xdiff: renamed third-party xdiff functions

Summary:
Renamed xdiff functions to avoid linking issues when using both libgit2-sys and xdiff.

When using repo_import tool (https://fburl.com/diffusion/8p6fhjt2) we have libgit2-sys dependency for importing git repos. However, when we derive blame data types, we need to use xdiff functionalities (from_no_parents: https://fburl.com/diffusion/pitukmyo -> diff_hunks: https://fburl.com/diffusion/9f8caan9 -> xdl_diff: https://fburl.com/diffusion/260x66hf). Both libgit2 and eden/scm have vendored versions of xdiff library. Therefore, libgit2-sys and eden/scm share functions with the same signatures, but have different behaviours and when we tried to derive blame, it used libgit2-sys's xdl_diff instead of eden's. This resulted in getting segfaults (https://fburl.com/paste/04gwalpo).
Note: repo_import is the first tool that has tried to import both and the first to run into this issue.

Reviewed By: StanislavGlebik

Differential Revision: D22432330

fbshipit-source-id: f2b965f3926a2dc45de1bf20e41dad70ca09cdfd

eden/scm/contrib/xdiff/xdiff.c

@@ -70,7 +70,7 @@ int main(int argc, char const *argv[])
 	    0, /* priv */
 	};
 
-	xdl_diff(&a, &b, &xpp, &xecfg, &ecb);
+	xdl_diff_vendored(&a, &b, &xpp, &xecfg, &ecb);
 
 	free(a.ptr);
 	free(b.ptr);

eden/scm/edenscm/mercurial/cext/xdiff.c

@@ -52,7 +52,7 @@ static PyObject* blocks(PyObject* self, PyObject* args) {
       rl, /* priv */
   };
 
-  if (xdl_diff(&a, &b, &xpp, &xecfg, &ecb) != 0) {
+  if (xdl_diff_vendored(&a, &b, &xpp, &xecfg, &ecb) != 0) {
     Py_DECREF(rl);
     return PyErr_NoMemory();
   }

eden/scm/lib/third-party/xdiff/xdiff.h

@@ -71,10 +71,10 @@ typedef struct s_xdemitconf {
 #define xdl_free(ptr) free(ptr)
 #define xdl_realloc(ptr,x) realloc(ptr,x)
 
-void *xdl_mmfile_first(mmfile_t *mmf, int64_t *size);
-int64_t xdl_mmfile_size(mmfile_t *mmf);
+void *xdl_mmfile_first_vendored(mmfile_t *mmf, int64_t *size);
+int64_t xdl_mmfile_size_vendored(mmfile_t *mmf);
 
-int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+int xdl_diff_vendored(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 	     xdemitconf_t const *xecfg, xdemitcb_t *ecb);
 
 #ifdef __cplusplus

eden/scm/lib/third-party/xdiff/xdiffi.c

@@ -269,7 +269,7 @@ static int64_t xdl_split(uint64_t const *ha1, int64_t off1, int64_t lim1,
  * the box splitting function. Note that the real job (marking changed lines)
  * is done in the two boundary reaching checks.
  */
-int xdl_recs_cmp(diffdata_t *dd1, int64_t off1, int64_t lim1,
+int xdl_recs_cmp_vendored(diffdata_t *dd1, int64_t off1, int64_t lim1,
 		 diffdata_t *dd2, int64_t off2, int64_t lim2,
 		 int64_t *kvdf, int64_t *kvdb, int need_min, xdalgoenv_t *xenv) {
 	uint64_t const *ha1 = dd1->ha, *ha2 = dd2->ha;
@@ -312,9 +312,9 @@ int xdl_recs_cmp(diffdata_t *dd1, int64_t off1, int64_t lim1,
 		/*
 		 * ... et Impera.
 		 */
-		if (xdl_recs_cmp(dd1, off1, spl.i1, dd2, off2, spl.i2,
+		if (xdl_recs_cmp_vendored(dd1, off1, spl.i1, dd2, off2, spl.i2,
 				 kvdf, kvdb, spl.min_lo, xenv) < 0 ||
-		    xdl_recs_cmp(dd1, spl.i1, lim1, dd2, spl.i2, lim2,
+		    xdl_recs_cmp_vendored(dd1, spl.i1, lim1, dd2, spl.i2, lim2,
 				 kvdf, kvdb, spl.min_hi, xenv) < 0) {
 
 			return -1;
@@ -325,7 +325,7 @@ int xdl_recs_cmp(diffdata_t *dd1, int64_t off1, int64_t lim1,
 }
 
