Gcc 3.4.3 to Gcc 4.8x

Gcc 3.4.3 to Gcc 4.8x

[Michael Richardson]

Good morning!  I’m assisting a client moving from/to the above-referenced versions.  Any known issues with this specific upgrade?

Thanks!

Re: Gcc 3.4.3 to Gcc 4.8x

[Jonathan Wakely]

On Thu, 5 Dec 2019 at 17:08, Michael Richardson wrote:
>
> Good morning!  I’m assisting a client moving from/to the above-referenced versions.  Any known issues with this specific upgrade?

Apart from the fact you're moving from a very ancient release to an
only slightly ancient release?

There are hundreds of differences between those versions, including a
stricter parser for C++ that will reject buggy code that used to be
accepted. You haven't even said what language front ends you'll be
using, so it's not really possible to be more specific about issues
you might encounter.

You can read the release notes for yourself:

https://gcc.gnu.org/gcc-4.0/changes.html
https://gcc.gnu.org/gcc-4.1/changes.html
https://gcc.gnu.org/gcc-4.2/changes.html
https://gcc.gnu.org/gcc-4.3/changes.html
https://gcc.gnu.org/gcc-4.4/changes.html
https://gcc.gnu.org/gcc-4.5/changes.html
https://gcc.gnu.org/gcc-4.6/changes.html
https://gcc.gnu.org/gcc-4.7/changes.html
https://gcc.gnu.org/gcc-4.8/changes.html

RE: Gcc 3.4.3 to Gcc 4.8x

[Dallman, John]

> Good morning!  I’m assisting a client moving from/to the above-referenced versions.  Any known issues with this specific upgrade?

I have not done that specific upgrade. I went from 3.3, to 4.0, to 4.3, to 4.8, with C code. Things I encountered along the way:

Later versions of GCC try much harder to re-use the stack space for variables declared in inner blocks. That means faulty code which uses pointers to variables that have gone out of scope is more likely to actually cause problems with later compilers. The code needs to be fixed.

You may well be able to turn up the optimisation: -O2 did not work well for me with GCC 3.3, but is good on GCC 4.8.

You may get more information if you say what platform(s) you're building for. I was doing 32-bit and 64-bit x86 for the relevant years, except that I dropped 32-bit during the GCC 4.3 period.

--
John Dallman
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