xdiff: include new xdiff from git

Update to the xdiff used in git v2.35.0, with updates to our build
configuration to ignore the sort of warnings that we normally care
about (signed/unsigned mismatch, unused, etc.)

Any git-specific abstraction bits are now redefined for our use in
`git-xdiff.h`.  It is a (wildly optimistic) hope that we can use that
indirection layer to standardize on a shared xdiff implementation.

Author: ethomson

src/CMakeLists.txt

@@ -206,7 +206,17 @@ endif()
 # errors for the xdiff sources until we've sorted them out
 if(MSVC)
 	set_source_files_properties(xdiff/xdiffi.c PROPERTIES COMPILE_FLAGS -WX-)
+	set_source_files_properties(xdiff/xemit.c PROPERTIES COMPILE_FLAGS -WX-)
+	set_source_files_properties(xdiff/xhistogram.c PROPERTIES COMPILE_FLAGS -WX-)
+	set_source_files_properties(xdiff/xmerge.c PROPERTIES COMPILE_FLAGS -WX-)
 	set_source_files_properties(xdiff/xutils.c PROPERTIES COMPILE_FLAGS -WX-)
+	set_source_files_properties(xdiff/xpatience.c PROPERTIES COMPILE_FLAGS -WX-)
+else()
+	set_source_files_properties(xdiff/xdiffi.c PROPERTIES COMPILE_FLAGS "-Wno-sign-compare -Wno-unused-parameter")
+	set_source_files_properties(xdiff/xemit.c PROPERTIES COMPILE_FLAGS "-Wno-sign-compare -Wno-unused-parameter")
+	set_source_files_properties(xdiff/xhistogram.c PROPERTIES COMPILE_FLAGS "-Wno-sign-compare")
+	set_source_files_properties(xdiff/xutils.c PROPERTIES COMPILE_FLAGS "-Wno-sign-compare")
+	set_source_files_properties(xdiff/xpatience.c PROPERTIES COMPILE_FLAGS "-Wno-sign-compare")
 endif()
 
 # Determine architecture of the machine

src/blame_git.c

@@ -393,7 +393,7 @@ static void fill_origin_blob(git_blame__origin *o, mmfile_t *file)
 	memset(file, 0, sizeof(*file));
 	if (o->blob) {
 		file->ptr = (char*)git_blob_rawcontent(o->blob);
-		file->size = (size_t)git_blob_rawsize(o->blob);
+		file->size = (long)git_blob_rawsize(o->blob);
 	}
 }
 

src/diff_xdiff.c

@@ -218,14 +218,9 @@ static int git_xdiff(git_patch_generated_output *output, git_patch_generated *pa
 	 * updates are needed to xo->params.flags
 	 */
 
-	git_patch_generated_old_data(&info.xd_old_data.ptr, &info.xd_old_data.size, patch);
-	git_patch_generated_new_data(&info.xd_new_data.ptr, &info.xd_new_data.size, patch);
-
-	if (info.xd_old_data.size > GIT_XDIFF_MAX_SIZE ||
-		info.xd_new_data.size > GIT_XDIFF_MAX_SIZE) {
-		git_error_set(GIT_ERROR_INVALID, "files too large for diff");
+	if (git_patch_generated_old_data(&info.xd_old_data.ptr, &info.xd_old_data.size, patch) < 0 ||
+	    git_patch_generated_new_data(&info.xd_new_data.ptr, &info.xd_new_data.size, patch) < 0)
 		return -1;
-	}
 
 	xdl_diff(&info.xd_old_data, &info.xd_new_data,
 		&xo->params, &xo->config, &xo->callback);
@@ -261,5 +256,5 @@ void git_xdiff_init(git_xdiff_output *xo, const git_diff_options *opts)
 	if (flags & GIT_DIFF_IGNORE_BLANK_LINES)
 		xo->params.flags |= XDF_IGNORE_BLANK_LINES;
 