 
-int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+int xdl_do_diff_vendored(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 		xdfenv_t *xe) {
 	int64_t ndiags;
 	int64_t *kvd, *kvdf, *kvdb;
@@ -367,7 +367,7 @@ int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 	dd2.rchg = xe->xdf2.rchg;
 	dd2.rindex = xe->xdf2.rindex;
 
-	if (xdl_recs_cmp(&dd1, 0, dd1.nrec, &dd2, 0, dd2.nrec,
+	if (xdl_recs_cmp_vendored(&dd1, 0, dd1.nrec, &dd2, 0, dd2.nrec,
 			 kvdf, kvdb, (xpp->flags & XDF_NEED_MINIMAL) != 0, &xenv) < 0) {
 
 		xdl_free(kvd);
@@ -817,7 +817,7 @@ static void xdl_bug(const char *msg)
  * This also helps in finding joinable change groups and reducing the diff
  * size.
  */
-int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, int64_t flags) {
+int xdl_change_compact_vendored(xdfile_t *xdf, xdfile_t *xdfo, int64_t flags) {
 	struct xdlgroup g, go;
 	int64_t earliest_end, end_matching_other;
 	int64_t groupsize;
@@ -971,7 +971,7 @@ int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, int64_t flags) {
 }
 
 
-int xdl_build_script(xdfenv_t *xe, xdchange_t **xscr) {
+int xdl_build_script_vendored(xdfenv_t *xe, xdchange_t **xscr) {
 	xdchange_t *cscr = NULL, *xch;
 	char *rchg1 = xe->xdf1.rchg, *rchg2 = xe->xdf2.rchg;
 	int64_t i1, i2, l1, l2;
@@ -985,7 +985,7 @@ int xdl_build_script(xdfenv_t *xe, xdchange_t **xscr) {
 			for (l2 = i2; rchg2[i2 - 1]; i2--);
 
 			if (!(xch = xdl_add_change(cscr, i1, i2, l1 - i1, l2 - i2))) {
-				xdl_free_script(cscr);
+				xdl_free_script_vendored(cscr);
 				return -1;
 			}
 			cscr = xch;
@@ -997,7 +997,7 @@ int xdl_build_script(xdfenv_t *xe, xdchange_t **xscr) {
 }
 
 
-void xdl_free_script(xdchange_t *xscr) {
+void xdl_free_script_vendored(xdchange_t *xscr) {
 	xdchange_t *xch;
 
 	while ((xch = xscr) != NULL) {
@@ -1012,7 +1012,7 @@ void xdl_free_script(xdchange_t *xscr) {
  * inside the differential hunk according to the specified configuration.
  * Also advance xscr if the first changes must be discarded.
  */
-xdchange_t *xdl_get_hunk(xdchange_t **xscr)
+xdchange_t *xdl_get_hunk_vendored(xdchange_t **xscr)
 {
 	xdchange_t *xch, *xchp, *lxch;
 	uint64_t ignored = 0; /* number of ignored blank lines */
@@ -1068,7 +1068,7 @@ static int xdl_call_hunk_func(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 	if ((xecfg->flags & XDL_EMIT_BDIFFHUNK) != 0) {
 		int64_t i1 = 0, i2 = 0, n1 = xe->xdf1.nrec, n2 = xe->xdf2.nrec;
 		for (xch = xscr; xch; xch = xche->next) {
-			xche = xdl_get_hunk(&xch);
+			xche = xdl_get_hunk_vendored(&xch);
 			if (!xch)
 				break;
 			if (xch != xche)
@@ -1087,7 +1087,7 @@ static int xdl_call_hunk_func(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 			return -1;
 	} else {
 		for (xch = xscr; xch; xch = xche->next) {
-			xche = xdl_get_hunk(&xch);
+			xche = xdl_get_hunk_vendored(&xch);
 			if (!xch)
 				break;
 			if (xecfg->hunk_func(xch->i1 + p,
@@ -1101,29 +1101,29 @@ static int xdl_call_hunk_func(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,
 	return 0;
 }
 
