On 25/08/2010 16:37, Christian Maeder wrote:
Christian Maeder schrieb:
Simon Marlow schrieb:
On 23/08/2010 17:45, Brandon S Allbery KF8NH wrote:
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On 8/23/10 11:57 , Christian Maeder wrote:
However, when I try to compile the simplest source with on older gcc-3.4.4 I get the link error below, but only for the threaded rts!
With ghc-6.12.1 and gcc-4.x.y (x< 3) I did not have such a problem when switching to a machine that only has gcc-3.4.4. You got lucky; mixing GCC major versions like that is not expected (much less guaranteed) to work in general. GCC evidently changed the way it implements some thread support routines between gcc3 and gcc4.
Why should it not be possible to create object files (like also dynamic libs) with (very) different compilers?
This is a case where the ABI changed between versions of gcc (I presume). It rarely happens with C code, but happens more often with C++, and, of course, in GHC we change the ABI with every single release so you should be used to this by now :-)
In particular, thread-local variables, which are used by the parallel GC.
I'm just testing if I get runtime problems, but the linking error goes away, if I put libgcc_eh.a from gcc-4.3.3 into ghc's libdir.
The hack seems to work, although it looks dangerous regarding other symbols from libgcc_eh.a that should be in sync with the used gcc-3.4.4.
I wouldn't trust it. Why do you need to mix code compiled by two different gcc versions? Cheers, Simon