if strings.HasPrefix(linksym, `"".`) {
		panic("non-canonical symbol name: " + linksym)
	}
	return linksym
}

// ReadSymABIs reads a symabis file that specifies definitions and
// references of text symbols by ABI.
//
// The symabis format is a set of lines, where each line is a sequence
// of whitespace-separated fields. The first field is a verb and is

// gives access to the comparison operation.
//
// It must be safe to call methods on a Reqs from multiple goroutines simultaneously.
// Because a Reqs may read the underlying graph from the network on demand,
// the MVS algorithms parallelize the traversal to overlap network delays.
type Reqs interface {
	// Required returns the module versions explicitly required by m itself.

	}
	if string(magbuf[:]) != magic {
		t.Errorf("%s: incorrect archive magic string %q", arname, magbuf)
	}

	off := int64(len(magic))
	for {
		if off&1 != 0 {
			var b [1]byte
			if _, err := f.Read(b[:]); err != nil {
				if err == io.EOF {
					break
				}
				t.Errorf("%s: error skipping alignment byte at %d: %v", arname, off, err)
			}
			off++
		}

		var hdrbuf [hdrlen]byte

				// Schedule flag register generation as late as possible.
				// This makes sure that we only have one live flags
				// value at a time.
				// Note that this case is after the case above, so values
				// which both read and generate flags are given ScoreReadFlags.
				score[v.ID] = ScoreFlags
			default:
				score[v.ID] = ScoreDefault
				// If we're reading flags, schedule earlier to keep flag lifetime short.