git · ezekielnewren · May 16, 2025 · May 28, 2025 · May 16, 2025 · May 16, 2025
diff --git a/Makefile b/Makefile
@@ -919,6 +919,11 @@ TEST_SHELL_PATH = $(SHELL_PATH)
 
 LIB_FILE = libgit.a
 XDIFF_LIB = xdiff/lib.a
+ifeq ($(DEBUG), 1)
+RUST_LIB = rust/target/debug/libxdiff.a
+else
+RUST_LIB = rust/target/release/libxdiff.a
+endif
 REFTABLE_LIB = reftable/libreftable.a
 
 GENERATED_H += command-list.h
@@ -1392,6 +1397,8 @@ UNIT_TEST_OBJS += $(UNIT_TEST_DIR)/lib-reftable.o
 GITLIBS = common-main.o $(LIB_FILE) $(XDIFF_LIB) $(REFTABLE_LIB) $(LIB_FILE)
 EXTLIBS =
 
+GITLIBS += $(RUST_LIB)
+
 GIT_USER_AGENT = git/$(GIT_VERSION)
 
 ifeq ($(wildcard sha1collisiondetection/lib/sha1.h),sha1collisiondetection/lib/sha1.h)
@@ -2925,6 +2932,14 @@ $(LIB_FILE): $(LIB_OBJS)
 $(XDIFF_LIB): $(XDIFF_OBJS)
 	$(QUIET_AR)$(RM) $@ && $(AR) $(ARFLAGS) $@ $^
 
+.PHONY: $(RUST_LIB)
+$(RUST_LIB):
+ifeq ($(DEBUG), 1)
+	cd rust && RUSTFLAGS="-Aunused_imports -Adead_code" cargo build --verbose
+else
+	cd rust && RUSTFLAGS="-Aunused_imports -Adead_code" cargo build --verbose --release
+endif
+
 $(REFTABLE_LIB): $(REFTABLE_OBJS)
 	$(QUIET_AR)$(RM) $@ && $(AR) $(ARFLAGS) $@ $^
 
@@ -3756,7 +3771,10 @@ cocciclean:
 	$(RM) -r .build/contrib/coccinelle
 	$(RM) contrib/coccinelle/*.cocci.patch
 
-clean: profile-clean coverage-clean cocciclean
+rustclean:
+	cd rust && cargo clean
+
+clean: profile-clean coverage-clean cocciclean rustclean
 	$(RM) -r .build $(UNIT_TEST_BIN)
 	$(RM) GIT-TEST-SUITES
 	$(RM) po/git.pot po/git-core.pot

diff --git a/ci/install-dependencies.sh b/ci/install-dependencies.sh
@@ -165,4 +165,18 @@ else
 	echo >&2 "::warning:: JGit wasn't installed, see above for clues why"
 fi
 
+if type rustc >/dev/null 2>&1
+then
+	echo "$(tput setaf6)Rust & Cargo Versions$(tput sgr0)"
+	rustc --version
+	cargo --version
+else
+	echo >&2 "WARNING: Rust wasn't installed, see above for clues why"
+fi
+
+curl https://sh.rustup.rs -sSf | sh -s -- -y --profile default --default-toolchain 1.87.0
+export PATH="$HOME/.cargo/bin:$PATH"
+"$HOME"/.cargo/bin/cargo --version
+echo "cargo installed at: $(command -v cargo)"
+
 end_group "Install dependencies"
diff --git a/git-compat-util.h b/git-compat-util.h
@@ -196,6 +196,23 @@ static inline int is_xplatform_dir_sep(int c)
 #include "compat/msvc.h"
 #endif
 
+/* rust types */
+typedef uint8_t   u8;
+typedef uint16_t  u16;
+typedef uint32_t  u32;
+typedef uint64_t  u64;
+
+typedef int8_t    i8;
+typedef int16_t   i16;
+typedef int32_t   i32;
+typedef int64_t   i64;
+
+typedef float     f32;
+typedef double    f64;
+
+typedef size_t    usize;
+typedef ptrdiff_t isize;
+
 /* used on Mac OS X */
 #ifdef PRECOMPOSE_UNICODE
 #include "compat/precompose_utf8.h"

diff --git a/meson.build b/meson.build
@@ -267,6 +267,36 @@ version_gen_environment.set('GIT_DATE', get_option('build_date'))
 version_gen_environment.set('GIT_USER_AGENT', get_option('user_agent'))
 version_gen_environment.set('GIT_VERSION', get_option('version'))
 
