testing: import new version of match.go

src/testing/match.go

@@ -14,41 +14,73 @@ import (
 
 // matcher sanitizes, uniques, and filters names of subtests and subbenchmarks.
 type matcher struct {
-	filter    []string
+	filter    filterMatch
+	skip      filterMatch
 	matchFunc func(pat, str string) (bool, error)
 
-	mu       sync.Mutex
-	subNames map[string]int64
+	mu sync.Mutex
+
+	// subNames is used to deduplicate subtest names.
+	// Each key is the subtest name joined to the deduplicated name of the parent test.
+	// Each value is the count of the number of occurrences of the given subtest name
+	// already seen.
+	subNames map[string]int32
 }
 
+type filterMatch interface {
+	// matches checks the name against the receiver's pattern strings using the
+	// given match function.
+	matches(name []string, matchString func(pat, str string) (bool, error)) (ok, partial bool)
+
+	// verify checks that the receiver's pattern strings are valid filters by
+	// calling the given match function.
+	verify(name string, matchString func(pat, str string) (bool, error)) error
+}
+
+// simpleMatch matches a test name if all of the pattern strings match in
+// sequence.
+type simpleMatch []string
+
+// alternationMatch matches a test name if one of the alternations match.
+type alternationMatch []filterMatch
+
 // TODO: fix test_main to avoid race and improve caching, also allowing to
 // eliminate this Mutex.
 var matchMutex sync.Mutex
 
-func newMatcher(matchString func(pat, str string) (bool, error), patterns, name string) *matcher {
+func allMatcher() *matcher {
+	return newMatcher(nil, "", "", "")
+}
+
+func newMatcher(matchString func(pat, str string) (bool, error), patterns, name, skips string) *matcher {
 	if isBaremetal {
-		// Probably not enough ram to load regexp, substitute something simpler.
 		matchString = fakeMatchString
 	}
 
-	var filter []string
-	if patterns != "" {
+	var filter, skip filterMatch
+	if patterns == "" {
+		filter = simpleMatch{} // always partial true
+	} else {
 		filter = splitRegexp(patterns)
-		for i, s := range filter {
-			filter[i] = rewrite(s)
+		if err := filter.verify(name, matchString); err != nil {
+			fmt.Fprintf(os.Stderr, "testing: invalid regexp for %s\n", err)
+			os.Exit(1)
 		}
-		// Verify filters before doing any processing.
-		for i, s := range filter {
-			if _, err := matchString(s, "non-empty"); err != nil {
-				fmt.Fprintf(os.Stderr, "testing: invalid regexp for element %d of %s (%q): %s\n", i, name, s, err)
-				os.Exit(1)
-			}
+	}
+	if skips == "" {
+		skip = alternationMatch{} // always false
+	} else {
+		skip = splitRegexp(skips)
+		if err := skip.verify("-test.skip", matchString); err != nil {
+			fmt.Fprintf(os.Stderr, "testing: invalid regexp for %v\n", err)
+			os.Exit(1)
 		}
 	}
 	return &matcher{
 		filter:    filter,
+		skip:      skip,
 		matchFunc: matchString,
-		subNames:  map[string]int64{},
+		subNames:  map[string]int32{},
 	}
 }
 
@@ -65,22 +97,83 @@ func (m *matcher) fullName(c *common, subname string) (name string, ok, partial
 	matchMutex.Lock()
 	defer matchMutex.Unlock()
 
-	// We check the full array of paths each time to allow for the case that
-	// a pattern contains a '/'.
+	// We check the full array of paths each time to allow for the case that a pattern contains a '/'.
 	elem := strings.Split(name, "/")
-	for i, s := range elem {
-		if i >= len(m.filter) {
-			break
-		}
-		if ok, _ := m.matchFunc(m.filter[i], s); !ok {
-			return name, false, false
-		}
+
+	// filter must match.
+	// accept partial match that may produce full match later.
+	ok, partial = m.filter.matches(elem, m.matchFunc)
+	if !ok {
+		return name, false, false
 	}
-	return name, true, len(elem) < len(m.filter)
+
+	// skip must not match.
+	// ignore partial match so we can get to more precise match later.
+	skip, partialSkip := m.skip.matches(elem, m.matchFunc)
+	if skip && !partialSkip {
+		return name, false, false
+	}
+
+	return name, ok, partial
 }
 
