From 2e8094b71237c139d08ab373513112b258c143e4 Mon Sep 17 00:00:00 2001
From: ISSOtm <eldredhabert0@gmail.com>
Date: Tue, 28 Jan 2020 11:07:46 +0100
Subject: [PATCH] Allow RGBASM to overwrite object files on Windows

---
 src/asm/output.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/asm/output.c b/src/asm/output.c
index 1c83f8e9..dce91101 100644
--- a/src/asm/output.c
+++ b/src/asm/output.c
@@ -19,6 +19,21 @@
 #include <unistd.h>
 #include <libgen.h>
 
+#ifdef _WIN32
+#include <windows.h>
+#include <winbase.h>
+/*
+ * The semantics of `rename` on Windows differ from POSIX in that it errors out
+ * when the target file exists, instead of overwriting it.
+ * Thus, shim `rename` with similar semantics (note that the return value of
+ * `MoveFileExA` is inverted, and it uses `GetLastError` instead of `errno`)
+ */
+#define rename(oldname, newname) \
+	MoveFileExA(oldname, newname, MOVEFILE_WRITE_THROUGH | \
+				      MOVEFILE_REPLACE_EXISTING) \
+	? 0 : (errno = GetLastError(), -1)
+#endif
+
 #include "asm/asm.h"
 #include "asm/charmap.h"
 #include "asm/fstack.h"