Vim Terminal Debug

tags: Vim, gdb, C, Go

Document

VIM REFERENCE MANUAL - Debugging terminal-debug

Debug C Application

Have a C Code Example

C source:

$ cat main.c 
#include <stdio.h>

int main(void) {
	int a = 0, b = 0;

	a = 1;
	b = 2;

	printf("%d + %d = %d\n", a, b, a+b);
}

Makefile:

$ cat Makefile 
CC=cc
SOURCE=main.c
BINARY=test

all:
	${CC} ${SOURCE} -g -o ${BINARY}

clean:
	rm ${BINARY}

Debug Procedure

1. make

2. vim main.c

3. Vim's command mode :packadd termdebug to load debug plugin, which has been included in Vim.

4. Start debug test application with commad :Termdebug test. It will split the terminal into 3 parts:

   • gdb window
   • program window
   • source window
     

5. The gdb window is the gdb. So, just use gdb as usual in the window.

6. Ctrl + w twice can jump between the windows.

7. Jump to the source window. Then, can go to the line and add a break point at the line by :Break. Finally, jump back to the gdb window to run the program. It will stop at the line.

Debug Go Application

Go application can be debugged with GDB as well.
https://go.dev/doc/gdb

I try to make it go with debug symbols directly.

$ go build -gcflags --help
# example/hello
usage: compile [options] file.go...
  -% int
    	debug non-static initializers
...
  -N	disable optimizations
...
  -l	disable inlining
...

To have better debug information, add -N -l into build's C flags, which disables optimizations and inlining.

Have a Go Code Example

Go source:

$ cat hello.go 
package main

import (
    "fmt"
)

func main() {
    a := 1
    b := 2

    fmt.Printf("%d + %d = %d\n", a, b, a+b)
}

$ cat go.mod 
module example/hello

go 1.19

Makefile:

$ cat Makefile 
GO=go
SOURCE=hello.go
BINARY=hello
CFLAGS="-N -l"

all:
	${GO} build -gcflags ${CFLAGS} -o ${BINARY} ${SOURCE}

clean:
	rm ${BINARY}

Debug Procedure

Same as Debug C Application's Debug Procedure