Pre-commit hooks (#2241)

* add pre-commit hook.
example of hook with fmt check.

* Add `CONTRIBUTING.md`.

.pre-commit-config.yaml

@@ -0,0 +1,9 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+repos:
+-   repo: local
+    hooks:
+      - id: fmt
+        name: fmt
+        entry: scripts/fmt_all.sh check
+        language: script

CONTRIBUTING.md

@@ -0,0 +1,18 @@
+# How to Contribute to LibAFL
+
+For bugs, feel free to open issues or contact us directly. Thank you for your support. <3
+
+## Pull Request guideline
+
+Even though we will gladly assist you in finishing up your PR, try to
+- keep all the crates compiling with *stable* rust (hide the eventual non-stable code under [`cfg`s](https://github.com/AFLplusplus/LibAFL/blob/main/libafl/build.rs#L26))
+- run `cargo +nightly fmt` on your code before pushing
+- check the output of `cargo clippy --all` or `./clippy.sh`
+- run `cargo build --no-default-features` to check for `no_std` compatibility (and possibly add `#[cfg(feature = "std")]`) to hide parts of your code.
+
+Some of the parts in this list may be hard, don't be afraid to open a PR if you cannot fix them by yourself, so we can help.
+
+### Pre-commit hooks
+
+Some of these checks can be performed automatically during commit using [pre-commit](https://pre-commit.com/).
+Once the package is installed, simply run `pre-commit install` to enable the hooks, the checks will run automatically before the commit becomes effective.

README.md

@@ -116,15 +116,7 @@ The best-tested fuzzer is [`./fuzzers/libfuzzer_libpng`](./fuzzers/libfuzzer_lib
 
 ## Contributing
 
-For bugs, feel free to open issues or contact us directly. Thank you for your support. <3
-
-Even though we will gladly assist you in finishing up your PR, try to
-- keep all the crates compiling with *stable* rust (hide the eventual non-stable code under [`cfg`s](https://github.com/AFLplusplus/LibAFL/blob/main/libafl/build.rs#L26))
-- run `cargo +nightly fmt` on your code before pushing
-- check the output of `cargo clippy --all` or `./clippy.sh`
-- run `cargo build --no-default-features` to check for `no_std` compatibility (and possibly add `#[cfg(feature = "std")]`) to hide parts of your code.
-
-Some of the parts in this list may be hard, don't be afraid to open a PR if you cannot fix them by yourself, so we can help.
+Please check out [CONTRIBUTING.md](CONTRIBUTING.md) for the contributing guideline.
 
 ## Cite
 

scripts/fmt_all.sh

@@ -10,6 +10,10 @@ if ! command -v parallel > /dev/null; then
     exit 1
 fi
 
+if [ "$1" = "check" ]; then
+  CHECK=1
+fi
+
 # Find main rust crates
 CRATES_TO_FMT=$(find "$LIBAFL_DIR" -type d \( -path "*/fuzzers/*" -o -path "*/target/*" -o -path "*/utils/noaslr" -o -path "*/utils/gdb_qemu" -o -path "*/docs/listings/baby_fuzzer/listing-*" \) -prune \
   -o -name "Cargo.toml" -print \
@@ -21,15 +25,30 @@ CRATES_TO_FMT+=$(find "$LIBAFL_DIR/fuzzers" "$LIBAFL_DIR/fuzzers/backtrace_baby_
 echo "Welcome to the happy fmt script. :)"
 
 if [ "$CHECK" ]; then
+  echo "Running fmt in check mode."
   CARGO_FLAGS="--check"
   CLANG_FLAGS="--dry-run"
 fi
 
 echo "[*] Formatting Rust crates..."
-echo "$CRATES_TO_FMT" | parallel "echo '[*] Running fmt for {}'; cargo +nightly fmt $CARGO_FLAGS --manifest-path {}"
+if ! echo "$CRATES_TO_FMT" | parallel --halt-on-error 1 "echo '[*] Running fmt for {}'; cargo +nightly fmt $CARGO_FLAGS --manifest-path {}"
+then
+  echo "Rust format failed."
+  exit 1
+fi
 
+if command -v clang-format-18 > /dev/null; then
   echo "[*] Formatting C(pp) files"
-# shellcheck disable=SC2046
-clang-format-18 "$CLANG_FLAGS" -i --style=file $(find . -type f \( -name '*.cpp' -o -iname '*.hpp' -o -name '*.cc' -o -name '*.cxx' -o -name '*.cc' -o -name '*.c' -o -name '*.h' \) | grep -v '/target/' | grep -v 'libpng-1\.6\.37' | grep -v 'stb_image\.h' | grep -v 'dlmalloc\.c' | grep -v 'QEMU-Nyx')
+
+  C_FILES=$(find "$LIBAFL_DIR" -type f \( -name '*.cpp' -o -iname '*.hpp' -o -name '*.cc' -o -name '*.cxx' -o -name '*.cc' -o -name '*.c' -o -name '*.h' \) | grep -v '/target/' | grep -v 'libpng-1\.6\.37' | grep -v 'stb_image\.h' | grep -v 'dlmalloc\.c' | grep -v 'QEMU-Nyx')
+  if ! clang-format-18 "$CLANG_FLAGS" -i --style=file "$C_FILES"
+  then
+    echo "C(pp) format failed."
+    exit 1
+  fi
+
+else
+  echo "Warning: clang-format-18 not found. C(pp) files formatting skipped."
+fi
 
 echo "[*] Done :)"