From 928b1394f0ac82aa5bcb14e914bb94d17634b974 Mon Sep 17 00:00:00 2001
From: Luna Duclos <luna.duclos@embark-studios.com>
Date: Thu, 15 Oct 2020 13:21:22 +0200
Subject: [PATCH] Implement a second more generic golink rule that can copy
 output from arbitrary rules

---
 .gitignore                                    |  3 ++
 BUILD                                         |  4 ++
 ...nto_workspace.sh => copy_into_workspace.sh |  0
 golink.bzl                                    | 53 +++++++++++++++++++
 proto/BUILD                                   |  5 --
 proto/proto.bzl                               | 30 ++---------
 6 files changed, 65 insertions(+), 30 deletions(-)
 rename proto/copy_into_workspace.sh => copy_into_workspace.sh (100%)
 create mode 100644 golink.bzl

diff --git a/.gitignore b/.gitignore
index ac51a05..236f395 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,4 @@
 bazel-*
+
+# IntellIJ project file
+golink.iml
diff --git a/BUILD b/BUILD
index e69de29..09d33e8 100644
--- a/BUILD
+++ b/BUILD
@@ -0,0 +1,4 @@
+exports_files(
+    ["copy_into_workspace.sh"],
+    visibility = ["//visibility:public"],
+)
diff --git a/proto/copy_into_workspace.sh b/copy_into_workspace.sh
similarity index 100%
rename from proto/copy_into_workspace.sh
rename to copy_into_workspace.sh
diff --git a/golink.bzl b/golink.bzl
new file mode 100644
index 0000000..f1fc747
--- /dev/null
+++ b/golink.bzl
@@ -0,0 +1,53 @@
+load("@bazel_skylib//lib:shell.bzl", "shell")
+
+def gen_copy_files_script(ctx, files):
+    content = ""
+    for f in files:
+        print(files)
+        line = "cp -f %s %s/;\n" % (f.path, ctx.attr.dir)
+        content += line
+    substitutions = {
+        "@@CONTENT@@": shell.quote(content),
+    }
+    out = ctx.actions.declare_file(ctx.label.name + ".sh")
+    ctx.actions.expand_template(
+        template = ctx.file._template,
+        output = out,
+        substitutions = substitutions,
+        is_executable = True,
+    )
+    runfiles = ctx.runfiles(files = [files[0]])
+    return [
+        DefaultInfo(
+            files = depset([out]),
+            runfiles = runfiles,
+            executable = out,
+        ),
+    ]
+
+def golink_impl(ctx, **kwargs):
+    print("Copying output files for rule %s" % ctx.attr.dep)
+    return gen_copy_files_script(ctx, ctx.files.dep)
+
+
+_golink = rule(
+    implementation = golink_impl,
+    executable = True,
+    attrs = {
+        "dir": attr.string(),
+        "dep": attr.label(),
+        "_template": attr.label(
+            default = ":copy_into_workspace.sh",
+            allow_single_file = True,
+        ),
+        # It is not used, just used for versioning since this is experimental
+        "version": attr.string(),
+    },
+)
+
+def golink(name, **kwargs):
+    if not "dir" in kwargs:
+        dir = native.package_name()
+        kwargs["dir"] = dir
+
+    _golink(name = name, **kwargs)
diff --git a/proto/BUILD b/proto/BUILD
index a979506..e8cb573 100644
--- a/proto/BUILD
+++ b/proto/BUILD
@@ -3,8 +3,3 @@ filegroup(
     srcs = glob(["*"]),
     visibility = ["//visibility:public"],
 )
-
-exports_files(
-    ["copy_into_workspace.sh"],
-    visibility = ["//visibility:public"],
-)
diff --git a/proto/proto.bzl b/proto/proto.bzl
index c12a22f..54a4a53 100644
--- a/proto/proto.bzl
+++ b/proto/proto.bzl
@@ -1,29 +1,9 @@
 load("@bazel_skylib//lib:shell.bzl", "shell")
+load("//:golink.bzl", "gen_copy_files_script")
+
 def go_proto_link_impl(ctx, **kwargs):
     print("Copying generated files for proto library %s" % ctx.attr.dep)
-    generated = ctx.attr.dep[OutputGroupInfo].go_generated_srcs.to_list()
-    content = ""
-    for f in generated:
-       line = "cp -f %s %s/;\n" % (f.path, ctx.attr.dir)
-       content += line
-    substitutions = {
-        "@@CONTENT@@": shell.quote(content),
-    }
-    out = ctx.actions.declare_file(ctx.label.name + ".sh")
-    ctx.actions.expand_template(
-        template = ctx.file._template,
-        output = out,
-        substitutions = substitutions,
-        is_executable = True,
-    )
-    runfiles = ctx.runfiles(files = [generated[0]])
-    return [
-        DefaultInfo(
-            files = depset([out]),
-            runfiles = runfiles,
-            executable = out,
-        ),
-    ]
+    return gen_copy_files_script(ctx, ctx.attr.dep[OutputGroupInfo].go_generated_srcs.to_list())
 
 _go_proto_link = rule(
     implementation = go_proto_link_impl,
@@ -32,7 +12,7 @@ _go_proto_link = rule(
         "dir": attr.string(),
         "dep": attr.label(),
         "_template": attr.label(
-            default = ":copy_into_workspace.sh",
+            default = "//:copy_into_workspace.sh",
             allow_single_file = True,
         ),
         # It is not used, just used for versioning since this is experimental
@@ -45,4 +25,4 @@ def go_proto_link(name, **kwargs):
         dir = native.package_name()
         kwargs["dir"] = dir
 
-    _go_proto_link(name = name, **kwargs)
\ No newline at end of file
+    _go_proto_link(name = name, **kwargs)