doc: improve developer documentation (#15)

CONTRIBUTING

@@ -25,6 +25,13 @@ This allow us to review and pull in new features or improvements individually.
 
 All pull requests SHOULD adhere to the [Conventional Commits specification](https://conventionalcommits.org/)
 
+## A Plea for Lean Software
+
+We value concise and readable code. Please, avoid large pull requests, unnecessary dependencies and 
+complicated abstractions. Some good examples of lean software are [tinygrad](https://github.com/tinygrad/tinygrad)
+or [llm.c](https://github.com/karpathy/llm.c) from which we take a lot of inspiration. You can also refer
+to this blog post to learn more: https://berthub.eu/articles/posts/a-2024-plea-for-lean-software/.
+
 ## License
 
 You must agree that your patch will be licensed under the Conventional Commit License, and when we change the license we will assume that you agreed with the change unless you object to the changes in time.

README.md

@@ -30,3 +30,9 @@ various binary analysis tasks.
 - **One-Size-Fits-All Solution:** TIR does not aim to be a one-size-fits-all
   tool for all binary analysis needs, but rather a modular framework that can
   be extended and customized as needed.
+
+## Building from source
+
+TIR is a Rust project, and can be built with `cargo`, just like any other Rust
+project. If you want to contribute to this repository, refer to our
+[Developer guide](docs/dev_guide.md) and [Contribution guide](./CONTRIBUTING).

docs/dev_guide.md

@@ -0,0 +1,73 @@
+# Developer Guide
+
+## Setting up Rust
+
+The easiest way to set up Rust toolchain is with https://rustup.rs/.
+By default, only stable toolchain is installed. Active Rust development
+also requires nightly toolchain:
+
+```sh
+rustup install nightly
+```
+
+## Building and testing
+
+Build is done with `cargo` tool, just like any other Rust project.
+
+```sh
+cargo build
+# or
+cargo build --release
+```
+
+Tests can also be done with `cargo test` command, but a much better way is to
+use `nextest` tool. To install it, do `cargo install cargo-nextest`. Then run
+tests with the following command:
+
+```sh
+cargo nextest r
+```
+
+`nextest` is much faster than the default test runner.
+
+### Running fuzz tests
+
+We also have fuzzing set up for each user input parser, like a disassembler
+or an IR parser. These tests also require an external tool, that can be
+installed with a command like `cargo install cargo-fuzz`. The usage is very
+simple:
+
+```sh
+# List tests
+cargo fuzz list
+# Run specific test
+cargo +nightly fuzz run fuzz_riscv_disassembler -- -max_total_time=60 -max_len=16384
+```
+
+### Collecting coverage info
+
+
+**WARNING!!!** Coverage tool creates a lot of temp files in your working
+directory. You better commit all your changes to be able to use git to
+clean up.
+
+Install dependencies:
+
+```sh
+rustup component add llvm-tools-preview
+cargo install grcov
+```
+
+Run tests with special flags:
+
+```sh
+CARGO_INCREMENTAL=0 RUSTFLAGS='-Cinstrument-coverage' LLVM_PROFILE_FILE='cargo-test-%p-%m.profraw' cargo test
+grcov . --binary-path target/debug/ -s . -t coveralls+ --branch --llvm \
+    --ignore '../*' --ignore "/*" --ignore 'macros/*' --ignore 'fuzz/*' \
+    --ignore '**/tests/**' -o target/coverage/html
+```
+
+Open `target/coverage/html/index.html` to see the report.
+
+Also `main` branch reports are available at
+https://coveralls.io/github/perf-toolbox/tir.