On Sat, Apr 30, 2011 at 7:09 AM, Wolfgang Denk wd@denx.de wrote:
Dear Macpaul Lin,
In message BANLkTi=haZVW17eNWYCmYf3McrGmbm-4Xw@mail.gmail.com you wrote:
I think we still have to discuss about the typedef's. What does the "new" typedef means?
It means adding any new code to U-Boot which includes "typedef"s.
According to the checkpatch result, "typedef" warning exists in 4 files. arch/nds32/include/asm/posix_types.h arch/nds32/include/asm/types.h arch/nds32/include/asm/global_data.h arch/nds32/include/asm/u-boot.h.
File arch/nds32/include/asm/posix_types.h and arch/nds32/include/asm/types.h come from the Linux kernel. Which is usually used for posix compatibility for Linux Kernel.
So these files should be fixed in Linux, too, because it is the Linux checkpatch tool which throws this warning.
I don't think this affects POSIX compatibility. Which typedef's are required by POSIX?
Which should be "old" features for posix and compatibility. However, you cannot say for a new architecture to support posix and other compatibility as "new" typedef. I've checked the latest kernel (2.6.38.1), arm, mips, avr32, powerpc consist these posix_types.h and types.h with "typedef".
Maybe this is old code that was added before checkpatch existed?
In Linux "CodingStyle"
" Chapter 5: Typedefs
Please don't use things like "vps_t".
It's a _mistake_ to use typedef for structures and pointers." [skip] "Lots of people think that typedefs "help readability". Not so. They are useful only for:" [skip] " (b) Clear integer types, where the abstraction _helps_ avoid confusion whether it is "int" or "long".
u8/u16/u32 are perfectly fine typedefs, although they fit into category (d) better than here.
NOTE! Again - there needs to be a _reason_ for this. If something is "unsigned long", then there's no reason to do
typedef unsigned long myflags_t;
but if there is a clear reason for why it under certain circumstances might be an "unsigned int" and under other configurations might be "unsigned long", then by all means go ahead and use a typedef."
I think posix_types may be an example of this case. nds32 have some types different from what has been defined in <asm-generic/posix_types.h>
As for commit time, the latest update for checkpatch.pl is in 2009-01-06 653d4876 (Andy Whitcroft 2007-06-23 17:16:34 -0700 1891) if ($line =~ /\btypedef\s/ && 8054576d (Andy Whitcroft 2009-01-06 14:41:26 -0800 1892) $line !~ /\btypedef\s+$Type\s*(\s**?$Ident\s*)\s*(/ && c45dcabd (Andy Whitcroft 2008-06-05 22:46:01 -0700 1893) $line !~ /\btypedef\s+$Type\s+$Ident\s*(/ && 8ed22cad (Andy Whitcroft 2008-10-15 22:02:32 -0700 1894) $line !~ /\b$typeTypedefs\b/ && 653d4876 (Andy Whitcroft 2007-06-23 17:16:34 -0700 1895) $line !~ /\b__bitwise(?:__|)\b/) { de7d4f0e (Andy Whitcroft 2007-07-15 23:37:22 -0700 1896) WARN("do not add new typedefs\n" . $herecurr); 0a920b5b (Andy Whitcroft 2007-06-01 00:46:48 -0700 1897) }
But Michal Simek's commit, which added posix_types.h is adapted in 2009-03-27. You can reference it by 6d9c3f208580 in Linux repo
It looks the kernel is not going to fix the "old" typedef for posix_types.h and types.h
Eventually they would not add these files as is any more today.
I think they say "please do not add any new typedef" might mean to those typedef used in drivers or protocols.
I mean all of them.
In the other 2 files arch/nds32/include/asm/global_data.h and arch/nds32/include/asm/u-boot.h, typedef was used for #449: FILE: arch/nds32/include/asm/global_data.h:46: +typedef struct global_data { +} gd_t; #1505: FILE: arch/nds32/include/asm/u-boot.h:41: +typedef struct bd_info { +} bd_t;
Ouch. You got me there... :-(
I don't know if you have any idea of fixing it in u-boot.
Well, the fix is basicly straightforward - replace all ocurrences of gd_t and bd_t in the U-Boot code. But this is a bigger issue and more work than I dare to push on you. I'm grinding my teeth, but I will accept these.
Best regards,
Wolfgang Denk
-- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de If ignorance is bliss, why aren't there more happy people? _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot