# xds-gdb: wrapper on gdb for XDS

`xds-gdb` is a wrapper on gdb debugger for X(cross) Development System.

This tool allows you to debug an application built with an xds-server without
the need to install gdb or any cross tool.

Two debugging models are supported:

1. native debugging

1. XDS remote debugging requiring an XDS agent/server setup. That allows you to easily cross debug your application.

 By default XDS debug model is used and you need to define `XDS_NATIVE_GDB`
variable to use native gdb debug mode instead.

> **SEE ALSO**: [xds-agent](https://github.com/iotbzh/xds-agent), a local agent
used to interface xds-server.
> **SEE ALSO**: [xds-server](https://github.com/iotbzh/xds-server), a REST API server
used to remotely cross build applications.
> **SEE ALSO**: [xds-cli](https://github.com/iotbzh/xds-cli), XDS command line tool.

## Configuration

 `xds-gdb` configuration is defined by variables (see listed below).
 These variables may be set using :

- environment variables (inherited),
- or a config file set with `XDS_CONFIG` environment variable, for example:
  `XDS_CONFIG=/tmp/my_xds_gdb_config.env xds-gdb`
- or by setting variables within a gdb ini file (see details below),
- or a "user" config file located in following directory (first found is taken):
  1. $(CURRENT_DIRECTORY)/.xds-gdb.env
  1. $(CURRENT_DIRECTORY)/../xds-gdb.env
  1. $(CURRENT_DIRECTORY)/target/xds-gdb.env
  1. $(HOME)/.config/xds/xds-gdb.env

### Configuration Variables

 `XDS_CONFIG` :
 Config file defining `XDS_xxx` configuration variables. Variables of this file
 will overwrite inherited environment variables. Variables definition may be
 prefixed or not by "export" keyword.
 Here is an example of config file

```bash
cat $HOME/myProject/xds-gdb.env

export XDS_AGENT_URL=http://localhost:8800
export XDS_PROJECT_ID=4021617e-ced0-11e7-acd2-3c970e49ad9b
export XDS_SDK_ID=c226821b-b5c0-386d-94fe-19f807946d03
```

`XDS_LOGLEVEL`

Set logging level (supported levels: panic, fatal, error, warn, info, debug)

`XDS_LOGFILE`

Set logging file, default `/tmp/xds-gdb.log`.

`XDS_NATIVE_GDB`

Use native gdb mode instead of XDS mode.

`XDS_PROJECT_ID`  *(mandatory in XDS mode)*

Project ID you want to build

`XDS_RPATH`

Relative path into project

`XDS_SDK_ID`   *(mandatory in XDS mode)*

Cross Sdk ID to use to build project

`XDS_AGENT_URL`

Local XDS agent url (default `http://localhost:8800`)

### Configuration variables set within gdb init command file

Above `XDS_xxx` variables may also be defined within gdb init command file
(see --command or -x option of genuine Gdb).
You must respect the following syntax: commented line including `:XDS-ENV:` tag

Example of gdb init file where we define project and sdk ID:

```bash
     # :XDS-ENV: XDS_PROJECT_ID=4021617e-ced0-11e7-acd2-3c970e49ad9b
     # :XDS-ENV: XDS_SDK_ID=c226821b-b5c0-386d-94fe-19f807946d03
```

## How to build xds-gdb from scratch

### Prerequisites

 You must install and setup [Go](https://golang.org/doc/install) version 1.8.1 or
 higher to compile this tool.

### Building

Clone this repo into your `$GOPATH/src/github.com/iotbzh` and use delivered Makefile:

```bash
 export GOPATH=$(realpath ~/workspace_go)
 mkdir -p $GOPATH/src/github.com/iotbzh
 cd $GOPATH/src/github.com/iotbzh
 git clone https://github.com/iotbzh/xds-gdb.git
 cd xds-gdb
 make
```

## Debug

Visual Studio Code launcher settings can be found into `.vscode/launch.json`.