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// 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 program provides the portable interface to a program being debugged.
package program // import "golang.org/x/debug/ogle/program"
import (
"io"
)
// Program is the interface to a (possibly remote) program being debugged.
// The process (if any) and text file associated with it may change during
// the session, but many resources are associated with the Program rather
// than process or text file so they persist across debuggging runs.
type Program interface {
// Open opens a virtual file associated with the process.
// Names are things like "text", "mem", "fd/2".
// Mode is one of "r", "w", "rw".
// Return values are open File and error.
// When the target binary is re-run, open files are
// automatically updated to refer to the corresponding
// file in the new process.
Open(name string, mode string) (File, error)
// SetArguments sets the command-line arguments for
// the next running of the target binary, excluding the
// target's binary name. That is, while debugging the
// echo command, to prepare a run of "echo hi" call
// SetArguments("hi")
SetArguments(args ...string)
// Run abandons the current running process, if any,
// and execs a new instance of the target binary file
// (which may have changed underfoot).
// Breakpoints and open files are re-established.
// The call hangs until the program stops executing,
// at which point it returns the program status.
Run() (Status, error)
// Stop stops execution of the current process but
// does not kill it.
Stop() (Status, error)
// Resume resumes execution of a stopped process.
// The call hangs until the program stops executing,
// at which point it returns the program status.
Resume() (Status, error)
// TODO: Step(). Where does the granularity happen,
// on the proxy end or the debugging control end?
// Kill kills the current process.
Kill() (Status, error)
// Breakpoint sets a breakpoint at the specified address.
// When the target binary is re-run, breakpoints are
// automatically re-established in the new process by
// re-evaluating the address.
// The address is the same mini-language accepted by Eval,
// which permits setting multiple breakpoints using a regular
// expression to match a set of symbols.
Breakpoint(address string) (PCs []uint64, err error)
// DeleteBreakpoint removes the breakpoint at the specified
// address. TODO: Probably the wrong interface.
DeleteBreakpoint(address string) error
// Eval evaluates the expression (typically an address) and returns
// its string representation(s). Multivalued expressions such as
// matches for regular expressions return multiple values.
// Syntax:
// re:regexp
// Returns a list of symbol names that match the expression
// addr:symbol
// Returns a one-element list holding the hexadecimal
// ("0x1234") value of the address of the symbol
// val:symbol
// Returns a one-element list holding the formatted
// value of the symbol
// 0x1234, 01234, 467
// Returns a one-element list holding the name of the
// symbol ("main.foo") at that address (hex, octal, decimal).
Eval(expr string) ([]string, error)
// Frames returns up to count stack frames from where the program
// is currently stopped.
Frames(count int) ([]Frame, error)
}
// The File interface provides access to file-like resources in the program.
// It implements only ReaderAt and WriterAt, not Reader and Writer, because
// random access is a far more common pattern for things like symbol tables,
// and because enormous address space of virtual memory makes routines
// like io.Copy dangerous.
type File interface {
io.ReaderAt
io.WriterAt
io.Closer
}
type Status struct {
PC, SP uint64
}
type Frame struct {
// PC is the hardware program counter.
PC uint64
// SP is the hardware stack pointer.
SP uint64
// File and Line are the source code location of the PC.
File string
Line int
// TODO: add arguments and return values.
// S is an unstructured string value used for debugging the ogle
// library. It is not guaranteed to be in any particular format.
S string
}