util: refactor misc utility stuff

arch/x86/boot/boot.c

@@ -4,9 +4,9 @@
 
 #include <arch/multiboot.h>
 
-#include <gay/cdefs.h>
 #include <gay/kprintf.h>
 #include <gay/types.h>
+#include <gay/util.h>
 
 enum vga_color {
 	VGA_COLOR_BLACK		= 0,

include/gay/cdefs.h

@@ -2,6 +2,20 @@
 
 #pragma once
 
+#ifndef __clang__
+#error "Unsupported compiler, please use clang"
+#endif
+
+#ifdef __cplusplus
+#define __restrict
+#else
+#define __restrict restrict
+#endif
+
+#define __aligned(bytes) __attribute__(( aligned(bytes) ))
+
+#define __section(name) __attribute__(( section(#name) ))
+
 #ifndef NULL
 #define NULL ((void *)0)
 #endif
@@ -14,31 +28,6 @@
 #define typeof(expr) __typeof(expr)
 #endif
 
-#define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
-
-/**
- * @brief Cast a pointer to a struct member out to the containing structure.
- *
- * @param ptr Pointer to the struct member
- * @param type Type of the containing structure
- * @param member Name of the member within the containing structure
- * @returns Pointer to the containing structure
- */
-#define container_of(ptr, type, member) \
-	((type *)( (void *)(ptr) - offsetof(type, member) ))
-
-/**
- * @brief Do an evil raw cast.
- *
- * @param type Type to cast to
- * @param expr Expression to cast
- * @returns The raw value of `expr`, cast to `type`
- */
-#define raw_cast(type, expr) ({		\
-	typeof(expr) __expr = (expr);	\
-	*(type *)&__expr;		\
-})
-
 /*
  * This file is part of GayBSD.
  * Copyright (c) 2021 fef <owo@fef.moe>.

include/gay/config.h.in

@@ -9,6 +9,8 @@
 
 #pragma once
 
+#cmakedefine DEBUG
+
 #define GAY_VERSION_MAJOR @gaybsd_VERSION_MAJOR@
 #define GAY_VERSION_MINOR @gaybsd_VERSION_MINOR@
 #define GAY_VERSION_PATCH @gaybsd_VERSION_PATCH@

include/gay/kprintf.h

@@ -8,8 +8,8 @@
 
 #include <stdarg.h>
 
+#include <gay/cdefs.h>
 #include <gay/types.h>
-#include <gay/toolchain.h>
 
 /**
  * @brief Print to the kernel log.

include/gay/util.h

@@ -0,0 +1,77 @@
+/* See the end of this file for copyright and license terms. */
+
+#pragma once
+
+#include <gay/cdefs.h>
+
+/**
+ * @brief Get the number of elements in a statically allocated array.
+ *
+ * @param a The array
+ * @returns The number of elements
+ */
+#define ARRAY_SIZE(a) ( sizeof(a) / sizeof(a[0]) )
+
+#define abs(x) ({		\
+	typeof(x) __x = (x);	\
+	__x < 0 ? -__x : __x;	\
+})
+
+#define max(a, b) ({		\
+	typeof(a) __a = (a);	\
+	typeof(b) __b = (b);	\
+	__a > __b ? __a : __b;	\
+})
+
+#define min(a, b) ({		\
+	typeof(a) __a = (a);	\
+	typeof(b) __b = (b);	\
+	__a < __b ? __a : __b;	\
+})
+
+/**
+ * @brief Cast a pointer to a struct member out to the containing structure.
+ *
+ * @param ptr Pointer to the struct member
+ * @param type Type of the containing structure
+ * @param member Name of the member within the containing structure
+ * @returns Pointer to the containing structure
+ */
+#define container_of(ptr, type, member) \
+	((type *)( (void *)(ptr) - offsetof(type, member) ))
+
+/**
+ * @brief Do an evil raw cast.
+ *
+ * @param type Type to cast to
+ * @param expr Expression to cast
+ * @returns The raw value of `expr`, cast to `type`
+ */
+#define raw_cast(type, expr) ({		\
+	typeof(expr) __expr = (expr);	\
+	*(type *)&__expr;		\
+})
+
+/**
+ * @brief Align `ptr` such that `ptr % n == 0`.
+ *
+ * @param ptr Pointer to align
+ * @param log The log2 of the alignment.  If negative, the pointer will be
+ *	aligned to the next lower address, otherwise to the next higher one.
+ * @returns The aligned pointer
+ */
+void *ptr_align(void *ptr, int log);
+
+/*
+ * This file is part of GayBSD.
+ * Copyright (c) 2021 fef <owo@fef.moe>.
+ *
+ * GayBSD is nonviolent software: you may only use, redistribute, and/or
+ * modify it under the terms of the Cooperative Nonviolent Public License
+ * (CNPL) as found in the LICENSE file in the source code root directory
+ * or at <https://git.pixie.town/thufie/npl-builder>; either version 7
+ * of the license, or (at your option) any later version.
+ *
+ * GayBSD comes with ABSOLUTELY NO WARRANTY, to the extent
+ * permitted by applicable law.  See the CNPL for details.
+ */

kernel/CMakeLists.txt

@@ -10,6 +10,7 @@ target_sources(gay_kernel PRIVATE
     clist.c
     kprintf.c
     main.c
+    util.c
 )
 
 # This file is part of GayBSD.

kernel/util.c

@@ -1,18 +1,18 @@
 /* See the end of this file for copyright and license terms. */
 
-#pragma once
+#include <gay/types.h>
+#include <gay/util.h>
 
-#ifndef __clang__
+void *ptr_align(void *ptr, int log)
-#error "Unsupported compiler, please use clang"
+{
-#endif
+	uintptr_t shifted = 1 << abs(log);
+	uintptr_t aligned = (uintptr_t)ptr & ~(shifted - 1);
 
-#ifdef __cplusplus
+	if (log > 0 && aligned != (uintptr_t)ptr)
-#define __restrict
+		aligned += shifted;
-#else
-#define __restrict restrict
-#endif
 
-#define __section(name) __attribute__(( section(#name) ))
+	return (void *)aligned;
+}
 
 /*
  * This file is part of GayBSD.