Switch everything to platforms
This patch switches the codebase over from using the "cpu"
mechanism to using bazel platforms. See
https://docs.bazel.build/versions/master/platforms.html for some more
information.
Most of the substantial changes are in //tools. Instead of using
`cc_toolchain_suite` rules, we now use regular `toolchain` rules that
are registered in the WORKSPACE. That also means that bazel now uses
the target platform to select the compiler.
All --cpu=* arguments should now be --config=* arguments. For example,
`--cpu=roborio` should now be `--config=roborio`. The CI script and
all documentation has been updated to reflect that.
The remainder of the changes revolve around tagging all targets with
`target_compatible_with`. The old mechanism allowed us to specify
repo-wide defaults. The new mechanism does not. That means every
target that didn't have any compatibility specified, now requires
compatibility with `@platforms//os:linux`.
I used buildozer for the vast majority of `target_compatible_with`
changes. buildozer automatically buildifies any BUILD files it
touches. That means this patch also contains a few non-functional
changes that I was too lazy to remove.
Change-Id: I66d6e6ad9161520ee397597cdb492585820a3acd
diff --git a/tools/platforms/BUILD b/tools/platforms/BUILD
new file mode 100644
index 0000000..65563bf
--- /dev/null
+++ b/tools/platforms/BUILD
@@ -0,0 +1,45 @@
+package(default_visibility = ["//visibility:public"])
+
+platform(
+ name = "linux_x86",
+ constraint_values = [
+ "@platforms//os:linux",
+ "@platforms//cpu:x86_64",
+ ],
+)
+
+platform(
+ name = "linux_armhf",
+ constraint_values = [
+ "@platforms//os:linux",
+ "@platforms//cpu:armv7",
+ "//tools/platforms/hardware:raspberry_pi",
+ ],
+)
+
+platform(
+ name = "linux_arm64",
+ constraint_values = [
+ "@platforms//os:linux",
+ "@platforms//cpu:arm64",
+ ],
+)
+
+platform(
+ name = "linux_roborio",
+ constraint_values = [
+ "@platforms//os:linux",
+ "@platforms//cpu:armv7",
+ "//tools/platforms/hardware:roborio",
+ ],
+)
+
+platform(
+ name = "cortex_m4f",
+ constraint_values = [
+ "@platforms//os:none",
+ "//tools/platforms/hardware:cortex_m4f",
+ ],
+)
+
+# TODO(phil): Create something for "cortex-m4f-k22" builds.