From d880332268f214941486b11b2c7397ad28cc9645 Mon Sep 17 00:00:00 2001
From: Zellyn Hunter <zellyn@gmail.com>
Date: Thu, 26 Jan 2017 20:50:44 -0600
Subject: [PATCH] asm: some work on as65 variant

---
 asm/flavors/as65/as65.go               | 47 +++++++++++++++++++++++++-
 asm/flavors/common/base.go             |  2 ++
 asm/flavors/tests/simple_parse_test.go |  2 ++
 asm/inst/instruction.go                |  1 +
 4 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/asm/flavors/as65/as65.go b/asm/flavors/as65/as65.go
index bc72612..a988dfb 100644
--- a/asm/flavors/as65/as65.go
+++ b/asm/flavors/as65/as65.go
@@ -1,6 +1,7 @@
 package as65
 
 import (
+	"errors"
 	"fmt"
 
 	"github.com/zellyn/go6502/asm/context"
@@ -11,9 +12,29 @@ import (
 	"github.com/zellyn/go6502/opcodes"
 )
 
+var defaultCMap = [256]byte{
+	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
+	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
+	0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
+	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
+	0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+	0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+	0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
+	0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
+	0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
+	0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
+	0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
+	0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
+}
+
 // As65 implements an as65-compatible assembler flavor.
 type As65 struct {
 	common.Base
+	cmap [256]byte
 }
 
 func New(sets opcodes.Set) *As65 {
@@ -38,13 +59,16 @@ func New(sets opcodes.Set) *As65 {
 		"EPZ":    {inst.TypeEqu, a.ParseEquate, inst.VarEquPageZero},
 		"DFB":    {inst.TypeData, a.ParseData, inst.VarBytes},
 
+		"db":  {inst.TypeData, a.ParseBytes, inst.VarBytes},
+		"fcb": {inst.TypeData, a.ParseData, inst.VarBytes},
 		"ds":  {inst.TypeData, a.ParseData, inst.VarBytesZero},
 		"rmb": {inst.TypeData, a.ParseData, inst.VarBytesZero},
-
 		"dw":  {inst.TypeData, a.ParseData, inst.VarWordsLe},
 		"fcw": {inst.TypeData, a.ParseData, inst.VarWordsLe},
 		"fdb": {inst.TypeData, a.ParseData, inst.VarWordsLe},
 
+		"cmap": {inst.TypeNone, a.ParseCMap, 0},
+
 		"DDB":   {inst.TypeData, a.ParseData, inst.VarWordsBe},
 		"ASC":   {inst.TypeData, a.ParseAscii, inst.VarAscii},
 		"DCI":   {inst.TypeData, a.ParseAscii, inst.VarAsciiFlip},
@@ -100,3 +124,24 @@ func New(sets opcodes.Set) *As65 {
 
 	return a
 }
+
+// ParseCMap parses a character mapping.
+// TODO(zellyn): implement
+func (a *As65) ParseCMap(ctx context.Context, in inst.I, lp *lines.Parse) (inst.I, error) {
+	lp.IgnoreRun(common.Whitespace)
+	if lp.Peek() == lines.Eol || lp.Peek() == a.CommentChar {
+		a.cmap = defaultCMap
+		return in, nil
+	}
+	return in, errors.New("TODO(zellyn): parse cmap instruction")
+}
+
+// ParseBytes parses a db instruction.
+func (a *As65) ParseBytes(ctx context.Context, in inst.I, lp *lines.Parse) (inst.I, error) {
+	lp.IgnoreRun(common.Whitespace)
+	return in, nil
+}
+
+func (a *As65) ParseByteList(lp *lines.Parse, cmap *[256]byte) (bytes []byte, final bool, err error) {
+	return nil, false, nil
+}
diff --git a/asm/flavors/common/base.go b/asm/flavors/common/base.go
index 77c75ab..9950378 100644
--- a/asm/flavors/common/base.go
+++ b/asm/flavors/common/base.go
@@ -436,6 +436,8 @@ func (a *Base) ParseOrg(ctx context.Context, in inst.I, lp *lines.Parse) (inst.I
 	return in, nil
 }
 
+// ParseAscii parses data definition instructions that have some
+// variant of ASCII as their data.
 func (a *Base) ParseAscii(ctx context.Context, in inst.I, lp *lines.Parse) (inst.I, error) {
 	lp.IgnoreRun(Whitespace)
 	a.SetAsciiVariation(ctx, &in, lp)
diff --git a/asm/flavors/tests/simple_parse_test.go b/asm/flavors/tests/simple_parse_test.go
index d89db3f..0a4c784 100644
--- a/asm/flavors/tests/simple_parse_test.go
+++ b/asm/flavors/tests/simple_parse_test.go
@@ -33,6 +33,8 @@ func TestSimpleCommonFunctions(t *testing.T) {
 		{aa, " beq $2347", "{beq $2347}", "f000"},
 		{aa, " dw $1234", "{data/wle $1234}", "3412"},
 		{aa, " ds 5", "{data/bz $0005}", "0000000000"},
+		// TODO(zellyn): make this work.
+		// {aa, ` db "\aError\r\n",0`, "{data/b xyzzy}", "4572726f720d0a00"},
 		{aa, " jmp $1234", "{jmp/abs $1234}", "4c3412"},
 		{aa, " jmp ($1234)", "{jmp/ind $1234}", "6c3412"},
 		{aa, " lda #$12", "{lda/imm (lsb $0012)}", "a912"},
diff --git a/asm/inst/instruction.go b/asm/inst/instruction.go
index 86cf513..17bc026 100644
--- a/asm/inst/instruction.go
+++ b/asm/inst/instruction.go
@@ -33,6 +33,7 @@ const (
 	TypeOp         // An actual asm opcode
 	TypeEnd        // End assembly
 	TypeSetting    // An on/off setting toggle
+	TypeDirective  // An assembler directive that was consumed
 )
 
 type Variant int