# Vim Terminal Debug

###### tags: `Vim`, `gdb`, `C`, `Go`

## Document

[VIM REFERENCE MANUAL - Debugging terminal-debug](https://vimhelp.org/terminal.txt.html#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](#Debug-Procedure)