Fix nondeterminisim in xmlnotice

SafePathPrefixes contains "prebuilts/" which is a prefix of another
entry "prebuilts/module_sdk" which can both match the same path.
SafePathPrefixes is a map, so the iteration order is nondeterminisitic.
Move both SafePathPrefixes and SafePrebuiltPrefixes into lists that
will always have a deterministic iteration order.

Bug: 230357391
Test: build NOTICE.xml.gz multiple times
Change-Id: Ibfcd6715b70f26164e0ef4d59f73b240f47f8db7

tools/compliance/noticeindex.go

@@ -360,19 +360,17 @@ func (ni *NoticeIndex) getLibName(noticeFor *TargetNode, h hash) string {
 						continue
 					}
 				}
-				for _, r := range OrderedSafePrebuiltPrefixes {
-					prefix := SafePrebuiltPrefixes[r]
-					match := r.FindString(licenseText)
+				for _, safePrebuiltPrefix := range safePrebuiltPrefixes {
+					match := safePrebuiltPrefix.re.FindString(licenseText)
 					if len(match) == 0 {
 						continue
 					}
-					strip := SafePathPrefixes[prefix]
-					if strip {
+					if safePrebuiltPrefix.strip {
 						// strip entire prefix
 						match = licenseText[len(match):]
 					} else {
 						// strip from prebuilts/ until safe prefix
-						match = licenseText[len(match)-len(prefix):]
+						match = licenseText[len(match)-len(safePrebuiltPrefix.prefix):]
 					}
 					// remove LICENSE or NOTICE or other filename
 					li := strings.LastIndex(match, "/")
@@ -392,10 +390,10 @@ func (ni *NoticeIndex) getLibName(noticeFor *TargetNode, h hash) string {
 				break
 			}
 		}
-		for prefix, strip := range SafePathPrefixes {
-			if strings.HasPrefix(p, prefix) {
-				if strip {
-					return p[len(prefix):]
+		for _, safePathPrefix := range safePathPrefixes {
+			if strings.HasPrefix(p, safePathPrefix.prefix) {
+				if safePathPrefix.strip {
+					return p[len(safePathPrefix.prefix):]
 				} else {
 					return p
 				}

tools/compliance/policy_policy.go

@@ -16,7 +16,6 @@ package compliance
 
 import (
 	"regexp"
-	"sort"
 	"strings"
 )
 
@@ -30,35 +29,31 @@ var (
 		"toolchain": "toolchain",
 	}
 
-	// SafePathPrefixes maps the path prefixes presumed not to contain any
+	// safePathPrefixes maps the path prefixes presumed not to contain any
 	// proprietary or confidential pathnames to whether to strip the prefix
 	// from the path when used as the library name for notices.
-	SafePathPrefixes = map[string]bool{
-		"external/":             true,
-		"art/":                  false,
-		"build/":                false,
-		"cts/":                  false,
-		"dalvik/":               false,
-		"developers/":           false,
-		"development/":          false,
-		"frameworks/":           false,
-		"packages/":             true,
-		"prebuilts/module_sdk/": true,
-		"prebuilts/":            false,
-		"sdk/":                  false,
-		"system/":               false,
-		"test/":                 false,
-		"toolchain/":            false,
-		"tools/":                false,
+	safePathPrefixes = []safePathPrefixesType{
+		{"external/", true},
+		{"art/", false},
+		{"build/", false},
+		{"cts/", false},
+		{"dalvik/", false},
+		{"developers/", false},
+		{"development/", false},
+		{"frameworks/", false},
+		{"packages/", true},
+		{"prebuilts/module_sdk/", true},
+		{"prebuilts/", false},
+		{"sdk/", false},
+		{"system/", false},
+		{"test/", false},
+		{"toolchain/", false},
+		{"tools/", false},
 	}
 
-	// SafePrebuiltPrefixes maps the regular expression to match a prebuilt
+	// safePrebuiltPrefixes maps the regular expression to match a prebuilt
 	// containing the path of a safe prefix to the safe prefix.
-	SafePrebuiltPrefixes = make(map[*regexp.Regexp]string)
-
-	// OrderedSafePrebuiltPrefixes lists the SafePrebuiltPrefixes ordered by
-	// increasing length.
-	OrderedSafePrebuiltPrefixes = make([]*regexp.Regexp, 0, 0)
+	safePrebuiltPrefixes []safePrebuiltPrefixesType
 
 	// ImpliesUnencumbered lists the condition names representing an author attempt to disclaim copyright.
 	ImpliesUnencumbered = LicenseConditionSet(UnencumberedCondition)
@@ -89,6 +84,16 @@ var (
 	ImpliesShared = LicenseConditionSet(ReciprocalCondition | RestrictedCondition | WeaklyRestrictedCondition)
 )
 
+type safePathPrefixesType struct {
+	prefix string
+	strip  bool
+}
+
+type safePrebuiltPrefixesType struct {
+	safePathPrefixesType
+	re *regexp.Regexp
+}
+
 var (
 	anyLgpl      = regexp.MustCompile(`^SPDX-license-identifier-LGPL.*`)
 	versionedGpl = regexp.MustCompile(`^SPDX-license-identifier-GPL-\p{N}.*`)
@@ -96,33 +101,15 @@ var (
 	ccBySa       = regexp.MustCompile(`^SPDX-license-identifier-CC-BY.*-SA.*`)
 )
 
-// byIncreasingLength implements `sort.Interface` to order regular expressions by increasing length.
-type byIncreasingLength []*regexp.Regexp
-
-func (l byIncreasingLength) Len() int      { return len(l) }
-func (l byIncreasingLength) Swap(i, j int) { l[i], l[j] = l[j], l[i] }
-func (l byIncreasingLength) Less(i, j int) bool {
-	ri := l[i].String()
-	rj := l[j].String()
-	if len(ri) == len(rj) {
-		return ri < rj
-	}
-	return len(ri) < len(rj)
-}
-
 func init() {
-	for prefix := range SafePathPrefixes {
-		if strings.HasPrefix(prefix, "prebuilts/") {
+	for _, safePathPrefix := range safePathPrefixes {
+		if strings.HasPrefix(safePathPrefix.prefix, "prebuilts/") {
 			continue
 		}
-		r := regexp.MustCompile("^prebuilts/(?:runtime/mainline/)?" + prefix)
-		SafePrebuiltPrefixes[r] = prefix
+		r := regexp.MustCompile("^prebuilts/(?:runtime/mainline/)?" + safePathPrefix.prefix)
+		safePrebuiltPrefixes = append(safePrebuiltPrefixes,
+			safePrebuiltPrefixesType{safePathPrefix, r})
 	}
-	OrderedSafePrebuiltPrefixes = make([]*regexp.Regexp, 0, len(SafePrebuiltPrefixes))
-	for r := range SafePrebuiltPrefixes {
-		OrderedSafePrebuiltPrefixes = append(OrderedSafePrebuiltPrefixes, r)
-	}
-	sort.Sort(byIncreasingLength(OrderedSafePrebuiltPrefixes))
 }
 
 // LicenseConditionSetFromNames returns a set containing the recognized `names` and