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-rw-r--r--src/cmd/vet/asmdecl.go533
1 files changed, 533 insertions, 0 deletions
diff --git a/src/cmd/vet/asmdecl.go b/src/cmd/vet/asmdecl.go
new file mode 100644
index 000000000..c23514c28
--- /dev/null
+++ b/src/cmd/vet/asmdecl.go
@@ -0,0 +1,533 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Identify mismatches between assembly files and Go func declarations.
+
+package main
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/token"
+ "regexp"
+ "strconv"
+ "strings"
+)
+
+// 'kind' is a kind of assembly variable.
+// The kinds 1, 2, 4, 8 stand for values of that size.
+type asmKind int
+
+// These special kinds are not valid sizes.
+const (
+ asmString asmKind = 100 + iota
+ asmSlice
+ asmInterface
+ asmEmptyInterface
+)
+
+// An asmArch describes assembly parameters for an architecture
+type asmArch struct {
+ name string
+ ptrSize int
+ intSize int
+ bigEndian bool
+}
+
+// An asmFunc describes the expected variables for a function on a given architecture.
+type asmFunc struct {
+ arch *asmArch
+ size int // size of all arguments
+ vars map[string]*asmVar
+ varByOffset map[int]*asmVar
+}
+
+// An asmVar describes a single assembly variable.
+type asmVar struct {
+ name string
+ kind asmKind
+ typ string
+ off int
+ size int
+ inner []*asmVar
+}
+
+var (
+ asmArch386 = asmArch{"386", 4, 4, false}
+ asmArchArm = asmArch{"arm", 4, 4, false}
+ asmArchAmd64 = asmArch{"amd64", 8, 8, false}
+
+ arches = []*asmArch{
+ &asmArch386,
+ &asmArchArm,
+ &asmArchAmd64,
+ }
+)
+
+var (
+ re = regexp.MustCompile
+ asmPlusBuild = re(`//\s+\+build\s+([^\n]+)`)
+ asmTEXT = re(`\bTEXT\b.*ยท([^\(]+)\(SB\)(?:\s*,\s*([0-9]+))?(?:\s*,\s*\$([0-9]+)(?:-([0-9]+))?)?`)
+ asmDATA = re(`\b(DATA|GLOBL)\b`)
+ asmNamedFP = re(`([a-zA-Z0-9_\xFF-\x{10FFFF}]+)(?:\+([0-9]+))\(FP\)`)
+ asmUnnamedFP = re(`[^+\-0-9]](([0-9]+)\(FP\))`)
+ asmOpcode = re(`^\s*(?:[A-Z0-9a-z_]+:)?\s*([A-Z]+)\s*([^,]*)(?:,\s*(.*))?`)
+)
+
+func asmCheck(pkg *Package) {
+ if !vet("asmdecl") {
+ return
+ }
+
+ // No work if no assembly files.
+ if !pkg.hasFileWithSuffix(".s") {
+ return
+ }
+
+ // Gather declarations. knownFunc[name][arch] is func description.
+ knownFunc := make(map[string]map[string]*asmFunc)
+
+ for _, f := range pkg.files {
+ if f.file != nil {
+ for _, decl := range f.file.Decls {
+ if decl, ok := decl.(*ast.FuncDecl); ok && decl.Body == nil {
+ knownFunc[decl.Name.Name] = f.asmParseDecl(decl)
+ }
+ }
+ }
+ }
+
+ var fn *asmFunc
+ for _, f := range pkg.files {
+ if !strings.HasSuffix(f.name, ".s") {
+ continue
+ }
+ Println("Checking file", f.name)
+
+ // Determine architecture from file name if possible.
+ var arch string
+ for _, a := range arches {
+ if strings.HasSuffix(f.name, "_"+a.name+".s") {
+ arch = a.name
+ break
+ }
+ }
+
+ lines := strings.SplitAfter(string(f.content), "\n")
+ for lineno, line := range lines {
+ lineno++
+
+ warnf := func(format string, args ...interface{}) {
+ f.Warnf(token.NoPos, "%s:%d: [%s] %s", f.name, lineno, arch, fmt.Sprintf(format, args...))
+ }
+
+ if arch == "" {
+ // Determine architecture from +build line if possible.
