delve是Go编程语言的调试器。
介绍
- Delve 的目标是为 Go 提供一个简单、功能齐全的调试工具
- Delve 易于调用和使用
安装
# Install the latest release:
$ go install github.com/go-delve/delve/cmd/dlv@latest
# Install at a specific version or pseudo-version:
$ go install github.com/go-delve/delve/cmd/dlv@v1.7.3
$ dlv --help
Delve is a source level debugger for Go programs.
Delve enables you to interact with your program by controlling the execution of the process,
evaluating variables, and providing information of thread / goroutine state, CPU register state and more.
The goal of this tool is to provide a simple yet powerful interface for debugging Go programs.
Pass flags to the program you are debugging using `--`, for example:
`dlv exec ./hello -- server --config conf/config.toml`
Usage:
dlv [command]
Available Commands:
attach Attach to running process and begin debugging.
connect Connect to a headless debug server with a terminal client.
core Examine a core dump.
dap Starts a headless TCP server communicating via Debug Adaptor Protocol (DAP).
debug Compile and begin debugging main package in current directory, or the package specified.
exec Execute a precompiled binary, and begin a debug session.
help Help about any command
test Compile test binary and begin debugging program.
trace Compile and begin tracing program.
version Prints version.
Additional help topics:
dlv backend Help about the --backend flag.
dlv log Help about logging flags.
dlv redirect Help about file redirection.
Use "dlv [command] --help" for more information about a command.
$ dlv debug .
Type 'help' for list of commands.
(dlv) help
The following commands are available:
Running the program:
call ------------------------ Resumes process, injecting a function call (EXPERIMENTAL!!!)
continue (alias: c) --------- Run until breakpoint or program termination.
next (alias: n) ------------- Step over to next source line.
rebuild --------------------- Rebuild the target executable and restarts it. It does not work if the executable was not built by delve.
restart (alias: r) ---------- Restart process.
step (alias: s) ------------- Single step through program.
step-instruction (alias: si) Single step a single cpu instruction.
stepout (alias: so) --------- Step out of the current function.
Manipulating breakpoints:
break (alias: b) ------- Sets a breakpoint.
breakpoints (alias: bp) Print out info for active breakpoints.
clear ------------------ Deletes breakpoint.
clearall --------------- Deletes multiple breakpoints.
condition (alias: cond) Set breakpoint condition.
on --------------------- Executes a command when a breakpoint is hit.
toggle ----------------- Toggles on or off a breakpoint.
trace (alias: t) ------- Set tracepoint.
watch ------------------ Set watchpoint.
Viewing program variables and memory:
args ----------------- Print function arguments.
display -------------- Print value of an expression every time the program stops.
examinemem (alias: x) Examine raw memory at the given address.
locals --------------- Print local variables.
print (alias: p) ----- Evaluate an expression.
regs ----------------- Print contents of CPU registers.
set ------------------ Changes the value of a variable.
vars ----------------- Print package variables.
whatis --------------- Prints type of an expression.
Listing and switching between threads and goroutines:
goroutine (alias: gr) -- Shows or changes current goroutine
goroutines (alias: grs) List program goroutines.
thread (alias: tr) ----- Switch to the specified thread.
threads ---------------- Print out info for every traced thread.
Viewing the call stack and selecting frames:
deferred --------- Executes command in the context of a deferred call.
down ------------- Move the current frame down.
frame ------------ Set the current frame, or execute command on a different frame.
stack (alias: bt) Print stack trace.
up --------------- Move the current frame up.
Other commands:
config --------------------- Changes configuration parameters.
disassemble (alias: disass) Disassembler.
dump ----------------------- Creates a core dump from the current process state
edit (alias: ed) ----------- Open where you are in $DELVE_EDITOR or $EDITOR
exit (alias: quit | q) ----- Exit the debugger.
funcs ---------------------- Print list of functions.
help (alias: h) ------------ Prints the help message.
libraries ------------------ List loaded dynamic libraries
list (alias: ls | l) ------- Show source code.
packages ------------------- Print list of packages.
source --------------------- Executes a file containing a list of delve commands
sources -------------------- Print list of source files.
target --------------------- Manages child process debugging.
transcript ----------------- Appends command output to a file.
types ---------------------- Print list of types
Type help followed by a command for full documentation.
