emitStuff.c

/*
 * Copyright (c) 1987 Fujitsu
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
/*
	emitStuff.c -- Routines to actually generate binary stuff for the
		       Macross assembler.

	Chip Morningstar -- Lucasfilm Ltd.

	14-November-1984
*/

#include "macrossTypes.h"
#include "macrossGlobals.h"
#include "actions.h"
#include "debugPrint.h"
#include "errorStuff.h"
#include "semanticMisc.h"

/*
   Emitted code is stored in places that are allocated dynamically as they
   are needed.  This saves us from having to keep umpteenK of code buffer
   around ALL the time and also lets us keep track of where code has actually
   been put for purposes of generating the final object module.

   The structure of the code storage is: there are two code region structs
   (type 'codeRegionType'), one each for absolute and relocatable code.  These
   are stored in the global array 'codeRegions' which is indexed by
   'currentCodeMode' which in turn indicates whether we are emitting aboslute
   or relocatable code.  Each of these region structs contains a vector of
   [currently 64] pointers to code segment structs (type 'codeSegmentType').
   Each code segment represents a [currently 1Kbyte] piece of the target
   processor address space; it contains the high and low addresses within
   that space that have been occupied up until now and a pointer to a
   [1Kbyte] buffer that actually contains the code.

   Initially, the code regions are filled with vectors of null pointers and
   there are no code segments allocated.  As code is emitted, the space for
   the code segments and their associated buffers is allocated using 'malloc'.
   Only the actual buffers needed are allocated, resulting in substantial
   storage savings.

   A complication that can arise from Macross 'struct's.  Structs are
   assembled in a small scratch buffer and then transferred to the main code
   buffers as needed.
 */


/* incarnateCodeBuffer causes code buffer space to actually be allocated */

void
incarnateCodeBuffer(int bufferNum, codeBufferKindType bufferKind)
{
	codeSegmentType	*newCodeSegment;
	codeBufferType	*newCodeBuffer;
	int		 i;

	newCodeSegment = typeAlloc(codeSegmentType);
	newCodeBuffer = typeAlloc(codeBufferType);
	for (i=0; i<CODE_BUFFER_SIZE; i++)
		(*newCodeBuffer)[i] = 0;
	newCodeSegment->codeStartAddress = 0xFFFF + 1;
	newCodeSegment->codeEndAddress = -1;
	newCodeSegment->codeBuffer = newCodeBuffer;
	codeRegions[(int)bufferKind]->codeSegments[bufferNum] =
		newCodeSegment;
}


/* putByte actually puts a byte in code storage somewhere, given the address
   and the byte itself.  It tracks down the appropriate code buffer, taking
   care to make sure said buffer actually exists before using it. */

  void
putByte(addressType address, byte byteValue)
{
	int		 bufferNum;
	int		 bufferPos;
	codeBufferType	*theBuffer;
	codeSegmentType	*theSegment;

	bufferNum = bufferNumber(address);
	bufferPos = bufferPosition(address);
	if (bufferNum >= CODE_BUFFERS_IN_ADDRESS_SPACE) {
		fatalError(ADDRESS_OUTSIDE_ADDRESS_SPACE_ERROR, address);
		return;
	}
	theSegment = codeRegions[(int)currentCodeMode]->codeSegments[
		bufferNum];
	if (theSegment == NULL) {
		incarnateCodeBuffer(bufferNum, currentCodeMode);
		theSegment = codeRegions[(int)currentCodeMode]->codeSegments[
			bufferNum];
	}
	theBuffer = theSegment->codeBuffer;
	if (currentCodeMode == RELOCATABLE_BUFFER && address >
			relocatableHighWaterMark)
		relocatableHighWaterMark = address;
	if (address > theSegment->codeEndAddress)
		theSegment->codeEndAddress = address;
	if (address < theSegment->codeStartAddress)
		theSegment->codeStartAddress = address;
	if (address > codeRegions[(int)currentCodeMode]->regionEndAddress)
		codeRegions[(int)currentCodeMode]->regionEndAddress = address;
	if (address < codeRegions[(int)currentCodeMode]->regionStartAddress)
		codeRegions[(int)currentCodeMode]->regionStartAddress =
			address;
	(*theBuffer)[bufferPos] = byteValue;
}


