summaryrefslogtreecommitdiff
path: root/README.md
blob: b683df1d0152c2d434c70a96803f2c9978d8eda8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
rebar
=====

rebar is an Erlang build tool that makes it easy to compile and  
test Erlang applications, port drivers and releases.

rebar is a self-contained Erlang script, so it's easy to distribute or even  
embed directly in a project. Where possible, rebar uses standard Erlang/OTP  
conventions for project structures, thus minimizing the amount of build  
configuration work. rebar also provides dependency management, enabling  
application writers to easily re-use common libraries from a variety of  
locations (git, hg, etc).

Building
--------

Information on building and installing Erlang/OTP can be found
in the `INSTALL.md` document.

### Dependencies

To build rebar you will need a working installation of Erlang R13B03 (or
later).

Should you want to clone the rebar repository, you will also require git.

#### Downloading

Clone the git repository:

    $ git clone git://github.com/basho/rebar.git

#### Building rebar

    $ cd rebar/
    $ ./bootstrap
    Recompile: src/getopt
    ...
    Recompile: src/rebar_utils
    ==> rebar (compile)
    Congratulations! You now have a self-contained script called "rebar" in
    your current working directory. Place this script anywhere in your path
    and you can use rebar to build OTP-compliant apps.


Contributing to rebar
=====================

Coding style
------------

Do not introduce trailing whitespace.

Do not introduce lines longer than 80 characters.

### Indentation

To have consistent indentation we have vi modeline/emacs local variable  
headers in rebar's source files. This works automatically with vi.  
With Emacs you have to declare <code>'erlang-indent-level</code>
set to <code>4</code>  
as a safe local variable value. If not configured Emacs will prompt  
you to save this as part of custom-set-variables:

    '(safe-local-variable-values (quote ((erlang-indent-level . 4))))
You can also tell Emacs to ignore file variables:

    (setq enable-local-variables nil
          enable-local-eval nil)


Writing Commit Messages
-----------------------

Structure your commit message like this:

<pre>
One line summary (less than 50 characters)

Longer description (wrap at 72 characters)
</pre>

### Summary

* Less than 50 characters
* What was changed
* Imperative present tense (fix, add, change)
> Fix bug 123  
> Add 'foobar' command  
> Change default timeout to 123  
* No period

### Description

* Wrap at 72 characters
* Why, explain intention and implementation approach
* Present tense

### Atomicity

* Break up logical changes
* Make whitespace changes separately

Dialyzer and Tidier
-------------------

Before you submit a patch check for discrepancies with
[Dialyzer](http://www.erlang.org/doc/man/dialyzer.html):

<pre>
$ cd rebar/
$ ./bootstrap debug
$ dialyzer ebin -Wunmatched_returns -Werror_handling -Wrace_conditions -Wunderspecs
</pre>

The following discrepancies are known and safe to ignore:
<pre>
rebar_templater.erl:249: The call rebar_templater:consult(
                                Cont1::erl_scan:return_cont(),'eof',
                                Acc::[any()])
                         contains an opaque term as 1st argument when terms
                         of different types are expected in these positions
rebar_utils.erl:144: Call to missing or unexported function escript:foldl/3
rebar_utils.erl:165: The created fun has no local return
</pre>

It is **strongly recommended** to check the code with
[Tidier](http://tidier.softlab.ntua.gr:20000/tidier/getstarted).  
Select all transformation options and enable **automatic**
transformation.  
If Tidier suggests a transformation apply the changes **manually**
to the source code.  
Do not use the code from the tarball (*out.tgz*) as it will have
white-space changes  
applied by Erlang's pretty-printer.