prog: add FieldName to Type

FieldName() is the name of the struct field or union option with this type.
TypeName() is now always the name of the type.

6 files changed, 23 insertions, 14 deletions

diff --git a/prog/analysis.go b/prog/analysis.go
index a4f399f98..a6ee3885b 100644
--- a/prog/analysis.go
+++ b/prog/analysis.go
@@ -185,7 +185,7 @@ func assignSizes(args []*Arg) {
 		if sys.IsPad(arg.Type) {
 			continue
 		}
-		argsMap[arg.Type.Name()] = arg
+		argsMap[arg.Type.FieldName()] = arg
 	}
 
 	// Fill in size arguments.
@@ -205,7 +205,7 @@ func assignSizes(args []*Arg) {
 			buf, ok := argsMap[typ.Buf]
 			if !ok {
 				panic(fmt.Sprintf("len field '%v' references non existent field '%v', argsMap: %+v",
-					typ.Name(), typ.Buf, argsMap))
+					typ.FieldName(), typ.Buf, argsMap))
 			}
 
 			*arg = *generateSize(buf.InnerArg(), typ)
diff --git a/prog/encoding.go b/prog/encoding.go
index 8c7c1674a..274e94a2d 100644
--- a/prog/encoding.go
+++ b/prog/encoding.go
@@ -108,7 +108,7 @@ func (a *Arg) serialize(buf io.Writer, vars map[*Arg]int, varSeq *int) {
 		}
 		buf.Write([]byte{delims[1]})
 	case ArgUnion:
-		fmt.Fprintf(buf, "@%v=", a.OptionType.Name())
+		fmt.Fprintf(buf, "@%v=", a.OptionType.FieldName())
 		a.Option.serialize(buf, vars, varSeq)
 	default:
 		panic("unknown arg kind")
@@ -318,7 +318,7 @@ func parseArg(typ sys.Type, p *parser, vars map[string]*Arg) (*Arg, error) {
 		p.Parse('=')
 		var optType sys.Type
 		for _, t2 := range t1.Options {
-			if name == t2.Name() {
+			if name == t2.FieldName() {
 				optType = t2
 				break
 			}
diff --git a/prog/mutation.go b/prog/mutation.go
index 2136c86f8..9841d31ca 100644
--- a/prog/mutation.go
+++ b/prog/mutation.go
@@ -184,8 +184,12 @@ func (p *Prog) Mutate(rs rand.Source, ncalls int, ct *ChoiceTable, corpus []*Pro
 						}
 					case *sys.UnionType:
 						optType := a.Options[r.Intn(len(a.Options))]
-						for optType.Name() == arg.OptionType.Name() {
+						maxIters := 1000
+						for i := 0; optType.FieldName() == arg.OptionType.FieldName(); i++ {
 							optType = a.Options[r.Intn(len(a.Options))]
+							if i >= maxIters {
+								panic(fmt.Sprintf("couldn't generate a different union option after %v iterations, type: %+v", maxIters, a))
+							}
 						}
 						p.removeArg(c, arg.Option)
 						opt, calls := r.generateArg(s, optType)
@@ -303,7 +307,7 @@ func Minimize(p0 *Prog, callIndex0 int, pred func(*Prog, int) bool, crash bool)
 
 	var rec func(p *Prog, call *Call, arg *Arg, path string) bool
 	rec = func(p *Prog, call *Call, arg *Arg, path string) bool {
-		path += fmt.Sprintf("-%v", arg.Type.Name())
+		path += fmt.Sprintf("-%v", arg.Type.FieldName())
 		switch typ := arg.Type.(type) {
 		case *sys.StructType:
 			for _, innerArg := range arg.Inner {
@@ -438,7 +442,7 @@ func (p *Prog) TrimAfter(idx int) {
 }
 
