nogo: add more staticcheck analyzers

nogo.yaml

@@ -267,3 +267,78 @@ analyzers:
       suppress:
         - "comment on exported type Translation" # Intentional.
         - "comment on exported type PinnedRange" # Intentional.
+
+  QF1001: # Apply De Morgan’s law
+    # Controversial.
+    internal:
+      exclude: [".*"]
+  QF1008: # Omit embedded fields from selector expression
+    # Controversial.
+    internal:
+      exclude: [".*"]
+  QF1002: # Convert untagged switch to tagged switch
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  QF1003: # Convert if/else-if chain to tagged switch
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  QF1004: # Use strings.ReplaceAll instead of Replace(..., -1)
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  QF1005: # Expand call to math.Pow
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  QF1011: # Omit redundant type from variable declaration
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  QF1012: # Use `fmt.Fprintf(x, ...)` instead of `x.Write(fmt.Sprintf(...))`
+    # disabled for now due to existing violations.
+    generated:
+      exclude: [".*"]
+    internal:
+      exclude: [".*"]
+  S1000: # Use plain channel ops instead of single-case select
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  S1001: # should use copy(to[:], from) instead of a loop
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  S1003: # Replace index+len check with strings.Contains
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  S1007: # Simplify regular expression by using raw string literal
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  S1008: # Simplify returning boolean expression
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  S1011: # Use append directly instead of looped appends
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  S1023: # Omit redundant control flow
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  S1025: # Drop redundant fmt.Sprintf for strings
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  S1038: # should use log.Printf(...) instead of log.Println(fmt.Sprintf(...))
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]
+  S1039: # Unnecessary use of `fmt.Sprint`
+    # disabled for now due to existing violations.
+    internal:
+      exclude: [".*"]

pkg/abi/linux/fuse.go

@@ -977,11 +977,7 @@ func (r *FUSEDirents) MarshalBytes(buf []byte) []byte {
 
 // UnmarshalBytes deserializes FUSEDirents from the src buffer.
 func (r *FUSEDirents) UnmarshalBytes(src []byte) []byte {
-	for {
-		if len(src) <= (*FUSEDirentMeta)(nil).SizeBytes() {
-			break
-		}
-
+	for len(src) > (*FUSEDirentMeta)(nil).SizeBytes() {
 		// Its unclear how many dirents there are in src. Each dirent is dynamically
 		// sized and so we can't make assumptions about how many dirents we can allocate.
 		if r.Dirents == nil {

pkg/aio/aio_test.go

@@ -80,7 +80,7 @@ func testRead(t *testing.T, newQueue func(cap int) (Queue, error)) {
 			done += chunkSize
 		}
 	}
-	if bytes.Compare(data, buf) != 0 {
+	if !bytes.Equal(data, buf) {
 		t.Errorf("bytes differ")
 	}
 }
@@ -153,7 +153,7 @@ func testReadv(t *testing.T, newQueue func(cap int) (Queue, error)) {
 			done += 2 * chunkSize
 		}
 	}
-	if bytes.Compare(data, buf) != 0 {
+	if !bytes.Equal(data, buf) {
 		t.Errorf("bytes differ")
 	}
 }
@@ -213,7 +213,7 @@ func testWrite(t *testing.T, newQueue func(cap int) (Queue, error)) {
 	if n, err := io.ReadFull(testFile, buf); err != nil {
 		t.Fatalf("failed to read temp file after %d bytes: %v", n, err)
 	}
-	if bytes.Compare(data, buf) != 0 {
+	if !bytes.Equal(data, buf) {
 		t.Errorf("bytes differ")
 	}
 }
@@ -286,7 +286,7 @@ func testWritev(t *testing.T, newQueue func(cap int) (Queue, error)) {
 	if n, err := io.ReadFull(testFile, buf); err != nil {
 		t.Fatalf("failed to read temp file after %d bytes: %v", n, err)
 	}
-	if bytes.Compare(data, buf) != 0 {
+	if !bytes.Equal(data, buf) {
 		t.Errorf("bytes differ")
 	}
 }

pkg/bpf/decoder.go

@@ -54,9 +54,9 @@ func decode(inst Instruction, line int, w *bytes.Buffer) error {
 	case Ldx:
 		err = decodeLdx(inst, w)
 	case St:
-		w.WriteString(fmt.Sprintf("M[%v] <- A", inst.K))
+		fmt.Fprintf(w, "M[%v] <- A", inst.K)
 	case Stx:
-		w.WriteString(fmt.Sprintf("M[%v] <- X", inst.K))
+		fmt.Fprintf(w, "M[%v] <- X", inst.K)
 	case Alu:
 		err = decodeAlu(inst, w)
 	case Jmp:
@@ -77,21 +77,21 @@ func decodeLd(inst Instruction, w *bytes.Buffer) error {
 