+if get_option('optimization') in ['2', '3', 's', 'z']
+  rust_target = 'release'
+  rust_args = ['--release']
+  rustflags = '-Aunused_imports -Adead_code'
+else
+  rust_target = 'debug'
+  rust_args = []
+  rustflags = '-Aunused_imports -Adead_code -C debuginfo=2 -C opt-level=1 -C force-frame-pointers=yes'
+endif
+
+
+rust_leaf = custom_target('rust_leaf',
+  output: 'libxdiff.a',
+  build_by_default: true,
+  build_always_stale: true,
+  command: ['cargo', 'build',
+            '--manifest-path', meson.project_source_root() / 'rust/Cargo.toml'
+  ] + rust_args,
+  env: {
+    'RUSTFLAGS': rustflags,
+  },
+  install: false,
+)
+
+rust_xdiff_dep = declare_dependency(
+  link_args: ['-L' + meson.project_source_root() / 'rust/target' / rust_target, '-lxdiff'],
+#  include_directories: include_directories('xdiff/include'),  # Adjust if you expose headers
+)
+
+
 compiler = meson.get_compiler('c')
 
 libgit_sources = [
@@ -1677,6 +1707,8 @@ version_def_h = custom_target(
 )
 libgit_sources += version_def_h
 
+libgit_dependencies += rust_xdiff_dep
+
 libgit = declare_dependency(
   link_with: static_library('git',
     sources: libgit_sources,

diff --git a/rust/Cargo.lock b/rust/Cargo.lock
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
@@ -0,0 +1,6 @@
+[workspace]
+members = [
+    "xdiff",
+    "interop",
+]
+resolver = "2"
diff --git a/rust/interop/Cargo.toml b/rust/interop/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "interop"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+name = "interop"
+path = "src/lib.rs"
+## staticlib to generate xdiff.a for use by gcc
+## cdylib (optional) to generate xdiff.so for use by gcc
+## rlib is required by the rust unit tests
+crate-type = ["staticlib", "rlib"]
+
+[dependencies]
diff --git a/rust/interop/src/lib.rs b/rust/interop/src/lib.rs
diff --git a/rust/xdiff/Cargo.toml b/rust/xdiff/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "xdiff"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+name = "xdiff"
+path = "src/lib.rs"
+## staticlib to generate xdiff.a for use by gcc
+## cdylib (optional) to generate xdiff.so for use by gcc
+## rlib is required by the rust unit tests
+crate-type = ["staticlib", "rlib"]
+
+[dependencies]
+interop = { path = "../interop" }
+xxhash-rust = { version = "0.8.15", features = ["xxh3"] }
diff --git a/rust/xdiff/src/lib.rs b/rust/xdiff/src/lib.rs
@@ -0,0 +1,7 @@
+
+
+#[no_mangle]
+unsafe extern "C" fn xxh3_64(ptr: *const u8, size: usize) -> u64 {
+    let slice = std::slice::from_raw_parts(ptr, size);
+    xxhash_rust::xxh3::xxh3_64(slice)
+}
diff --git a/xdiff/xdiffi.c b/xdiff/xdiffi.c
@@ -418,7 +418,7 @@ static int get_indent(xrecord_t *rec)
 	long i;
 	int ret = 0;
 
-	for (i = 0; i < rec->size; i++) {
+	for (i = 0; i < (long) rec->size; i++) {
 		char c = rec->ptr[i];
 
 		if (!XDL_ISSPACE(c))
@@ -1005,11 +1005,11 @@ static void xdl_mark_ignorable_lines(xdchange_t *xscr, xdfenv_t *xe, long flags)
 
 		rec = &xe->xdf1.recs[xch->i1];
 		for (i = 0; i < xch->chg1 && ignore; i++)
-			ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
+			ignore = xdl_blankline((const char*) rec[i]->ptr, rec[i]->size, flags);
 
 		rec = &xe->xdf2.recs[xch->i2];
 		for (i = 0; i < xch->chg2 && ignore; i++)
-			ignore = xdl_blankline(rec[i]->ptr, rec[i]->size, flags);
+			ignore = xdl_blankline((const char*)rec[i]->ptr, rec[i]->size, flags);
 
