[U-Boot] [PATCH 1/7] types.h: define (u)int8_t, (u)int16_t, (u)int32_t based on compiler info (MAD)

[Masahiro Yamada]

The intent of this series is to show the nasty problems introduced
by <stdint.h>.

Simon and I are already discussing this in the following thread:
http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/203954
http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/198550/focus=205880

   -----

Commit 0d296cc2d3b8 (Provide option to avoid defining a custom version
of uintptr_t.) introduced CONFIG_USE_STDINT.  If it is enabled,
<stdint.h> is included and uint64_t, u_int64_t, int64_t are defined
based on the compiler-provided information.  While, inconsistently,
that commit left uint_{8,16,32}_t, u_int{8,16,32}t, int_{8,16,32}t
to be hard-coded in include/linux/types.h.

This causes type conflicts between the typedefs defined in the compiler's
<stdint.h> and the ones hard-coded in include/linux/types.h.

As you may know, 'uint32_t' is defined as 'unsigned long' in some compilers
such as bare metal ARM toolchain, whereas it is defined as 'unsigned int'
in kernel.org ones.
(This is also clearly mentioned in Linux's arch/arm/include/asm/types.h)

If you make a decision to use a compiler-provided <stdint.h>,
we cannot hard-code the fixed-width types.
To avoid the type conflicts, we must make all of them compiler-dependent
consistently.

You can reproduce this problem, for example, with a Linaro toolchain.

Visit "http://www.linaro.org/downloads/" and download "Bare-metal toolchain
for Cortex-R/M and Cortex-A".

$ make USE_STDINT=1 CROSS_COMPILE=arm-none-eabi- omap4_panda_defconfig all
  HOSTCC  scripts/basic/fixdep
  HOSTCC  scripts/kconfig/conf.o
   [snip]
  CC      lib/asm-offsets.s
In file included from /opt/gcc-arm-none-eabi-4_7-2013q1/bin/../lib/gcc/arm-none-eabi/4.7.3/include/stdint.h:5:0,
                 from include/compiler.h:117,
                 from include/image.h:19,
                 from include/common.h:82,
                 from lib/asm-offsets.c:15:
/opt/gcc-arm-none-eabi-4_7-2013q1/bin/../lib/gcc/arm-none-eabi/4.7.3/include/stdint-gcc.h:40:24: error: conflicting types for 'int32_t'
In file included from include/common.h:21:0,
                 from lib/asm-offsets.c:15:
include/linux/types.h:99:17: note: previous declaration of 'int32_t' was here
In file included from /opt/gcc-arm-none-eabi-4_7-2013q1/bin/../lib/gcc/arm-none-eabi/4.7.3/include/stdint.h:5:0,
                 from include/compiler.h:117,
                 from include/image.h:19,
                 from include/common.h:82,
                 from lib/asm-offsets.c:15:
/opt/gcc-arm-none-eabi-4_7-2013q1/bin/../lib/gcc/arm-none-eabi/4.7.3/include/stdint-gcc.h:52:25: error: conflicting types for 'uint32_t'
In file included from include/common.h:21:0,
                 from lib/asm-offsets.c:15:
include/linux/types.h:105:17: note: previous declaration of 'uint32_t' was here

Signed-off-by: Masahiro Yamada <yamada.m at jp.panasonic.com>
Cc: Gabe Black <gabeblack at chromium.org>
Cc: Simon Glass <sjg at chromium.org>
Cc: Bill Richardson <wfrichar at google.com>
Cc: Tom Rini <trini at ti.com>
---

 include/linux/types.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/linux/types.h b/include/linux/types.h
index c9a8d9a..5549479 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -91,18 +91,33 @@ typedef unsigned long		ulong;
 #ifndef __BIT_TYPES_DEFINED__
 #define __BIT_TYPES_DEFINED__
 
+#if defined(CONFIG_USE_STDINT)
+typedef		__UINT8_TYPE__	u_int8_t;
+typedef		__INT8_TYPE__	int8_t;
+typedef		__UINT16_TYPE__	u_int16_t;
+typedef		__INT16_TYPE__	int16_t;
+typedef		__UINT32_TYPE__	u_int32_t;
+typedef		__INT32_TYPE__	int32_t;
+#else
 typedef		__u8		u_int8_t;
 typedef		__s8		int8_t;
 typedef		__u16		u_int16_t;
 typedef		__s16		int16_t;
 typedef		__u32		u_int32_t;
 typedef		__s32		int32_t;
+#endif
 
 #endif /* !(__BIT_TYPES_DEFINED__) */
 
+#if defined(CONFIG_USE_STDINT)
+typedef		__UINT8_TYPE__	uint8_t;
+typedef		__UINT16_TYPE__	uint16_t;
+typedef		__UINT32_TYPE__	uint32_t;
+#else
 typedef		__u8		uint8_t;
 typedef		__u16		uint16_t;
 typedef		__u32		uint32_t;
+#endif
 
 #if defined(__GNUC__) && !defined(__STRICT_ANSI__) && \
 	(!defined(CONFIG_USE_STDINT) || !defined(__INT64_TYPE__))
-- 
1.9.1