MDEV-21907: Fix some -Wconversion outside InnoDB

Some .c and .cc files are compiled as part of Mariabackup.
Enabling -Wconversion for InnoDB would also enable it for
Mariabackup. The .h files are being included during
InnoDB or Mariabackup compilation.

Notably, GCC 5 (but not GCC 4 or 6 or later versions)
would report -Wconversion for x|=y when the type is
unsigned char. So, we will either write x=(uchar)(x|y)
or disable the -Wconversion warning for GCC 5.

bitmap_set_bit(), bitmap_flip_bit(), bitmap_clear_bit(), bitmap_is_set():
Always implement as inline functions.

1 files changed, 14 insertions, 35 deletions

diff --git a/include/my_bitmap.h b/include/my_bitmap.h
index 1b0fbe40d2e..f19254404c1 100644
--- a/include/my_bitmap.h
+++ b/include/my_bitmap.h
@@ -1,5 +1,5 @@
 /* Copyright (c) 2001, 2011, Oracle and/or its affiliates.
-   Copyright (c) 2009-2011, Monty Program Ab
+   Copyright (c) 2009, 2020, MariaDB Corporation.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -89,56 +89,35 @@ extern void bitmap_lock_clear_bit(MY_BITMAP *map, uint bitmap_bit);
 #define no_bytes_in_map(map) (((map)->n_bits + 7)/8)
 #define no_words_in_map(map) (((map)->n_bits + 31)/32)
 #define bytes_word_aligned(bytes) (4*((bytes + 3)/4))
-#define _bitmap_set_bit(MAP, BIT) (((uchar*)(MAP)->bitmap)[(BIT) / 8] \
-                                  |= (1 << ((BIT) & 7)))
-#define _bitmap_flip_bit(MAP, BIT) (((uchar*)(MAP)->bitmap)[(BIT) / 8] \
-                                  ^= (1 << ((BIT) & 7)))
-#define _bitmap_clear_bit(MAP, BIT) (((uchar*)(MAP)->bitmap)[(BIT) / 8] \
-                                  &= ~ (1 << ((BIT) & 7)))
-#define _bitmap_is_set(MAP, BIT) (uint) (((uchar*)(MAP)->bitmap)[(BIT) / 8] \
-                                         & (1 << ((BIT) & 7)))
-/*
-  WARNING!
-
-  The below symbols are inline functions in DEBUG builds and macros in
-  non-DEBUG builds. The latter evaluate their 'bit' argument twice.
-
-  NEVER use an increment/decrement operator with the 'bit' argument.
-  It would work with DEBUG builds, but fails later in production builds!
-
-  FORBIDDEN: bitmap_set_bit($my_bitmap, (field++)->field_index);
-*/
-#ifndef DBUG_OFF
+/* The following functions must be compatible with create_last_word_mask()! */
 static inline void
 bitmap_set_bit(MY_BITMAP *map,uint bit)
 {
-  DBUG_ASSERT(bit < (map)->n_bits);
-  _bitmap_set_bit(map,bit);
+  uchar *b= (uchar*) map->bitmap + bit / 8;
+  DBUG_ASSERT(bit < map->n_bits);
+  *b= (uchar) (*b | 1U << (bit & 7));
 }
 static inline void
 bitmap_flip_bit(MY_BITMAP *map,uint bit)
 {
-  DBUG_ASSERT(bit < (map)->n_bits);
-  _bitmap_flip_bit(map,bit);
+  uchar *b= (uchar*) map->bitmap + bit / 8;
+  DBUG_ASSERT(bit < map->n_bits);
+  *b= (uchar) (*b ^ 1U << (bit & 7));
 }
 static inline void
 bitmap_clear_bit(MY_BITMAP *map,uint bit)
 {
-  DBUG_ASSERT(bit < (map)->n_bits);
-  _bitmap_clear_bit(map,bit);
+  uchar *b= (uchar*) map->bitmap + bit / 8;
+  DBUG_ASSERT(bit < map->n_bits);
+  *b= (uchar) (*b & ~(1U << (bit & 7)));
 }
 static inline uint
 bitmap_is_set(const MY_BITMAP *map,uint bit)
 {
-  DBUG_ASSERT(bit < (map)->n_bits);
-  return _bitmap_is_set(map,bit);
+  const uchar *b= (const uchar*) map->bitmap + bit / 8;
+  DBUG_ASSERT(bit < map->n_bits);
+  return !!(*b & (1U << (bit & 7)));
 }
-#else
-#define bitmap_set_bit(MAP, BIT) _bitmap_set_bit(MAP, BIT)
-#define bitmap_flip_bit(MAP, BIT) _bitmap_flip_bit(MAP, BIT)
-#define bitmap_clear_bit(MAP, BIT) _bitmap_clear_bit(MAP, BIT)
-#define bitmap_is_set(MAP, BIT) _bitmap_is_set(MAP, BIT)
-#endif
 
 static inline my_bool bitmap_cmp(const MY_BITMAP *map1, const MY_BITMAP *map2)
 {