Merge pull request #77 from xairy/array_as_blob

Emit BufferBlob for array[int8]

3 files changed, 29 insertions, 3 deletions

diff --git a/sys/align.go b/sys/align.go
index 6e8563da4..055a433f8 100644
--- a/sys/align.go
+++ b/sys/align.go
@@ -48,14 +48,19 @@ func addAlignment(t *StructType) {
 			off += pad
 			fields = append(fields, makePad(pad))
 		}
-		off += f.Size()
 		fields = append(fields, f)
 		if at, ok := f.(ArrayType); ok && (at.Kind == ArrayRandLen || (at.Kind == ArrayRangeLen && at.RangeBegin != at.RangeEnd)) {
 			varLen = true
 		}
+		if at, ok := f.(BufferType); ok && (at.Kind == BufferBlobRand || (at.Kind == BufferBlobRange && at.RangeBegin != at.RangeEnd)) {
+			varLen = true
+		}
 		if varLen && i != len(t.Fields)-1 {
 			panic("embed array in middle of a struct")
 		}
+		if !varLen {
+			off += f.Size()
+		}
 	}
 	if align != 0 && off%align != 0 && !varLen {
 		pad := align - off%align
diff --git a/sys/decl.go b/sys/decl.go
index f792f541c..275bbb380 100644
--- a/sys/decl.go
+++ b/sys/decl.go
@@ -100,7 +100,8 @@ func (t FileoffType) Align() uintptr {
 type BufferKind int
 
 const (
-	BufferBlob BufferKind = iota
+	BufferBlobRand BufferKind = iota
+	BufferBlobRange
 	BufferString
 	BufferSockaddr
 	BufferFilesystem
@@ -110,7 +111,9 @@ const (
 
 type BufferType struct {
 	TypeCommon
-	Kind BufferKind
+	Kind       BufferKind
+	RangeBegin uintptr // for BufferBlobRange kind
+	RangeEnd   uintptr // for BufferBlobRange kind
 }
 
 func (t BufferType) Size() uintptr {
@@ -119,6 +122,11 @@ func (t BufferType) Size() uintptr {
 		return 14
 	case BufferAlgName:
 		return 64
+	case BufferBlobRange:
+		if t.RangeBegin == t.RangeEnd {
+			return t.RangeBegin
+		}
+		fallthrough
 	default:
 		panic(fmt.Sprintf("buffer size is not statically known: %v", t.Name()))
 	}
diff --git a/sys/test.txt b/sys/test.txt
index a01c6b3c2..6420ed54c 100644
--- a/sys/test.txt
+++ b/sys/test.txt
@@ -51,6 +51,8 @@ syz_union0 [
 # Arrays.
 
 syz_test$array0(a0 ptr[in, syz_array_struct])
+syz_test$array1(a0 ptr[in, syz_array_trailing])
+syz_test$array2(a0 ptr[in, syz_array_blob])
 
 # Struct with a variable-length array or variable-length unions.
 syz_array_struct {
@@ -63,3 +65,14 @@ syz_array_union [
 	f0	int16
 	f1	int64
 ] [varlen]
+
+syz_array_trailing {
+	f0	int8
+	f1	array[int8, 4:8]
+}
+
+syz_array_blob {
+	f0	int16
+	f1	array[int8, 16]
+	f2	int16
+}