Remove GoSource/GoLibrary from test/binary rules (#4044)

**What type of PR is this?**
Starlark cleanup

**What does this PR do? Why is it needed?**
We don't want go_binary or go_test targets to be included in `deps` or
`embed`. We have a check for it today, but we can push this into the
starlark type system by ensuring they don't have these providers.

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

Fixes #

**Other notes for review**

---------

Co-authored-by: Fabian Meumertzheim <fabian@meumertzhe.im>

go/private/context.bzl

@@ -284,10 +284,7 @@ def _library_to_source(go, attr, library, coverage_instrumented):
         "pgoprofile": getattr(attr, "pgoprofile", None),
     }
 
-    for dep in source["deps"]:
-        _check_binary_dep(go, dep, "deps")
     for e in getattr(attr, "embed", []):
-        _check_binary_dep(go, e, "embed")
         _merge_embed(source, e)
 
     source["deps"] = _dedup_archives(source["deps"])
@@ -324,24 +321,6 @@ def _collect_runfiles(go, data, deps):
         [get_source(t).runfiles for t in deps],
     )
 
-def _check_binary_dep(go, dep, edge):
-    """Checks that this rule doesn't depend on a go_binary or go_test.
-
-    go_binary and go_test may return providers with useful information for other
-    rules (like go_path), but go_binary and go_test may not depend on other
-    go_binary and go_test targets. Their dependencies may be built in
-    different modes, resulting in conflicts and opaque errors.
-    """
-    if (type(dep) == "Target" and
-        DefaultInfo in dep and
-        getattr(dep[DefaultInfo], "files_to_run", None) and
-        dep[DefaultInfo].files_to_run.executable):
-        fail("rule {rule} depends on executable {dep} via {edge}. This is not safe for cross-compilation. Depend on go_library instead.".format(
-            rule = str(go.label),
-            dep = str(dep.label),
-            edge = edge,
-        ))
-
 def _check_importpaths(ctx):
     paths = []
     p = getattr(ctx.attr, "importpath", "")

go/private/rules/binary.bzl

@@ -141,8 +141,6 @@ def _go_binary_impl(ctx):
     validation_output = archive.data._validation_output
 
     providers = [
-        library,
-        source,
         archive,
         OutputGroupInfo(
             cgo_exports = archive.cgo_exports,

go/private/rules/cross.bzl

@@ -15,8 +15,6 @@
 load(
     "//go/private:providers.bzl",
     "GoArchive",
-    "GoLibrary",
-    "GoSource",
 )
 load(
     "//go/private/rules:transition.bzl",
@@ -84,8 +82,6 @@ def _go_cross_impl(ctx):
     providers = [
         ctx.attr.target[provider]
         for provider in [
-            GoLibrary,
-            GoSource,
             GoArchive,
             OutputGroupInfo,
             CcInfo,
@@ -100,7 +96,7 @@ _go_cross_kwargs = {
         "target": attr.label(
             doc = """Go binary target to transition to the given platform and/or sdk_version.
             """,
-            providers = [GoLibrary, GoSource, GoArchive],
+            providers = [GoArchive],
             mandatory = True,
         ),
         "platform": attr.label(

tests/core/starlark/BUILD.bazel

@@ -1,9 +1,12 @@
 load(":common_tests.bzl", "common_test_suite")
 load(":context_tests.bzl", "context_test_suite")
+load(":provider_tests.bzl", "provider_test_suite")
 load(":sdk_tests.bzl", "sdk_test_suite")
 
 common_test_suite()
 
 context_test_suite()
 
+provider_test_suite()
+
 sdk_test_suite()

tests/core/starlark/provider_tests.bzl

@@ -0,0 +1,69 @@
+load("@bazel_skylib//lib:unittest.bzl", "analysistest", "asserts")
+load("//go:def.bzl", "go_binary", "go_library", "go_test")
+
+# go_binary and go_test targets must not be used as deps/embed attributes;
+# their dependencies may be built in different modes, resulting in conflicts and opaque errors.
+def _providers_test_impl(ctx):
+    env = analysistest.begin(ctx)
+    asserts.expect_failure(env, "does not have mandatory providers")
+    return analysistest.end(env)
+
+providers_test = analysistest.make(
+    _providers_test_impl,
+    expect_failure = True,
+)
+
+def provider_test_suite():
+    go_binary(
+        name = "go_binary",
+        tags = ["manual"],
+    )
+
+    go_library(
+        name = "lib_binary_deps",
+        deps = [":go_binary"],
+        tags = ["manual"],
+    )
+
+    providers_test(
+        name = "go_binary_deps_test",
+        target_under_test = ":lib_binary_deps",
+    )
+
+    go_library(
+        name = "lib_binary_embed",
+        embed = [":go_binary"],
+        tags = ["manual"],
+    )
+
+    providers_test(
+        name = "go_binary_embed_test",
+        target_under_test = ":lib_binary_embed",
+    )
+
+    go_test(
+        name = "go_test",
+        tags = ["manual"],
+    )
+
+    go_library(
+        name = "lib_test_deps",
+        deps = [":go_test"],
+        tags = ["manual"],
+    )
+
+    providers_test(
+        name = "go_test_deps_test",
+        target_under_test = ":lib_test_deps",
+    )
+
+    go_library(
+        name = "lib_embed_test",
+        embed = [":go_test"],
+        tags = ["manual"],
+    )
+
+    providers_test(
+        name = "go_test_embed_test",
+        target_under_test = ":lib_embed_test",
+    )