ruleguard: pass imports table to gogrep pattern compiler (#343)

This avoids any miscompiled patterns as well as allows
more precise matching of package symbols in function call contexts.

analyzer/analyzer_test.go

@@ -45,6 +45,7 @@ var tests = []struct {
 	{name: "uber"},
 	{name: "localfunc"},
 	{name: "goversion", flags: map[string]string{"go": "1.16"}},
+	{name: "imports"},
 }
 
 func TestDirectiveComments(t *testing.T) {

analyzer/testdata/src/imports/f1.go

@@ -0,0 +1,27 @@
+package imports
+
+import (
+	crand "crypto/rand"
+	"math/rand"
+)
+
+func _() {
+	_, _ = crand.Read(nil) // want `\Qcrypto/rand`
+	_, _ = rand.Read(nil)  // want `\Qmath/rand`
+}
+
+func _() {
+	_, _ = rand.Read(nil)  // want `\Qmath/rand`
+	_, _ = crand.Read(nil) // want `\Qcrypto/rand`
+}
+
+func _() {
+	var rand distraction
+	_, _ = rand.Read(nil)
+}
+
+type distraction struct{}
+
+func (distraction) Read(p []byte) (int, error) {
+	return 0, nil
+}

analyzer/testdata/src/imports/rules.go

@@ -0,0 +1,17 @@
+//go:build ignore
+// +build ignore
+
+package gorules
+
+import (
+	"github.com/quasilyte/go-ruleguard/dsl"
+)
+
+func testMathRand(m dsl.Matcher) {
+	m.Match(`rand.Read($*_)`).Report(`math/rand`)
+}
+
+func testCryptoRand(m dsl.Matcher) {
+	m.Import(`crypto/rand`)
+	m.Match(`rand.Read($*_)`).Report(`crypto/rand`)
+}

go.mod

@@ -7,6 +7,6 @@ require (
 	github.com/google/go-cmp v0.5.6
 	github.com/quasilyte/go-ruleguard/dsl v0.3.12-0.20220101150716-969a394a9451
 	github.com/quasilyte/go-ruleguard/rules v0.0.0-20211022131956-028d6511ab71
-	github.com/quasilyte/gogrep v0.0.0-20211226113550-e12a97c7d96d
+	github.com/quasilyte/gogrep v0.0.0-20220103110004-ffaa07af02e3
 	golang.org/x/tools v0.0.0-20201230224404-63754364767c
 )

go.sum

@@ -23,6 +23,10 @@ github.com/quasilyte/go-ruleguard/rules v0.0.0-20211022131956-028d6511ab71 h1:CN
 github.com/quasilyte/go-ruleguard/rules v0.0.0-20211022131956-028d6511ab71/go.mod h1:4cgAphtvu7Ftv7vOT2ZOYhC6CvBxZixcasr8qIOTA50=
 github.com/quasilyte/gogrep v0.0.0-20211226113550-e12a97c7d96d h1:HUyLC9v8wzT8PBFdZjGehLLNSPzQMXDsbREsMHxwma8=
 github.com/quasilyte/gogrep v0.0.0-20211226113550-e12a97c7d96d/go.mod h1:wSEyW6O61xRV6zb6My3HxrQ5/8ke7NE2OayqCHa3xRM=
+github.com/quasilyte/gogrep v0.0.0-20220103102714-b302ec19c4fe h1:4QqQfYkJRjKR94aebELDiHFj/f+5lFKtQTVOt7luT20=
+github.com/quasilyte/gogrep v0.0.0-20220103102714-b302ec19c4fe/go.mod h1:wSEyW6O61xRV6zb6My3HxrQ5/8ke7NE2OayqCHa3xRM=
+github.com/quasilyte/gogrep v0.0.0-20220103110004-ffaa07af02e3 h1:P4QPNn+TK49zJjXKERt/vyPbv/mCHB/zQ4flDYOMN+M=
+github.com/quasilyte/gogrep v0.0.0-20220103110004-ffaa07af02e3/go.mod h1:wSEyW6O61xRV6zb6My3HxrQ5/8ke7NE2OayqCHa3xRM=
 github.com/yuin/goldmark v1.1.32/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=

ruleguard/ir_loader.go

@@ -253,15 +253,15 @@ func (l *irLoader) loadRuleGroup(group *ir.RuleGroup) error {
 	}
 
 	for _, rule := range group.Rules {
-		if err := l.loadRule(rule); err != nil {
+		if err := l.loadRule(group, rule); err != nil {
 			return err
 		}
 	}
 
 	return nil
 }
 
-func (l *irLoader) loadRule(rule ir.Rule) error {
+func (l *irLoader) loadRule(group *ir.RuleGroup, rule ir.Rule) error {
 	proto := goRule{
 		line:       rule.Line,
 		group:      l.group,
@@ -282,7 +282,7 @@ func (l *irLoader) loadRule(rule ir.Rule) error {
 	}
 
 	for _, pat := range rule.SyntaxPatterns {
-		if err := l.loadSyntaxRule(proto, info, rule, pat.Value, pat.Line); err != nil {
+		if err := l.loadSyntaxRule(group, proto, info, rule, pat.Value, pat.Line); err != nil {
 			return err
 		}
 	}
@@ -312,15 +312,24 @@ func (l *irLoader) loadCommentRule(resultProto goRule, rule ir.Rule, src string,
 	return nil
 }
 
-func (l *irLoader) loadSyntaxRule(resultProto goRule, filterInfo filterInfo, rule ir.Rule, src string, line int) error {
+func (l *irLoader) loadSyntaxRule(group *ir.RuleGroup, resultProto goRule, filterInfo filterInfo, rule ir.Rule, src string, line int) error {
 	result := resultProto
 	result.line = line
 
+	var imports map[string]string
+	if len(group.Imports) != 0 {
+		imports = make(map[string]string)
+		for _, imported := range group.Imports {
+			imports[imported.Name] = imported.Path
+		}
+	}
+
 	gogrepConfig := gogrep.CompileConfig{
 		Fset:      l.gogrepFset,
 		Src:       src,
 		Strict:    false,
 		WithTypes: true,
+		Imports:   imports,
 	}
 	pat, info, err := gogrep.Compile(gogrepConfig)
 	if err != nil {