(dlv)
使用
package main
import (
"fmt"
)
func tribonacci(n int) int {
if n < 2 {
return n
}
if n == 2 {
return 1
}
cache := make([]int, n+1)
cache[0], cache[1], cache[2] = 0, 1, 1
for i := 3; i <= n; i++ {
cache[i] = cache[i-1] + cache[i-2] + cache[i-3]
}
return cache[n]
}
func main() {
fmt.Println(tribonacci(15))
}
debug
使用的命令
break(b) 设置断点
b xxx/databases/mysql.init.0
breakpoints(bp) 查看断点clearall 清理断点continue(c) 执行到下一个断点next(n) 下一步set 设置变量funcs <func-name> 搜索函数reset(r) 重置step(s) 进入函数list(l) 查看文件
exit 退出
$ dlv debug .
Type 'help' for list of commands.
(dlv) b main.main
Breakpoint 1 set at 0x10ae96e for main.main() ./main.go:23
(dlv) l main.go:15
Showing /Users/xiexianbin/Downloads/abc/main.go:15 (PC: 0x10ae78f)
10: }
11: if n == 2 {
12: return 1
13: }
14:
15: cache := make([]int, n+1)
16: cache[0], cache[1], cache[2] = 0, 1, 1
17: for i := 3; i <= n; i++ {
18: cache[i] = cache[i-1] + cache[i-2] + cache[i-3]
19: }
20: return cache[n]
(dlv) b main.go:18
Breakpoint 2 set at 0x10ae82f for main.tribonacci() ./main.go:18
(dlv) bp
Breakpoint runtime-fatal-throw (enabled) at 0x437960,0x437a60 for (multiple functions)() <multiple locations>:0 (0)
Breakpoint unrecovered-panic (enabled) at 0x437dc0 for runtime.fatalpanic() /usr/lib/go-1.20/src/runtime/panic.go:1141 (0)
print runtime.curg._panic.arg
Breakpoint 1 (enabled) at 0x49cb0a for main.main() ./main.go:23 (0)
Breakpoint 2 (enabled) at 0x49c9b9 for main.tribonacci() ./main.go:18 (0)
(dlv) c
> main.main() ./main.go:23 (hits goroutine(1):1 total:1) (PC: 0x49cb0a)
18: cache[i] = cache[i-1] + cache[i-2] + cache[i-3]
19: }
20: return cache[n]
21: }
22:
=> 23: func main() {
24: fmt.Println(tribonacci(15))
25: }
(dlv) n
> main.main() ./main.go:24 (PC: 0x49cb18)
19: }
20: return cache[n]
21: }
22:
23: func main() {
=> 24: fmt.Println(tribonacci(15))
25: }
(dlv) s
> main.tribonacci() ./main.go:7 (PC: 0x49c8ca)
2:
3: import (
4: "fmt"
5: )
6:
=> 7: func tribonacci(n int) int {
8: if n < 2 {
9: return n
10: }
11: if n == 2 {
12: return 1
(dlv) c
> main.tribonacci() ./main.go:18 (hits goroutine(1):1 total:1) (PC: 0x49c9b9)
13: }
14:
15: cache := make([]int, n+1)
16: cache[0], cache[1], cache[2] = 0, 1, 1
17: for i := 3; i <= n; i++ {
=> 18: cache[i] = cache[i-1] + cache[i-2] + cache[i-3]
19: }
20: return cache[n]
21: }
22:
23: func main() {
(dlv) p i
3
(dlv) p n
15
...
(dlv) locals
cache = []int len: 16, cap: 16, [...]
i = 5
(dlv) set i = 2
(dlv) locals
cache = []int len: 16, cap: 16, [...]
i = 2
(dlv) clearall main.main
Breakpoint 1 cleared at 0x49cb0a for main.main() ./main.go:23
(dlv) funcs tribonacci
main.tribonacci
(dlv) exit