On 28/01/2025 00:19, Josh Steadmon wrote:
Introduce libgit-sys, a Rust wrapper crate that allows Rust code to call
functions in libgit.a. 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`.
It's great to see some tests. This is looking good, I've left a couple
of small comments below.
+contrib/libgit-sys/partial_symbol_export.o: contrib/libgit-sys/public_symbol_export.o libgit.a reftable/libreftable.a xdiff/lib.a
+ $(LD) -r $^ -o $@
This is a very long line and the ones below are pretty long - perhaps we
could put the list of sources in a variable?
+contrib/libgit-sys/hidden_symbol_export.o: contrib/libgit-sys/partial_symbol_export.o
+ $(OBJCOPY) --localize-hidden $^ $@
+
+contrib/libgit-sys/libgitpub.a: contrib/libgit-sys/hidden_symbol_export.o
+ $(AR) $(ARFLAGS) $@ $^
> [...]
diff --git a/contrib/libgit-sys/public_symbol_export.c b/contrib/libgit-sys/public_symbol_export.c
new file mode 100644
index 0000000000..cd1602206e
--- /dev/null
+++ b/contrib/libgit-sys/public_symbol_export.c
@@ -0,0 +1,22 @@
+/* Shim to publicly export Git symbols. These must be renamed so that the
Style: Multiline comments start with an empty "/*" so this should be
/*
* Shim ...
+ * original symbols can be hidden. Renaming these with a "libgit_" prefix also
+ * avoids conflicts with other libraries such as libgit2.
+ */
Best Wishes
Phillip
+#include "git-compat-util.h"
+#include "contrib/libgit-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/libgit-sys/public_symbol_export.h b/contrib/libgit-sys/public_symbol_export.h
new file mode 100644
index 0000000000..a3372f93fa
--- /dev/null
+++ b/contrib/libgit-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/libgit-sys/src/lib.rs b/contrib/libgit-sys/src/lib.rs
new file mode 100644
index 0000000000..d4853f3074
--- /dev/null
+++ b/contrib/libgit-sys/src/lib.rs
@@ -0,0 +1,46 @@
+#[cfg(has_std__ffi__c_char)]
+use std::ffi::c_char;
+
+#[cfg(not(has_std__ffi__c_char))]
+#[allow(non_camel_case_types)]
+pub type c_char = i8;
+
+extern crate libz_sys;
+
+extern "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
+ );
+ }
+}
diff --git a/t/Makefile b/t/Makefile
index daa5fcae86..53ba01c21b 100644
--- a/t/Makefile
+++ b/t/Makefile
@@ -177,3 +177,13 @@ perf:
.PHONY: pre-clean $(T) aggregate-results clean valgrind perf \
check-chainlint clean-chainlint test-chainlint $(UNIT_TESTS)
+
+.PHONY: libgit-sys-test
+libgit-sys-test:
+ $(QUIET)(\
+ cd ../contrib/libgit-sys && \
+ cargo test \
+ )
+ifdef INCLUDE_LIBGIT_RS
+all:: libgit-sys-test
+endif