 	switch inst.OpCode & loadModeMask {
 	case Imm:
-		w.WriteString(fmt.Sprintf("%v", inst.K))
+		fmt.Fprintf(w, "%v", inst.K)
 	case Abs:
-		w.WriteString(fmt.Sprintf("P[%v:", inst.K))
+		fmt.Fprintf(w, "P[%v:", inst.K)
 		if err := decodeLdSize(inst, w); err != nil {
 			return err
 		}
 		w.WriteString("]")
 	case Ind:
-		w.WriteString(fmt.Sprintf("P[X+%v:", inst.K))
+		fmt.Fprintf(w, "P[X+%v:", inst.K)
 		if err := decodeLdSize(inst, w); err != nil {
 			return err
 		}
 		w.WriteString("]")
 	case Mem:
-		w.WriteString(fmt.Sprintf("M[%v]", inst.K))
+		fmt.Fprintf(w, "M[%v]", inst.K)
 	case Len:
 		w.WriteString("len")
 	default:
@@ -120,13 +120,13 @@ func decodeLdx(inst Instruction, w *bytes.Buffer) error {
 
 	switch inst.OpCode & loadModeMask {
 	case Imm:
-		w.WriteString(fmt.Sprintf("%v", inst.K))
+		fmt.Fprintf(w, "%v", inst.K)
 	case Mem:
-		w.WriteString(fmt.Sprintf("M[%v]", inst.K))
+		fmt.Fprintf(w, "M[%v]", inst.K)
 	case Len:
 		w.WriteString("len")
 	case Msh:
-		w.WriteString(fmt.Sprintf("4*(P[%v:1]&0xf)", inst.K))
+		fmt.Fprintf(w, "4*(P[%v:1]&0xf)", inst.K)
 	default:
 		return fmt.Errorf("invalid BPF LDX instruction: %v", linux.BPFInstruction(inst))
 	}
@@ -172,7 +172,7 @@ func decodeAlu(inst Instruction, w *bytes.Buffer) error {
 func decodeSource(inst Instruction, w *bytes.Buffer) error {
 	switch inst.OpCode & srcAluJmpMask {
 	case K:
-		w.WriteString(fmt.Sprintf("%v", inst.K))
+		fmt.Fprintf(w, "%v", inst.K)
 	case X:
 		w.WriteString("X")
 	default:
@@ -205,10 +205,9 @@ func decodeJmp(inst Instruction, line int, w *bytes.Buffer) error {
 		if err := decodeSource(inst, w); err != nil {
 			return err
 		}
-		w.WriteString(
-			fmt.Sprintf(") ? %s : %s",
-				printJmpTarget(uint32(inst.JumpIfTrue), line),
-				printJmpTarget(uint32(inst.JumpIfFalse), line)))
+		fmt.Fprintf(w, ") ? %s : %s",
+			printJmpTarget(uint32(inst.JumpIfTrue), line),
+			printJmpTarget(uint32(inst.JumpIfFalse), line))
 	}
 	return nil
 }
@@ -227,7 +226,7 @@ func decodeRet(inst Instruction, w *bytes.Buffer) error {
 	code := inst.OpCode & srcRetMask
 	switch code {
 	case K:
-		w.WriteString(fmt.Sprintf("%v", inst.K))
+		fmt.Fprintf(w, "%v", inst.K)
 	case A:
 		w.WriteString("A")
 	default:

pkg/context/context.go

@@ -101,7 +101,7 @@ func (nt *NoTask) Interrupt() {
 
 // Interrupted implements Blocker.Interrupted.
 func (nt *NoTask) Interrupted() bool {
-	return nt.cancel != nil && len(nt.cancel) > 0
+	return len(nt.cancel) > 0
 }
 
 // Killed implements Blocker.Killed.

