pkg/compiler: add glob type

* all: add new typename dirname

The current way to check files under sysfs or proc is:
- define a string to represent each file
- open the file
- pass the fd to write / read / close

The issues above are:
- Need to know what file present on target device
- Need to write openat for each file

With dirname added, which will open one file
in the directory randomly and then pass the fd to
write/read/close.

* all: use typename glob to match filename

Fixes #481

7 files changed, 37 insertions, 3 deletions

diff --git a/prog/encoding.go b/prog/encoding.go
index 140636865..e66535e2a 100644
--- a/prog/encoding.go
+++ b/prog/encoding.go
@@ -853,7 +853,7 @@ func encodeData(buf *bytes.Buffer, data []byte, readable, cstr bool) {
 }
 
 func isReadableDataType(typ *BufferType) bool {
-	return typ.Kind == BufferString || typ.Kind == BufferFilename
+	return typ.Kind == BufferString || typ.Kind == BufferFilename || typ.Kind == BufferGlob
 }
 
 func isReadableData(data []byte) bool {
diff --git a/prog/hints.go b/prog/hints.go
index a26185010..c66242357 100644
--- a/prog/hints.go
+++ b/prog/hints.go
@@ -102,7 +102,7 @@ func generateHints(compMap CompMap, arg Arg, exec func()) {
 		case BufferFilename:
 			// This can generate escaping paths and is probably not too useful anyway.
 			return
-		case BufferString:
+		case BufferString, BufferGlob:
 			if len(t.Values) != 0 {
 				// These are frequently file names or complete enumerations.
 				// Mutating these may be useful iff we intercept strcmp
diff --git a/prog/mutation.go b/prog/mutation.go
index af6a458f0..9d6dc2118 100644
--- a/prog/mutation.go
+++ b/prog/mutation.go
@@ -349,6 +349,12 @@ func (t *BufferType) mutate(r *randGen, s *state, arg Arg, ctx ArgCtx) (calls []
 		}
 	case BufferFilename:
 		a.data = []byte(r.filename(s, t))
+	case BufferGlob:
+		if len(t.Values) != 0 {
+			a.data = r.randString(s, t)
+		} else {
+			a.data = []byte(r.filename(s, t))
+		}
 	case BufferText:
 		data := append([]byte{}, a.Data()...)
 		a.data = r.mutateText(t.Text, data)
diff --git a/prog/prio.go b/prog/prio.go
index 2c3436151..4cf3daf90 100644
--- a/prog/prio.go
+++ b/prog/prio.go
@@ -97,7 +97,7 @@ func (target *Target) calcResourceUsage() map[string]map[int]weights {
 		case *BufferType:
 			switch a.Kind {
 			case BufferBlobRand, BufferBlobRange, BufferText:
-			case BufferString:
+			case BufferString, BufferGlob:
 				if a.SubKind != "" {
 					noteUsage(uses, c, 2, ctx.Dir, fmt.Sprintf("str-%v", a.SubKind))
 				}
diff --git a/prog/rand.go b/prog/rand.go
index a78f7e343..7ab5068cb 100644
--- a/prog/rand.go
+++ b/prog/rand.go
@@ -734,6 +734,8 @@ func (a *BufferType) generate(r *randGen, s *state, dir Dir) (arg Arg, calls []*
 			return MakeOutDataArg(a, dir, sz), nil
 		}
 		return MakeDataArg(a, dir, []byte(r.filename(s, a))), nil
+	case BufferGlob:
+		return MakeDataArg(a, dir, r.randString(s, a)), nil
 	case BufferText:
 		if dir == DirOut {
 			return MakeOutDataArg(a, dir, uint64(r.Intn(100))), nil
diff --git a/prog/target.go b/prog/target.go
index f2eaf6ead..974880c22 100644
--- a/prog/target.go
+++ b/prog/target.go
@@ -227,6 +227,31 @@ func (target *Target) DefaultChoiceTable() *ChoiceTable {
 	return target.defaultChoiceTable
 }
 
+func (target *Target) GetGlobs() []string {
+	var globs []string
+	ForeachType(target.Syscalls, func(typ Type, ctx TypeCtx) {
+		switch a := typ.(type) {
+		case *BufferType:
+			if a.Kind == BufferGlob && a.SubKind != "" {
+				globs = append(globs, a.SubKind)
+			}
+		}
+	})
+
+	return globs
+}
+
+func (target *Target) UpdateGlobFilesForType(globFiles map[string][]string) {
+	ForeachType(target.Syscalls, func(typ Type, ctx TypeCtx) {
+		switch a := typ.(type) {
+		case *BufferType:
+			if a.Kind == BufferGlob && a.SubKind != "" {
+				a.Values = globFiles[a.SubKind]
+			}
+		}
+	})
+}
+
 type Gen struct {
 	r *randGen
 	s *state
diff --git a/prog/types.go b/prog/types.go
index fb680f0a1..66ce3ced0 100644
--- a/prog/types.go
+++ b/prog/types.go
@@ -481,6 +481,7 @@ const (
 	BufferString
 	BufferFilename
 	BufferText
+	BufferGlob
 )
 
 type TextKind int