hohn/codeql
1
0
Fork 0
mirror of https://github.com/github/codeql.git synced 2025-12-16 16:53:25 +01:00
Code Issues Packages Projects Releases Wiki Activity

Python: CG trace: Updated README

Browse Source
This commit is contained in:
Rasmus Wriedt Larsen
2020-07-24 19:35:06 +02:00
parent ecafc760e8
commit bb80635dc3
1 changed files with 29 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

35
python/tools/recorded-call-graph-metrics/README.md
View File

@@ -4,18 +4,28 @@ also known as _call graph tracing_.
Execute a python program and for each call being made, record the call and callee. This allows us to compare call graph resolution from static analysis with actual data -- that is, can we statically determine the target of each actual call correctly.
## How do I give it a spin?
Using the call graph tracer does incur heave toll on the performance. Expect 10x longer to execute program.
After following setup instructions below, you should be able to reproduce the example trace by running
Number of calls recorded vary a little from run to run. I have not been able to pinpoint why.
```
cg-trace --xml example/simple.xml example/simple.py
## Running against real projects
Currently it's possible to gather metrics from traced runs against two projects (defined in [projects.json](./projects.json)): `youtube-dl` and `wcwidth`.
To run against all projects, use
```bash
$ ./helper.sh all $(./helper.sh projects)
```
You can also run traces for all tests and build a database by running `tests/create-test-db.sh`. Then run the queries inside the `ql/` directory.
To view the results, use
```
$ head -n 100 projects/*/Metrics.txt
```
## Local development
## Setup
### Setup
1. Ensure you have at least Python 3.7
@@ -47,9 +57,22 @@ You can also run traces for all tests and build a database by running `tests/cre
6. Enjoy writing code, and being able to run `cg-trace` on your command line :tada:
### Using it
After following setup instructions above, you should be able to reproduce the example trace by running
```
cg-trace --xml example/simple.xml example/simple.py
```
You can also run traces for all tests and build a database by running `tests/create-test-db.sh`. Then run the queries inside the `ql/` directory.
## Tracing Limitations
### Multi-threading
Should be possible by using [`threading.setprofile`](https://docs.python.org/3.8/library/threading.html#threading.setprofile), but that hasn't been done yet.
### Code that uses `sys.setprofile`
Since that is our mechanism for recording calls, any code that uses `sys.setprofile` will not work together with the call-graph tracer.