Added asmc package

src/asmc/dllCall.go

@@ -0,0 +1,41 @@
+package asmc
+
+import (
+	"strings"
+
+	"git.akyoto.dev/cli/q/src/asm"
+	"git.akyoto.dev/cli/q/src/x86"
+)
+
+func (c *compiler) dllCall(x asm.Instruction) {
+	size := 4
+	// TODO: R15 could be in use.
+	c.code = x86.MoveRegisterRegister(c.code, x86.R15, x86.RSP)
+	c.code = x86.AlignStack(c.code)
+	c.code = x86.SubRegisterNumber(c.code, x86.RSP, 32)
+	c.code = x86.CallAtAddress(c.code, 0x00_00_00_00)
+	position := len(c.code) - size
+	c.code = x86.MoveRegisterRegister(c.code, x86.RSP, x86.R15)
+
+	label := x.Data.(*asm.Label)
+	pointer := &pointer{
+		Position: Address(position),
+		OpSize:   2,
+		Size:     uint8(size),
+	}
+
+	pointer.Resolve = func() Address {
+		dot := strings.Index(label.Name, ".")
+		library := label.Name[:dot]
+		funcName := label.Name[dot+1:]
+		index := c.dlls.Index(library, funcName)
+
+		if index == -1 {
+			panic("unknown DLL function " + label.Name)
+		}
+
+		return Address(index * 8)
+	}
+
+	c.dllPointers = append(c.dllPointers, pointer)
+}