-	xo->callback.outf = git_xdiff_cb;
+	xo->callback.out_line = git_xdiff_cb;
 }

src/merge_file.c

@@ -86,22 +86,30 @@ static int merge_file__xdiff(
 
 	memset(&xmparam, 0x0, sizeof(xmparam_t));
 
+	if (ours->size > LONG_MAX ||
+	    theirs->size > LONG_MAX ||
+	    (ancestor && ancestor->size > LONG_MAX)) {
+		git_error_set(GIT_ERROR_MERGE, "failed to merge files");
+		error = -1;
+		goto done;
+	}
+
 	if (ancestor) {
 		xmparam.ancestor = (options.ancestor_label) ?
 			options.ancestor_label : ancestor->path;
 		ancestor_mmfile.ptr = (char *)ancestor->ptr;
-		ancestor_mmfile.size = ancestor->size;
+		ancestor_mmfile.size = (long)ancestor->size;
 	}
 
 	xmparam.file1 = (options.our_label) ?
 		options.our_label : ours->path;
 	our_mmfile.ptr = (char *)ours->ptr;
-	our_mmfile.size = ours->size;
+	our_mmfile.size = (long)ours->size;
 
 	xmparam.file2 = (options.their_label) ?
 		options.their_label : theirs->path;
 	their_mmfile.ptr = (char *)theirs->ptr;
-	their_mmfile.size = theirs->size;
+	their_mmfile.size = (long)theirs->size;
 
 	if (options.favor == GIT_MERGE_FILE_FAVOR_OURS)
 		xmparam.favor = XDL_MERGE_FAVOR_OURS;

src/patch_generate.c

@@ -750,18 +750,34 @@ git_diff_driver *git_patch_generated_driver(git_patch_generated *patch)
 	return patch->ofile.driver;
 }
 
-void git_patch_generated_old_data(
-	char **ptr, size_t *len, git_patch_generated *patch)
+int git_patch_generated_old_data(
+	char **ptr, long *len, git_patch_generated *patch)
 {
+	if (patch->ofile.map.len > LONG_MAX ||
+	    patch->ofile.map.len > GIT_XDIFF_MAX_SIZE) {
+		git_error_set(GIT_ERROR_INVALID, "files too large for diff");
+		return -1;
+	}
+
 	*ptr = patch->ofile.map.data;
-	*len = patch->ofile.map.len;
+	*len = (long)patch->ofile.map.len;
+
+	return 0;
 }
 
-void git_patch_generated_new_data(
-	char **ptr, size_t *len, git_patch_generated *patch)
+int git_patch_generated_new_data(
+	char **ptr, long *len, git_patch_generated *patch)
 {
+	if (patch->ofile.map.len > LONG_MAX ||
+	    patch->ofile.map.len > GIT_XDIFF_MAX_SIZE) {
+		git_error_set(GIT_ERROR_INVALID, "files too large for diff");
+		return -1;
+	}
+
 	*ptr = patch->nfile.map.data;
-	*len = patch->nfile.map.len;
+	*len = (long)patch->nfile.map.len;
+
+	return 0;
 }
 
 static int patch_generated_file_cb(

src/patch_generate.h

@@ -39,10 +39,10 @@ typedef struct git_patch_generated git_patch_generated;
 
 extern git_diff_driver *git_patch_generated_driver(git_patch_generated *);
 
