1 files changed, 55 insertions, 0 deletions
diff --git a/src/libgit2/common.h b/src/libgit2/common.h
new file mode 100644
index 000000000..bb9ec5ac1
--- /dev/null
+++ b/src/libgit2/common.h
@@ -0,0 +1,55 @@
+/*
+ * 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.
+ */
+#ifndef INCLUDE_common_h__
+#define INCLUDE_common_h__
+
+#include "git2_util.h"
+#include "errors.h"
+
+/*
+* Include the declarations for deprecated functions; this ensures
+* that they're decorated with the proper extern/visibility attributes.
+*/
+#include "git2/deprecated.h"
+
+#include "posix.h"
+
+/**
+ * Initialize a structure with a version.
+ */
+GIT_INLINE(void) git__init_structure(void *structure, size_t len, unsigned int version)
+{
+	memset(structure, 0, len);
+	*((int*)structure) = version;
+}
+#define GIT_INIT_STRUCTURE(S,V) git__init_structure(S, sizeof(*S), V)
+
+#define GIT_INIT_STRUCTURE_FROM_TEMPLATE(PTR,VERSION,TYPE,TPL) do { \
+	TYPE _tmpl = TPL; \
+	GIT_ERROR_CHECK_VERSION(&(VERSION), _tmpl.version, #TYPE);      \
+	memcpy((PTR), &_tmpl, sizeof(_tmpl)); } while (0)
+
+/**
+ * Check a versioned structure for validity
+ */
+GIT_INLINE(int) git_error__check_version(const void *structure, unsigned int expected_max, const char *name)
+{
+	unsigned int actual;
+
+	if (!structure)
+		return 0;
+
+	actual = *(const unsigned int*)structure;
+	if (actual > 0 && actual <= expected_max)
+		return 0;
+
+	git_error_set(GIT_ERROR_INVALID, "invalid version %d on %s", actual, name);
+	return -1;
+}
+#define GIT_ERROR_CHECK_VERSION(S,V,N) if (git_error__check_version(S,V,N) < 0) return -1
+
+#endif