+ if m := asmPlusBuild.FindStringSubmatch(line); m != nil {
+ Fields:
+ for _, fld := range strings.Fields(m[1]) {
+ for _, a := range arches {
+ if a.name == fld {
+ arch = a.name
+ break Fields
+ }
+ }
+ }
+ }
+ }
+
+ if m := asmTEXT.FindStringSubmatch(line); m != nil {
+ if arch == "" {
+ f.Warnf(token.NoPos, "%s: cannot determine architecture for assembly file", f.name)
+ return
+ }
+ fn = knownFunc[m[1]][arch]
+ if fn != nil {
+ size, _ := strconv.Atoi(m[4])
+ if size != fn.size && (m[2] != "7" || size != 0) {
+ warnf("wrong argument size %d; expected $...-%d", size, fn.size)
+ }
+ }
+ continue
+ } else if strings.Contains(line, "TEXT") && strings.Contains(line, "SB") {
+ // function, but not visible from Go (didn't match asmTEXT), so stop checking
+ fn = nil
+ continue
+ }
+
+ if asmDATA.FindStringSubmatch(line) != nil {
+ fn = nil
+ }
+ if fn == nil {
+ continue
+ }
+
+ for _, m := range asmUnnamedFP.FindAllStringSubmatch(line, -1) {
+ warnf("use of unnamed argument %s", m[1])
+ }
+
+ for _, m := range asmNamedFP.FindAllStringSubmatch(line, -1) {
+ name := m[1]
+ off := 0
+ if m[2] != "" {
+ off, _ = strconv.Atoi(m[2])
+ }
+ v := fn.vars[name]
+ if v == nil {
+ // Allow argframe+0(FP).
+ if name == "argframe" && off == 0 {
+ continue
+ }
+ v = fn.varByOffset[off]
+ if v != nil {
+ warnf("unknown variable %s; offset %d is %s+%d(FP)", name, off, v.name, v.off)
+ } else {
+ warnf("unknown variable %s", name)
+ }
+ continue
+ }
+ asmCheckVar(warnf, fn, line, m[0], off, v)
+ }
+ }
+ }
+}
+
+// asmParseDecl parses a function decl for expected assembly variables.
+func (f *File) asmParseDecl(decl *ast.FuncDecl) map[string]*asmFunc {
+ var (
+ arch *asmArch
+ fn *asmFunc
+ offset int
+ failed bool
+ )
+
+ addVar := func(outer string, v asmVar) {
+ if vo := fn.vars[outer]; vo != nil {
+ vo.inner = append(vo.inner, &v)
+ }
+ fn.vars[v.name] = &v
+ for i := 0; i < v.size; i++ {
+ fn.varByOffset[v.off+i] = &v
+ }
+ }
+
+ addParams := func(list []*ast.Field) {
+ for i, fld := range list {
+ // Determine alignment, size, and kind of type in declaration.
+ var align, size int
+ var kind asmKind
+ names := fld.Names
+ typ := f.gofmt(fld.Type)
+ switch t := fld.Type.(type) {
+ default:
+ switch typ {
+ default:
+ f.Warnf(fld.Type.Pos(), "unknown assembly argument type %s", typ)
+ failed = true
+ return
+ case "int8", "uint8", "byte", "bool":
+ size = 1
+ case "int16", "uint16":
+ size = 2
+ case "int32", "uint32", "float32":
+ size = 4
+ case "int64", "uint64", "float64":
+ align = arch.ptrSize
+ size = 8
+ case "int", "uint":
+ size = arch.intSize
+ case "uintptr", "iword", "Word", "Errno", "unsafe.Pointer":
+ size = arch.ptrSize
+ case "string":
+ size = arch.ptrSize * 2
+ align = arch.ptrSize
+ kind = asmString
+ }
+ case *ast.ChanType, *ast.FuncType, *ast.MapType, *ast.StarExpr:
+ size = arch.ptrSize
+ case *ast.InterfaceType:
+ align = arch.ptrSize
+ size = 2 * arch.ptrSize
+ if len(t.Methods.List) > 0 {
+ kind = asmInterface
+ } else {
+ kind = asmEmptyInterface
+ }
+ case *ast.ArrayType:
+ if t.Len == nil {
+ size = arch.ptrSize + 2*arch.intSize
+ align = arch.ptrSize
+ kind = asmSlice
+ break
+ }
+ f.Warnf(fld.Type.Pos(), "unsupported assembly argument type %s", typ)
+ failed = true
+ case *ast.StructType:
+ f.Warnf(fld.Type.Pos(), "unsupported assembly argument type %s", typ)
+ failed = true
+ }
+ if align == 0 {
+ align = size
+ }
+ if kind == 0 {
+ kind = asmKind(size)
+ }
+ offset += -offset & (align - 1)
+
+ // Create variable for each name being declared with this type.