-extern void git_patch_generated_old_data(
-	char **, size_t *, git_patch_generated *);
-extern void git_patch_generated_new_data(
-	char **, size_t *, git_patch_generated *);
+extern int git_patch_generated_old_data(
+	char **, long *, git_patch_generated *);
+extern int git_patch_generated_new_data(
+	char **, long *, git_patch_generated *);
 extern int git_patch_generated_from_diff(
 	git_patch **, git_diff *, size_t);
 

src/xdiff/git-xdiff.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+/*
+ * This file provides the necessary indirection between xdiff and
+ * libgit2.  libgit2-specific functionality should live here, so
+ * that git and libgit2 can share a common xdiff implementation.
+ */
+
+#ifndef INCLUDE_git_xdiff_h__
+#define INCLUDE_git_xdiff_h__
+
+#include "regexp.h"
+
+#define xdl_malloc(x) git__malloc(x)
+#define xdl_free(ptr) git__free(ptr)
+#define xdl_realloc(ptr, x) git__realloc(ptr, x)
+
+#define XDL_BUG(msg) GIT_ASSERT(msg)
+
+#define xdl_regex_t git_regexp
+#define xdl_regmatch_t git_regmatch
+
+GIT_INLINE(int) xdl_regexec_buf(
+	const xdl_regex_t *preg, const char *buf, size_t size,
+	size_t nmatch, xdl_regmatch_t pmatch[], int eflags)
+{
+	GIT_UNUSED(preg);
+	GIT_UNUSED(buf);
+	GIT_UNUSED(size);
+	GIT_UNUSED(nmatch);
+	GIT_UNUSED(pmatch);
+	GIT_UNUSED(eflags);
+	GIT_ASSERT("not implemented");
+	return -1;
+}
+
+#endif

src/xdiff/xdiff.h

@@ -23,6 +23,8 @@
 #if !defined(XDIFF_H)
 #define XDIFF_H
 
+#include "git-xdiff.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif /* #ifdef __cplusplus */
@@ -50,16 +52,9 @@ extern "C" {
 
 /* xdemitconf_t.flags */
 #define XDL_EMIT_FUNCNAMES (1 << 0)
+#define XDL_EMIT_NO_HUNK_HDR (1 << 1)
 #define XDL_EMIT_FUNCCONTEXT (1 << 2)
 
-#define XDL_MMB_READONLY (1 << 0)
-
-#define XDL_MMF_ATOMIC (1 << 0)
-
-#define XDL_BDOP_INS 1
-#define XDL_BDOP_CPY 2
-#define XDL_BDOP_INSB 3
-
 /* merge simplification levels */
 #define XDL_MERGE_MINIMAL 0
 #define XDL_MERGE_EAGER 1
@@ -73,28 +68,37 @@ extern "C" {
 
 /* merge output styles */
 #define XDL_MERGE_DIFF3 1
+#define XDL_MERGE_ZEALOUS_DIFF3 2
 
 typedef struct s_mmfile {
 	char *ptr;
-	size_t size;
+	long size;
 } mmfile_t;
 
 typedef struct s_mmbuffer {
 	char *ptr;
-	size_t size;
+	long size;
 } mmbuffer_t;
 
 typedef struct s_xpparam {
 	unsigned long flags;
 
+	/* -I<regex> */
+	xdl_regex_t **ignore_regex;
+	size_t ignore_regex_nr;
+
 	/* See Documentation/diff-options.txt. */
 	char **anchors;
 	size_t anchors_nr;
 } xpparam_t;
 
 typedef struct s_xdemitcb {
 	void *priv;
-	int (*outf)(void *, mmbuffer_t *, int);
+	int (*out_hunk)(void *,
+			long old_begin, long old_nr,
+			long new_begin, long new_nr,
+			const char *func, long funclen);
+	int (*out_line)(void *, mmbuffer_t *, int);
 } xdemitcb_t;
 
 typedef long (*find_func_t)(const char *line, long line_len, char *buffer, long buffer_size, void *priv);
@@ -117,10 +121,6 @@ typedef struct s_bdiffparam {
 } bdiffparam_t;
 
 
-#define xdl_malloc(x) git__malloc(x)
-#define xdl_free(ptr) git__free(ptr)
-#define xdl_realloc(ptr,x) git__realloc(ptr,x)
-
 void *xdl_mmfile_first(mmfile_t *mmf, long *size);
 long xdl_mmfile_size(mmfile_t *mmf);