-int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+int xdl_diff_vendored(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 	     xdemitconf_t const *xecfg, xdemitcb_t *ecb) {
 	xdchange_t *xscr;
 	xdfenv_t xe;
 
-	if (xdl_do_diff(mf1, mf2, xpp, &xe) < 0) {
+	if (xdl_do_diff_vendored(mf1, mf2, xpp, &xe) < 0) {
 
 		return -1;
 	}
-	if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
-	    xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
-	    xdl_build_script(&xe, &xscr) < 0) {
+	if (xdl_change_compact_vendored(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
+	    xdl_change_compact_vendored(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
+	    xdl_build_script_vendored(&xe, &xscr) < 0) {
 
 		xdl_free_env(&xe);
 		return -1;
 	}
 
 	if (xdl_call_hunk_func(&xe, xscr, ecb, xecfg) < 0) {
-		xdl_free_script(xscr);
+		xdl_free_script_vendored(xscr);
 		xdl_free_env(&xe);
 		return -1;
 	}
-	xdl_free_script(xscr);
+	xdl_free_script_vendored(xscr);
 	xdl_free_env(&xe);
 
 	return 0;

eden/scm/lib/third-party/xdiff/xdiffi.h

@@ -46,13 +46,13 @@ typedef struct s_xdchange {
 
 
 
-int xdl_recs_cmp(diffdata_t *dd1, int64_t off1, int64_t lim1,
+int xdl_recs_cmp_vendored(diffdata_t *dd1, int64_t off1, int64_t lim1,
 		 diffdata_t *dd2, int64_t off2, int64_t lim2,
 		 int64_t *kvdf, int64_t *kvdb, int need_min, xdalgoenv_t *xenv);
-int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
+int xdl_do_diff_vendored(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 		xdfenv_t *xe);
-int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, int64_t flags);
-int xdl_build_script(xdfenv_t *xe, xdchange_t **xscr);
-void xdl_free_script(xdchange_t *xscr);
+int xdl_change_compact_vendored(xdfile_t *xdf, xdfile_t *xdfo, int64_t flags);
+int xdl_build_script_vendored(xdfenv_t *xe, xdchange_t **xscr);
+void xdl_free_script_vendored(xdchange_t *xscr);
 
 #endif /* #if !defined(XDIFFI_H) */

eden/scm/lib/third-party/xdiff/xprepare.c

@@ -270,7 +270,7 @@ static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, int64_t narec,
 	}
 
 	nrec = 0;
-	if ((cur = blk = xdl_mmfile_first(mf, &bsize)) != NULL) {
+	if ((cur = blk = xdl_mmfile_first_vendored(mf, &bsize)) != NULL) {
 		for (top = blk + bsize; cur < top; ) {
 			prev = cur;
 			hav = xdl_hash_record(&cur, top);

eden/scm/lib/third-party/xdiff/xutils.c

@@ -40,14 +40,14 @@ int64_t xdl_bogosqrt(int64_t n) {
 }
 
 
-void *xdl_mmfile_first(mmfile_t *mmf, int64_t *size)
+void *xdl_mmfile_first_vendored(mmfile_t *mmf, int64_t *size)
 {
 	*size = mmf->size;
 	return mmf->ptr;
 }
 
 
-int64_t xdl_mmfile_size(mmfile_t *mmf)
+int64_t xdl_mmfile_size_vendored(mmfile_t *mmf)
 {
 	return mmf->size;
 }
@@ -104,7 +104,7 @@ int64_t xdl_guess_lines(mmfile_t *mf, int64_t sample) {
 	int64_t nl = 0, size, tsize = 0;
 	char const *data, *cur, *top;
 