-func splitRegexp(s string) []string {
-	a := make([]string, 0, strings.Count(s, "/"))
+// clearSubNames clears the matcher's internal state, potentially freeing
+// memory. After this is called, T.Name may return the same strings as it did
+// for earlier subtests.
+func (m *matcher) clearSubNames() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	for key := range m.subNames {
+		delete(m.subNames, key)
+	}
+}
+
+func (m simpleMatch) matches(name []string, matchString func(pat, str string) (bool, error)) (ok, partial bool) {
+	for i, s := range name {
+		if i >= len(m) {
+			break
+		}
+		if ok, _ := matchString(m[i], s); !ok {
+			return false, false
+		}
+	}
+	return true, len(name) < len(m)
+}
+
+func (m simpleMatch) verify(name string, matchString func(pat, str string) (bool, error)) error {
+	for i, s := range m {
+		m[i] = rewrite(s)
+	}
+	// Verify filters before doing any processing.
+	for i, s := range m {
+		if _, err := matchString(s, "non-empty"); err != nil {
+			return fmt.Errorf("element %d of %s (%q): %s", i, name, s, err)
+		}
+	}
+	return nil
+}
+
+func (m alternationMatch) matches(name []string, matchString func(pat, str string) (bool, error)) (ok, partial bool) {
+	for _, m := range m {
+		if ok, partial = m.matches(name, matchString); ok {
+			return ok, partial
+		}
+	}
+	return false, false
+}
+
+func (m alternationMatch) verify(name string, matchString func(pat, str string) (bool, error)) error {
+	for i, m := range m {
+		if err := m.verify(name, matchString); err != nil {
+			return fmt.Errorf("alternation %d of %s", i, err)
+		}
+	}
+	return nil
+}
+
+func splitRegexp(s string) filterMatch {
+	a := make(simpleMatch, 0, strings.Count(s, "/"))
+	b := make(alternationMatch, 0, strings.Count(s, "|"))
 	cs := 0
 	cp := 0
 	for i := 0; i < len(s); {
@@ -108,33 +201,90 @@ func splitRegexp(s string) []string {
 				i = 0
 				continue
 			}
+		case '|':
+			if cs == 0 && cp == 0 {
+				a = append(a, s[:i])
+				s = s[i+1:]
+				i = 0
+				b = append(b, a)
+				a = make(simpleMatch, 0, len(a))
+				continue
+			}
 		}
 		i++
 	}
-	return append(a, s)
+
+	a = append(a, s)
+	if len(b) == 0 {
+		return a
+	}
+	return append(b, a)
 }
 
 // unique creates a unique name for the given parent and subname by affixing it
 // with one or more counts, if necessary.
 func (m *matcher) unique(parent, subname string) string {
-	name := fmt.Sprintf("%s/%s", parent, subname)
-	empty := subname == ""
-	for {
-		next, exists := m.subNames[name]
-		if !empty && !exists {
-			m.subNames[name] = 1 // next count is 1
-			return name
-		}
-		// Name was already used. We increment with the count and append a
-		// string with the count.
-		m.subNames[name] = next + 1
+	base := parent + "/" + subname
 
-		// Add a count to guarantee uniqueness.
-		name = fmt.Sprintf("%s#%02d", name, next)
-		empty = false
+	for {
+		n := m.subNames[base]
+		if n < 0 {
+			panic("subtest count overflow")
+		}
+		m.subNames[base] = n + 1
+
+		if n == 0 && subname != "" {
+			prefix, nn := parseSubtestNumber(base)
+			if len(prefix) < len(base) && nn < m.subNames[prefix] {
+				// This test is explicitly named like "parent/subname#NN",
+				// and #NN was already used for the NNth occurrence of "parent/subname".
+				// Loop to add a disambiguating suffix.
+				continue
+			}
+			return base
+		}
+
+		name := fmt.Sprintf("%s#%02d", base, n)
+		if m.subNames[name] != 0 {
+			// This is the nth occurrence of base, but the name "parent/subname#NN"
+			// collides with the first occurrence of a subtest *explicitly* named
+			// "parent/subname#NN". Try the next number.
+			continue
+		}
+
+		return name
 	}
 }
 
+// parseSubtestNumber splits a subtest name into a "#%02d"-formatted int32
+// suffix (if present), and a prefix preceding that suffix (always).
+func parseSubtestNumber(s string) (prefix string, nn int32) {
+	i := strings.LastIndex(s, "#")
+	if i < 0 {
+		return s, 0
+	}
+
+	prefix, suffix := s[:i], s[i+1:]
+	if len(suffix) < 2 || (len(suffix) > 2 && suffix[0] == '0') {
+		// Even if suffix is numeric, it is not a possible output of a "%02" format
+		// string: it has either too few digits or too many leading zeroes.
+		return s, 0
+	}
+	if suffix == "00" {
+		if !strings.HasSuffix(prefix, "/") {
+			// We only use "#00" as a suffix for subtests named with the empty
+			// string — it isn't a valid suffix if the subtest name is non-empty.
+			return s, 0
+		}
+	}
+
+	n, err := strconv.ParseInt(suffix, 10, 32)
+	if err != nil || n < 0 {
+		return s, 0
+	}
+	return prefix, int32(n)
+}
+
 // rewrite rewrites a subname to having only printable characters and no white
 // space.
 func rewrite(s string) string {
@@ -171,14 +321,3 @@ func isSpace(r rune) bool {
 	}
 	return false
 }
-
-// A fake regexp matcher.
-// Inflexible, but saves 50KB of flash and 50KB of RAM per -size full,
-// and lets tests pass on cortex-m.
-func fakeMatchString(pat, str string) (bool, error) {
-	if pat == ".*" {
-		return true, nil
-	}
-	matched := strings.Contains(str, pat)
-	return matched, nil
-}