[PATCHv2] Handle not explicitly zero terminated strings in merge sections

[Bernd Edlinger]

On 09/14/18 21:01, Jakub Jelinek wrote:
> On Fri, Sep 14, 2018 at 06:39:38PM +0000, Bernd Edlinger wrote:
>> Hi,
>>
>> this is an upate of the string-merge section, it is based on the V2-STRING_CST
>> semantic patch series, which was finally installed yesterday.
>> It merges single-byte string constants with or without terminating NUL.
>> The patch has the same Ada and C test cases that were already in the V1 patch.
>>
>> Thus there are no pre-requisite patches necessary at this time.
>>
>> Bootstrapped and reg-tested on x86_64-pc-linux-gnu.
>> Is it OK for trunk?
> 
> I believe SHF_MERGE | SHF_STRINGS sections should only ever contain
> zero-terminated strings.
> See e.g. SCO ELF documentation:
> "The size of each element is specified in the section header's sh_entsize field. If the SHF_STRINGS flag is also set, the data elements consist of null-terminated character strings."
> http://www.sco.com/developers/gabi/2003-12-17/ch4.sheader.html
> https://docs.oracle.com/cd/E23824_01/html/819-0690/ggdlu.html
> 
> So, please never put non-zero terminated strings into MS sections.
> 

Yes, that is of course clear.

The idea is, if the string itself is not zero-terminated
another zero is added, that is only done in at the assembly level.

Strings with embedded zero bytes are not put in the merge section.


Bernd.