Link a Dynamic library built from a higher version gcc?

MichelleL · 08-06-2015, 03:17 PM

Hi,

I have a third-party .so library and want to link it from my own program. However the .so library is built on a higher version of gcc and higher version of SLES (the library is written in C++ by the way) than my program. How do I find out whether the two compilation suites are compatible or not?

Thanks in advance!

Keruskerfuerst · 08-07-2015, 03:00 AM

I dont think that will work.

MichelleL · 08-07-2015, 10:10 AM

Thanks Keruskerfuerst,

Are there any particular reasons, or is it a general rule of thumb? It would be appreciated if you could point me to some information.

knudfl · 08-07-2015, 01:14 PM

Quote:

How do I find out whether the two compilation suites are compatible or not ?

Very simple : $ ldd <third-party>.so

... A `library.so' built on a later OS will usually depend on a later libc.so.6 .

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MichelleL · 08-07-2015, 01:31 PM

Thanks knudfl,

I tried running 'ldd <third-party>.so' on both build environments and the list of shared libraries are printed in both cases. In the lower gcc environment, libc.so.6 is linked to libc-2.4.so; while on the higher environment, libc.so.6 is linked to libc-2.17.so. My follow-up question is how to determine the compatibility between the libc.so.6 libraries? I am not an expert on gcc so please bare with me.

knudfl · 08-07-2015, 09:02 PM

Re #5.

If nothing is missing by $ ldd <third-party>.so
... then you should be able to use the library with no issues.

MichelleL · 08-10-2015, 12:51 PM

Nothing is missing by 'ldd <third-party>.so' in both environment. However when I tried to link the library in the lower version gcc environment, g++ issues the following error:

'<third-party>.so' file not recognized: File format not recognized
collect2: ld returned 1 exit status

The same linking command works in the higher version gcc environment.
Something else is still missing?

knudfl · 08-10-2015, 02:27 PM

Re #7.

? May be one of the OS`s has a different architecture ?
The deciding command is : $ uname -m

And this command decides the file architecture : $ file <third-party>.so

MichelleL · 08-10-2015, 02:39 PM

No. Both OS are x86_64. One is SLES 10 and the other is SLES 11. The $ file <third-party>.so output is this:

ELF 64-bit LSB shared object, AMD x86-64, version 1 (SYSV), stripped