pkg/cpuid/cpuid.go

@@ -233,9 +233,10 @@ func readHWCap(auxvFilepath string) (hwCap, error) {
 	for i := 0; i < l; i++ {
 		tag := binary.LittleEndian.Uint64(auxv[i*16:])
 		val := binary.LittleEndian.Uint64(auxv[i*16+8:])
-		if tag == _AT_HWCAP {
+		switch tag {
+		case _AT_HWCAP:
 			c.hwCap1 = val
-		} else if tag == _AT_HWCAP2 {
+		case _AT_HWCAP2:
 			c.hwCap2 = val
 		}
 

pkg/fspath/fspath.go

@@ -161,10 +161,7 @@ func (it Iterator) Next() Iterator {
 	// aren't at the end of the path, there is definitely another path
 	// component.
 	i := it.end + 1
-	for {
-		if it.partialPathname[i] != pathSep {
-			break
-		}
+	for it.partialPathname[i] == pathSep {
 		i++
 	}
 	nextPartialPathname := it.partialPathname[i:]

pkg/lisafs/testsuite/testsuite.go

@@ -251,7 +251,7 @@ func readFDAndCmp(ctx context.Context, t *testing.T, fdLisa lisafs.ClientFD, off
 		t.Errorf("partial read: buf size = %d, read = %d", len(want), n)
 		return
 	}
-	if bytes.Compare(buf, want) != 0 {
+	if !bytes.Equal(buf, want) {
 		t.Errorf("bytes read differ from what was expected: want = %v, got = %v", want, buf)
 	}
 }
@@ -365,7 +365,7 @@ func testRegularFileIO(ctx context.Context, t *testing.T, tester Tester, root li
 		t.Errorf("host read failed: %v", err)
 	} else if n != len(hostReadData) {
 		t.Errorf("partial read: buf size = %d, read = %d", len(hostReadData), n)
-	} else if bytes.Compare(hostReadData, data) != 0 {
+	} else if !bytes.Equal(hostReadData, data) {
 		t.Errorf("bytes read differ from what was expected: want = %v, got = %v", data, hostReadData)
 	}
 

pkg/log/log.go

@@ -327,7 +327,7 @@ func Stacks(all bool) []byte {
 }
 
 // stackRegexp matches one level within a stack trace.
-var stackRegexp = regexp.MustCompile("(?m)^\\S+\\(.*\\)$\\r?\\n^\\t\\S+:\\d+.*$\\r?\\n")
+var stackRegexp = regexp.MustCompile(`(?m)^\S+\(.*\)$\r?\n^\t\S+:\d+.*$\r?\n`)
 
 // LocalStack returns the local goroutine stack, excluding the top N entries.
 // LocalStack's own entry is excluded by default and does not need to be counted in excludeTopN.

pkg/metric/metric.go

@@ -514,7 +514,7 @@ func nameToPrometheusName(name string) string {
 	return strings.ReplaceAll(strings.TrimPrefix(name, "/"), "/", "_")
 }
 
-var validMetricNameRegexp = re.MustCompile("^(?:/[_\\w]+)+$")
+var validMetricNameRegexp = re.MustCompile(`^(?:/[_\w]+)+$`)
 
 // verifyName verifies that the given metric name is a valid path-style metric
 // name.

pkg/metric/metric_test.go

@@ -1149,9 +1149,7 @@ func TestMetricProfiling(t *testing.T) {
 			for i, m := range test.metricNames {
 				var fields []Field
 				if i == 0 {
-					for _, f := range test.firstMetricFields {
-						fields = append(fields, f)
-					}
+					fields = append(fields, test.firstMetricFields...)
 				}
 				newMetric, err := NewUint64Metric(m, Uint64Metadata{
 					Cumulative:  true,

pkg/safemem/seq_test.go

@@ -156,7 +156,7 @@ func TestBlockSeqIterBlocks(t *testing.T) {
 			srcs := test.BlockSeq()
 			// "Note that a non-nil empty slice and a nil slice ... are not
 			// deeply equal." - reflect
-			slices := make([][]byte, 0, 0)
+			slices := make([][]byte, 0)
 			for !srcs.IsEmpty() {
 				src := srcs.Head()
 				slices = append(slices, src.ToSlice())
@@ -193,7 +193,7 @@ func TestBlockSeqIterBytes(t *testing.T) {
 				}
 				srcs = nextSrcs
 			}
-			if got := string(dst.Bytes()); got != test.want {
+			if got := dst.String(); got != test.want {
 				t.Errorf("Copied string: got %q, wanted %q", got, test.want)
 			}
 		})

pkg/segment/set.go

@@ -447,7 +447,7 @@ func (s *Set) InsertWithoutMergingUnchecked(gap GapIterator, r Range, val Value)
 	if splitMaxGap {
 		gap.node.updateMaxGapLeaf()
 	}
-	return Iterator{gap.node, gap.index}
+	return Iterator(gap)
 }
 
