add struct-group.h

c/debug.c

@@ -19,12 +19,13 @@
 #define DEBUG_DEBUG
 #endif
 
+#include "bits.h"
 #include "debug.h"
 
 #define NANOSEC  1000000000                       /* nano sec in sec */
 #define MILLISEC 1000000                          /* milli sec in sec */
 
-static s64 timer_start;                           /* in nanosecond */
+static long long timer_start;                     /* in nanosecond */
 static u32 debug_level=0;
 
 void debug_level_set(u32 level)
@@ -48,7 +49,7 @@ void debug_init(u32 level)
     log(0, "timer started.\n");
 }
 
-inline static s64 timer_elapsed()
+inline static long long timer_elapsed()
 {
     struct timespec timer;
 
@@ -56,7 +57,6 @@ inline static s64 timer_elapsed()
     return (timer.tv_sec * NANOSEC + timer.tv_nsec) - timer_start;
 }
 
-
 /* void debug - log function
  * @timestamp : boolean
  * @indent    : indent level (2 spaces each)
@@ -75,9 +75,9 @@ void debug(u32 level, bool timestamp, u32 indent, const char *src,
         printf("%*s", 2*(indent-1), "");
 
     if (timestamp) {
-        s64 diff = timer_elapsed();
+        long long diff = timer_elapsed();
-        printf("%ld.%03ld ", diff/NANOSEC, (diff/1000000)%1000);
+        printf("%lld.%03lld ", diff/NANOSEC, (diff/1000000)%1000);
-        printf("%010ld ", diff);
+        printf("%010lld ", diff);
     }
 
     if (src) {

c/include/bits.h

@@ -25,10 +25,10 @@
 #endif
 
 /* no plan to support 32bits for now...
+ * #if __WORDSIZE != 64
+ * #error "Only 64 bits word size supported."
+ * #endif
  */
-#if __WORDSIZE != 64
-#error "Only 64 bits word size supported."
-#endif
 
 /* fixed-size types
  */
@@ -44,11 +44,30 @@ typedef uint8_t  u8;
 
 /* convenience types
  */
+typedef long long int llong;
+typedef unsigned long long int ullong;
 typedef unsigned long int ulong;
 typedef unsigned int uint;
 typedef unsigned short ushort;
 typedef unsigned char uchar;
 
+/* define common types sizes
+ */
+#define BITS_PER_CHAR 8
+
+#ifndef BITS_PER_SHORT
+#define BITS_PER_SHORT (BITS_PER_CHAR * sizeof (short))
+#endif
+#ifndef BITS_PER_INT
+#define BITS_PER_INT   (BITS_PER_CHAR * sizeof (int))
+#endif
+#ifndef BITS_PER_LONG
+#define BITS_PER_LONG  (BITS_PER_CHAR * sizeof (long))
+#endif
+#ifndef BITS_PER_LLONG
+#define BITS_PER_LLONG (BITS_PER_CHAR * sizeof (long long))
+#endif
+
 /* count set bits:  10101000 -> 3
  *                  ^ ^ ^
  */
@@ -73,6 +92,27 @@ static __always_inline int popcount64(u64 n)
 #   endif
 }
 
+static __always_inline int popcount32(u32 n)
+{
+#   if __has_builtin(__builtin_popcount)
+#   ifdef DEBUG_BITS
+    log_f(1, "builtin.\n");
+#   endif
+    return __builtin_popcount(n);
+
+#   else
+#   ifdef DEBUG_BITS
+    log_f(1, "emulated.\n");
+#   endif
+    int count = 0;
+    while (n) {
+        count++;
+        n &= (n - 1);
+    }
+    return count;
+#   endif
+}
+
 /* char is a special case, as it can be signed or unsigned
  */
 typedef signed char schar;
@@ -242,27 +282,6 @@ static __always_inline uint ffs32(u32 n)
 #   endif
 }
 
