// The backprop loop counter and main backprop loop run in their own execution
// frame (conceptually, the main forward loop and forward loop counter run
// together in a frame, then the backprop loop counter and backprop loop run
// together in a different frame). This returns the frame name to use for the
// backprop while loops.
// TODO(skyewm): make sure this is unique among existing frame names
string BackPropFrameName(const string& forward_frame_name) {

            }
        }

        private void appendFrame(String prefix, StackTraceElement frame, StackTraceRelevance relevance) throws IOException {
            listener.beforeFrame(frame, relevance);

            builder.append(prefix)
                .append("\tat ")
                .append(frame.toString())
                .append(lineSeparator);
        }

		// and registers that ever contain a pointer.
		if frame.varp != 0 {
			size := frame.varp - frame.sp
			if size > 0 {
				scanConservative(frame.sp, size, nil, gcw, state)
			}
		}

		// Scan arguments to this frame.
		if n := frame.argBytes(); n != 0 {
			// TODO: We could pass the entry argument map
			// to narrow this down further.
			scanConservative(frame.argp, n, nil, gcw, state)
		}

		return nil, nil
	}

	// Find assembly files to work on.
	var sfiles []string
	for _, fname := range pass.OtherFiles {
		if strings.HasSuffix(fname, ".s") && pass.Pkg.Path() != "runtime" {
			sfiles = append(sfiles, fname)
		}
	}

	for _, fname := range sfiles {
		content, tf, err := analysisutil.ReadFile(pass, fname)
		if err != nil {
			return nil, err
		}

		lines := strings.SplitAfter(string(content), "\n")

	MOVW	R2, ret+8(FP)
	RET

// cgocallback(fn, frame unsafe.Pointer, ctxt uintptr)
// See cgocall.go for more details.
TEXT ·cgocallback(SB),NOSPLIT,$12-12
	NO_LOCAL_POINTERS

	// Skip cgocallbackg, just dropm when fn is nil, and frame is the saved g.
	// It is used to dropm while thread is exiting.
	MOVW	fn+0(FP), R5
	BNE	R5, loadg
	// Restore the g from frame.
	MOVW	frame+4(FP), g
	JMP	dropm

loadg:

// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package trace

// Frame is a frame in stack traces.
type Frame struct {
	PC   uint64
	Fn   string
	File string
	Line int
}

const (
	// Special P identifiers:
	FakeP    = 1000000 + iota
	TimerP   // depicts timer unblocks
	NetpollP // depicts network unblocks

		t.Fatalf("unexpected: %v %d %v", err, n, buf)
	}
	// read the remaining frame
	buf = make([]byte, 2)
	if n, err := r.Read(buf); err != nil && n != 2 && bytes.Equal(buf, []byte{0x03, 0x04}) {
		t.Fatalf("unexpected: %v %d %v", err, n, buf)
	}
	// read with buffer equal to frame
	buf = make([]byte, 3)
	if n, err := r.Read(buf); err != nil && n != 3 && bytes.Equal(buf, []byte{0x05, 0x06, 0x07}) {

     *
     * @see Throwable#toString()
     */
    String getHeader();

    /**
     * Stack frames from the original exception.
     */
    List<StackTraceElement> getStackTrace();

    /**
     * Relevance of a given stack frame in the {@link #getStackTrace() stack trace}.
     */
    StackTraceRelevance getStackTraceRelevance(int frameIndex);

    /**

	if err != nil {
		return Event{}, err
	}
	if spec.IsStack {
		len := int(args[1])
		for i := 0; i < len; i++ {
			// Each stack frame has four args: pc, func ID, file ID, line number.
			frame, err := r.readArgs(4)
			if err != nil {
				return Event{}, err
			}
			args = append(args, frame...)
		}
	}
	var data []byte
	if spec.HasData {
		data, err = r.readData()
		if err != nil {
			return Event{}, err
		}
	}

        this.classifiers = ImmutableList.copyOf(classifiers);
    }

    @Nullable
    @Override
    public StackTraceRelevance classify(StackTraceElement frame) {
        for (StackTraceClassifier classifier : classifiers) {
            StackTraceRelevance relevance = classifier.classify(frame);
            if (relevance != null) {
                return relevance;
            }
        }
        return null;
    }