chore: move golangci-lint & meta to separate PR-only workflow (#10119)

For now. Existing code is not golangci-lint clean, but new PRs should
be, ideally.

.github/workflows/build-syncthing.yaml

@@ -86,26 +86,6 @@ jobs:
           LOKI_PASSWORD: ${{ secrets.LOKI_PASSWORD }}
           LOKI_LABELS: "go=${{ matrix.go }},runner=${{ matrix.runner }},repo=${{ github.repository }},ref=${{ github.ref }}"
 
-  #
-  # Meta checks for formatting, copyright, etc
-  #
-
-  correctness:
-    name: Check correctness
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-
-      - uses: actions/setup-go@v5
-        with:
-          go-version: ${{ env.GO_VERSION }}
-          cache: false
-          check-latest: true
-
-      - name: Check correctness
-        run: |
-          go test -v ./meta
-
   #
   # The basic checks job is a virtual one that depends on the matrix tests,
   # the correctness checks, and various builds that we always do. This makes
@@ -120,14 +100,12 @@ jobs:
     runs-on: ubuntu-latest
     needs:
       - build-test
-      - correctness
       - package-linux
       - package-cross
       - package-source
       - package-debian
       - package-windows
       - govulncheck
-      - golangci
     steps:
       - uses: actions/checkout@v4
 
@@ -1021,22 +999,3 @@ jobs:
           go run build.go assets
           go install golang.org/x/vuln/cmd/govulncheck@latest
           govulncheck ./...
-
-  golangci:
-    runs-on: ubuntu-latest
-    name: Run golangci-lint
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-go@v5
-        with:
-          go-version: ${{ env.GO_VERSION }}
-          cache: false
-          check-latest: true
-
-      - name: ensure asset generation
-        run: go run build.go assets
-
-      - name: golangci-lint
-        uses: golangci/golangci-lint-action@v8
-        with:
-          only-new-issues: true

.github/workflows/pr-linters.yaml

@@ -0,0 +1,49 @@
+name: Run PR linters
+
+on:
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pull-requests: read
+
+jobs:
+
+  #
+  # golangci-lint runs a suite of static analysis checks on the code
+  #
+
+  golangci:
+    runs-on: ubuntu-latest
+    name: Golangci-lint
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: 'stable'
+
+      - name: ensure asset generation
+        run: go run build.go assets
+
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v8
+        with:
+          only-new-issues: true
+
+  #
+  # Meta checks for formatting, copyright, etc
+  #
+
+  meta:
+    name: Meta checks
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: 'stable'
+
+      - run: |
+          go run build.go assets
+          go test -v ./meta

meta/metalint_test.go

@@ -1,118 +0,0 @@
-// Copyright (C) 2017 The Syncthing Authors.
-//
-// This Source Code Form is subject to the terms of the Mozilla Public
-// License, v. 2.0. If a copy of the MPL was not distributed with this file,
-// You can obtain one at https://mozilla.org/MPL/2.0/.
-
-package meta
-
-import (
-	"bytes"
-	"log"
-	"os/exec"
-	"strings"
-	"testing"
-)
-
-var (
-	// fast linters complete in a fraction of a second and might as well be
-	// run always as part of the build
-	fastLinters = []string{
-		"deadcode",
-		"golint",
-		"ineffassign",
-		"vet",
-	}
-
-	// slow linters take several seconds and are run only as part of the
-	// "metalint" command.
-	slowLinters = []string{
-		"gosimple",
-		"staticcheck",
-		"structcheck",
-		"unused",
-		"varcheck",
-	}
-
-	// Which parts of the tree to lint
-	lintDirs = []string{
-		".",
-		"../cmd/...",
-		"../lib/...",
-		"../script/...",
-	}
-
-	// Messages to ignore
-	lintExcludes = []string{
-		".pb.go",
-		"should have comment",
-		"protocol.Vector composite literal uses unkeyed fields",
-		"cli.Requires composite literal uses unkeyed fields",
-		"Use DialContext instead",   // Go 1.7
-		"os.SEEK_SET is deprecated", // Go 1.7
-		"SA4017",                    // staticcheck "is a pure function but its return value is ignored"
-	}
-)
-
-func TestCheckMetalint(t *testing.T) {
-	if !isGometalinterInstalled() {
-		return
-	}
-
-	gometalinter(t, lintDirs, lintExcludes...)
-}
-
-func isGometalinterInstalled() bool {
-	if _, err := runError("gometalinter", "--disable-all"); err != nil {
-		log.Println("gometalinter is not installed")
-		return false
-	}
-	return true
-}
-
-func gometalinter(_ *testing.T, dirs []string, excludes ...string) bool {
-	params := []string{"--disable-all", "--concurrency=2", "--deadline=300s"}
-
-	for _, linter := range fastLinters {
-		params = append(params, "--enable="+linter)
-	}
-
-	if !testing.Short() {
-		for _, linter := range slowLinters {
-			params = append(params, "--enable="+linter)
-		}
-	}
-
-	for _, exclude := range excludes {
-		params = append(params, "--exclude="+exclude)
-	}
-
-	params = append(params, dirs...)
-
-	bs, _ := runError("gometalinter", params...)
-
-	nerr := 0
-	lines := make(map[string]struct{})
-	for _, line := range strings.Split(string(bs), "\n") {
-		if line == "" {
-			continue
-		}
-		if _, ok := lines[line]; ok {
-			continue
-		}
-		log.Println(line)
-		if strings.Contains(line, "executable file not found") {
-			log.Println(` - Try "go run build.go setup" to install missing tools`)
-		}
-		lines[line] = struct{}{}
-		nerr++
-	}
-
-	return nerr == 0
-}
-
-func runError(cmd string, args ...string) ([]byte, error) {
-	ecmd := exec.Command(cmd, args...)
-	bs, err := ecmd.CombinedOutput()
-	return bytes.TrimSpace(bs), err
-}