No comments on this topic? Nobody cares even if I revert commit 0d296cc and 4166ecb ?
On Wed, 26 Nov 2014 16:45:51 +0900 Masahiro Yamada <yamad...@jp.panasonic.com> wrote: > Hi Tom, Simon, other developers, > > > > Since commit 0d296cc2d3b8 (Provide option to avoid defining a custom version > of uintptr_t) > and commit 4166ecb247a1 (Add some standard headers external code might need), > I have been wondering if they were right decisions. > > > > As arch/arm/include/asm/types.h of Linux Kernel says, > using 'stdint.h' is not feasible. > > -------------------------------------->8------------------------------------- > /* > * The C99 types uintXX_t that are usually defined in 'stdint.h' are not as > * unambiguous on ARM as you would expect. For the types below, there is a > * difference on ARM between GCC built for bare metal ARM, GCC built for glibc > * and the kernel itself, which results in build errors if you try to build > with > * -ffreestanding and include 'stdint.h' (such as when you include > 'arm_neon.h' > * in order to use NEON intrinsics) > * > * As the typedefs for these types in 'stdint.h' are based on builtin defines > * supplied by GCC, we can tweak these to align with the kernel's idea of > those > * types, so 'linux/types.h' and 'stdint.h' can be safely included from the > same > * source file (provided that -ffreestanding is used). > * > * int32_t uint32_t uintptr_t > * bare metal GCC long unsigned long unsigned int > * glibc GCC int unsigned int unsigned int > * kernel int unsigned int unsigned long > */ > --------------------------------------8<---------------------------------------- > > > Actually, the kernel never includes <stdint.h> except host programs. > > > Commit 0d296cc2d3b8 introduced "USE_STDINT", but it causes type conflicts > depending on which GCC is used. > > > With ARM bare metal GCC, > > yamada@beagle:~/workspace/u-boot$ make omap3_beagle_defconfig all > CROSS_COMPILE=arm-none-eabi- USE_STDINT=1 > # > # configuration written to .config > # > # > # configuration written to spl/.config > # > scripts/kconfig/conf --silentoldconfig Kconfig > scripts/kconfig/conf --silentoldconfig Kconfig > CHK include/config.h > GEN include/autoconf.mk > GEN include/autoconf.mk.dep > GEN spl/include/autoconf.mk > CHK include/config/uboot.release > CHK include/generated/version_autogenerated.h > CHK include/generated/timestamp_autogenerated.h > UPD include/generated/timestamp_autogenerated.h > CC lib/asm-offsets.s > In file included from > /opt/arm-2011.03/bin/../lib/gcc/arm-none-eabi/4.5.2/include/stdint.h:5:0, > from include/compiler.h:117, > from include/image.h:19, > from include/common.h:85, > from lib/asm-offsets.c:15: > /opt/arm-2011.03/bin/../lib/gcc/arm-none-eabi/4.5.2/include/stdint-gcc.h:40:24: > error: conflicting types for 'int32_t' > include/linux/types.h:99:17: note: previous declaration of 'int32_t' was here > /opt/arm-2011.03/bin/../lib/gcc/arm-none-eabi/4.5.2/include/stdint-gcc.h:52:25: > error: conflicting types for 'uint32_t' > include/linux/types.h:105:17: note: previous declaration of 'uint32_t' was > here > make[2]: *** [lib/asm-offsets.s] Error 1 > make[1]: *** [prepare0] Error 2 > make: *** [__build_one_by_one] Error 2 > > > > > OK, we can fix "int32_t" and "uint32_t", but it still seems strange to see > that > "uint32_t" is defined as "unsigned long", whereas "u32" is defined as > "unsigned int". > > If so, must we fix "u32", "s32", ... all the fixed-width typedefs ? > > I notice including <linux/types.h> in the U-Boot source tree and > <stdint.h> provided by your compiler at the same time is a nightmare. > > If we lean toward <stdint.h>, we must ban <linux/types.h>, > but <stdint.h> is not available all the time. > For example, kernel.org tool-chains do not provide <stdint.h>. > > Maybe we can drastically re-write <linux/types.h> and friends > to resolve the type conflicts, but I do not think we should not drift apart > from the kernel > because we have borrowed many source files from Linux. > > > > > Best Regards > Masahiro Yamada > > _______________________________________________ > U-Boot mailing list > U-Boot@lists.denx.de > http://lists.denx.de/mailman/listinfo/u-boot _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