/* mapByte is like 'putByte', but places its values in the struct assembly
   buffer */

  void
mapByte(int address, byte byteValue)
{
	if (address < MAXIMUM_ALLOWED_STRUCT_SIZE)
		structScratchBuffer[address] = byteValue;
}


/* emitByte outputs one byte at the current location in either the current
   code buffer or the current struct assembly buffer */

  void
emitByte(byte byteValue)
{
	if (debug || emitPrint)
		if (structNestingDepth == 0)
			printf("emitByte(%x: %x)\n", currentLocationCounter.
							value, byteValue);
		else
			printf("emitByte in struct (%x: %x)\n",
					currentFieldOffset, byteValue);
	if (structNestingDepth == 0) {
		putByte(currentLocationCounter.value++, byteValue);
	} else {
		mapByte(currentFieldOffset++, byteValue);
	}
}


/* emitWord similarly emits a word */

  void
emitWord(wordType wordValue)
{
	byteToWordType	convert;
	int		loByte, hiByte;

/* We hack around with this, even though it's less portable, so that we can
   avoid doing a division and a modulo on every word we emit (since code
   emission is in the inner loop). */

#ifdef BYTESWAPPED
	loByte = 1;
	hiByte = 0;
#else
	loByte = 0;
	hiByte = 1;
#endif
	convert.wordPart = wordValue;
	if (debug || emitPrint)
		if (structNestingDepth == 0)
			printf("emitWord(%x: %x)\n", currentLocationCounter.
							value, wordValue);
		else
			printf("emitWord in struct (%x: %x)\n",
					currentFieldOffset, wordValue);
	if (structNestingDepth == 0) {
#if TARGET_CPU == CPU_6502
		putByte(currentLocationCounter.value++,
						convert.bytePart[loByte]);
		putByte(currentLocationCounter.value++,
						convert.bytePart[hiByte]);
#elif TARGET_CPU == CPU_68000
		putByte(currentLocationCounter.value++,
						convert.bytePart[hiByte]);
		putByte(currentLocationCounter.value++,
						convert.bytePart[loByte]);
#endif
	} else {
#if TARGET_CPU == CPU_6502
		mapByte(currentFieldOffset++, convert.bytePart[loByte]);
		mapByte(currentFieldOffset++, convert.bytePart[hiByte]);
#elif TARGET_CPU == CPU_68000
		mapByte(currentFieldOffset++, convert.bytePart[hiByte]);
		mapByte(currentFieldOffset++, convert.bytePart[loByte]);
#endif
	}
}

/* emitLong similarly emits a long */

  void
emitLong(longType longValue)
{
	byteToLongType	convert;
	int		loByte, secondByte, thirdByte, hiByte;

/* We hack around with this, even though it's less portable, so that we can
   avoid doing a division and a modulo on every long we emit (since code
   emission is in the inner loop). */

#ifdef BYTESWAPPED
	/* Sun workstation... */
	loByte = 3;
	secondByte = 2;
	thirdByte = 1;
	hiByte = 0;
#else
	/* Vax... */
	loByte = 0;
	secondByte = 1;
	thirdByte = 2;
	hiByte = 3;
#endif
	convert.longPart = longValue;
	if (debug || emitPrint)
		if (structNestingDepth == 0)
			printf("emitLong(%x: %x)\n", currentLocationCounter.
							value, longValue);
		else
			printf("emitLong in struct (%x: %x)\n",
					currentFieldOffset, longValue);
	if (structNestingDepth == 0) {
#if TARGET_CPU == CPU_6502
		putByte(currentLocationCounter.value++,
						convert.bytePart[loByte]);
		putByte(currentLocationCounter.value++,
						convert.bytePart[secondByte]);
		putByte(currentLocationCounter.value++,
						convert.bytePart[thirdByte]);
		putByte(currentLocationCounter.value++,
						convert.bytePart[hiByte]);
#elif TARGET_CPU == CPU_68000
		putByte(currentLocationCounter.value++,
						convert.bytePart[hiByte]);
		putByte(currentLocationCounter.value++,
						convert.bytePart[thirdByte]);
		putByte(currentLocationCounter.value++,
						convert.bytePart[secondByte]);
		putByte(currentLocationCounter.value++,
						convert.bytePart[loByte]);
#endif
	} else {
#if TARGET_CPU == CPU_6502
		mapByte(currentFieldOffset++, convert.bytePart[loByte]);
		mapByte(currentFieldOffset++, convert.bytePart[secondByte]);
		mapByte(currentFieldOffset++, convert.bytePart[thirdByte]);
		mapByte(currentFieldOffset++, convert.bytePart[hiByte]);
#elif TARGET_CPU == CPU_68000
		mapByte(currentFieldOffset++, convert.bytePart[hiByte]);
		mapByte(currentFieldOffset++, convert.bytePart[thirdByte]);
		mapByte(currentFieldOffset++, convert.bytePart[secondByte]);
		mapByte(currentFieldOffset++, convert.bytePart[loByte]);
#endif
	}
}


