features: fix documentation

Exporting feature tests as variables means that they can't be
navigated to in online documentation. Fix this by exporting
functions instead.

Signed-off-by: Lorenz Bauer <[email protected]>

Author: lmb

features/misc.go

@@ -12,7 +12,11 @@ import (
 // Upstream commit c04c0d2b968a ("bpf: increase complexity limit and maximum program size").
 //
 // See the package documentation for the meaning of the error return value.
-var HaveLargeInstructions = internal.NewFeatureTest(">4096 instructions", "5.2", func() error {
+func HaveLargeInstructions() error {
+	return haveLargeInstructions()
+}
+
+var haveLargeInstructions = internal.NewFeatureTest(">4096 instructions", "5.2", func() error {
 	const maxInsns = 4096
 
 	insns := make(asm.Instructions, maxInsns, maxInsns+1)
@@ -32,7 +36,11 @@ var HaveLargeInstructions = internal.NewFeatureTest(">4096 instructions", "5.2",
 // Upstream commit 2589726d12a1 ("bpf: introduce bounded loops").
 //
 // See the package documentation for the meaning of the error return value.
-var HaveBoundedLoops = internal.NewFeatureTest("bounded loops", "5.3", func() error {
+func HaveBoundedLoops() error {
+	return haveBoundedLoops()
+}
+
+var haveBoundedLoops = internal.NewFeatureTest("bounded loops", "5.3", func() error {
 	return probeProgram(&ebpf.ProgramSpec{
 		Type: ebpf.SocketFilter,
 		Instructions: asm.Instructions{
@@ -49,7 +57,11 @@ var HaveBoundedLoops = internal.NewFeatureTest("bounded loops", "5.3", func() er
 // Upstream commit 92b31a9af73b ("bpf: add BPF_J{LT,LE,SLT,SLE} instructions").
 //
 // See the package documentation for the meaning of the error return value.
-var HaveV2ISA = internal.NewFeatureTest("v2 ISA", "4.14", func() error {
+func HaveV2ISA() error {
+	return haveV2ISA()
+}
+
+var haveV2ISA = internal.NewFeatureTest("v2 ISA", "4.14", func() error {
 	return probeProgram(&ebpf.ProgramSpec{
 		Type: ebpf.SocketFilter,
 		Instructions: asm.Instructions{
@@ -66,7 +78,11 @@ var HaveV2ISA = internal.NewFeatureTest("v2 ISA", "4.14", func() error {
 // Upstream commit 092ed0968bb6 ("bpf: verifier support JMP32").
 //
 // See the package documentation for the meaning of the error return value.
-var HaveV3ISA = internal.NewFeatureTest("v3 ISA", "5.1", func() error {
+func HaveV3ISA() error {
+	return haveV3ISA()
+}
+
+var haveV3ISA = internal.NewFeatureTest("v3 ISA", "5.1", func() error {
 	return probeProgram(&ebpf.ProgramSpec{
 		Type: ebpf.SocketFilter,
 		Instructions: asm.Instructions{