lockedExt = mp.lockedExt
		mp.lockedExt = 0

		mp.lockedg.set(newg)
		newg.lockedm.set(mp)
		gp.lockedm = 0

		// Mark the calling goroutine as being at an async
		// safe-point, since it has a few conservative frames
		// at the bottom of the stack. This also prevents
		// stack shrinks.
		gp.asyncSafePoint = true

		// Stash newg away so we can execute it below (mcall's
		// closure can't capture anything).

	// cases the answer is definite. We let ctrlflow figure
	// that out.
	fn := typeutil.StaticCallee(c.pass.TypesInfo, call)
	if fn == nil {
		return true // callee not statically known; be conservative
	}

	// Function or method declared in this package?
	if di, ok := c.funcDecls[fn]; ok {
		c.buildDecl(fn, di)
		return !di.noReturn
	}

	// Not declared in this package.

  // should be revisited for new resource-allocators that might potentially
  // break our currently guaranteed correctness.
  // For context, we are very conservative here compared to
  // `auto_control_deps.py` where it is assumed that allocated resource values
  // NEVER alias. We should align our assumptions in the future.
  static constexpr int64_t kUnknownResourceId = -1;

			// presumably a qualified identifier
			return &ast.SelectorExpr{
				Sel: ast.NewIdent(typ.Sel.Name),
				X:   &ast.Ident{Name: id.Name, NamePos: pos},
			}
		}
	}
	return nil // shouldn't happen, but be conservative and don't panic
}

func (r *reader) filterSpecList(list []ast.Spec, tok token.Token) []ast.Spec {
	if tok == token.CONST {
		// Propagate any type information that would get lost otherwise

		// Path rooted in the current drive.
		return false
	}
	if stringslite.IndexByte(path, ':') >= 0 {
		// Colons are only valid when marking a drive letter ("C:foo").
		// Rejecting any path with a colon is conservative but safe.
		return false
	}
	hasDots := false // contains . or .. path elements
	for p := path; p != ""; {
		var part string
		part, p, _ = cutPath(p)
		if part == "." || part == ".." {
			hasDots = true

// statement following stmt is reachable.
func (d *deadState) findDead(stmt ast.Stmt) {
	// Is this a labeled goto target?
	// If so, assume it is reachable due to the goto.
	// This is slightly conservative, in that we don't
	// check that the goto is reachable, so
	//	L: goto L
	// will not provoke a warning.
	// But it's good enough.
	if x, isLabel := stmt.(*ast.LabeledStmt); isLabel && d.hasGoto[x.Label.Name] {

	var lim syscall.Rlimit
	err := syscall.Getrlimit(syscall.RLIMIT_CORE, &lim)
	if err != nil {
		t.Fatalf("error getting rlimit: %v", err)
	}
	// Minimum RLIMIT_CORE max to allow. This is a conservative estimate.
	// Most systems allow infinity.
	const minRlimitCore = 100 << 20 // 100 MB
	if lim.Max < minRlimitCore {
		t.Skipf("RLIMIT_CORE max too low: %#+v", lim)
	}

			switch {
			case typVal.IsType():
				// Type conversion, which is safe.
			case typVal.IsBuiltin():
				// Builtin func, conservatively assumed to not
				// be safe for now.
				safe = false
				return false
			default:
				// A non-builtin func or method call.
				// Conservatively assume that all of them have
				// side effects for now.
				safe = false
				return false
			}
		case *ast.UnaryExpr:

// It must be called when there are no other file system operations happening.
func sysWriteBits() fs.FileMode {
	// Read current umask. There's no way to read it without also setting it,
	// so set it conservatively and then restore the original one.
	m := syscall.Umask(0o777)
	syscall.Umask(m)    // restore bits
	if m&0o22 == 0o22 { // group and world are unwritable by default
		return 0o700
	}

// size of input tensors. The exception is that ops whose cost is irrelevant to
// input sizes, such as tf.Shape and tf.Reshape, are whitelisted to have cheap
// cost. This cost analysis is expected to be used conservatively (eg. use a low
// threshold to decide whether a cost is cheap or expensive), as it might not be
// accurate in some cases.
//
class CostAnalysis {
 public:
  explicit CostAnalysis(