+ if len(names) == 0 {
+ name := "unnamed"
+ if decl.Type.Results != nil && len(decl.Type.Results.List) > 0 && &list[0] == &decl.Type.Results.List[0] && i == 0 {
+ // Assume assembly will refer to single unnamed result as r.
+ name = "ret"
+ }
+ names = []*ast.Ident{{Name: name}}
+ }
+ for _, id := range names {
+ name := id.Name
+ addVar("", asmVar{
+ name: name,
+ kind: kind,
+ typ: typ,
+ off: offset,
+ size: size,
+ })
+ switch kind {
+ case 8:
+ if arch.ptrSize == 4 {
+ w1, w2 := "lo", "hi"
+ if arch.bigEndian {
+ w1, w2 = w2, w1
+ }
+ addVar(name, asmVar{
+ name: name + "_" + w1,
+ kind: 4,
+ typ: "half " + typ,
+ off: offset,
+ size: 4,
+ })
+ addVar(name, asmVar{
+ name: name + "_" + w2,
+ kind: 4,
+ typ: "half " + typ,
+ off: offset + 4,
+ size: 4,
+ })
+ }
+
+ case asmEmptyInterface:
+ addVar(name, asmVar{
+ name: name + "_type",
+ kind: asmKind(arch.ptrSize),
+ typ: "interface type",
+ off: offset,
+ size: arch.ptrSize,
+ })
+ addVar(name, asmVar{
+ name: name + "_data",
+ kind: asmKind(arch.ptrSize),
+ typ: "interface data",
+ off: offset + arch.ptrSize,
+ size: arch.ptrSize,
+ })
+
+ case asmInterface:
+ addVar(name, asmVar{
+ name: name + "_itable",
+ kind: asmKind(arch.ptrSize),
+ typ: "interface itable",
+ off: offset,
+ size: arch.ptrSize,
+ })
+ addVar(name, asmVar{
+ name: name + "_data",
+ kind: asmKind(arch.ptrSize),
+ typ: "interface data",
+ off: offset + arch.ptrSize,
+ size: arch.ptrSize,
+ })
+
+ case asmSlice:
+ addVar(name, asmVar{
+ name: name + "_base",
+ kind: asmKind(arch.ptrSize),
+ typ: "slice base",
+ off: offset,
+ size: arch.ptrSize,
+ })
+ addVar(name, asmVar{
+ name: name + "_len",
+ kind: asmKind(arch.intSize),
+ typ: "slice len",
+ off: offset + arch.ptrSize,
+ size: arch.intSize,
+ })
+ addVar(name, asmVar{
+ name: name + "_cap",
+ kind: asmKind(arch.intSize),
+ typ: "slice cap",
+ off: offset + arch.ptrSize + arch.intSize,
+ size: arch.intSize,
+ })
+
+ case asmString:
+ addVar(name, asmVar{
+ name: name + "_base",
+ kind: asmKind(arch.ptrSize),
+ typ: "string base",
+ off: offset,
+ size: arch.ptrSize,
+ })
+ addVar(name, asmVar{
+ name: name + "_len",
+ kind: asmKind(arch.intSize),
+ typ: "string len",
+ off: offset + arch.ptrSize,
+ size: arch.intSize,
+ })
+ }
+ offset += size
+ }
+ }
+ }
+
+ m := make(map[string]*asmFunc)
+ for _, arch = range arches {
+ fn = &asmFunc{
+ arch: arch,
+ vars: make(map[string]*asmVar),
+ varByOffset: make(map[int]*asmVar),
+ }
+ offset = 0
+ addParams(decl.Type.Params.List)
+ if decl.Type.Results != nil && len(decl.Type.Results.List) > 0 {
+ offset += -offset & (arch.ptrSize - 1)
+ addParams(decl.Type.Results.List)
+ }
+ fn.size = offset
+ m[arch.name] = fn
+ }
+
+ if failed {
+ return nil
+ }
+ return m
+}
+
+// asmCheckVar checks a single variable reference.