-static __always_inline int popcount32(u32 n)
-{
-#   if __has_builtin(__builtin_popcount)
-#   ifdef DEBUG_BITS
-    log_f(1, "builtin.\n");
-#   endif
-    return __builtin_popcount(n);
-
-#   else
-#   ifdef DEBUG_BITS
-    log_f(1, "emulated.\n");
-#   endif
-    int count = 0;
-    while (n) {
-        count++;
-        n &= (n - 1);
-    }
-    return count;
-#   endif
-}
-
 /*  rolXX are taken from kernel's <linux/bitops.h> are are:
  * SPDX-License-Identifier: GPL-2.0
  */

c/include/br.h

@@ -18,6 +18,8 @@
 #ifndef _BR_H
 #define _BR_H
 
+#include "struct-group.h"
+
 /* Indirect stringification.  Doing two levels allows the parameter to be a
  * macro itself.  For example, compile with -DFOO=bar, __stringify(FOO)
  * converts to "bar".
@@ -31,6 +33,17 @@
 #define __PASTE(x, y)       ___PASTE(x, y)
 #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
 
+/* unused/used parameters/functions
+ * https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-unused-function-attribute
+ * https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-unused-type-attribute
+ * https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-unused-variable-attribute
+ * https://gcc.gnu.org/onlinedocs/gcc/Label-Attributes.html#index-unused-label-attribute
+ * https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-used-function-attribute
+ * https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-used-variable-attribute
+ */
+#define __unused             __attribute__((__unused__))
+#define __used               __attribute__((__used__))
+
 /* see https://lkml.org/lkml/2018/3/20/845 for explanation of this monster
  */
 #define __is_constexpr(x) \

c/include/debug.h

@@ -25,6 +25,7 @@
 #ifdef DEBUG_DEBUG
 void debug_init(u32 level);
 void debug_level_set(u32 level);
+u32  debug_level_get(void);
 void _printf debug(u32 level, bool timestamp,
                    u32 indent, const char *src,
                    u32 line, const char *, ...);

c/include/pjwhash-inline.h

@@ -0,0 +1,53 @@
+/* pjwhash-inline.h - PJW hash function, inline version.
+ *
+ * Copyright (C) 2021-2022 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#ifndef _PJWHASH_INLINE_H
+#define _PJWHASH_INLINE_H
+
+#include "bits.h"
+
+#define THREE_QUARTERS ((int) ((BITS_PER_INT * 3) / 4))
+#define ONE_EIGHTH     ((int) (BITS_PER_INT / 8))
+#define HIGH_BITS      ( ~((uint)(~0) >> ONE_EIGHTH ))
+
+#ifndef _pjw_inline
+#define _pjw_inline static inline
+#endif
+
+/**
+ * unsigned int pjwhash - PJW hash function
+ * @key:    the key address.
+ * @length: the length of key.
+ *
+ * This hash was created by Peter Jay Weinberger (AT&T Bell Labs):
+ * https://en.wikipedia.org/wiki/PJW_hash_function
+ *
+ * Return: the PJW hash.
+ */
+_pjw_inline uint pjwhash(const void* key, uint length)
+{
+   uint hash = 0, high;
+   const u8 *k = key;
+
+   for (uint i = 0; i < length; ++k, ++i) {
+       hash = (hash << ONE_EIGHTH) + *k;
+      high = hash & HIGH_BITS;
+      if (high != 0) {
+          hash ^= high >> THREE_QUARTERS;
+          hash &= ~high;
+      }
+   }
+   return hash;
+}
+
+#endif  /* _PJWHASH_INLINE_H */

c/include/pjwhash.h

@@ -0,0 +1,30 @@
+/* pjwhash.h - PJW hash function, extern version.
+ *
+ * Copyright (C) 2021-2022 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ */
+
+#ifndef _PJWHASH_H
+#define _PJWHASH_H
+
+#include "bits.h"
+
+/**
+ * unsigned int pjwhash - PJW hash function
+ * @key:    the key address.
+ * @length: the length of key.
+ *
+ * This hash was created by Peter Jay Weinberger (AT&T Bell Labs):
+ * https://en.wikipedia.org/wiki/PJW_hash_function
+ *
+ * Return: the PJW hash.
+ */
+extern uint  pjwhash (const void* key, uint length);
+
+#endif  /* _PJWHASH_H */

