start example/test for components access

examples/components/asm.go

@@ -0,0 +1,21 @@
+// +build ignore
+
+package main
+
+import (
+	. "github.com/mmcloughlin/avo/build"
+)
+
+func main() {
+	Package("github.com/mmcloughlin/avo/examples/components")
+
+	// Add confirms that we correctly deduce the packing of Struct.
+	TEXT("Add", "func(x uint64, s Struct, y uint64) uint64")
+	x := Load(Param("x"), GP64v())
+	y := Load(Param("y"), GP64v())
+	ADDQ(x, y)
+	Store(y, ReturnIndex(0))
+	RET()
+
+	Generate()
+}

examples/components/components.go

@@ -0,0 +1,20 @@
+package components
+
+type Struct struct {
+	Byte       byte
+	Uint32     uint32
+	Uint64     uint64
+	Float32    float32
+	Float64    float64
+	String     string
+	Slice      []Sub
+	Array      [5]Sub
+	Complex64  complex64
+	Complex128 complex128
+}
+
+type Sub struct {
+	A uint64
+	B [3]byte
+	C uint16
+}

examples/components/components.s

@@ -0,0 +1,10 @@
+
+#include "textflag.h"
+
+// func Add(x uint64, s Struct, y uint64) uint64
+TEXT ·Add(SB),0,$0-200
+	MOVQ	x(FP), AX
+	MOVQ	y+184(FP), CX
+	ADDQ	AX, CX
+	MOVQ	CX, ret+192(FP)
+	RET	

examples/components/components_test.go

@@ -0,0 +1,15 @@
+package components
+
+import (
+	"testing"
+	"testing/quick"
+)
+
+//go:generate go run asm.go -out components.s -stubs stub.go
+
+func TestAdd(t *testing.T) {
+	expect := func(x uint64, s Struct, y uint64) uint64 { return x + y }
+	if err := quick.CheckEqual(Add, expect, nil); err != nil {
+		t.Fatal(err)
+	}
+}

examples/components/stub.go

@@ -0,0 +1,3 @@
+package components
+
+func Add(x uint64, s Struct, y uint64) uint64