collection: rename CollectionSpec.BTF to .Types

In preparation of renaming the btf.Spec type itself down the line, once
.BTF.ext data has been lifted into per-insn metadata, cement the interface
that will be used to query the CollectionSpec for its type information.

A CollectionSpec now provides Maps, Programs and Types.

Signed-off-by: Timo Beckers <timo@isovalent.com>

cmd/bpf2go/output.go

@@ -255,7 +255,7 @@ func output(args outputArgs) error {
 	}
 
 	// Collect any types which we've been asked for explicitly.
-	cTypes, err := collectCTypes(spec.BTF, args.cTypes)
+	cTypes, err := collectCTypes(spec.Types, args.cTypes)
 	if err != nil {
 		return err
 	}

collection.go

@@ -27,8 +27,8 @@ type CollectionSpec struct {
 	Maps     map[string]*MapSpec
 	Programs map[string]*ProgramSpec
 
-	// The BTF used by maps and programs.
-	BTF *btf.Spec
+	// Types holds type information about Maps and Programs.
+	Types *btf.Spec
 
 	// ByteOrder specifies whether the ELF was compiled for
 	// big-endian or little-endian architectures.
@@ -45,7 +45,7 @@ func (cs *CollectionSpec) Copy() *CollectionSpec {
 		Maps:      make(map[string]*MapSpec, len(cs.Maps)),
 		Programs:  make(map[string]*ProgramSpec, len(cs.Programs)),
 		ByteOrder: cs.ByteOrder,
-		BTF:       cs.BTF.Copy(),
+		Types:     cs.Types.Copy(),
 	}
 
 	for name, spec := range cs.Maps {
@@ -413,7 +413,7 @@ func (cl *collectionLoader) loadMap(mapName string) (*Map, error) {
 		return nil, fmt.Errorf("missing map %s", mapName)
 	}
 
-	if mapSpec.BTF != nil && cl.coll.BTF != mapSpec.BTF.Spec {
+	if mapSpec.BTF != nil && cl.coll.Types != mapSpec.BTF.Spec {
 		return nil, fmt.Errorf("map %s: BTF doesn't match collection", mapName)
 	}
 
@@ -442,7 +442,7 @@ func (cl *collectionLoader) loadProgram(progName string) (*Program, error) {
 		return nil, fmt.Errorf("cannot load program %s: program type is unspecified", progName)
 	}
 
-	if progSpec.BTF != nil && cl.coll.BTF != progSpec.BTF.Spec() {
+	if progSpec.BTF != nil && cl.coll.Types != progSpec.BTF.Spec() {
 		return nil, fmt.Errorf("program %s: BTF doesn't match collection", progName)
 	}
 

collection_test.go

@@ -67,7 +67,7 @@ func TestCollectionSpecCopy(t *testing.T) {
 				License: "MIT",
 			},
 		},
-		BTF: &btf.Spec{},
+		Types: &btf.Spec{},
 	}
 	cpy := cs.Copy()
 
@@ -83,8 +83,8 @@ func TestCollectionSpecCopy(t *testing.T) {
 		t.Error("Copy returned same Programs")
 	}
 
-	if cpy.BTF == cs.BTF {
-		t.Error("Copy returned same BTF")
+	if cpy.Types == cs.Types {
+		t.Error("Copy returned same Types")
 	}
 }