[U-Boot] GCC 5.x compile errors

[U-Boot] GCC 5.x compile errors

[ANDY KENNEDY]

Attempted to build u-boot with gcc 5.x for mipsel 32.  Result was that
I get brokenness around arch/mips/include/asm/io.h and
arch/mips/include/asm/system.h.  The source lines all look something
like:

extern inline void func()
{
	func text ;
}

Question:  Is that valid C text?  I have never seen such.  Also, what
does this mean from a header file?  The way I read this is

extern = the following declare exists in global space (no code here)

inline = use this function definition in line in place of creating a
	   text ref section

I would expect these two to be mutually exclusive????

Please enlighten me!

Thanks,
Andy

[U-Boot] GCC 5.x compile errors

[Albert ARIBAUD]

Hello ANDY,

On Tue, 30 Jun 2015 22:02:38 +0000, ANDY KENNEDY
<ANDY.KENNEDY@adtran.com> wrote:
> Attempted to build u-boot with gcc 5.x for mipsel 32.  Result was that
> I get brokenness around arch/mips/include/asm/io.h and
> arch/mips/include/asm/system.h.  The source lines all look something
> like:
> 
> extern inline void func()
> {
> 	func text ;
> }
> 
> Question:  Is that valid C text?  I have never seen such.  Also, what
> does this mean from a header file?  The way I read this is
> 
> extern = the following declare exists in global space (no code here)
> 
> inline = use this function definition in line in place of creating a
> 	   text ref section
> 
> I would expect these two to be mutually exclusive????
> 
> Please enlighten me!

Actually, extern vs static takes a meaning for inline functions
different from the one for traditional non-inline ones.

	"If you specify both inline and extern in the function
	definition, then the definition is used only for inlining.
	In no case is the function compiled on its own, not even
	if you refer to its address explicitly. Such an address
	becomes an external reference, as if you had only declared
	the function, and had not defined it."

See https://gcc.gnu.org/onlinedocs/gcc/Inline.html for all the gory
details on inline functions (this is for the latest version; if you're
working with a specific, older, gcc version, look up the corresponding
page, in case subtle changes were introduced).

> Thanks,
> Andy

Amicalement,
-- 
Albert.

[U-Boot] GCC 5.x compile errors

[Daniel Schwierzeck]

Am 01.07.2015 um 07:53 schrieb Albert ARIBAUD:
> Hello ANDY,
> 
> On Tue, 30 Jun 2015 22:02:38 +0000, ANDY KENNEDY
> <ANDY.KENNEDY@adtran.com> wrote:
>> Attempted to build u-boot with gcc 5.x for mipsel 32.  Result was that
>> I get brokenness around arch/mips/include/asm/io.h and
>> arch/mips/include/asm/system.h.  The source lines all look something
>> like:
>>
>> extern inline void func()
>> {
>> 	func text ;
>> }
>>
>> Question:  Is that valid C text?  I have never seen such.  Also, what
>> does this mean from a header file?  The way I read this is
>>
>> extern = the following declare exists in global space (no code here)
>>
>> inline = use this function definition in line in place of creating a
>> 	   text ref section
>>
>> I would expect these two to be mutually exclusive????
>>
>> Please enlighten me!
> 
> Actually, extern vs static takes a meaning for inline functions
> different from the one for traditional non-inline ones.
> 
> 	"If you specify both inline and extern in the function
> 	definition, then the definition is used only for inlining.
> 	In no case is the function compiled on its own, not even
> 	if you refer to its address explicitly. Such an address
> 	becomes an external reference, as if you had only declared
> 	the function, and had not defined it."
> 
> See https://gcc.gnu.org/onlinedocs/gcc/Inline.html for all the gory
> details on inline functions (this is for the latest version; if you're
> working with a specific, older, gcc version, look up the corresponding
> page, in case subtle changes were introduced).
> 

the kernel changed it all to "static inline" long time ago. We should do
the same. I'll send a patch to fix it.

-- 
- Daniel