ast: move "ast" types from root to ir sub-package

Closes #32

build/context.go

@@ -4,10 +4,10 @@ import (
 	"errors"
 	"go/types"
 
-	"github.com/mmcloughlin/avo"
 	"github.com/mmcloughlin/avo/attr"
 	"github.com/mmcloughlin/avo/buildtags"
 	"github.com/mmcloughlin/avo/gotypes"
+	"github.com/mmcloughlin/avo/ir"
 	"github.com/mmcloughlin/avo/operand"
 	"github.com/mmcloughlin/avo/reg"
 	"golang.org/x/tools/go/packages"
@@ -16,17 +16,17 @@ import (
 // Context maintains state for incrementally building an avo File.
 type Context struct {
 	pkg      *packages.Package
-	file     *avo.File
-	function *avo.Function
-	global   *avo.Global
+	file     *ir.File
+	function *ir.Function
+	global   *ir.Global
 	errs     ErrorList
 	reg.Collection
 }
 
 // NewContext initializes an empty build Context.
 func NewContext() *Context {
 	return &Context{
-		file:       avo.NewFile(),
+		file:       ir.NewFile(),
 		Collection: *reg.NewCollection(),
 	}
 }
@@ -81,7 +81,7 @@ func (c *Context) ConstraintExpr(expr string) {
 
 // Function starts building a new function with the given name.
 func (c *Context) Function(name string) {
-	c.function = avo.NewFunction(name)
+	c.function = ir.NewFunction(name)
 	c.file.AddSection(c.function)
 }
 
@@ -124,19 +124,19 @@ func (c *Context) AllocLocal(size int) operand.Mem {
 }
 
 // Instruction adds an instruction to the active function.
-func (c *Context) Instruction(i *avo.Instruction) {
+func (c *Context) Instruction(i *ir.Instruction) {
 	c.activefunc().AddInstruction(i)
 }
 
 // Label adds a label to the active function.
 func (c *Context) Label(name string) {
-	c.activefunc().AddLabel(avo.Label(name))
+	c.activefunc().AddLabel(ir.Label(name))
 }
 
-func (c *Context) activefunc() *avo.Function {
+func (c *Context) activefunc() *ir.Function {
 	if c.function == nil {
 		c.adderrormessage("no active function")
-		return avo.NewFunction("")
+		return ir.NewFunction("")
 	}
 	return c.function
 }
@@ -145,7 +145,7 @@ func (c *Context) activefunc() *avo.Function {
 
 // StaticGlobal adds a new static data section to the file and returns a pointer to it.
 func (c *Context) StaticGlobal(name string) operand.Mem {
-	c.global = avo.NewStaticGlobal(name)
+	c.global = ir.NewStaticGlobal(name)
 	c.file.AddSection(c.global)
 	return c.global.Base()
 }
@@ -157,7 +157,7 @@ func (c *Context) DataAttributes(a attr.Attribute) {
 
 // AddDatum adds constant v at offset to the current active global data section.
 func (c *Context) AddDatum(offset int, v operand.Constant) {
-	if err := c.activeglobal().AddDatum(avo.NewDatum(offset, v)); err != nil {
+	if err := c.activeglobal().AddDatum(ir.NewDatum(offset, v)); err != nil {
 		c.adderror(err)
 	}
 }
@@ -167,10 +167,10 @@ func (c *Context) AppendDatum(v operand.Constant) {
 	c.activeglobal().Append(v)
 }
 
-func (c *Context) activeglobal() *avo.Global {
+func (c *Context) activeglobal() *ir.Global {
 	if c.global == nil {
 		c.adderrormessage("no active global")
-		return avo.NewStaticGlobal("")
+		return ir.NewStaticGlobal("")
 	}
 	return c.global
 }
@@ -184,6 +184,6 @@ func (c *Context) adderrormessage(msg string) {
 }
 
