btf/cmd/genbtftypes: (cilium#1218) a generator that generates btf_typ…

…es.go structs.

This is guaranteed to match the kernel struct defenitions.

btf/btf_types.go

@@ -131,28 +131,6 @@ func parseBTFHeader(r io.Reader, bo binary.ByteOrder) (*btfHeader, error) {
 
 var btfTypeLen = binary.Size(btfType{})
 
-// btfType is equivalent to struct btf_type in Documentation/bpf/btf.rst.
-type btfType struct {
-	NameOff uint32
-	/* "info" bits arrangement
-	 * bits  0-15: vlen (e.g. # of struct's members), linkage
-	 * bits 16-23: unused
-	 * bits 24-28: kind (e.g. int, ptr, array...etc)
-	 * bits 29-30: unused
-	 * bit     31: kind_flag, currently used by
-	 *             struct, union and fwd
-	 */
-	Info uint32
-	/* "size" is used by INT, ENUM, STRUCT and UNION.
-	 * "size" tells the size of the type it is describing.
-	 *
-	 * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
-	 * FUNC and FUNC_PROTO.
-	 * "type" is a type_id referring to another type.
-	 */
-	SizeType uint32
-}
-
 var btfTypeSize = int(unsafe.Sizeof(btfType{}))
 
 func unmarshalBtfType(bt *btfType, b []byte, bo binary.ByteOrder) (int, error) {
@@ -348,12 +326,6 @@ func (bi *btfInt) SetBits(bits byte) {
 	bi.Raw = writeBits(bi.Raw, btfIntBitsLen, btfIntBitsShift, uint32(bits))
 }
 
-type btfArray struct {
-	Type      TypeID
-	IndexType TypeID
-	Nelems    uint32
-}
-
 var btfArrayLen = int(unsafe.Sizeof(btfArray{}))
 
 func unmarshalBtfArray(ba *btfArray, b []byte, bo binary.ByteOrder) (int, error) {
@@ -367,12 +339,6 @@ func unmarshalBtfArray(ba *btfArray, b []byte, bo binary.ByteOrder) (int, error)
 	return btfArrayLen, nil
 }
 
-type btfMember struct {
-	NameOff uint32
-	Type    TypeID
-	Offset  uint32
-}
-
 var btfMemberLen = int(unsafe.Sizeof(btfMember{}))
 
 func unmarshalBtfMembers(members []btfMember, b []byte, bo binary.ByteOrder) (int, error) {
@@ -392,12 +358,6 @@ func unmarshalBtfMembers(members []btfMember, b []byte, bo binary.ByteOrder) (in
 	return off, nil
 }
 
-type btfVarSecinfo struct {
-	Type   TypeID
-	Offset uint32
-	Size   uint32
-}
-
 var btfVarSecinfoLen = int(unsafe.Sizeof(btfVarSecinfo{}))
 
 func unmarshalBtfVarSecInfos(secinfos []btfVarSecinfo, b []byte, bo binary.ByteOrder) (int, error) {
@@ -417,10 +377,6 @@ func unmarshalBtfVarSecInfos(secinfos []btfVarSecinfo, b []byte, bo binary.ByteO
 	return off, nil
 }
 
-type btfVariable struct {
-	Linkage uint32
-}
-
 var btfVariableLen = int(unsafe.Sizeof(btfVariable{}))
 
 func unmarshalBtfVariable(bv *btfVariable, b []byte, bo binary.ByteOrder) (int, error) {
@@ -432,11 +388,6 @@ func unmarshalBtfVariable(bv *btfVariable, b []byte, bo binary.ByteOrder) (int,
 	return btfVariableLen, nil
 }
 
-type btfEnum struct {
-	NameOff uint32
-	Val     uint32
-}
-
 var btfEnumLen = int(unsafe.Sizeof(btfEnum{}))
 
 func unmarshalBtfEnums(enums []btfEnum, b []byte, bo binary.ByteOrder) (int, error) {
@@ -455,12 +406,6 @@ func unmarshalBtfEnums(enums []btfEnum, b []byte, bo binary.ByteOrder) (int, err
 	return off, nil
 }
 
-type btfEnum64 struct {
-	NameOff uint32
-	ValLo32 uint32
-	ValHi32 uint32
-}
-
 var btfEnum64Len = int(unsafe.Sizeof(btfEnum64{}))
 
 func unmarshalBtfEnums64(enums []btfEnum64, b []byte, bo binary.ByteOrder) (int, error) {
@@ -480,11 +425,6 @@ func unmarshalBtfEnums64(enums []btfEnum64, b []byte, bo binary.ByteOrder) (int,
 	return off, nil
 }
 
-type btfParam struct {
-	NameOff uint32
-	Type    TypeID
-}
-
 var btfParamLen = int(unsafe.Sizeof(btfParam{}))
 
 func unmarshalBtfParams(params []btfParam, b []byte, bo binary.ByteOrder) (int, error) {
@@ -503,10 +443,6 @@ func unmarshalBtfParams(params []btfParam, b []byte, bo binary.ByteOrder) (int,
 	return off, nil
 }
 
-type btfDeclTag struct {
-	ComponentIdx uint32
-}
-
 var btfDeclTagLen = int(unsafe.Sizeof(btfDeclTag{}))
 
 func unmarshalBtfDeclTag(bdt *btfDeclTag, b []byte, bo binary.ByteOrder) (int, error) {

btf/cmd/genbtftypes/.gitignore

@@ -0,0 +1 @@
+genbtftypes