Binutils backwards incompatibilities?

Binutils backwards incompatibilities?

[Jeff Baker]

Is there any way to easily get a list of any potential backwards 
incompatibilities between binutils versions?  We're finally looking to 
move forward to a newer version (from 2.12.1 to 2.15, at least) but 
management needs to know about any gotchas before they'll sign off.

Re: Binutils backwards incompatibilities?

[Nick Clifton]

Hi Jeff,

> Is there any way to easily get a list of any potential backwards 
> incompatibilities between binutils versions?  We're finally looking to 
> move forward to a newer version (from 2.12.1 to 2.15, at least) but 
> management needs to know about any gotchas before they'll sign off.

Have a look at the NEWS files in the ld/ binutils/ and gas/ subdirectories.

In general there should not be any backwards incompatibilities from a 
user's perspective, with the possible exception of toolchains that have 
been rendered obsolete and are no longer supported.

 From an application point view, (ie an application that uses the BFD 
library) there have been quite a few changes in the API, especially 
between 2.14 and 2.15.  These are not normally documented, but will 
become obvious as soon as the application is rebuilt.

Cheers
   Nick

Re: Binutils backwards incompatibilities?

[Jeff Baker]

I am aware of a couple of incompatibilities with SH4 support.  For one a 
subset of the relocations were renumbered; the second involves the 
treatment of relocation addends.  We ship our kernel in such a manner 
that it needs to be relocated as it's being added to a boot image.  The 
relocation addend change means that you can't relocate a kernel built 
with an older toolchain with the newer toolchain or vice versa.

Is this the kind of stuff I'd find in the NEWS files?

Nick Clifton wrote:
> Hi Jeff,
> 
> 
>>Is there any way to easily get a list of any potential backwards 
>>incompatibilities between binutils versions?  We're finally looking to
> 
> 
>>move forward to a newer version (from 2.12.1 to 2.15, at least) but 
>>management needs to know about any gotchas before they'll sign off.
> 
> 
> Have a look at the NEWS files in the ld/ binutils/ and gas/
> subdirectories.
> 
> In general there should not be any backwards incompatibilities from a 
> user's perspective, with the possible exception of toolchains that have 
> been rendered obsolete and are no longer supported.
> 
>  From an application point view, (ie an application that uses the BFD 
> library) there have been quite a few changes in the API, especially 
> between 2.14 and 2.15.  These are not normally documented, but will 
> become obvious as soon as the application is rebuilt.
> 
> Cheers
>    Nick

Re: Binutils backwards incompatibilities?

[Nick Clifton]

Hi Jeff,

> I am aware of a couple of incompatibilities with SH4 support.  For one a 
> subset of the relocations were renumbered; the second involves the 
> treatment of relocation addends.  We ship our kernel in such a manner 
> that it needs to be relocated as it's being added to a boot image.  The 
> relocation addend change means that you can't relocate a kernel built 
> with an older toolchain with the newer toolchain or vice versa.
> 
> Is this the kind of stuff I'd find in the NEWS files?

Not really no.  The gas/NEWS file does mention that SH4A support was 
added for 2.15 but nothing is mentioned about reloc renumbering.

The long answer to your original question is that there is no formal 
system for collecting potential incompatibilities between different 
binutils releases and documenting them.  Thus if you need to find out if 
a newer release will still work with binaries created with an older 
release the only way to be sure is to try it and see.

Cheers
   Nick

Re: Binutils backwards incompatibilities?

[Jeff Baker]

I was afraid you'd say that :)

Thanks.

Nick Clifton wrote:
> Hi Jeff,
> 
> 
>>I am aware of a couple of incompatibilities with SH4 support.  For one
> 
> a 
> 
>>subset of the relocations were renumbered; the second involves the 
>>treatment of relocation addends.  We ship our kernel in such a manner 
>>that it needs to be relocated as it's being added to a boot image.
> 
> The 
> 
>>relocation addend change means that you can't relocate a kernel built 
>>with an older toolchain with the newer toolchain or vice versa.
>>
>>Is this the kind of stuff I'd find in the NEWS files?
> 
> 
> Not really no.  The gas/NEWS file does mention that SH4A support was 
> added for 2.15 but nothing is mentioned about reloc renumbering.
> 
> The long answer to your original question is that there is no formal 
> system for collecting potential incompatibilities between different 
> binutils releases and documenting them.  Thus if you need to find out if
> 
> a newer release will still work with binaries created with an older 
> release the only way to be sure is to try it and see.
> 
> Cheers
>    Nick