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6502bench/SourceGen/AsmGen/GenCommon.cs
Andy McFadden 99cd0d3ac1 Improve handling of C64 PRG header
C64 PRG files are pretty common.  Their salient feature is that they
start with a 16-bit value that is used as the load address.  The
value is commonly generated by the assembler itself, rather than
explicitly added to the source file.

Not all assemblers know what a PRG file is, and some of them handle
it in ways that are difficult to guarantee in SourceGen.  ACME adds
the 16-bit header when the output file name ends in ".prg", cc65
uses a modified config file, 64tass uses a different command-line
option, and Merlin 32 has no idea what they are.

This change adds PRG file detection and handling to the 64tass code
generator.  Doing so required making a few changes to the gen/asm
interfaces, because we now need to have the generator pass additional
flags to the assembler, and sometimes we need code generation to
start somewhere other than offset zero.  Overall the changes were
pretty minor.

The 20042-address-changes test needed a 6502-only variant.  A new test
(20040-address-changes) has been added and given a PRG header.  As
part of this change the 65816 variant was changed to use addresses
in bank 2, which uncovered a code generation bug that this change
also fixes.

The 64tass --long-address flag doesn't appear to be necessary for
files <= 65536 bytes long, so we no longer emit it for those.

(issue #90)
2020-10-17 16:45:13 -07:00

504 lines
25 KiB
C#

/*
* Copyright 2019 faddenSoft
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using Asm65;
namespace SourceGen.AsmGen {
public class GenCommon {
/// <summary>
/// Generates assembly source.
///
/// This code is common to all generators.
/// </summary>
/// <param name="gen">Reference to generator object (presumably the caller).</param>
/// <param name="sw">Text output sink.</param>
/// <param name="worker">Background worker object, for progress updates and
/// cancelation requests.</param>
public static void Generate(IGenerator gen, StreamWriter sw, BackgroundWorker worker) {
DisasmProject proj = gen.Project;
Formatter formatter = gen.SourceFormatter;
int offset = gen.StartOffset;
bool doAddCycles = gen.Settings.GetBool(AppSettings.SRCGEN_SHOW_CYCLE_COUNTS, false);
LocalVariableLookup lvLookup = new LocalVariableLookup(proj.LvTables, proj,
gen.Localizer.LabelMap, gen.Quirks.LeadingUnderscoreSpecial,
gen.Quirks.NoRedefinableSymbols);
GenerateHeader(gen, sw);
// Used for M/X flag tracking.
StatusFlags prevFlags = StatusFlags.AllIndeterminate;
int lastProgress = 0;
while (offset < proj.FileData.Length) {
Anattrib attr = proj.GetAnattrib(offset);
if (attr.IsInstructionStart && offset > 0 &&
proj.GetAnattrib(offset - 1).IsData) {
// Transition from data to code. (Don't add blank line for inline data.)
gen.OutputLine(string.Empty);
}
// Long comments come first.
if (proj.LongComments.TryGetValue(offset, out MultiLineComment longComment)) {
List<string> formatted = longComment.FormatText(formatter, string.Empty);
foreach (string str in formatted) {
gen.OutputLine(str);
}
}
// Check for address change.
int orgAddr = proj.AddrMap.Get(offset);
if (orgAddr >= 0) {
gen.OutputOrgDirective(offset, orgAddr);
}
List<DefSymbol> lvars = lvLookup.GetVariablesDefinedAtOffset(offset);
if (lvars != null) {
// table defined here
gen.OutputLocalVariableTable(offset, lvars,
lvLookup.GetMergedTableAtOffset(offset));
}
if (attr.IsInstructionStart) {
// Generate M/X reg width directive, if necessary.
// NOTE: we can suppress the initial directive if we know what the
// target assembler's default assumption is. Probably want to handle
// that in the ORG output handler.
if (proj.CpuDef.HasEmuFlag) {
StatusFlags curFlags = attr.StatusFlags;
curFlags.M = attr.StatusFlags.IsShortM ? 1 : 0;
curFlags.X = attr.StatusFlags.IsShortX ? 1 : 0;
if (curFlags.M != prevFlags.M || curFlags.X != prevFlags.X) {
// changed, output directive
gen.OutputRegWidthDirective(offset, prevFlags.M, prevFlags.X,
curFlags.M, curFlags.X);
}
prevFlags = curFlags;
}
// Look for embedded instructions.
int len;
for (len = 1; len < attr.Length; len++) {
if (proj.GetAnattrib(offset + len).IsInstructionStart) {
break;
}
}
// Output instruction.
GenerateInstruction(gen, sw, lvLookup, offset, len, doAddCycles);
if (attr.DoesNotContinue) {
gen.OutputLine(string.Empty);
}
offset += len;
} else {
gen.OutputDataOp(offset);
offset += attr.Length;
}
// Update progress meter. We don't want to spam it, so just ping it 10x.
int curProgress = (offset * 10) / proj.FileData.Length;
if (lastProgress != curProgress) {
if (worker.CancellationPending) {
Debug.WriteLine("GenCommon got cancellation request");
return;
}
lastProgress = curProgress;
worker.ReportProgress(curProgress * 10);
//System.Threading.Thread.Sleep(500);
}
}
}
private static void GenerateHeader(IGenerator gen, StreamWriter sw) {
DisasmProject proj = gen.Project;
Formatter formatter = gen.SourceFormatter;
// Check for header comment.
if (proj.LongComments.TryGetValue(LineListGen.Line.HEADER_COMMENT_OFFSET,
out MultiLineComment headerComment)) {
List<string> formatted = headerComment.FormatText(formatter, string.Empty);
foreach (string str in formatted) {
gen.OutputLine(str);
}
}
gen.OutputAsmConfig();
// Format symbols.
bool prevConst = false;
foreach (DefSymbol defSym in proj.ActiveDefSymbolList) {
if (prevConst && !defSym.IsConstant) {
// Output a blank line between the constants and the address equates.
gen.OutputLine(string.Empty);
}
// Use an operand length of 1 so values are shown as concisely as possible.
string valueStr = PseudoOp.FormatNumericOperand(formatter, proj.SymbolTable,
gen.Localizer.LabelMap, defSym.DataDescriptor, defSym.Value, 1,
PseudoOp.FormatNumericOpFlags.OmitLabelPrefixSuffix);
string labelStr = gen.Localizer.ConvLabel(defSym.Label);
gen.OutputEquDirective(labelStr, valueStr, defSym.Comment);
prevConst = defSym.IsConstant;
}
// If there was at least one symbol, output a blank line.
if (proj.ActiveDefSymbolList.Count != 0) {
gen.OutputLine(string.Empty);
}
}
private static void GenerateInstruction(IGenerator gen, StreamWriter sw,
LocalVariableLookup lvLookup, int offset, int instrBytes, bool doAddCycles) {
DisasmProject proj = gen.Project;
Formatter formatter = gen.SourceFormatter;
byte[] data = proj.FileData;
Anattrib attr = proj.GetAnattrib(offset);
string labelStr = string.Empty;
if (attr.Symbol != null) {
labelStr = gen.Localizer.ConvLabel(attr.Symbol.Label);
}
OpDef op = proj.CpuDef.GetOpDef(data[offset]);
int operand = op.GetOperand(data, offset, attr.StatusFlags);
int instrLen = op.GetLength(attr.StatusFlags);
OpDef.WidthDisambiguation wdis = OpDef.WidthDisambiguation.None;
if (op.IsWidthPotentiallyAmbiguous) {
wdis = OpDef.GetWidthDisambiguation(instrLen, operand);
}
if (gen.Quirks.SinglePassAssembler && wdis == OpDef.WidthDisambiguation.None &&
(op.AddrMode == OpDef.AddressMode.DP ||
op.AddrMode == OpDef.AddressMode.DPIndexX) ||
op.AddrMode == OpDef.AddressMode.DPIndexY) {
// Could be a forward reference to a direct-page label. For ACME, we don't
// care if it's forward or not.
if ((gen.Quirks.SinglePassNoLabelCorrection && IsLabelReference(gen, offset)) ||
IsForwardLabelReference(gen, offset)) {
wdis = OpDef.WidthDisambiguation.ForceDirect;
}
}
if (wdis == OpDef.WidthDisambiguation.ForceLongMaybe &&
gen.Quirks.SinglePassAssembler &&
IsForwardLabelReference(gen, offset)) {
// Assemblers like cc65 can't tell if a symbol reference is Absolute or
// Long if they haven't seen the symbol yet. Irrelevant for ACME, which
// doesn't currently handle 65816 outside bank 0.
wdis = OpDef.WidthDisambiguation.ForceLong;
}
string opcodeStr = formatter.FormatOpcode(op, wdis);
string formattedOperand = null;
int operandLen = instrLen - 1;
PseudoOp.FormatNumericOpFlags opFlags = PseudoOp.FormatNumericOpFlags.OmitLabelPrefixSuffix;
bool isPcRelBankWrap = false;
// Tweak branch instructions. We want to show the absolute address rather
// than the relative offset (which happens with the OperandAddress assignment
// below), and 1-byte branches should always appear as a 4-byte hex value.
// Unless we're outside bank 0 on 65816, in which case most assemblers require
// them to be 6-byte hex values.
if (op.AddrMode == OpDef.AddressMode.PCRel ||
op.AddrMode == OpDef.AddressMode.DPPCRel) {
Debug.Assert(attr.OperandAddress >= 0);
operandLen = 2;
opFlags |= PseudoOp.FormatNumericOpFlags.IsPcRel;
} else if (op.AddrMode == OpDef.AddressMode.PCRelLong ||
op.AddrMode == OpDef.AddressMode.StackPCRelLong) {
opFlags |= PseudoOp.FormatNumericOpFlags.IsPcRel;
} else if (op.AddrMode == OpDef.AddressMode.Imm ||
op.AddrMode == OpDef.AddressMode.ImmLongA ||
op.AddrMode == OpDef.AddressMode.ImmLongXY) {
opFlags |= PseudoOp.FormatNumericOpFlags.HasHashPrefix;
}
if ((opFlags & PseudoOp.FormatNumericOpFlags.IsPcRel) != 0) {
int branchDist = attr.Address - attr.OperandAddress;
isPcRelBankWrap = branchDist > 32767 || branchDist < -32768;
}
if (op.IsAbsolutePBR) {
opFlags |= PseudoOp.FormatNumericOpFlags.IsAbsolutePBR;
}
// 16-bit operands outside bank 0 need to include the bank when computing
// symbol adjustment.
int operandForSymbol = operand;
if (attr.OperandAddress >= 0) {
operandForSymbol = attr.OperandAddress;
}
// Check Length to watch for bogus descriptors. (ApplyFormatDescriptors() should
// now be screening bad descriptors out, so we may not need the Length test.)
if (attr.DataDescriptor != null && attr.Length == attr.DataDescriptor.Length) {
FormatDescriptor dfd = gen.ModifyInstructionOperandFormat(offset,
attr.DataDescriptor, operand);
// Format operand as directed.
if (op.AddrMode == OpDef.AddressMode.BlockMove) {
// Special handling for the double-operand block move.
string opstr1 = PseudoOp.FormatNumericOperand(formatter, proj.SymbolTable,
gen.Localizer.LabelMap, dfd, operand >> 8, 1,
PseudoOp.FormatNumericOpFlags.OmitLabelPrefixSuffix);
string opstr2 = PseudoOp.FormatNumericOperand(formatter, proj.SymbolTable,
gen.Localizer.LabelMap, dfd, operand & 0xff, 1,
PseudoOp.FormatNumericOpFlags.OmitLabelPrefixSuffix);
if (gen.Quirks.BlockMoveArgsReversed) {
string tmp = opstr1;
opstr1 = opstr2;
opstr2 = tmp;
}
string hash = gen.Quirks.BlockMoveArgsNoHash ? "" : "#";
formattedOperand = hash + opstr1 + "," + hash + opstr2;
} else if (op.AddrMode == OpDef.AddressMode.DPPCRel) {
// Special handling for double-operand BBR/BBS. The instruction generally
// behaves like a branch, so format that first.
string branchStr = PseudoOp.FormatNumericOperand(formatter,
proj.SymbolTable, gen.Localizer.LabelMap, dfd,
operandForSymbol, operandLen, opFlags);
string dpStr = formatter.FormatHexValue(operand & 0xff, 2);
formattedOperand = dpStr + "," + branchStr;
} else {
if (attr.DataDescriptor.IsStringOrCharacter) {
gen.UpdateCharacterEncoding(dfd);
}
formattedOperand = PseudoOp.FormatNumericOperand(formatter, proj.SymbolTable,
lvLookup, gen.Localizer.LabelMap, dfd,
offset, operandForSymbol, operandLen, opFlags);
}
} else {
// Show operand value in hex.
if (op.AddrMode == OpDef.AddressMode.BlockMove) {
int arg1, arg2;
if (gen.Quirks.BlockMoveArgsReversed) {
arg1 = operand & 0xff;
arg2 = operand >> 8;
} else {
arg1 = operand >> 8;
arg2 = operand & 0xff;
}
string hash = gen.Quirks.BlockMoveArgsNoHash ? "" : "#";
formattedOperand = hash + formatter.FormatHexValue(arg1, 2) + "," +
hash + formatter.FormatHexValue(arg2, 2);
} else if (op.AddrMode == OpDef.AddressMode.DPPCRel) {
formattedOperand = formatter.FormatHexValue(operand & 0xff, 2) + "," +
formatter.FormatHexValue(operandForSymbol, operandLen * 2);
} else {
if (operandLen == 2 && !(op.IsAbsolutePBR && gen.Quirks.Need24BitsForAbsPBR) &&
(opFlags & PseudoOp.FormatNumericOpFlags.IsPcRel) == 0) {
// This is necessary for 16-bit operands, like "LDA abs" and "PEA val",
// when outside bank zero. The bank is included in the operand address,
// but we don't want to show it here. We may need it for JSR/JMP though,
// and the bank is required for relative branch instructions.
operandForSymbol &= 0xffff;
}
formattedOperand = formatter.FormatHexValue(operandForSymbol, operandLen * 2);
}
}
string operandStr = formatter.FormatOperand(op, formattedOperand, wdis);
if (gen.Quirks.StackIntOperandIsImmediate &&
op.AddrMode == OpDef.AddressMode.StackInt) {
// COP $02 is standard, but some require COP #$02
operandStr = '#' + operandStr;
}
// The BBR/BBS/RMB/SMB instructions include a bit index (0-7). The standard way is
// to make it part of the mnemonic, but some assemblers make it an argument.
if (gen.Quirks.BitNumberIsArg && op.IsNumberedBitOp) {
// Easy way: do some string manipulation.
