Loïc Minier loic.minier@linaro.org writes:
I'm trying to extend the *link: specs to pass a different -dynamic-linker depending on the float ABI. But I didn't manage to build a construct which would preserve the order of the flags; if I do something like: %{msoft-float:-dynamic-linker V1} %{mfloat-abi=softfp:-dynamic-linker V2}
Then I get V2 for "-mfloat-abi=softfp -msoft-float" instead of V1.
In gcc/gcc.c I found some docs on spec file syntax; I see one can use %{S*&T*} and %{S*:X}, but apparently %{S*&T*:X} isn't allowed, so I can't manipulate the value. I tried to use %{msoft-float*:-dynamic-linker V1} %{mfloat-abi=softfp*:-dynamic-linker V2} but that gives the same effect (the msoft-float flags are grouped together in the original order and put first, then the mfloat-abi=softfp are grouped together in the original order and put second).
I didn't manage to get %{msoft-float*:%<msoft-float -dynamic-linker V1} to work; in fact I didn't get supressions to work.
Having later command-line options reverse earlier ones isn't fully supported in this kind of context. The same problem applies to multilibs. E.g. if you say "-marm -mthumb" in a toolchain that has ARM and Thumb multilibs, there's no guarantee that you'll link against the Thumb ones.
Joseph Myers is in the process of overhauling the driver's command-line processing. It might be easier to do what you want once he's finished.
Richard