Support //gosocialcheck:trusted directive to silence warnings

Fix issue 8

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

Author: AkihiroSuda

README.md

@@ -34,6 +34,28 @@ import 'github.com/lmittmann/tint': module 'github.com/lmittmann/tint@v1.0.7' do
 ```
 
 ## Hints
+### Allowlist
+
+Use `//gosocialcheck:trusted` [directives](https://github.com/AkihiroSuda/gomoddirectivecomments) in `go.mod` to silence alerts for trustworthy modules.
+
+e.g.,
+```go-module
+//gosocialcheck:trusted
+require (
+	golang.org/x/sync v0.19.0
+)
+```
+
+or
+
+```go-module
+require (
+	golang.org/x/sync v0.19.0 //gosocialcheck:trusted
+)
+```
+
+Note: The directive ignores the module version.
+
 ### GitHub API rate limit
 gosocialcheck uses the GitHub API for the following operations:
 - Fetch git tags, via `api.github.com`.

go.mod

@@ -4,13 +4,19 @@ module github.com/AkihiroSuda/gosocialcheck
 
 go 1.24.0
 
+// My own packages and golang.org/x packages are trusted
+//gosocialcheck:trusted
+require (
+	github.com/AkihiroSuda/gomoddirectivecomments v0.1.0
+	golang.org/x/mod v0.33.0
+	golang.org/x/sync v0.19.0 // gomodjail:unconfined
+	golang.org/x/tools v0.41.0 // gomodjail:unconfined
+)
+
 require (
 	github.com/lmittmann/tint v1.1.3 // gomodjail:unconfined
 	github.com/spf13/cobra v1.10.2 // gomodjail:unconfined
 	github.com/spf13/pflag v1.0.10
-	golang.org/x/mod v0.32.0
-	golang.org/x/sync v0.19.0 // gomodjail:unconfined
-	golang.org/x/tools v0.41.0 // gomodjail:unconfined
 	gopkg.in/yaml.v3 v3.0.1
 	gotest.tools/v3 v3.5.2
 )

go.sum

@@ -1,3 +1,5 @@
+github.com/AkihiroSuda/gomoddirectivecomments v0.1.0 h1:5sKxYIkq9GGs0DTnuPNVm2Z/LmhKdTN+8QblThzTKqg=
+github.com/AkihiroSuda/gomoddirectivecomments v0.1.0/go.mod h1:flXOhVLWfsi4FuFhFoc9F3m7wAH2RT4aM3fVyQROKt4=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
@@ -12,8 +14,8 @@ github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An
 github.com/spf13/pflag v1.0.10 h1:4EBh2KAYBwaONj6b2Ye1GiHfwjqyROoF4RwYO+vPwFk=
 github.com/spf13/pflag v1.0.10/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
-golang.org/x/mod v0.32.0 h1:9F4d3PHLljb6x//jOyokMv3eX+YDeepZSEo3mFJy93c=
-golang.org/x/mod v0.32.0/go.mod h1:SgipZ/3h2Ci89DlEtEXWUk/HteuRin+HHhN+WbNhguU=
+golang.org/x/mod v0.33.0 h1:tHFzIWbBifEmbwtGz65eaWyGiGZatSrT9prnU8DbVL8=
+golang.org/x/mod v0.33.0/go.mod h1:swjeQEj+6r7fODbD2cqrnje9PnziFuw4bmLbBZFrQ5w=
 golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
 golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
 golang.org/x/tools v0.41.0 h1:a9b8iMweWG+S0OBnlU36rzLp20z1Rp10w+IY2czHTQc=

pkg/analyzer/analyzer.go

@@ -15,6 +15,7 @@ import (
 	"strings"
 	"sync"
 
+	gomoddirectivecomments "github.com/AkihiroSuda/gomoddirectivecomments"
 	"golang.org/x/mod/modfile"
 	"golang.org/x/mod/module"
 	"golang.org/x/tools/go/analysis"
@@ -28,6 +29,11 @@ type Opts struct {
 	Cache *cache.Cache
 }
 
+const (
+	directivePolicyUntrusted = "untrusted"
+	directivePolicyTrusted   = "trusted"
+)
+
 func New(ctx context.Context, opts Opts) (*analysis.Analyzer, error) {
 	inst := &instance{
 		Opts:          opts,
@@ -76,6 +82,10 @@ func run(ctx context.Context, inst *instance) func(*analysis.Pass) (any, error)
 		if goMod.Module.Mod.Path != pass.Module.Path {
 			return nil, fmt.Errorf("%s: expected %q, got %q", goModFilename, pass.Module.Path, goMod.Module.Mod.Path)
 		}
+		policies, err := gomoddirectivecomments.Parse(goMod, "gosocialcheck", directivePolicyUntrusted)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse gosocialcheck directives in %q: %w", goModFilename, err)
+		}
 		// TODO: cache go.sum
 		goSumFilename := filepath.Join(modDir, "go.sum")
 		// pass.ReadFile does not support go.sum
@@ -102,6 +112,10 @@ func run(ctx context.Context, inst *instance) func(*analysis.Pass) (any, error)
 					slog.DebugContext(ctx, "module entry not found (negligible for stdlib and local imports)", "path", p)
 					continue
 				}
+				if policies[modV.Path] == directivePolicyTrusted {
+					slog.DebugContext(ctx, "module marked as trusted via gosocialcheck:trusted directive", "path", modV.Path)
+					continue
+				}
 				h1 := goSum[modV.Path+" "+modV.Version]
 				inst.processedSumsMu.RLock()
 				_, h1Processed := inst.processedSums[h1]