1 files changed, 55 insertions, 0 deletions
diff --git a/core/errorhelper.c b/core/errorhelper.c
new file mode 100644
index 000000000..66c01fd21
--- /dev/null
+++ b/core/errorhelper.c
@@ -0,0 +1,55 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifdef __clang__
+// Clang has a bug on zero-initialization of C structs.
+#pragma clang diagnostic ignored "-Wmissing-field-initializers"
+#endif
+#include "dive.h"
+#include "membuffer.h"
+
+#define VA_BUF(b, fmt) do { va_list args; va_start(args, fmt); put_vformat(b, fmt, args); va_end(args); } while (0)
+
+static struct membuffer error_string_buffer = { 0 };
+static void (*error_cb)(void) = NULL;
+/*
+ * Note that the act of "getting" the error string
+ * buffer doesn't de-allocate the buffer, but it does
+ * set the buffer length to zero, so that any future
+ * error reports will overwrite the string rather than
+ * append to it.
+ */
+const char *get_error_string(void)
+{
+	const char *str;
+
+	if (!error_string_buffer.len)
+		return "";
+	str = mb_cstring(&error_string_buffer);
+	error_string_buffer.len = 0;
+	return str;
+}
+
+int report_error(const char *fmt, ...)
+{
+	struct membuffer *buf = &error_string_buffer;
+
+	/* Previous unprinted errors? Add a newline in between */
+	if (buf->len)
+		put_bytes(buf, "\n", 1);
+	VA_BUF(buf, fmt);
+	mb_cstring(buf);
+
+	/* if an error callback is registered, call it */
+	if (error_cb)
+		error_cb();
+
+	return -1;
+}
+
+void report_message(const char *msg)
+{
+	(void)report_error("%s", msg);
+}
+
+void set_error_cb(void(*cb)(void)) {
+	error_cb = cb;
+}