 		xch->ignore = ignore;
 	}
@@ -1020,7 +1020,7 @@ static int record_matches_regex(xrecord_t *rec, xpparam_t const *xpp) {
 	size_t i;
 
 	for (i = 0; i < xpp->ignore_regex_nr; i++)
-		if (!regexec_buf(xpp->ignore_regex[i], rec->ptr, rec->size, 1,
+		if (!regexec_buf(xpp->ignore_regex[i], (const char*) rec->ptr, rec->size, 1,
 				 &regmatch, 0))
 			return 1;
 

diff --git a/xdiff/xemit.c b/xdiff/xemit.c
@@ -24,7 +24,7 @@
 
 static long xdl_get_rec(xdfile_t *xdf, long ri, char const **rec) {
 
-	*rec = xdf->recs[ri]->ptr;
+	*rec = (char const*) xdf->recs[ri]->ptr;
 
 	return xdf->recs[ri]->size;
 }

diff --git a/xdiff/xmerge.c b/xdiff/xmerge.c
@@ -101,8 +101,8 @@ static int xdl_merge_cmp_lines(xdfenv_t *xe1, int i1, xdfenv_t *xe2, int i2,
 	xrecord_t **rec2 = xe2->xdf2.recs + i2;
 
 	for (i = 0; i < line_count; i++) {
-		int result = xdl_recmatch(rec1[i]->ptr, rec1[i]->size,
-			rec2[i]->ptr, rec2[i]->size, flags);
+		int result = xdl_recmatch((const char*) rec1[i]->ptr, rec1[i]->size,
+			(const char*) rec2[i]->ptr, rec2[i]->size, flags);
 		if (!result)
 			return -1;
 	}
@@ -324,8 +324,8 @@ static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
 
 static int recmatch(xrecord_t *rec1, xrecord_t *rec2, unsigned long flags)
 {
-	return xdl_recmatch(rec1->ptr, rec1->size,
-			    rec2->ptr, rec2->size, flags);
+	return xdl_recmatch((char const*) rec1->ptr, rec1->size,
+			    (char const*) rec2->ptr, rec2->size, flags);
 }
 
 /*
@@ -383,10 +383,10 @@ static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
 		 */
 		t1.ptr = (char *)xe1->xdf2.recs[m->i1]->ptr;
 		t1.size = xe1->xdf2.recs[m->i1 + m->chg1 - 1]->ptr
-			+ xe1->xdf2.recs[m->i1 + m->chg1 - 1]->size - t1.ptr;
+			+ xe1->xdf2.recs[m->i1 + m->chg1 - 1]->size - (u8 const*) t1.ptr;
 		t2.ptr = (char *)xe2->xdf2.recs[m->i2]->ptr;
 		t2.size = xe2->xdf2.recs[m->i2 + m->chg2 - 1]->ptr
-			+ xe2->xdf2.recs[m->i2 + m->chg2 - 1]->size - t2.ptr;
+			+ xe2->xdf2.recs[m->i2 + m->chg2 - 1]->size - (u8 const*) t2.ptr;
 		if (xdl_do_diff(&t1, &t2, xpp, &xe) < 0)
 			return -1;
 		if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
@@ -440,7 +440,7 @@ static int line_contains_alnum(const char *ptr, long size)
 static int lines_contain_alnum(xdfenv_t *xe, int i, int chg)
 {
 	for (; chg; chg--, i++)
-		if (line_contains_alnum(xe->xdf2.recs[i]->ptr,
+		if (line_contains_alnum((char const*) xe->xdf2.recs[i]->ptr,
 				xe->xdf2.recs[i]->size))
 			return 1;
 	return 0;

diff --git a/xdiff/xpatience.c b/xdiff/xpatience.c
@@ -121,7 +121,7 @@ static void insert_record(xpparam_t const *xpp, int line, struct hashmap *map,
 		return;
 	map->entries[index].line1 = line;
 	map->entries[index].hash = record->ha;
-	map->entries[index].anchor = is_anchor(xpp, map->env->xdf1.recs[line - 1]->ptr);
+	map->entries[index].anchor = is_anchor(xpp, (const char*) map->env->xdf1.recs[line - 1]->ptr);
 	if (!map->first)
 		map->first = map->entries + index;
 	if (map->last) {