fix Issue 7044 - Missing a way to control the order of arguments pass…

[WalterBright]

…ed to the linker makes impossible to link some programs

https://issues.dlang.org/show_bug.cgi?id=7044

Adds the -confsection=name switch.

[MartinNowak]

See https://issues.dlang.org/show_bug.cgi?id=7044#c51 for a discussion of the shortcomings of this solution.

[WalterBright]

rebased for ddmd

[andralex]

@WalterBright @MartinNowak ping?

[dlang-bot]

Thanks for your pull request, @WalterBright!

Bugzilla references

Auto-close	Bugzilla	Description
✓	7044	Missing a way to control the order of arguments passed to the linker makes impossible to link some programs

[andralex]

@WalterBright @MartinNowak ping :)

[JinShil]

I don't care for this solution for much the same reason @MartinNowak mentioned in the bug report and because I think better solutions exist.

I don't think -defaultLib and -debugLib should exist and be given special treatment by the compiler. Rather I think the problem should be generalized and phobos/druntime should be treated just like any other library. If we want to link libraries by default, then those libraries should be added to the default DFLAGS in dmd.conf.

Then to address linker order, we simply use the order specified on the command line appended or prepended to DFLAGS. If we want to make it even more flexible, we can append an order to the -L flag, so -L2=xxx -L0=yyy -L2=www -L1=zzz would create linker flags in the order of yyy zzz xxx www. -L with no order number will always go last (or first if you prefer).

To mitigate breakage, we can always place -defaultLib and -debugLib at -L2 (or some other middle of the road order), so users can easily place libraries before or after at their discretion without overriding the default DFLAGS.

If users need to override the defaults in dmd.conf, they can always do -conf= and build the command line from scratch.

[WalterBright]

Should be completely re-evaluated.