From c44932fe03a5b15695bdd0cf5ec63481ad383f5f Mon Sep 17 00:00:00 2001
From: "YU-WEI,HSU" <blackfire106.1231@gmail.com>
Date: Sat, 9 Aug 2025 23:14:31 +0800
Subject: [PATCH] Move abs function from memory.c to new math.c

The abs() function is a mathematical utility and does not belong in
lib/memory.c, which is intended for memory manipulation routines.
This commit moves abs() to a new lib/math.c file to improve semantic
consistency and maintainability, and to provide a dedicated place for
future math-related functions.

Fixes: #17
---
 Makefile     | 2 +-
 lib/math.c   | 9 +++++++++
 lib/memory.c | 6 ------
 3 files changed, 10 insertions(+), 7 deletions(-)
 create mode 100644 lib/math.c

diff --git a/Makefile b/Makefile
index 060e9f2..61576a1 100644
--- a/Makefile
+++ b/Makefile
@@ -21,7 +21,7 @@ KERNEL_OBJS := timer.o mqueue.o pipe.o semaphore.o mutex.o error.o syscall.o tas
 KERNEL_OBJS := $(addprefix $(BUILD_KERNEL_DIR)/,$(KERNEL_OBJS))
 deps += $(KERNEL_OBJS:%.o=%.o.d)
 
-LIB_OBJS := ctype.o malloc.o memory.o random.o stdio.o string.o queue.o
+LIB_OBJS := ctype.o malloc.o math.o memory.o random.o stdio.o string.o queue.o
 LIB_OBJS := $(addprefix $(BUILD_LIB_DIR)/,$(LIB_OBJS))
 deps += $(LIB_OBJS:%.o=%.o.d)
 
diff --git a/lib/math.c b/lib/math.c
new file mode 100644
index 0000000..771ee22
--- /dev/null
+++ b/lib/math.c
@@ -0,0 +1,9 @@
+/* libc: Math function. */
+
+#include <lib/libc.h>
+
+/* Returns the absolute value of an integer. */
+int32_t abs(int32_t n)
+{
+    return n >= 0 ? n : -n;
+}
diff --git a/lib/memory.c b/lib/memory.c
index 9a32e81..949fa1c 100644
--- a/lib/memory.c
+++ b/lib/memory.c
@@ -122,9 +122,3 @@ int32_t memcmp(const void *cs, const void *ct, uint32_t n)
      */
     return (n == 0) ? 0 : ((*r1 < *r2) ? -1 : 1);
 }
-
-/* Returns the absolute value of an integer. */
-int32_t abs(int32_t n)
-{
-    return n >= 0 ? n : -n;
-}