Source code of Windows XP (NT5)
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//----------------------------------------------------------------------------
//
// Copyright (C) Microsoft Corporation, 1991-2001.
//
//----------------------------------------------------------------------------
#include "ntsdp.hpp"
#include "i386_asm.h"
UCHAR PeekAsmChar(void);
ULONG PeekAsmToken(PULONG);
void AcceptAsmToken(void);
ULONG GetAsmToken(PULONG);
ULONG NextAsmToken(PULONG);
ULONG GetAsmReg(PUCHAR, PULONG);
void GetAsmOperand(PASM_VALUE);
void GetAsmExpr(PASM_VALUE, UCHAR);
void GetAsmOrTerm(PASM_VALUE, UCHAR);
void GetAsmAndTerm(PASM_VALUE, UCHAR);
void GetAsmNotTerm(PASM_VALUE, UCHAR);
void GetAsmRelTerm(PASM_VALUE, UCHAR);
void GetAsmAddTerm(PASM_VALUE, UCHAR);
void GetAsmMulTerm(PASM_VALUE, UCHAR);
void GetAsmSignTerm(PASM_VALUE, UCHAR);
void GetAsmByteTerm(PASM_VALUE, UCHAR);
void GetAsmOffTerm(PASM_VALUE, UCHAR);
void GetAsmColnTerm(PASM_VALUE, UCHAR);
void GetAsmDotTerm(PASM_VALUE, UCHAR);
void GetAsmIndxTerm(PASM_VALUE, UCHAR);
void AddAsmValues(PASM_VALUE, PASM_VALUE);
void SwapPavs(PASM_VALUE, PASM_VALUE);
extern PUCHAR pchAsmLine;
struct _AsmRes {
PCHAR pchRes;
ULONG valueRes;
} AsmReserved[] = {
{ "mod", ASM_MULOP_MOD },
{ "shl", ASM_MULOP_SHL },
{ "shr", ASM_MULOP_SHR },
{ "and", ASM_ANDOP_CLASS },
{ "not", ASM_NOTOP_CLASS },
{ "or", ASM_OROP_OR },
{ "xor", ASM_OROP_XOR },
{ "eq", ASM_RELOP_EQ },
{ "ne", ASM_RELOP_NE },
{ "le", ASM_RELOP_LE },
{ "lt", ASM_RELOP_LT },
{ "ge", ASM_RELOP_GE },
{ "gt", ASM_RELOP_GT },
{ "by", ASM_UNOP_BY },
{ "wo", ASM_UNOP_WO },
{ "dw", ASM_UNOP_DW },
{ "poi", ASM_UNOP_POI },
{ "low", ASM_LOWOP_LOW },
{ "high", ASM_LOWOP_HIGH },
{ "offset", ASM_OFFOP_CLASS },
{ "ptr", ASM_PTROP_CLASS },
{ "byte", ASM_SIZE_BYTE },
{ "word", ASM_SIZE_WORD },
{ "dword", ASM_SIZE_DWORD },
{ "fword", ASM_SIZE_FWORD },
{ "qword", ASM_SIZE_QWORD },
{ "tbyte", ASM_SIZE_TBYTE }
};
#define RESERVESIZE (sizeof(AsmReserved) / sizeof(struct _AsmRes))
UCHAR regSize[] = {
sizeB, // byte
sizeW, // word
sizeD, // dword
sizeW, // segment
sizeD, // control
sizeD, // debug
sizeD, // trace
sizeT, // float
sizeT // float with index
};
UCHAR regType[] = {
regG, // byte - general
regG, // word - general
regG, // dword - general
regS, // segment
regC, // control
regD, // debug
regT, // trace
regF, // float (st)
regI // float-index (st(n))
};
UCHAR tabWordReg[8] = { // rm value
(UCHAR)-1, // AX - error
(UCHAR)-1, // CX - error
(UCHAR)-1, // DX - error
7, // BX - 111
(UCHAR)-1, // SP - error
6, // BP - 110
4, // SI - 100
5, // DI - 101
};
UCHAR rm16Table[16] = { // new rm left rm right rm
(UCHAR)-1, // error 100 = [SI] 100 = [SI]
(UCHAR)-1, // error 100 = [SI] 101 = [DI]
2, // 010 = [BP+SI] 100 = [SI] 110 = [BP]
0, // 000 = [BX+SI] 100 = [SI] 111 = [BX]
(UCHAR)-1, // error 101 = [DI] 100 = [SI]
(UCHAR)-1, // error 101 = [DI] 101 = [DI]
3, // 011 = [BP+DI] 101 = [DI] 110 = [BP]
1, // 001 = [BX+DI] 101 = [DI] 111 = [BX]
2, // 010 = [BP+SI] 110 = [BP] 100 = [SI]
3, // 011 = [BP+DI] 110 = [BP] 101 = [DI]
(UCHAR)-1, // error 110 = [BP] 110 = [BP]
(UCHAR)-1, // error 110 = [BP] 111 = [BX]
0, // 000 = [BX+SI] 111 = [BX] 100 = [SI]
1, // 001 = [BX+DI] 111 = [BX] 101 = [DI]
(UCHAR)-1, // error 111 = [BX] 110 = [BP]
(UCHAR)-1 // error 111 = [BX] 111 = [BX]
};
PUCHAR savedpchAsmLine;
ULONG savedAsmClass;
ULONG savedAsmValue;
/*** PeekAsmChar - peek the next non-white-space character
*
* Purpose:
* Return the next non-white-space character and update
* pchAsmLine to point to it.
