1 files changed, 84 insertions, 0 deletions
diff --git a/src/util/errors.h b/src/util/errors.h
new file mode 100644
index 0000000..8d58775
--- /dev/null
+++ b/src/util/errors.h
@@ -0,0 +1,84 @@
+/*
+ * 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_errors_h__
+#define INCLUDE_errors_h__
+
+#include "git2_util.h"
+#include "git2/sys/errors.h"
+
+/* Initialize the error thread-state. */
+int git_error_global_init(void);
+
+/*
+ * `vprintf`-style formatting for the error message for this thread.
+ */
+void git_error_vset(int error_class, const char *fmt, va_list ap);
+
+/**
+ * Determines whether an error exists.
+ */
+bool git_error_exists(void);
+
+/**
+ * Set error message for user callback if needed.
+ *
+ * If the error code in non-zero and no error message is set, this
+ * sets a generic error message.
+ *
+ * @return This always returns the `error_code` parameter.
+ */
+GIT_INLINE(int) git_error_set_after_callback_function(
+	int error_code, const char *action)
+{
+	if (error_code) {
+		if (!git_error_exists())
+			git_error_set(GIT_ERROR_CALLBACK,
+				"%s callback returned %d", action, error_code);
+	}
+	return error_code;
+}
+
+#ifdef GIT_WIN32
+#define git_error_set_after_callback(code) \
+	git_error_set_after_callback_function((code), __FUNCTION__)
+#else
+#define git_error_set_after_callback(code) \
+	git_error_set_after_callback_function((code), __func__)
+#endif
+
+/**
+ * Gets the system error code for this thread.
+ */
+int git_error_system_last(void);
+
+/**
+ * Sets the system error code for this thread.
+ */
+void git_error_system_set(int code);
+
+/**
+ * Capture current error state to restore later, returning error code.
+ * If `error_code` is zero, this does not clear the current error state.
+ * You must either restore this error state, or free it.
+ *
+ * This function returns 0 on success, or -1 on failure. If the function
+ * fails, the `out` structure is set to the failure error message and
+ * the normal system error message is not updated.
+ */
+extern int git_error_save(git_error **out);
+
+/**
+ * Restore thread error state to the given value. The given value is
+ * freed and `git_error_free` need not be called on it.
+ */
+extern int git_error_restore(git_error *error);
+
+/** Free an error state. */
+extern void git_error_free(git_error *error);
+
+#endif