google test and gmock on Aix

[istvangonczi]

Just a quick note, I was able to figure out how to get google test and google mock compiling on Aix using g++, and I give a quick summary here:

This was done on Aix 6.1, using the IBM freeware yum installable gcc 8.3 toolchain. The same should work on higher Aix versions as well. I have 7.1 and 7.2 available. will try it on 7.2 in a bit.

On Aix, the gcc 8.3 compiler has an unusual behavior, which is different from (e.g.) Linux:
Any include locations given with the -isystem compiler option will cause all includes found there to be silently wrapped in
extern "C" { .... }.

Some of the gtest/gmock include files do contain templates, which are not supported inside extern"C" sections. Templates must rely on decorations, which are turned off when C linkage rules are in effect. The large number of resulting errors are all stemming from these silent extern "C"-s not playing well with templates. Again, these gcc introduced extern "C" { -s are not visible, so you would not be able to see these using find/grep.

The solution: change all -isystem directives to -I (capital I) directives. Feel free to ask questions.
Hopefully this makes it easier for some folks to run gtest and gmock on Aix.

Cheers

Steve Gonczi

[Prabsy]

how do we compile a gtest program on AIX?