+func asmCheckVar(warnf func(string, ...interface{}), fn *asmFunc, line, expr string, off int, v *asmVar) {
+ m := asmOpcode.FindStringSubmatch(line)
+ if m == nil {
+ warnf("cannot find assembly opcode")
+ }
+
+ // Determine operand sizes from instruction.
+ // Typically the suffix suffices, but there are exceptions.
+ var src, dst, kind asmKind
+ op := m[1]
+ switch fn.arch.name + "." + op {
+ case "386.FMOVLP":
+ src, dst = 8, 4
+ case "arm.MOVD":
+ src = 8
+ case "arm.MOVW":
+ src = 4
+ case "arm.MOVH", "arm.MOVHU":
+ src = 2
+ case "arm.MOVB", "arm.MOVBU":
+ src = 1
+ default:
+ if fn.arch.name == "386" || fn.arch.name == "amd64" {
+ if strings.HasPrefix(op, "F") && (strings.HasSuffix(op, "D") || strings.HasSuffix(op, "DP")) {
+ // FMOVDP, FXCHD, etc
+ src = 8
+ break
+ }
+ if strings.HasPrefix(op, "F") && (strings.HasSuffix(op, "F") || strings.HasSuffix(op, "FP")) {
+ // FMOVFP, FXCHF, etc
+ src = 4
+ break
+ }
+ if strings.HasSuffix(op, "SD") {
+ // MOVSD, SQRTSD, etc
+ src = 8
+ break
+ }
+ if strings.HasSuffix(op, "SS") {
+ // MOVSS, SQRTSS, etc
+ src = 4
+ break
+ }
+ if strings.HasPrefix(op, "SET") {
+ // SETEQ, etc
+ src = 1
+ break
+ }
+ switch op[len(op)-1] {
+ case 'B':
+ src = 1
+ case 'W':
+ src = 2
+ case 'L':
+ src = 4
+ case 'D', 'Q':
+ src = 8
+ }
+ }
+ }
+ if dst == 0 {
+ dst = src
+ }
+
+ // Determine whether the match we're holding
+ // is the first or second argument.
+ if strings.Index(line, expr) > strings.Index(line, ",") {
+ kind = dst
+ } else {
+ kind = src
+ }
+
+ vk := v.kind
+ vt := v.typ
+ switch vk {
+ case asmInterface, asmEmptyInterface, asmString, asmSlice:
+ // allow reference to first word (pointer)
+ vk = v.inner[0].kind
+ vt = v.inner[0].typ
+ }
+
+ if off != v.off {
+ var inner bytes.Buffer
+ for i, vi := range v.inner {
+ if len(v.inner) > 1 {
+ fmt.Fprintf(&inner, ",")
+ }
+ fmt.Fprintf(&inner, " ")
+ if i == len(v.inner)-1 {
+ fmt.Fprintf(&inner, "or ")
+ }
+ fmt.Fprintf(&inner, "%s+%d(FP)", vi.name, vi.off)
+ }
+ warnf("invalid offset %s; expected %s+%d(FP)%s", expr, v.name, v.off, inner.String())
+ return
+ }
+ if kind != 0 && kind != vk {
+ var inner bytes.Buffer
+ if len(v.inner) > 0 {
+ fmt.Fprintf(&inner, " containing")
+ for i, vi := range v.inner {
+ if i > 0 && len(v.inner) > 2 {
+ fmt.Fprintf(&inner, ",")
+ }
+ fmt.Fprintf(&inner, " ")
+ if i > 0 && i == len(v.inner)-1 {
+ fmt.Fprintf(&inner, "and ")
+ }
+ fmt.Fprintf(&inner, "%s+%d(FP)", vi.name, vi.off)
+ }
+ }
+ warnf("invalid %s of %s; %s is %d-byte value%s", op, expr, vt, vk, inner.String())
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-14 09:25:59 +0000