 func mutationArgs(c *Call) (args, bases []*Arg) {
-	foreachArg(c, func(arg, base *Arg, parent *[]*Arg) {
+	foreachArg(c, func(arg, base *Arg, _ *[]*Arg) {
 		switch typ := arg.Type.(type) {
 		case *sys.StructType:
 			if isSpecialStruct(typ) == nil {
diff --git a/prog/validation.go b/prog/validation.go
index 5eea42e65..f03ec10b8 100644
--- a/prog/validation.go
+++ b/prog/validation.go
@@ -59,6 +59,9 @@ func (c *Call) validate(ctx *validCtx) error {
 		if arg.Type.Name() != typ.Name() {
 			return fmt.Errorf("syscall %v: type name mismatch: %v vs %v", c.Meta.Name, arg.Type.Name(), typ.Name())
 		}
+		if arg.Type.FieldName() != typ.FieldName() {
+			return fmt.Errorf("syscall %v: field name mismatch: %v vs %v", c.Meta.Name, arg.Type.FieldName(), typ.FieldName())
+		}
 		if arg.Type.Dir() == sys.DirOut {
 			if (arg.Val != 0 && arg.Val != arg.Type.Default()) || arg.AddrPage != 0 || arg.AddrOffset != 0 {
 				// We generate output len arguments, which makes sense
diff --git a/sys/decl.go b/sys/decl.go
index a495ffd4a..3c98d1038 100644
--- a/sys/decl.go
+++ b/sys/decl.go
@@ -29,6 +29,7 @@ const (
 
 type Type interface {
 	Name() string
+	FieldName() string
 	Dir() Dir
 	Optional() bool
 	Default() uintptr
@@ -49,6 +50,7 @@ func IsPad(t Type) bool {
 
 type TypeCommon struct {
 	TypeName   string
+	FldName    string // for struct fields and named args
 	ArgDir     Dir
 	IsOptional bool
 }
@@ -57,6 +59,10 @@ func (t *TypeCommon) Name() string {
 	return t.TypeName
 }
 
+func (t *TypeCommon) FieldName() string {
+	return t.FldName
+}
+
 func (t *TypeCommon) Optional() bool {
 	return t.IsOptional
 }
diff --git a/sysgen/sysgen.go b/sysgen/sysgen.go
index 867561ad7..6906c7697 100644
--- a/sysgen/sysgen.go
+++ b/sysgen/sysgen.go
@@ -265,10 +265,6 @@ func generateStructEntry(str Struct, key structKey, out io.Writer) {
 	if str.IsUnion {
 		typ = "UnionType"
 	}
-	name := key.field
-	if name == "" {
-		name = key.name
-	}
 	packed := ""
 	if str.Packed {
 		packed = ", packed: true"
@@ -281,8 +277,8 @@ func generateStructEntry(str Struct, key structKey, out io.Writer) {
 	if str.Align != 0 {
 		align = fmt.Sprintf(", align: %v", str.Align)
 	}
-	fmt.Fprintf(out, "\"%v\": &%v{TypeCommon: TypeCommon{TypeName: \"%v\", ArgDir: %v, IsOptional: %v} %v %v %v},\n",
-		key, typ, name, fmtDir(key.dir), false, packed, align, varlen)
+	fmt.Fprintf(out, "\"%v\": &%v{TypeCommon: TypeCommon{TypeName: \"%v\", FldName: \"%v\", ArgDir: %v, IsOptional: %v} %v %v %v},\n",
+		key, typ, key.name, key.field, fmtDir(key.dir), false, packed, align, varlen)
 }
 
 func generateStructFields(str Struct, key structKey, desc *Description, consts map[string]uint64, out io.Writer) {
@@ -379,7 +375,7 @@ func generateArg(
 		}
 	}
 	common := func() string {
-		return fmt.Sprintf("TypeCommon: TypeCommon{TypeName: %v, ArgDir: %v, IsOptional: %v}", name, fmtDir(dir), opt)
+		return fmt.Sprintf("TypeCommon: TypeCommon{TypeName: \"%v\", FldName: %v, ArgDir: %v, IsOptional: %v}", typ, name, fmtDir(dir), opt)
 	}
 	intCommon := func(typeSize uint64, bigEndian bool, bitfieldLen uint64) string {
 		// BitfieldOff and BitfieldLst will be filled in in initAlign().