Preserve nogo runfiles (#4270)

**What type of PR is this?**

Bug fix

**What does this PR do? Why is it needed?**

**Which issues(s) does this PR fix?**

Fixes #4255

**Other notes for review**

Author: fmeum

go/private/actions/archive.bzl

@@ -60,7 +60,9 @@ def emit_archive(go, source = None, _recompile_suffix = "", recompile_internal_d
     out_cgo_export_h = None  # set if cgo used in c-shared or c-archive mode
 
     nogo = get_nogo(go)
-    if nogo:
+
+    # nogo is a FilesToRunProvider and some targets don't have it, some have it but no executable.
+    if nogo != None and nogo.executable != None:
         out_facts = go.declare_file(go, name = source.name, ext = pre_ext + ".facts")
         out_nogo_log = go.declare_file(go, name = source.name, ext = pre_ext + ".nogo.log")
         out_nogo_validation = go.declare_file(go, name = source.name, ext = pre_ext + ".nogo")

go/private/actions/compilepkg.bzl

@@ -83,9 +83,9 @@ def emit_compilepkg(
     if out_lib == None:
         fail("out_lib is a required parameter")
 
-    have_nogo = nogo != None
+    have_nogo = nogo != None and nogo.executable != None
     if have_nogo != (out_facts != None):
-        fail("nogo must be specified if and only if out_facts is specified")
+        fail("nogo must be specified if and only if out_facts is specified", nogo)
     if have_nogo != (out_nogo_log != None):
         fail("nogo must be specified if and only if out_nogo_log is specified")
     if have_nogo != (out_nogo_validation != None):
@@ -213,7 +213,7 @@ def emit_compilepkg(
         execution_requirements = execution_requirements,
     )
 
-    if nogo:
+    if have_nogo:
         _run_nogo(
             go,
             shared_args = shared_args,
@@ -242,7 +242,7 @@ def _run_nogo(
     """Runs nogo on Go source files, including those generated by cgo."""
     sdk = go.sdk
 
-    inputs_direct = (sources + [nogo, sdk.package_list] +
+    inputs_direct = (sources + [sdk.package_list] +
                      [archive.data.facts_file for archive in archives if archive.data.facts_file] +
                      [archive.data.export_file for archive in archives])
     inputs_transitive = [sdk.tools, sdk.headers, go.stdlib.libs]
@@ -257,7 +257,7 @@ def _run_nogo(
     nogo_args.add("-out_facts", out_facts)
     nogo_args.add("-out_log", out_log)
     nogo_args.add("-out_fix", out_fix)
-    nogo_args.add("-nogo", nogo)
+    nogo_args.add("-nogo", nogo.executable)
 
     # This action runs nogo and produces the facts files for downstream nogo actions.
     # It is important that this action doesn't fail if nogo produces findings, which allows users
@@ -268,6 +268,7 @@ def _run_nogo(
     # on findings to get the same debugging experience as with other failures.
     go.actions.run(
         inputs = depset(inputs_direct, transitive = inputs_transitive),
+        tools = [nogo],
         outputs = outputs,
         mnemonic = "RunNogo",
         executable = go.toolchain._builder,

go/private/context.bzl

@@ -661,11 +661,10 @@ def _go_context_data_impl(ctx):
         print("WARNING: --features=race is no longer supported. Use --@io_bazel_rules_go//go/config:race instead.")
     if "msan" in ctx.features:
         print("WARNING: --features=msan is no longer supported. Use --@io_bazel_rules_go//go/config:msan instead.")
-    nogo = ctx.files.nogo[0] if ctx.files.nogo else None
     providers = [
         GoContextInfo(
             coverdata = ctx.attr.coverdata[0][GoArchive],
-            nogo = nogo,
+            nogo = ctx.attr.nogo[DefaultInfo].files_to_run,
         ),
         ctx.attr.stdlib[GoStdLib],
         ctx.attr.go_config[GoConfigInfo],