Pull NuttX up to the 6.24 release.

Merge branch 'nuttx-merge-5447'

1 files changed, 33 insertions, 2 deletions

diff --git a/nuttx/include/stdbool.h b/nuttx/include/stdbool.h
index f11219912..9c16aee29 100644
--- a/nuttx/include/stdbool.h
+++ b/nuttx/include/stdbool.h
@@ -42,10 +42,33 @@
 
 #include <nuttx/config.h>
 
+/* If CONFIG_ARCH_STDBOOL_H is set, then the archecture will provide its own
+ * stdbool.h file.  In this case, this header file will simply re-direct to
+ * the architecture-specfiic stdbool.h header file.
+ */
+
 #ifdef CONFIG_ARCH_STDBOOL_H
 #  include <arch/stdbool.h>
+
+/* NuttX will insist that the sizeof(bool) is 8-bits.  The sizeof of _Bool
+ * used by any specific compiler is implementation specific:  It can vary from
+ * compiler-to-compiler and even vary between different versions of the same
+ * compiler.  Compilers seems to be converging to sizeof(_Bool) == 1.  If that
+ * is true for your compiler, you should define CONFIG_C99_BOOL8 in your NuttX
+ * configuration for better standards compatibility.
+ *
+ * CONFIG_C99_BOOL8 - Means (1) your C++ compiler has sizeof(_Bool) == 8,
+ * (2) your C compiler supports the C99 _Bool intrinsic type, and (2) that
+ * the C99 _Bool type also has size 1.
+ */
+
 #else
+
+ /* nuttx/compiler.h may also define or undefine CONFIG_C99_BOOL8 */
+
 #  include <nuttx/compiler.h>
+
+#if !defined(__cplusplus) || !defined(CONFIG_C99_BOOL8)
 #  include <stdint.h>
 
 /****************************************************************************
@@ -58,10 +81,15 @@
  * NOTE: Under C99 'bool' is required to be defined to be the intrinsic type
  * _Bool.  However, in this NuttX context, we need backward compatibility
  * to pre-C99 standards where _Bool is not an intrinsic type.  Hence, we
- * use _Bool8 as the underlying type.
+ * use _Bool8 as the underlying type (unless CONFIG_C99_BOOL8 is defined)
  */
 
-#define bool  _Bool8
+#ifdef CONFIG_C99_BOOL8
+#  define bool _Bool
+#else
+#  define bool _Bool8
+#endif
+
 #define true  1
 #define false 0
 
@@ -83,7 +111,10 @@
  * as the underlying type.
  */
 
+#ifndef CONFIG_C99_BOOL8
 typedef uint8_t _Bool8;
+#endif
 
+#endif /* __cplusplus && CONFIG_C99_BOOL8 */
 #endif /* CONFIG_ARCH_STDBOOL_H */
 #endif /* __INCLUDE_STDBOOL_H */