c/include/struct-group.h

@@ -0,0 +1,105 @@
+/* struct-group.h - mirrored structure macros.
+ *
+ * Copyright (C) 2021-2022 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ * Some parts are taken from Linux's kernel <linux/stddef.h> and others, and are :
+ * SPDX-License-Identifier: GPL-2.0
+ *
+ */
+
+#ifndef _STRUCT_GROUP_H
+#define _STRUCT_GROUP_H
+
+/**
+ * __struct_group() - Create a mirrored named and anonyomous struct
+ *
+ * @TAG: The tag name for the named sub-struct (usually empty)
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @ATTRS: Any struct attributes (usually empty)
+ * @MEMBERS: The member declarations for the mirrored structs
+ *
+ * Used to create an anonymous union of two structs with identical layout
+ * and size: one anonymous and one named. The former's members can be used
+ * normally without sub-struct naming, and the latter can be used to
+ * reason about the start, end, and size of the group of struct members.
+ * The named struct can also be explicitly tagged for layer reuse, as well
+ * as both having struct attributes appended.
+ */
+#define __struct_group(TAG, NAME, ATTRS, MEMBERS...) \
+	union { \
+		struct { MEMBERS } ATTRS; \
+		struct TAG { MEMBERS } ATTRS NAME; \
+	}
+
+/**
+ * DECLARE_FLEX_ARRAY() - Declare a flexible array usable in a union
+ *
+ * @TYPE: The type of each flexible array element
+ * @NAME: The name of the flexible array member
+ *
+ * In order to have a flexible array member in a union or alone in a
+ * struct, it needs to be wrapped in an anonymous struct with at least 1
+ * named member, but that member can be empty.
+ */
+#define DECLARE_FLEX_ARRAY(TYPE, NAME)	\
+	struct { \
+		struct { } __empty_ ## NAME; \
+		TYPE NAME[]; \
+	}
+
+/**
+ * struct_group() - Wrap a set of declarations in a mirrored struct
+ *
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @MEMBERS: The member declarations for the mirrored structs
+ *
+ * Used to create an anonymous union of two structs with identical
+ * layout and size: one anonymous and one named. The former can be
+ * used normally without sub-struct naming, and the latter can be
+ * used to reason about the start, end, and size of the group of
+ * struct members.
+ */
+#define struct_group(NAME, MEMBERS...)	\
+	__struct_group(/* no tag */, NAME, /* no attrs */, MEMBERS)
+
+/**
+ * struct_group_attr() - Create a struct_group() with trailing attributes
+ *
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @ATTRS: Any struct attributes to apply
+ * @MEMBERS: The member declarations for the mirrored structs
+ *
+ * Used to create an anonymous union of two structs with identical
+ * layout and size: one anonymous and one named. The former can be
+ * used normally without sub-struct naming, and the latter can be
+ * used to reason about the start, end, and size of the group of
+ * struct members. Includes structure attributes argument.
+ */
+#define struct_group_attr(NAME, ATTRS, MEMBERS...) \
+	__struct_group(/* no tag */, NAME, ATTRS, MEMBERS)
+
+/**
+ * struct_group_tagged() - Create a struct_group with a reusable tag
+ *
+ * @TAG: The tag name for the named sub-struct
+ * @NAME: The identifier name of the mirrored sub-struct
+ * @MEMBERS: The member declarations for the mirrored structs
+ *
+ * Used to create an anonymous union of two structs with identical
+ * layout and size: one anonymous and one named. The former can be
+ * used normally without sub-struct naming, and the latter can be
+ * used to reason about the start, end, and size of the group of
+ * struct members. Includes struct tag argument for the named copy,
+ * so the specified layout can be reused later.
+ */
+#define struct_group_tagged(TAG, NAME, MEMBERS...) \
+	__struct_group(TAG, NAME, /* no attrs */, MEMBERS)
+
+#endif  /* _STRUCT_GROUP_H */

c/pjwhash.c

@@ -0,0 +1,20 @@
+/* pjwhash.c - PJW hash function.
+ *
+ * Copyright (C) 2021-2022 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ *
+ */
+
+#define _pjw_inline extern
+
+//#include "bits.h"
+//extern unsigned int  pjwhash (const void* key, uint length);
+
+#include "pjwhash.h"
+#include "pjwhash-inline.h"