build/analysis/importsort: init
This adds an analyzer which enforces import sorting as per
CODING_STANDARDS.md. It is not yet enabled in nogo.
This effectively duplicates some logic that is present in goimports.
However, that logic is mostly within an 'internal' package in x/tools,
and would be somewhat tricky to make work within the framework of an
analysis.Analyser (as it expects to also mutate a file). Thus, we
end up writing the analysis logic ourselves. Tests are provided to make
sure this logic doesn't rot away.
We also move some common logic from 'noioutil' to a new 'lib' package,
and implement the last piece of the puzzle there: a code generator to
provide information about the toolchain's stdlib as a map/set.
Change-Id: Ia0f32d6f9122e13117d18ae781d8255c6e3a887d
Reviewed-on: https://review.monogon.dev/c/monogon/+/494
Reviewed-by: Leopold Schabel <leo@nexantic.com>
diff --git a/build/analysis/lib/BUILD.bazel b/build/analysis/lib/BUILD.bazel
new file mode 100644
index 0000000..42666bf
--- /dev/null
+++ b/build/analysis/lib/BUILD.bazel
@@ -0,0 +1,18 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+ name = "go_default_library",
+ srcs = [
+ "generated.go",
+ "stdlib_packages.go",
+ ],
+ importpath = "source.monogon.dev/build/analysis/lib",
+ visibility = ["//visibility:public"],
+)
+
+genrule(
+ name = "stdlib_packages",
+ outs = ["stdlib_packages.go"],
+ cmd = "$(location //build/analysis/lib/genstd) $@",
+ tools = ["//build/analysis/lib/genstd"],
+)
diff --git a/build/analysis/lib/generated.go b/build/analysis/lib/generated.go
new file mode 100644
index 0000000..209a73f
--- /dev/null
+++ b/build/analysis/lib/generated.go
@@ -0,0 +1,29 @@
+package lib
+
+import (
+ "go/ast"
+ "strings"
+)
+
+const (
+ genPrefix = "// Code generated"
+ genSuffix = "DO NOT EDIT."
+)
+
+// IsGeneratedFile returns true if the file is generated according to
+// https://golang.org/s/generatedcode and other heuristics.
+func IsGeneratedFile(file *ast.File) bool {
+ for _, c := range file.Comments {
+ for _, t := range c.List {
+ if strings.HasPrefix(t.Text, genPrefix) && strings.HasSuffix(t.Text, genSuffix) {
+ return true
+ }
+ // Generated testmain.go stubs from rules_go - for some reason, they don't
+ // contain the expected markers.
+ if strings.Contains(t.Text, "This package must be initialized before packages being tested.") {
+ return true
+ }
+ }
+ }
+ return false
+}
diff --git a/build/analysis/lib/genstd/BUILD.bazel b/build/analysis/lib/genstd/BUILD.bazel
new file mode 100644
index 0000000..044eb95
--- /dev/null
+++ b/build/analysis/lib/genstd/BUILD.bazel
@@ -0,0 +1,18 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+
+go_library(
+ name = "go_default_library",
+ srcs = ["main.go"],
+ importpath = "source.monogon.dev/build/analysis/lib/genstd",
+ visibility = ["//visibility:private"],
+ deps = [
+ "//build/toolbase/gotoolchain:go_default_library",
+ "@org_golang_x_tools//go/packages:go_default_library",
+ ],
+)
+
+go_binary(
+ name = "genstd",
+ embed = [":go_default_library"],
+ visibility = ["//visibility:public"],
+)
diff --git a/build/analysis/lib/genstd/main.go b/build/analysis/lib/genstd/main.go
new file mode 100644
index 0000000..eae356b
--- /dev/null
+++ b/build/analysis/lib/genstd/main.go
@@ -0,0 +1,70 @@
+// This tool generates //build/analysis/lib:stdlib_packages.go, which contains a
+// set of all Go stdlib packges. This is generated ahead of time in the build
+// system as it can be an expensive operation that also depends on the presence
+// of a working `go` tool environment, so we want to do this as rarely as
+// possible.
+package main
+
+import (
+ "fmt"
+ "os"
+ "path/filepath"
+ "sort"
+ "strings"
+
+ "golang.org/x/tools/go/packages"
+
+ "source.monogon.dev/build/toolbase/gotoolchain"
+)
+
+func main() {
+ os.Setenv("PATH", filepath.Dir(gotoolchain.Go))
+
+ gocache, err := os.MkdirTemp("/tmp", "gocache")
+ if err != nil {
+ panic(err)
+ }
+ defer os.RemoveAll(gocache)
+
+ gopath, err := os.MkdirTemp("/tmp", "gopath")
+ if err != nil {
+ panic(err)
+ }
+ defer os.RemoveAll(gopath)
+
+ os.Setenv("GOCACHE", gocache)
+ os.Setenv("GOPATH", gopath)
+
+ pkgs, err := packages.Load(nil, "std")
+ if err != nil {
+ panic(err)
+ }
+ sort.Slice(pkgs, func(i, j int) bool { return pkgs[i].PkgPath < pkgs[j].PkgPath })
+
+ if len(os.Args) != 2 {
+ panic("must be called with output file name")
+ }
+
+ out, err := os.Create(os.Args[1])
+ if err != nil {
+ panic(err)
+ }
+ defer out.Close()
+
+ fmt.Fprintf(out, "// Code generated by //build/analysis/lib/genstd. DO NOT EDIT.\n")
+ fmt.Fprintf(out, "package lib\n\n")
+ fmt.Fprintf(out, "// StdlibPackages is a set of all package paths that are part of the Go standard\n")
+ fmt.Fprintf(out, "// library.\n")
+ fmt.Fprintf(out, "var StdlibPackages = map[string]bool{\n")
+ for _, pkg := range pkgs {
+ path := pkg.PkgPath
+ if strings.Contains(path, "/internal/") {
+ continue
+ }
+ if strings.HasPrefix(path, "vendor/") {
+ continue
+ }
+ fmt.Fprintf(out, "\t%q: true,\n", pkg.PkgPath)
+ }
+ fmt.Fprintf(out, "}\n")
+}