*
* Input:
* pchAsmLine - present command line position.
*
* Returns:
* next non-white-space character
*
*************************************************************************/
UCHAR PeekAsmChar (void)
{
UCHAR ch;
do
ch = *pchAsmLine++;
while (ch == ' ' || ch == '\t');
pchAsmLine--;
return ch;
}
/*** PeekAsmToken - peek the next command line token
*
* Purpose:
* Return the next command line token, but do not advance
* the pchAsmLine pointer.
*
* Input:
* pchAsmLine - present command line position.
*
* Output:
* *pvalue - optional value of token
* Returns:
* class of token
*
* Notes:
* savedAsmClass, savedAsmValue, and savedpchAsmLine saves the
* token getting state for future peeks.
* To get the next token, a GetAsmToken or AcceptAsmToken call
* must first be made.
*
*************************************************************************/
ULONG PeekAsmToken (PULONG pvalue)
{
UCHAR *pchTemp;
// Get next class and value, but do not
// move pchAsmLine, but save it in savedpchAsmLine.
// Do not report any error condition.
if (savedAsmClass == (ULONG)-1) {
pchTemp = pchAsmLine;
savedAsmClass = NextAsmToken(&savedAsmValue);
savedpchAsmLine = pchAsmLine;
pchAsmLine = pchTemp;
}
*pvalue = savedAsmValue;
return savedAsmClass;
}
/*** AcceptAsmToken - accept any peeked token
*
* Purpose:
* To reset the PeekAsmToken saved variables so the next PeekAsmToken
* will get the next token in the command line.
*
* Input:
* None.
*
* Output:
* None.
*
*************************************************************************/
void AcceptAsmToken (void)
{
savedAsmClass = (ULONG)-1;
pchAsmLine = savedpchAsmLine;
}
/*** GetAsmToken - peek and accept the next token
*
* Purpose:
* Combines the functionality of PeekAsmToken and AcceptAsmToken
* to return the class and optional value of the next token
* as well as updating the command pointer pchAsmLine.
*
* Input:
* pchAsmLine - present command string pointer
*
* Output:
* *pvalue - pointer to the token value optionally set.
* Returns:
* class of the token read.
*
* Notes:
* An illegal token returns the value of ERROR_CLASS with *pvalue
* being the error number, but produces no actual error.
*
*************************************************************************/
ULONG GetAsmToken (PULONG pvalue)
{
ULONG opclass;
if (savedAsmClass != (ULONG)-1) {
opclass = savedAsmClass;
savedAsmClass = (ULONG)-1;
*pvalue = savedAsmValue;
pchAsmLine = savedpchAsmLine;
}
else
opclass = NextAsmToken(pvalue);
if (opclass == ASM_ERROR_CLASS)
error(*pvalue);
return opclass;
}
/*** NextAsmToken - process the next token
*
* Purpose:
* Parse the next token from the present command string.
* After skipping any leading white space, first check for
* any single character tokens or register variables. If
* no match, then parse for a number or variable. If a
* possible variable, check the reserved word list for operators.
*
* Input:
* pchAsmLine - pointer to present command string
*
* Output:
* *pvalue - optional value of token returned
* pchAsmLine - updated to point past processed token
* Returns:
* class of token returned
*
* Notes:
* An illegal token returns the value of ERROR_CLASS with *pvalue
* being the error number, but produces no actual error.