-	if ((cur = data = xdl_mmfile_first(mf, &size)) != NULL) {
+	if ((cur = data = xdl_mmfile_first_vendored(mf, &size)) != NULL) {
 		for (top = data + size; nl < sample && cur < top; ) {
 			nl++;
 			if (!(cur = memchr(cur, '\n', top - cur)))
@@ -116,7 +116,7 @@ int64_t xdl_guess_lines(mmfile_t *mf, int64_t sample) {
 	}
 
 	if (nl && tsize)
-		nl = xdl_mmfile_size(mf) / (tsize / nl);
+		nl = xdl_mmfile_size_vendored(mf) / (tsize / nl);
 
 	return nl + 1;
 }

eden/scm/lib/xdiff-sys/src/bin/xdiff-sys-bin.rs

@@ -13,7 +13,7 @@ extern crate xdiff_sys;
 use std::env;
 use std::fs;
 use std::os::raw::{c_char, c_int, c_void};
-use xdiff_sys::{mmfile_t, xdemitcb_t, xdemitconf_t, xdl_diff, xpparam_t};
+use xdiff_sys::{mmfile_t, xdemitcb_t, xdemitconf_t, xdl_diff_vendored, xpparam_t};
 
 extern "C" fn hunk_func(a1: i64, a2: i64, b1: i64, b2: i64, _priv: *mut c_void) -> c_int {
     print!("@@ -{},{} +{},{} @@\n", a1, a2, b1, b2);
@@ -48,7 +48,7 @@ fn main() -> Result<(), std::io::Error> {
     };
 
     unsafe {
-        xdl_diff(&mut a_mmfile, &mut b_mmfile, &xpp, &xecfg, &mut ecb);
+        xdl_diff_vendored(&mut a_mmfile, &mut b_mmfile, &xpp, &xecfg, &mut ecb);
     }
     Ok(())
 }

eden/scm/lib/xdiff-sys/src/bindgen.rs

@@ -214,13 +214,16 @@ fn bindgen_test_layout_s_xdemitconf() {
 }
 pub type xdemitconf_t = s_xdemitconf;
 extern "C" {
-    pub fn xdl_mmfile_first(mmf: *mut mmfile_t, size: *mut i64) -> *mut ::std::os::raw::c_void;
+    pub fn xdl_mmfile_first_vendored(
+        mmf: *mut mmfile_t,
+        size: *mut i64,
+    ) -> *mut ::std::os::raw::c_void;
 }
 extern "C" {
-    pub fn xdl_mmfile_size(mmf: *mut mmfile_t) -> i64;
+    pub fn xdl_mmfile_size_vendored(mmf: *mut mmfile_t) -> i64;
 }
 extern "C" {
-    pub fn xdl_diff(
+    pub fn xdl_diff_vendored(
         mf1: *mut mmfile_t,
         mf2: *mut mmfile_t,
         xpp: *const xpparam_t,

eden/scm/lib/xdiff-sys/src/lib.rs

@@ -5,7 +5,7 @@
  * GNU General Public License version 2.
  */
 
-// A small subset of xdiff bindings that is just enough to run xdl_diff
+// A small subset of xdiff bindings that is just enough to run xdl_diff_vendored
 #![allow(non_camel_case_types)]
 #![allow(non_snake_case)]
 
@@ -19,7 +19,7 @@ mod tests {
     use std::os::raw::{c_char, c_int, c_void};
 
     #[test]
-    fn test_xdl_diff() {
+    fn test_xdl_diff_vendored() {
         extern "C" fn hunk_func(a1: i64, a2: i64, b1: i64, b2: i64, _priv: *mut c_void) -> c_int {
             let mut _priv = unsafe { (_priv as *mut Vec<(i64, i64, i64, i64)>).as_mut() };
             if let Some(result) = _priv {
@@ -49,7 +49,7 @@ mod tests {
         };
 
         unsafe {
-            xdl_diff(&mut a_mmfile, &mut b_mmfile, &xpp, &xecfg, &mut ecb);
+            xdl_diff_vendored(&mut a_mmfile, &mut b_mmfile, &xpp, &xecfg, &mut ecb);
         }
         assert_eq!(result, [(1, 1, 1, 0), (4, 0, 3, 1)]);
     }

eden/scm/lib/xdiff/src/lib.rs

@@ -102,7 +102,7 @@ where
     };
 
     unsafe {
-        ffi::xdl_diff(&mut old_mmfile, &mut new_mmfile, &xpp, &xecfg, &mut ecb);
+        ffi::xdl_diff_vendored(&mut old_mmfile, &mut new_mmfile, &xpp, &xecfg, &mut ecb);
     }
     return result;
 }