char bitIndex = opcodeStr[opcodeStr.Length - 1];
opcodeStr = opcodeStr.Substring(0, opcodeStr.Length - 1);
operandStr = bitIndex.ToString() + "," + operandStr;
}
string eolComment = proj.Comments[offset];
if (doAddCycles) {
bool branchCross = (attr.Address & 0xff00) != (operandForSymbol & 0xff00);
int cycles = proj.CpuDef.GetCycles(op.Opcode, attr.StatusFlags, attr.BranchTaken,
branchCross);
if (cycles > 0) {
if (!string.IsNullOrEmpty(eolComment)) {
eolComment = cycles.ToString() + " " + eolComment;
} else {
eolComment = cycles.ToString();
}
} else {
if (!string.IsNullOrEmpty(eolComment)) {
eolComment = (-cycles).ToString() + "+ " + eolComment;
} else {
eolComment = (-cycles).ToString() + "+";
}
}
}
string commentStr = formatter.FormatEolComment(eolComment);
string replMnemonic = gen.ModifyOpcode(offset, op);
if (attr.Length != instrBytes) {
// This instruction has another instruction inside it. Throw out what we
// computed and just output as bytes.
gen.GenerateShortSequence(offset, instrBytes, out opcodeStr, out operandStr);
} else if (isPcRelBankWrap && gen.Quirks.NoPcRelBankWrap) {
// Some assemblers have trouble generating PC-relative operands that wrap
// around the bank. Output as raw hex.
gen.GenerateShortSequence(offset, instrBytes, out opcodeStr, out operandStr);
} else if (op.AddrMode == OpDef.AddressMode.BlockMove &&
gen.Quirks.BlockMoveArgsReversed) {
// On second thought, just don't even output the wrong thing.
gen.GenerateShortSequence(offset, instrBytes, out opcodeStr, out operandStr);
} else if (replMnemonic == null) {
// No mnemonic exists for this opcode.
gen.GenerateShortSequence(offset, instrBytes, out opcodeStr, out operandStr);
} else if (replMnemonic != string.Empty) {
// A replacement mnemonic has been provided.
opcodeStr = formatter.FormatMnemonic(replMnemonic, wdis);
}
gen.OutputLine(labelStr, opcodeStr, operandStr, commentStr);
// Assemblers like Merlin32 try to be helpful and track SEP/REP, but they do the
// wrong thing if we're in emulation mode. Force flags back to short.
if (proj.CpuDef.HasEmuFlag && gen.Quirks.TracksSepRepNotEmu && op == OpDef.OpREP_Imm) {
if ((operand & 0x30) != 0 && attr.StatusFlags.IsEmulationMode) {
gen.OutputRegWidthDirective(offset, 0, 0, 1, 1);
}
}
}
/// <summary>
/// Determines whether the instruction at the specified offset has an operand that is
/// a forward reference. This only matters for single-pass assemblers.
/// </summary>
/// <param name="gen">Source generator reference.</param>
/// <param name="offset">Offset of instruction opcode.</param>
/// <returns>True if the instruction's operand is a forward reference to a label.</returns>
private static bool IsForwardLabelReference(IGenerator gen, int offset) {
return (GetLabelOffsetFromOperand(gen, offset) > offset);
}
/// <summary>
/// Determines whether the instruction at the specified offset has an operand
/// that references a symbol.
/// </summary>
/// <param name="gen">Source generator reference.</param>
/// <param name="offset">Offset of instruction opcode.</param>
/// <returns>True if the instruction's operand is a forward reference to a label.</returns>
private static bool IsLabelReference(IGenerator gen, int offset) {
return (GetLabelOffsetFromOperand(gen, offset) >= 0);
}
/// <summary>
/// Determines the offset of the label that the operand's symbol references.
/// </summary>
/// <param name="gen">Source generator reference.</param>
/// <param name="offset">Offset of instruction opcode.</param>
/// <returns>The offset of the label, or -1 if the operand isn't a symbolic reference
/// to a known label.</returns>
private static int GetLabelOffsetFromOperand(IGenerator gen, int offset) {
DisasmProject proj = gen.Project;
Debug.Assert(proj.GetAnattrib(offset).IsInstructionStart);
FormatDescriptor dfd = proj.GetAnattrib(offset).DataDescriptor;
if (dfd == null || !dfd.HasSymbol) {
return -1;
}
return proj.FindLabelOffsetByName(dfd.SymbolRef.Label);
}
/// <summary>
/// Configures some common format config items from the app settings. Uses a
/// passed-in settings object, rather than the global settings.
