g++/stl -frepo problem? (was: library renaming due to changed libstdc++ configuration)
I wrote earlier
> I've noticed that with recent updates, I'm suddenly getting tons of
> undefined function errors resulting from STL-related template
> instantiation. [I've attached an example at the end of this message.]
Er, any comments on this? It's driving me nuts that I now can't compile
my program... but I can't find any obvious problem with what I'm doing.
As the problem started pretty much exactly with the latest g++/libstdc++
upgrades, I wonder...
Summary of problem: compilation with g++ gives "undefined reference"
for references to some STL template function instantiations, despite
using -frepo (which AFAIK should automatically recompile something to
instantiate all missing functions). [See previous message for some
I've explored this problem further since my original message, which has
yielded a bit more info:
+ The missing methods have "O " lines in various .rpo files, and the
source for the methods (e.g., std::vector<...>::_M_insert_aux) is
available in the header files; as I understand it, -frepo should
cause the linker to pick one of the files that lists a missing
method in its .rpo file, and recompile it to instantiate the
function and change the .rpo entry to "C " -- but it doesn't seem to
be doing this (though it apparently used to).
+ Whether it works or not actually seems to depend on the order with
which entries are put into the .rpo files: I have some old .rpo
files left around (from before the recent libstdc++ changes), and if
I recompile using these as a "base" (they get updated during
compilation of course), then the compilation succeeds!! However if
I then type "make clean" and recompile everything, linking fails.
[Could this be a collect2 bug?]
+ When using google to search for reports of similar problems, I saw
that in the past such symptoms could result from having multiple
versions of libstdc++ installed; I've made sure I only have one
(libstdc++6-4.0-dev version 4.0.2-4, and libstdc++6 version 4.0.2-4).
+ I've had the same problem on two different machines (both of which
track unstable but have a somewhat different collection of packages
Should I report this as a bug against g++?
[I've tried, but failed to find a concise test case; however there's no
problem to share my source code if someone wants to debug this, and I
can supply the "make it work" old versions of my .rpo files that I
If this is simple user error, I apologize for all the noise.