From eeb69c7119ab5d22c2ae65b5b7676b0b0a62f3ad Mon Sep 17 00:00:00 2001
From: Ryan Dwyer <ryandwyer1@gmail.com>
Date: Tue, 27 Sep 2022 00:30:03 +1000
Subject: [PATCH] Decompile sprintf

---
 src/lib/ultra/libc/sprintf.c | 54 ++++++++++++------------------------
 1 file changed, 18 insertions(+), 36 deletions(-)

diff --git a/src/lib/ultra/libc/sprintf.c b/src/lib/ultra/libc/sprintf.c
index 17eb35e94..1ac640312 100644
--- a/src/lib/ultra/libc/sprintf.c
+++ b/src/lib/ultra/libc/sprintf.c
@@ -1,42 +1,25 @@
-#include <ultra64.h>
+#include <ultratypes.h>
 #include "stdarg.h"
 
+char _Printf(char *(*prout)(char *, const char *, size_t), char *dst, const char *fmt, va_list args);
+
 char *proutSprintf(char *dst, const char *src, size_t count)
 {
-	return (char *)memcpy((u8 *)dst, (u8 *)src, count) + count;
+	return (char *) memcpy((u8 *) dst, (u8 *) src, count) + count;
 }
 
-#if MATCHING
-GLOBAL_ASM(
-glabel sprintf
-/*    136b4:	27bdffe0 */ 	addiu	$sp,$sp,-32
-/*    136b8:	afa40020 */ 	sw	$a0,0x20($sp)
-/*    136bc:	afbf0014 */ 	sw	$ra,0x14($sp)
-/*    136c0:	afa50024 */ 	sw	$a1,0x24($sp)
-/*    136c4:	afa60028 */ 	sw	$a2,0x28($sp)
-/*    136c8:	afa7002c */ 	sw	$a3,0x2c($sp)
-/*    136cc:	3c047001 */ 	lui	$a0,%hi(proutSprintf)
-/*    136d0:	24843690 */ 	addiu	$a0,$a0,%lo(proutSprintf)
-/*    136d4:	27a70028 */ 	addiu	$a3,$sp,0x28
-/*    136d8:	8fa60024 */ 	lw	$a2,0x24($sp)
-/*    136dc:	0c013b40 */ 	jal	_Printf
-/*    136e0:	8fa50020 */ 	lw	$a1,0x20($sp)
-/*    136e4:	04400004 */ 	bltz	$v0,.L000136f8
-/*    136e8:	00401825 */ 	or	$v1,$v0,$zero
-/*    136ec:	8fae0020 */ 	lw	$t6,0x20($sp)
-/*    136f0:	01c27821 */ 	addu	$t7,$t6,$v0
-/*    136f4:	a1e00000 */ 	sb	$zero,0x0($t7)
-.L000136f8:
-/*    136f8:	8fbf0014 */ 	lw	$ra,0x14($sp)
-/*    136fc:	27bd0020 */ 	addiu	$sp,$sp,0x20
-/*    13700:	03e00008 */ 	jr	$ra
-/*    13704:	00000000 */ 	nop
-);
-#else
-// Mismatch:
-// Goal takes v0 from _Printf and copies it to v1 but leaves v0 unmodified.
-// The below copies v0 to v1 then back to v0 for the return.
-int sprintf(char *dst, const char *fmt, ...)
+/**
+ * Note: A match has only been found for this function if it returns void
+ * rather than the written length. However, there is code elsewhere in the game
+ * that reads sprintf's return value. ans is left in v0 so it happens to work
+ * correctly. Either the decompilation is accurate and the calling code uses an
+ * incorrect declaration for sprintf, or the decompilation is inaccurate and
+ * it actually returns ans.
+ *
+ * Also note this file is using an incorrect declaration for _Printf.
+ * _Printf returns an int, not a char.
+ */
+void sprintf(char *dst, const char *fmt, ...)
 {
 	int ans;
 	va_list ap;
@@ -45,11 +28,10 @@ int sprintf(char *dst, const char *fmt, ...)
 	ans = _Printf(proutSprintf, dst, fmt, ap);
 
 	if (ans >= 0) {
-		dst[ans] = 0;
+		dst[ans] = '\0';
 	}
 
 	va_end(ap);
 
-	return ans;
+	if ((ans && ans) != 0);
 }
-#endif