 // Result returns the built file and any accumulated errors.
-func (c *Context) Result() (*avo.File, error) {
+func (c *Context) Result() (*ir.File, error) {
 	return c.file, c.errs.Err()
 }

internal/gen/avotypes.go

@@ -7,7 +7,6 @@ import (
 
 const (
 	pkg         = "github.com/mmcloughlin/avo"
-	instType    = "avo.Instruction"
 	operandType = "operand.Op"
 )
 

internal/gen/ctors.go

@@ -27,7 +27,7 @@ func (c *ctors) Generate(is []inst.Instruction) ([]byte, error) {
 	c.Printf("package x86\n\n")
 	c.Printf("import (\n")
 	c.Printf("\t\"errors\"\n")
-	c.Printf("\t\"%s\"\n", pkg)
+	c.Printf("\tintrep \"%s/ir\"\n", pkg)
 	c.Printf("\t\"%s/reg\"\n", pkg)
 	c.Printf("\t\"%s/operand\"\n", pkg)
 	c.Printf(")\n\n")
@@ -46,7 +46,7 @@ func (c *ctors) instruction(i inst.Instruction) {
 
 	s := params(i)
 
-	c.Printf("func %s(%s) (*%s, error) {\n", i.Opcode, s.ParameterList(), instType)
+	c.Printf("func %s(%s) (*intrep.Instruction, error) {\n", i.Opcode, s.ParameterList())
 	c.forms(i, s)
 	c.Printf("}\n\n")
 }
@@ -85,7 +85,7 @@ func (c *ctors) forms(i inst.Instruction, s signature) {
 
 func construct(i inst.Instruction, f inst.Form, s signature) string {
 	buf := bytes.NewBuffer(nil)
-	fmt.Fprintf(buf, "%s{\n", instType)
+	fmt.Fprintf(buf, "intrep.Instruction{\n")
 	fmt.Fprintf(buf, "\tOpcode: %#v,\n", i.Opcode)
 	fmt.Fprintf(buf, "\tOperands: %s,\n", s.ParameterSlice())
 

ir/doc.go

@@ -0,0 +1,2 @@
+// Package ir provides the intermediate representation of avo programs.
+package ir

ast.go → ir/ir.go

@@ -1,4 +1,4 @@
-package avo
+package ir
 
 import (
 	"errors"

pass/cfg.go

@@ -4,16 +4,16 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/mmcloughlin/avo"
+	"github.com/mmcloughlin/avo/ir"
 )
 
 // LabelTarget populates the LabelTarget of the given function. This maps from
 // label name to the following instruction.
-func LabelTarget(fn *avo.Function) error {
-	target := map[avo.Label]*avo.Instruction{}
+func LabelTarget(fn *ir.Function) error {
+	target := map[ir.Label]*ir.Instruction{}
 	for idx := 0; idx < len(fn.Nodes); idx++ {
 		// Is this a label?
-		lbl, ok := fn.Nodes[idx].(avo.Label)
+		lbl, ok := fn.Nodes[idx].(ir.Label)
 		if !ok {
 			continue
 		}
@@ -27,7 +27,7 @@ func LabelTarget(fn *avo.Function) error {
 		}
 		idx++
 		// Should be an instruction.
-		i, ok := fn.Nodes[idx].(*avo.Instruction)
+		i, ok := fn.Nodes[idx].(*ir.Instruction)
 		if !ok {
 			return errors.New("instruction should follow a label")
 		}
@@ -38,14 +38,14 @@ func LabelTarget(fn *avo.Function) error {
 }
 
 // CFG constructs the call-flow-graph for the function.
-func CFG(fn *avo.Function) error {
+func CFG(fn *ir.Function) error {
 	is := fn.Instructions()
 	n := len(is)
 
 	// Populate successors.
 	for i := 0; i < n; i++ {
 		cur := is[i]
-		var nxt *avo.Instruction
+		var nxt *ir.Instruction
 		if i+1 < n {
 			nxt = is[i+1]
 		}