 // InsertRange inserts the given segment into the set. If the new segment can
@@ -586,7 +586,7 @@ func (s *Set) Remove(seg Iterator) GapIterator {
 	if trackGaps != 0 {
 		seg.node.updateMaxGapLeaf()
 	}
-	return seg.node.rebalanceAfterRemove(GapIterator{seg.node, seg.index})
+	return seg.node.rebalanceAfterRemove(GapIterator(seg))
 }
 
 // RemoveAll removes all segments from the set. All existing iterators are
@@ -1735,7 +1735,7 @@ func (seg Iterator) PrevGap() GapIterator {
 		// must be in a leaf node.
 		return seg.node.children[seg.index].lastSegment().NextGap()
 	}
-	return GapIterator{seg.node, seg.index}
+	return GapIterator(seg)
 }
 
 // NextGap returns the gap immediately after the iterated segment.
@@ -2036,26 +2036,26 @@ func (n *node) String() string {
 func (n *node) writeDebugString(buf *bytes.Buffer, prefix string) {
 	if n.hasChildren != (n.nrSegments > 0 && n.children[0] != nil) {
 		buf.WriteString(prefix)
-		buf.WriteString(fmt.Sprintf("WARNING: inconsistent value of hasChildren: got %v, want %v\n", n.hasChildren, !n.hasChildren))
+		fmt.Fprintf(buf, "WARNING: inconsistent value of hasChildren: got %v, want %v\n", n.hasChildren, !n.hasChildren)
 	}
 	for i := 0; i < n.nrSegments; i++ {
 		if child := n.children[i]; child != nil {
 			cprefix := fmt.Sprintf("%s- % 3d ", prefix, i)
 			if child.parent != n || child.parentIndex != i {
 				buf.WriteString(cprefix)
-				buf.WriteString(fmt.Sprintf("WARNING: inconsistent linkage to parent: got (%p, %d), want (%p, %d)\n", child.parent, child.parentIndex, n, i))
+				fmt.Fprintf(buf, "WARNING: inconsistent linkage to parent: got (%p, %d), want (%p, %d)\n", child.parent, child.parentIndex, n, i)
 			}
 			child.writeDebugString(buf, fmt.Sprintf("%s- % 3d ", prefix, i))
 		}
 		buf.WriteString(prefix)
 		if n.hasChildren {
 			if trackGaps != 0 {
-				buf.WriteString(fmt.Sprintf("- % 3d: %v => %v, maxGap: %d\n", i, n.keys[i], n.values[i], n.maxGap.Get()))
+				fmt.Fprintf(buf, "- % 3d: %v => %v, maxGap: %d\n", i, n.keys[i], n.values[i], n.maxGap.Get())
 			} else {
-				buf.WriteString(fmt.Sprintf("- % 3d: %v => %v\n", i, n.keys[i], n.values[i]))
+				fmt.Fprintf(buf, "- % 3d: %v => %v\n", i, n.keys[i], n.values[i])
 			}
 		} else {
-			buf.WriteString(fmt.Sprintf("- % 3d: %v => %v\n", i, n.keys[i], n.values[i]))
+			fmt.Fprintf(buf, "- % 3d: %v => %v\n", i, n.keys[i], n.values[i])
 		}
 	}
 	if child := n.children[n.nrSegments]; child != nil {

pkg/sentry/devices/nvproxy/nvproxy_test.go

@@ -271,9 +271,7 @@ func TestFilterCapabilities(t *testing.T) {
 		}
 		capSets = append(capSets, individualCap)
 	}
-	for _, capSet := range nvconf.PopularCapabilitySets() {
-		capSets = append(capSets, capSet)
-	}
+	capSets = append(capSets, nvconf.PopularCapabilitySets()...)
 
 	// Build all the ABIs.
 	Init()

pkg/sentry/devices/tpuproxy/tpuproxy.go

@@ -71,7 +71,7 @@ func RegisterTPUv4Device(ctx context.Context, creds *auth.Credentials, root vfs.
 		return err
 	}
 
-	deviceIDStr := strings.Replace(buf.String(), "0x", "", -1)
+	deviceIDStr := strings.ReplaceAll(buf.String(), "0x", "")
 	deviceID, err := strconv.ParseInt(strings.TrimSpace(deviceIDStr), 16, 64)
 	if err != nil {
 		return fmt.Errorf("parsing PCI device ID: %w", err)

pkg/sentry/fdcollector/fdcollector.go

@@ -109,5 +109,5 @@ func (c *Agent) String() string {
 	// c.buf.Bytes(), which may be modified after c.mu.Unlock(). If you change
 	// this function to return []byte for some reason, c.buf.Bytes() needs to
 	// be cloned instead.
-	return string(c.buf.Bytes())
+	return c.buf.String()
 }