/// </summary>
/// <param name="settings">Application settings.</param>
/// <param name="config">Format config struct.</param>
public static void ConfigureFormatterFromSettings(AppSettings settings,
ref Formatter.FormatConfig config) {
config.mUpperHexDigits =
settings.GetBool(AppSettings.FMT_UPPER_HEX_DIGITS, false);
config.mUpperOpcodes =
settings.GetBool(AppSettings.FMT_UPPER_OP_MNEMONIC, false);
config.mUpperPseudoOpcodes =
settings.GetBool(AppSettings.FMT_UPPER_PSEUDO_OP_MNEMONIC, false);
config.mUpperOperandA =
settings.GetBool(AppSettings.FMT_UPPER_OPERAND_A, false);
config.mUpperOperandS =
settings.GetBool(AppSettings.FMT_UPPER_OPERAND_S, false);
config.mUpperOperandXY =
settings.GetBool(AppSettings.FMT_UPPER_OPERAND_XY, false);
config.mSpacesBetweenBytes =
settings.GetBool(AppSettings.FMT_SPACES_BETWEEN_BYTES, false);
config.mAddSpaceLongComment =
settings.GetBool(AppSettings.FMT_ADD_SPACE_FULL_COMMENT, true);
config.mOperandWrapLen =
settings.GetInt(AppSettings.FMT_OPERAND_WRAP_LEN, 0);
config.mForceAbsOpcodeSuffix =
settings.GetString(AppSettings.FMT_OPCODE_SUFFIX_ABS, string.Empty);
config.mForceLongOpcodeSuffix =
settings.GetString(AppSettings.FMT_OPCODE_SUFFIX_LONG, string.Empty);
config.mForceAbsOperandPrefix =
settings.GetString(AppSettings.FMT_OPERAND_PREFIX_ABS, string.Empty);
config.mForceLongOperandPrefix =
settings.GetString(AppSettings.FMT_OPERAND_PREFIX_LONG, string.Empty);
string exprMode = settings.GetString(AppSettings.FMT_EXPRESSION_MODE, string.Empty);
config.mExpressionMode = Formatter.FormatConfig.ParseExpressionMode(exprMode);
// Not doing the delimiter patterns here, because what's in the config file is
// intended for on-screen display, and hence likely to be unsuited for an assembler.
// Ditto for the local variable prefix.
}
/// <summary>
/// Checks to see if the junk alignment directive is compatible with the actual
/// address. This is used to screen out alignment values that no longer match up
/// with the actual addresses.
/// </summary>
/// <param name="offset">File offset of directive.</param>
/// <param name="dfd">Format descriptor.</param>
/// <param name="addrMap">Offset to address map.</param>
/// <returns>True if the .junk alignment directive is correct, false if it's
/// incorrect or not an alignment sub-type (e.g. None).</returns>
public static bool CheckJunkAlign(int offset, FormatDescriptor dfd,
CommonUtil.AddressMap addrMap) {
Debug.Assert(dfd.FormatType == FormatDescriptor.Type.Junk);
if (dfd.FormatSubType == FormatDescriptor.SubType.None) {
return false;
}
Debug.Assert(dfd.IsAlignedJunk);
// Just check the address. Shouldn't need to check the length.
int lastOffset = offset + dfd.Length - 1;
int alignToAddr = addrMap.OffsetToAddress(lastOffset) + 1;
int alignPwr = FormatDescriptor.AlignmentToPower(dfd.FormatSubType);
int alignMask = (1 << alignPwr) - 1;
bool result = (alignToAddr & alignMask) == 0;
//Debug.WriteLine(dfd.FormatSubType + " at +" + offset.ToString("x6") +
// "(" + alignToAddr.ToString("x4") + "): " + result);
return result;
}
}
}