Resurrect Go rules, in a style compatible with the open-source 'go' t…

…ool.

go/def/BUILD

@@ -0,0 +1,7 @@
+load("/tools/go/build_rules/go_rules", "go_binary", "go_prefix", "go_library")
+
+go_library(
+ name = "go_default_library",
+ srcs = [ "lib.go" ],
+ visibility = ["//visibility:public" ],
+)

go/def/lib.go

@@ -0,0 +1,3 @@
+package def
+
+func PI() float64 { return 3.141596 }

go/pkg/BUILD

@@ -0,0 +1,23 @@
+
+load("/tools/go/build_rules/go_rules", "go_binary", "go_prefix", "go_library", "go_test")
+go_prefix("github.com/bazelbuild/examples")
+
+go_binary(
+ name = "hello",
+ srcs = [ "hello.go" ],
+ deps = [ ":lib",
+ "//go/def:go_default_library",
+ "//go/pkg/vendor/golang_org/bradfitz/grumble:go_default_library"
+ ],
+ )
+
+# non-default library, eg for protobufs.
+go_library(
+ name = "lib",
+ srcs = [ "lib.go" ])
+
+go_test(
+ name = "lib_test",
+ srcs = [ "lib_test.go" ],
+ library = ":lib",
+)

go/pkg/hello.go

@@ -0,0 +1,12 @@
+package main
+
+import (
+ "fmt"
+ "github.com/bazelbuild/examples/go/pkg/lib"
+ "github.com/bazelbuild/examples/go/def"
+ "golang_org/bradfitz/grumble"
+)
+
+func main() {
+ fmt.Println("hello", lib.M(), def.PI(), grumble.Record());
+}

go/pkg/lib.go

@@ -0,0 +1,3 @@
+package lib
+
+func M() int { return 42 }

go/pkg/lib_test.go

@@ -0,0 +1,12 @@
+package lib
+
+import (
+ "testing"
+
+)
+
+func TestM(t *testing.T) {
+ if M() != 42 {
+ t.Errorf("got %d want 42", M())
+ }
+}

go/pkg/vendor/golang_org/bradfitz/grumble/BUILD

@@ -0,0 +1,6 @@
+load("/tools/go/build_rules/go_rules", "go_binary", "go_prefix", "go_library")
+
+go_library(
+ name = "go_default_library",
+ srcs = [ "grumble.go" ],
+ visibility = [ "//visibility:public" ])

go/pkg/vendor/golang_org/bradfitz/grumble/grumble.go

@@ -0,0 +1,3 @@
+package grumble
+
+func Record() string { return "broken" }

tools/go/BUILD

@@ -0,0 +1,9 @@
+package(default_visibility = ["//visibility:public"])
+
+load("/tools/go/build_rules/go_rules", "go_binary")
+
+go_binary(
+ name = "generate_test_main",
+ srcs = ["generate_test_main.go"],
+)
+

tools/go/README.md

@@ -0,0 +1,81 @@
+Go rules
+--------
+
+The rules should be considered experimental. They support:
+
+ * libraries
+ * binaries
+ * tests
+ * vendoring
+
+They currently do not support (in order of importance):
+
+ * //+build tags
+ * multiple target configurations
+ * C/C++ interoperation (cgo, swig etc.)
+ * coverage
+ * race detector
+
+
+Setup
+-----
+
+* Decide on the name of your package, eg. "github.com/joe/project"
+
+* Copy tools/go/toolchain/WORKSPACE.go-toolchain to WORKSPACE
+
+* Add a BUILD file to your the top of your workspace, containing
+
+ load("/tools/go/build_rules/go_rules", "go_prefix")
+ go_prefix("github.com/joe/project")
+
+* For a library "github.com/joe/project/lib", create lib/BUILD, containing
+
+ load("/tools/go/build_rules/go_rules", "go_library")
+ go_library(
+ name = "go_default_library",
+ srcs = [ "file.go" ])
+
+* Inside your, project, you can use this library by declaring a dependency
+
+ go_binary( ...
+ deps = [ "//lib:go_default_library" ])
+
+* In this case, import the library as "github.com/joe/project/lib".
+
+* For vendored libraries, you may depend on
+ "//lib/vendor/github_com/user/project:go_default_library". Vendored
+ libraries should have BUILD files like normal libraries.
+
+* To declare a test,
+
+ go_test(
+ name = "mytest",
+ srcs = ["file_test.go"],
+ library = ":go_default_library")
+
+FAQ
+---
+
+# Can I still use the =go= tool?
+
+Yes, this setup was deliberately chosen to be compatible with the =go=
+tool. Just make sure your workspace lives under
+
+ $GOROOT/src/github.com/joe/project/
+
+and it should work.
+
+# Do I have to specify dependencies twice?
+
+Yes, once in the BUILD file, once in the source file. Bazel does not
+examine file contents and is language agnostic, so it cannot infer the
+dependencies.
+
+We will shortly provide a tool that can generate and update BUILD
+files by analyszing source code; stay tuned.
+
+Disclaimer
+----------
+
+These rules are not supported by Google's Go team.