From d9302c07488ded9ede1ddf171774ac8563dec63a Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Thu, 2 Jul 2020 18:13:54 +0000
Subject: [PATCH] vendor: `yosys` is not a required tool for proprietary
 toolchains.

Since commit b9799b4c, the discovery mechanism for the Yosys required
to produce Verilog is different from the usual require_tool(); namely
it is possible to produce Verilog without a `yosys` binary on PATH.

Fixes #419.
---
 nmigen/vendor/lattice_ecp5.py        | 1 -
 nmigen/vendor/lattice_ice40.py       | 1 -
 nmigen/vendor/lattice_machxo_2_3l.py | 1 -
 nmigen/vendor/xilinx_7series.py      | 5 +----
 nmigen/vendor/xilinx_spartan_3_6.py  | 1 -
 nmigen/vendor/xilinx_ultrascale.py   | 5 +----
 6 files changed, 2 insertions(+), 12 deletions(-)

diff --git a/nmigen/vendor/lattice_ecp5.py b/nmigen/vendor/lattice_ecp5.py
index cfa20ee..c1a1366 100644
--- a/nmigen/vendor/lattice_ecp5.py
+++ b/nmigen/vendor/lattice_ecp5.py
@@ -176,7 +176,6 @@ class LatticeECP5Platform(TemplatedPlatform):
     # Diamond templates
 
     _diamond_required_tools = [
-        "yosys",
         "pnmainc",
         "ddtcmd"
     ]
diff --git a/nmigen/vendor/lattice_ice40.py b/nmigen/vendor/lattice_ice40.py
index fcfa1c0..da490a8 100644
--- a/nmigen/vendor/lattice_ice40.py
+++ b/nmigen/vendor/lattice_ice40.py
@@ -172,7 +172,6 @@ class LatticeICE40Platform(TemplatedPlatform):
     # iCECube2 templates
 
     _icecube2_required_tools = [
-        "yosys",
         "synthesis",
         "synpwrap",
         "tclsh",
diff --git a/nmigen/vendor/lattice_machxo_2_3l.py b/nmigen/vendor/lattice_machxo_2_3l.py
index 0eb348e..b94d26d 100644
--- a/nmigen/vendor/lattice_machxo_2_3l.py
+++ b/nmigen/vendor/lattice_machxo_2_3l.py
@@ -39,7 +39,6 @@ class LatticeMachXO2Or3LPlatform(TemplatedPlatform):
     grade   = "C" # [C]ommercial, [I]ndustrial
 
     required_tools = [
-        "yosys",
         "pnmainc",
         "ddtcmd"
     ]
diff --git a/nmigen/vendor/xilinx_7series.py b/nmigen/vendor/xilinx_7series.py
index c9b44f1..0bf5424 100644
--- a/nmigen/vendor/xilinx_7series.py
+++ b/nmigen/vendor/xilinx_7series.py
@@ -53,10 +53,7 @@ class Xilinx7SeriesPlatform(TemplatedPlatform):
     speed   = abstractproperty()
     grade   = None
 
-    required_tools = [
-        "yosys",
-        "vivado"
-    ]
+    required_tools = ["vivado"]
     file_templates = {
         **TemplatedPlatform.build_script_templates,
         "build_{{name}}.sh": r"""
diff --git a/nmigen/vendor/xilinx_spartan_3_6.py b/nmigen/vendor/xilinx_spartan_3_6.py
index a4b4d99..0de16d2 100644
--- a/nmigen/vendor/xilinx_spartan_3_6.py
+++ b/nmigen/vendor/xilinx_spartan_3_6.py
@@ -59,7 +59,6 @@ class XilinxSpartan3Or6Platform(TemplatedPlatform):
     speed   = abstractproperty()
 
     required_tools = [
-        "yosys",
         "xst",
         "ngdbuild",
         "map",
diff --git a/nmigen/vendor/xilinx_ultrascale.py b/nmigen/vendor/xilinx_ultrascale.py
index c144229..6f90517 100644
--- a/nmigen/vendor/xilinx_ultrascale.py
+++ b/nmigen/vendor/xilinx_ultrascale.py
@@ -53,10 +53,7 @@ class XilinxUltraScalePlatform(TemplatedPlatform):
     speed   = abstractproperty()
     grade   = None
 
-    required_tools = [
-        "yosys",
-        "vivado"
-    ]
+    required_tools = ["vivado"]
     file_templates = {
         **TemplatedPlatform.build_script_templates,
         "build_{{name}}.sh": r"""
-- 
2.30.2