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This initial patch defines build rules and an interface that exposes user agent string getter functions as a proof of concept. This library can be tested with `cargo test`. In later commits, a higher-level library providing a more Rust-friendly interface will be added at `contrib/cgit-rs`. Symbols in cgit-sys can collide with symbols from other libraries such as libgit2. We avoid this by first exposing library symbols in public_symbol_export.[ch]. These symbols are prepended with "libgit_" to avoid collisions and set to visible using a visibility pragma. In build.rs, Rust builds contrib/cgit-rs/cgit-sys/libcgit.a, which also contains libgit.a and other dependent libraries, with -fvisibility=hidden to hide all symbols within those libraries that haven't been exposed with a visibility pragma. Co-authored-by: Kyle Lippincott Co-authored-by: Calvin Wan Co-authored-by: Josh Steadmon Signed-off-by: Calvin Wan Signed-off-by: Kyle Lippincott Signed-off-by: Josh Steadmon --- .gitignore | 1 + Makefile | 13 ++++++ contrib/cgit-rs/cgit-sys/Cargo.lock | 7 ++++ contrib/cgit-rs/cgit-sys/Cargo.toml | 9 +++++ contrib/cgit-rs/cgit-sys/README.md | 15 +++++++ contrib/cgit-rs/cgit-sys/build.rs | 32 +++++++++++++++ .../cgit-rs/cgit-sys/public_symbol_export.c | 20 ++++++++++ .../cgit-rs/cgit-sys/public_symbol_export.h | 8 ++++ contrib/cgit-rs/cgit-sys/src/lib.rs | 40 +++++++++++++++++++ 9 files changed, 145 insertions(+) create mode 100644 contrib/cgit-rs/cgit-sys/Cargo.lock create mode 100644 contrib/cgit-rs/cgit-sys/Cargo.toml create mode 100644 contrib/cgit-rs/cgit-sys/README.md create mode 100644 contrib/cgit-rs/cgit-sys/build.rs create mode 100644 contrib/cgit-rs/cgit-sys/public_symbol_export.c create mode 100644 contrib/cgit-rs/cgit-sys/public_symbol_export.h create mode 100644 contrib/cgit-rs/cgit-sys/src/lib.rs diff --git a/.gitignore b/.gitignore index 8caf3700c2..567cc9888f 100644 --- a/.gitignore +++ b/.gitignore @@ -248,3 +248,4 @@ Release/ /git.VC.db *.dSYM /contrib/buildsystems/out +/contrib/cgit-rs/cgit-sys/target diff --git a/Makefile b/Makefile index 7caeb3c872..db8af99f20 100644 --- a/Makefile +++ b/Makefile @@ -653,6 +653,8 @@ CURL_CONFIG = curl-config GCOV = gcov STRIP = strip SPATCH = spatch +LD = ld +OBJCOPY = objcopy export TCL_PATH TCLTK_PATH @@ -2713,6 +2715,7 @@ OBJECTS += $(XDIFF_OBJS) OBJECTS += $(FUZZ_OBJS) OBJECTS += $(REFTABLE_OBJS) $(REFTABLE_TEST_OBJS) OBJECTS += $(UNIT_TEST_OBJS) +OBJECTS += contrib/cgit-rs/cgit-sys/public_symbol_export.o ifndef NO_CURL OBJECTS += http.o http-walker.o remote-curl.o @@ -3720,6 +3723,7 @@ clean: profile-clean coverage-clean cocciclean $(RM) $(htmldocs).tar.gz $(manpages).tar.gz $(MAKE) -C Documentation/ clean $(RM) Documentation/GIT-EXCLUDED-PROGRAMS + $(RM) -r contrib/cgit-rs/cgit-sys/target ifndef NO_PERL $(RM) -r perl/build/ endif @@ -3865,3 +3869,12 @@ $(UNIT_TEST_PROGS): $(UNIT_TEST_BIN)/%$X: $(UNIT_TEST_DIR)/%.o \ build-unit-tests: $(UNIT_TEST_PROGS) unit-tests: $(UNIT_TEST_PROGS) t/helper/test-tool$X $(MAKE) -C t/ unit-tests + +contrib/cgit-rs/cgit-sys/partial_symbol_export.o: contrib/cgit-rs/cgit-sys/public_symbol_export.o libgit.a reftable/libreftable.a xdiff/lib.a + $(LD) -r $^ -o $@ + +contrib/cgit-rs/cgit-sys/hidden_symbol_export.o: contrib/cgit-rs/cgit-sys/partial_symbol_export.o + $(OBJCOPY) --localize-hidden $^ $@ + +contrib/cgit-rs/cgit-sys/libcgit.a: contrib/cgit-rs/cgit-sys/hidden_symbol_export.o + $(AR) $(ARFLAGS) $@ $^ diff --git a/contrib/cgit-rs/cgit-sys/Cargo.lock b/contrib/cgit-rs/cgit-sys/Cargo.lock new file mode 100644 index 0000000000..419a6d42f2 --- /dev/null +++ b/contrib/cgit-rs/cgit-sys/Cargo.lock @@ -0,0 +1,7 @@ +# This file is automatically @generated by Cargo. +# It is not intended for manual editing. +version = 3 + +[[package]] +name = "cgit-sys" +version = "0.1.0" diff --git a/contrib/cgit-rs/cgit-sys/Cargo.toml b/contrib/cgit-rs/cgit-sys/Cargo.toml new file mode 100644 index 0000000000..e840f04024 --- /dev/null +++ b/contrib/cgit-rs/cgit-sys/Cargo.toml @@ -0,0 +1,9 @@ +[package] +name = "cgit-sys" +version = "0.1.0" +edition = "2021" +build = "build.rs" +links = "git" + +[lib] +path = "src/lib.rs" diff --git a/contrib/cgit-rs/cgit-sys/README.md b/contrib/cgit-rs/cgit-sys/README.md new file mode 100644 index 0000000000..7a59602c30 --- /dev/null +++ b/contrib/cgit-rs/cgit-sys/README.md @@ -0,0 +1,15 @@ +# cgit-info + +A small hacky proof-of-concept showing how to provide a Rust FFI for the Git +library. + +## Building + +`cargo build` automatically builds and picks up on changes made to both +the Rust wrapper and git.git code so there is no need to run `make` +beforehand. + +## Running + +Assuming you don't make any changes to the Git source, you can just work from +`contrib/cgit-rs` and use `cargo build` or `cargo run` as usual. diff --git a/contrib/cgit-rs/cgit-sys/build.rs b/contrib/cgit-rs/cgit-sys/build.rs new file mode 100644 index 0000000000..e29d703870 --- /dev/null +++ b/contrib/cgit-rs/cgit-sys/build.rs @@ -0,0 +1,32 @@ +use std::env; +use std::path::PathBuf; + +pub fn main() -> std::io::Result<()> { + let crate_root = PathBuf::from(env::var_os("CARGO_MANIFEST_DIR").unwrap()); + let git_root = crate_root.join("../../.."); + let dst = PathBuf::from(env::var_os("OUT_DIR").unwrap()); + + let make_output = std::process::Command::new("make") + .env_remove("PROFILE") + .current_dir(git_root.clone()) + .args([ + "CFLAGS=-fvisibility=hidden", + "contrib/cgit-rs/cgit-sys/libcgit.a", + ]) + .output() + .expect("Make failed to run"); + if !make_output.status.success() { + panic!( + "Make failed:\n stdout = {}\n stderr = {}\n", + String::from_utf8(make_output.stdout).unwrap(), + String::from_utf8(make_output.stderr).unwrap() + ); + } + std::fs::copy(crate_root.join("libcgit.a"), dst.join("libcgit.a"))?; + println!("cargo::rustc-link-search=native={}", dst.display()); + println!("cargo::rustc-link-lib=cgit"); + println!("cargo::rustc-link-lib=z"); + println!("cargo::rerun-if-changed={}", git_root.display()); + + Ok(()) +} diff --git a/contrib/cgit-rs/cgit-sys/public_symbol_export.c b/contrib/cgit-rs/cgit-sys/public_symbol_export.c new file mode 100644 index 0000000000..deef4488c0 --- /dev/null +++ b/contrib/cgit-rs/cgit-sys/public_symbol_export.c @@ -0,0 +1,20 @@ +// Shim to publicly export Git symbols. These must be renamed so that the +// original symbols can be hidden. Renaming these with a "libgit_" prefix also +// avoid conflicts with other libraries such as libgit2. + +#include "contrib/cgit-rs/cgit-sys/public_symbol_export.h" +#include "version.h" + +#pragma GCC visibility push(default) + +const char *libgit_user_agent(void) +{ + return git_user_agent(); +} + +const char *libgit_user_agent_sanitized(void) +{ + return git_user_agent_sanitized(); +} + +#pragma GCC visibility pop diff --git a/contrib/cgit-rs/cgit-sys/public_symbol_export.h b/contrib/cgit-rs/cgit-sys/public_symbol_export.h new file mode 100644 index 0000000000..a3372f93fa --- /dev/null +++ b/contrib/cgit-rs/cgit-sys/public_symbol_export.h @@ -0,0 +1,8 @@ +#ifndef PUBLIC_SYMBOL_EXPORT_H +#define PUBLIC_SYMBOL_EXPORT_H + +const char *libgit_user_agent(void); + +const char *libgit_user_agent_sanitized(void); + +#endif /* PUBLIC_SYMBOL_EXPORT_H */ diff --git a/contrib/cgit-rs/cgit-sys/src/lib.rs b/contrib/cgit-rs/cgit-sys/src/lib.rs new file mode 100644 index 0000000000..bc33c6c498 --- /dev/null +++ b/contrib/cgit-rs/cgit-sys/src/lib.rs @@ -0,0 +1,40 @@ +use std::ffi::c_char; + +extern "C" { + // From version.c + pub fn libgit_user_agent() -> *const c_char; + pub fn libgit_user_agent_sanitized() -> *const c_char; +} + +#[cfg(test)] +mod tests { + use std::ffi::CStr; + + use super::*; + + #[test] + fn user_agent_starts_with_git() { + let c_str = unsafe { CStr::from_ptr(libgit_user_agent()) }; + let agent = c_str + .to_str() + .expect("User agent contains invalid UTF-8 data"); + assert!( + agent.starts_with("git/"), + r#"Expected user agent to start with "git/", got: {}"#, + agent + ); + } + + #[test] + fn sanitized_user_agent_starts_with_git() { + let c_str = unsafe { CStr::from_ptr(libgit_user_agent_sanitized()) }; + let agent = c_str + .to_str() + .expect("Sanitized user agent contains invalid UTF-8 data"); + assert!( + agent.starts_with("git/"), + r#"Expected user agent to start with "git/", got: {}"#, + agent + ); + } +}