/* emitByteValue takes the byte to be emitted out of a 'valueType' */

  void
emitByteValue(valueType *byteValue)
{
    if (byteValue->kindOfValue == ABSOLUTE_VALUE || byteValue->kindOfValue ==
	    RELOCATABLE_VALUE || byteValue->kindOfValue == UNDEFINED_VALUE) {
	if (byteCheck(byteValue->value) && byteValue->kindOfValue!=FAIL) {
	    if (debug || emitPrint) {
		if (structNestingDepth == 0)
		    printf("emitByteValue(%x: ",currentLocationCounter.value);
		else
		    printf("emitByteValue in struct (%x:",currentFieldOffset);
		printValue(byteValue);
		printf(")\n");
	    }
	    emitByte(byteValue->value);
	}
    } else {
	if (byteValue->kindOfValue != FAIL)
	    error(NON_ADDRESS_BYTE_VALUE_ERROR, valueKindString(byteValue->
	    	kindOfValue));
    }
}


/* emitString similarly spits out a string of bytes */

  void
emitString(stringType *string)
{
	if (debug || emitPrint)
		if (structNestingDepth == 0)
			printf("emitString(%x: \"%s\")\n",
				currentLocationCounter.value, string);
		else
			printf("emitString in struct(%x: \"%s\")\n",
				currentFieldOffset, string);
/* Horrible terrible no good very bad cretinous ugly hack, but no graceful
   way to avoid it:  a 0xFF byte in the string means output a 0x00 byte in
   the object.  This is so we can embed nuls in strings without embedding
   nuls in strings, so to speak.  We assume that the character 0xFF is not
   likely to be needed since ASCII (and ATASCII) is a seven bit character
   code. */
	while (*string != 0)
		if ((*string & 0xFF) == 0xFF) {
			emitByte('\0');
			string++;
		} else {
			emitByte(*string++);
		}
}


/* emitWordValue emits a word out of a 'valueType' */

  void
emitWordValue(valueType *wordValue)
{
    if (wordValue->kindOfValue == ABSOLUTE_VALUE || wordValue->kindOfValue ==
	    RELOCATABLE_VALUE || wordValue->kindOfValue == UNDEFINED_VALUE) {
	if (wordCheck(wordValue->value) && wordValue->kindOfValue!=FAIL) {
	    if (debug || emitPrint) {
		if (structNestingDepth == 0)
		    printf("emitWordValue(%x: ",currentLocationCounter.value);
		else
		    printf("emitWordValue in struct (%x:",currentFieldOffset);
		printValue(wordValue);
		printf(")\n");
	    }
	emitWord(wordValue->value);
	}
    } else {
	if (wordValue->kindOfValue != FAIL)
	    error(NON_ADDRESS_WORD_VALUE_ERROR, valueKindString(wordValue->
		kindOfValue));
    }
}


/* emitLongValue emits a long out of a 'valueType' */

  void
emitLongValue(valueType *longValue)
{
    if (longValue->kindOfValue == ABSOLUTE_VALUE || longValue->kindOfValue ==
	    RELOCATABLE_VALUE || longValue->kindOfValue == UNDEFINED_VALUE) {
	if (longValue->kindOfValue != FAIL) {
	    if (debug || emitPrint) {
		if (structNestingDepth == 0)
		    printf("emitLongValue(%x: ",currentLocationCounter.value);
		else
		    printf("emitLongValue in struct (%x:",currentFieldOffset);
		printValue(longValue);
		printf(")\n");
	    }
	    emitLong(longValue->value);
	}
    } else {
	if (longValue->kindOfValue != FAIL)
	    error(NON_ADDRESS_LONG_VALUE_ERROR, valueKindString(longValue->
		kindOfValue));
    }
}


