Refactor build script toolchain lookups.
authorEmily <vcs@emily.moe>
Sun, 13 Oct 2019 13:53:24 +0000 (14:53 +0100)
committerwhitequark <cz@m-labs.hk>
Sun, 13 Oct 2019 13:53:24 +0000 (13:53 +0000)
commitbe5e5561e265b3c598f86865e3a528125f8dc664
tree17e05413f9136a791fd7f1c1756e5f3b8eac8eb7
parent1de77632e8096eeca02044a48b1a4b5144f0279b
Refactor build script toolchain lookups.

Now environment variable overrides no longer infect the build scripts.

_toolchain.overrides is dropped as probably misguided in the first place.

Fixes #251.
nmigen/_toolchain.py
nmigen/build/plat.py
nmigen/vendor/intel.py
nmigen/vendor/lattice_ecp5.py
nmigen/vendor/lattice_ice40.py
nmigen/vendor/lattice_machxo2.py
nmigen/vendor/xilinx_7series.py
nmigen/vendor/xilinx_spartan_3_6.py
nmigen/vendor/xilinx_ultrascale.py