blob: 0d6f14bd9b3a78c7a08402b35313de3e41740b2b (
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
|
# README
The `count-deps` executable is used in the test-suite to detect when
the number of dependencies of certain modules change ([this blog
post](https://blog.shaynefletcher.org/2020/10/ghc-lib-parser-module-count.html)
gives one example of where and why this can be useful).
More generally it's useful for obtaining insight into a modules'
dependency graph. As used in the tests it produces (1) a count of a
modules' dependencies together with the list of depended upon modules
. However, it can also (2), print a modules' dependency graph in dot
language syntax suitable for rendering with "graphviz" (open source
graph visualization software).
## Installing graphviz
To render graphs generated by `count-deps`, first visit [the graphviz
downloads page](https://graphviz.org/download/) to download and
install graphviz on your system.
## `count-deps` usage examples:
- `make`:
1. ``inplace/bin/count-deps `inplace/bin/ghc-stage2 --print-libdir` "GHC.Parser"``
2. ``inplace/bin/count-deps `inplace/bin/ghc-stage2 --print-libdir` "GHC.Parser" --dot``
- `hadrian`:
1. ``_build/stage1/bin/count-deps `_build/stage1/bin/ghc --print-libdir` "GHC.Parser"``
2. ``_build/stage1/bin/count-deps `_build/stage1/bin/ghc --print-libdir` "GHC.Parser" --dot``
## Rendering dependency graphs
To render a graph obtained using a type 2 command:
- Copy the output to a file ('`deps.dot`' say)
- Render it with a command like (preprocess with `tred` to remove
edges implied by transitivity)
```bash
tred deps.dot > deps-tred.dot&& dot -Tpdf -o deps.pdf deps-tred.dot
```
|