/* pokeByteValue is like 'emitByte' but it's random access */

  void
pokeByteValue(addressType location, valueType *value)
{
	currentLocationCounter.value = location;
	emitByteValue(value);
}


/* ditto pokeWordValue */

  void
pokeWordValue(addressType location, valueType *value)
{
	currentLocationCounter.value = location;
	emitWordValue(value);
}


/* ditto pokeLongValue */

  void
pokeLongValue(addressType location, valueType *value)
{
	currentLocationCounter.value = location;
	emitLongValue(value);
}


/* ditto pokeRelativeByteValue.  This is a special case used in fixing up
   relative branches */

  void
pokeRelativeByteValue(addressType location, valueType *value)
{
	int	offset;

	currentLocationCounter.value = location;
	offset = value->value - (location - targetOffset) - 1;
	if (offset < 0)
		offset--;
/*	if (currentCodeMode == RELOCATABLE_BUFFER)
		offset = 0;*/
	if (isByteOffset(offset)) {
		emitByte(offset);
	} else {
		error(RELATIVE_OFFSET_TOO_LARGE_ERROR);
	}
}

/* ditto pokeRelativeWordValue.  This is a special case used in fixing up
   relative branches */

  void
pokeRelativeWordValue(addressType location, valueType *value)
{
	int	offset;

	currentLocationCounter.value = location;
	offset = value->value - (location - targetOffset);
	if (isWordOffset(offset)) {
		emitWord(offset);
	} else {
		error(RELATIVE_OFFSET_TOO_LARGE_ERROR);
	}
}


/* getByte fetches a byte back out of the labyrinth of code buffers */

  byte
getByte(addressType address)
{
	int		 bufferNum;
	int		 bufferPos;
	codeBufferType	*theBuffer;
	codeSegmentType	*theSegment;

	bufferNum = bufferNumber(address);
	bufferPos = bufferPosition(address);
	theSegment = codeRegions[(int)currentCodeMode]->codeSegments[
		bufferNum];
	if (theSegment == NULL)
		return(0);
	else
		return((*(theSegment->codeBuffer))[bufferPos]);
}

  void
emitRelativeByteOffset(valueType *target)
{
	int	saveTargetOffset;

	if (target == NULL) {
		emitByte(0);
	} else {
		(target->value)++;
		saveTargetOffset = targetOffset;
		targetOffset = 0;
		pokeRelativeByteValue(currentLocationCounter.value, target);
		targetOffset = saveTargetOffset;
		(target->value)--;
	}
}

  void
emitRelativeWordOffset(valueType *target)
{
	int	saveTargetOffset;

	if (target == NULL) {
		emitWord(0);
	} else {
		saveTargetOffset = targetOffset;
		targetOffset = 0;
		pokeRelativeWordValue(currentLocationCounter.value, target);
		targetOffset = saveTargetOffset;
	}
}

/* fixupBranch repairs a previously undefined branch once the branch address
   has become known. */

  void
fixupBranch(valueType *location, valueType target)
{
	valueType	saveCurrentLocation;
	int		saveTargetOffset;
	int		i;

	saveCurrentLocation = currentLocationCounter;
	saveTargetOffset = targetOffset;
	targetOffset = 0;
	for (i=0; i<COMPOUND_BRANCH_MAX; i++) {
		if (location[i].value >= 0)
			pokeRelativeByteValue(location[i].value, &target);
	}
	targetOffset = saveTargetOffset;
	currentLocationCounter = saveCurrentLocation;
}


/* fixupJump similarly repairs a jump */

  void
fixupJump(simpleFixupListType *locations, valueType target)
{
	valueType		 saveCurrentLocation;
	simpleFixupListType	*oldLocation;

	saveCurrentLocation = currentLocationCounter;
	while (locations != NULL) {
		currentLocationCounter = locations->locationToFixup;
		noteAnonymousReference();
		target.value -= targetOffset;
		if (positionIndependentCodeMode)
			pokeRelativeByteValue(locations->locationToFixup.
				value, &target);
		else
			pokeWordValue(locations->locationToFixup.value,
				&target);
		target.value += targetOffset;
		oldLocation = locations;
		locations = locations->nextFixup;
		free(oldLocation);
	}
	currentLocationCounter = saveCurrentLocation;
}