*
*************************************************************************/
ULONG NextAsmToken (PULONG pvalue)
{
ULONG base;
UCHAR chSymbol[MAX_SYMBOL_LEN];
UCHAR chPreSym[9];
ULONG cbSymbol = 0;
UCHAR fNumber = TRUE;
UCHAR fSymbol = TRUE;
UCHAR fForceReg = FALSE;
ULONG errNumber = 0;
UCHAR ch;
UCHAR chlow;
UCHAR chtemp;
UCHAR limit1 = '9';
UCHAR limit2 = '9';
UCHAR fDigit = FALSE;
ULONG value = 0;
ULONG tmpvalue;
ULONG index;
PDEBUG_IMAGE_INFO pImage;
ULONG64 value64;
base = g_DefaultRadix;
// skip leading white space
ch = PeekAsmChar();
chlow = (UCHAR)tolower(ch);
pchAsmLine++;
// test for special character operators and register variable
switch (chlow) {
case '\0':
pchAsmLine--;
return ASM_EOL_CLASS;
case ',':
return ASM_COMMA_CLASS;
case '+':
*pvalue = ASM_ADDOP_PLUS;
return ASM_ADDOP_CLASS;
case '-':
*pvalue = ASM_ADDOP_MINUS;
return ASM_ADDOP_CLASS;
case '*':
*pvalue = ASM_MULOP_MULT;
return ASM_MULOP_CLASS;
case '/':
*pvalue = ASM_MULOP_DIVIDE;
return ASM_MULOP_CLASS;
case ':':
return ASM_COLNOP_CLASS;
case '(':
return ASM_LPAREN_CLASS;
case ')':
return ASM_RPAREN_CLASS;
case '[':
return ASM_LBRACK_CLASS;
case ']':
return ASM_RBRACK_CLASS;
case '@':
fForceReg = TRUE;
chlow = (UCHAR)tolower(*pchAsmLine); pchAsmLine++;
break;
case '.':
return ASM_DOTOP_CLASS;
case '\'':
for (index = 0; index < 5; index++) {
ch = *pchAsmLine++;
if (ch == '\'' || ch == '\0')
break;
value = (value << 8) + (ULONG)ch;
}
if (ch == '\0' || index == 0 || index == 5) {
pchAsmLine--;
*pvalue = SYNTAX;
return ASM_ERROR_CLASS;
}
pchAsmLine++;
*pvalue = value;
return ASM_NUMBER_CLASS;
}
// if first character is a decimal digit, it cannot
// be a symbol. leading '0' implies octal, except
// a leading '0x' implies hexadecimal.
if (chlow >= '0' && chlow <= '9') {
if (fForceReg) {
*pvalue = SYNTAX;
return ASM_ERROR_CLASS;
}
fSymbol = FALSE;
if (chlow == '0') {
ch = *pchAsmLine++;
chlow = (UCHAR)tolower(ch);
if (chlow == 'x') {
base = 16;
ch = *pchAsmLine++;
chlow = (UCHAR)tolower(ch);
}
else if (chlow == 'n') {
base = 10;
ch = *pchAsmLine++;
chlow = (UCHAR)tolower(ch);
}
else {
base = 8;
fDigit = TRUE;
}
}
}
// a number can start with a letter only if base is
// hexadecimal and it is a hexadecimal digit 'a'-'f'.
else if ((chlow < 'a' && chlow > 'f') || base != 16)
fNumber = FALSE;
// set limit characters for the appropriate base.
if (base == 8)
limit1 = '7';
if (base == 16)
limit2 = 'f';
// perform processing while character is a letter,
// digit, or underscore.
while ((chlow >= 'a' && chlow <= 'z') ||
(chlow >= '0' && chlow <= '9') || (chlow == '_')) {
// if possible number, test if within proper range,
// and if so, accumulate sum.
if (fNumber) {
if ((chlow >= '0' && chlow <= limit1) ||
(chlow >= 'a' && chlow <= limit2)) {
fDigit = TRUE;
tmpvalue = value * base;
if (tmpvalue < value)
errNumber = OVERFLOW;
chtemp = (UCHAR)(chlow - '0');
if (chtemp > 9)
chtemp -= 'a' - '0' - 10;
value = tmpvalue + (ULONG)chtemp;
if (value < tmpvalue)
errNumber = OVERFLOW;
}
else {
fNumber = FALSE;
errNumber = SYNTAX;
}
}
if (fSymbol) {
if (cbSymbol < 9)
chPreSym[cbSymbol] = chlow;
if (cbSymbol < MAX_SYMBOL_LEN - 1)
chSymbol[cbSymbol++] = ch;
}
ch = *pchAsmLine++;
chlow = (UCHAR)tolower(ch);
}
// back up pointer to first character after token.
pchAsmLine--;
if (cbSymbol < 9)
chPreSym[cbSymbol] = '\0';
// if fForceReg, check for register name and return
// success or failure
if (fForceReg)
if ((index = GetAsmReg(chPreSym, pvalue)) != 0) {
if (index == ASM_REG_SEGMENT)
if (PeekAsmChar() == ':') {
pchAsmLine++;
index = ASM_SEGOVR_CLASS;
}
return index; // class type returned by GetAsmReg
}
else {
*pvalue = BADREG;
return ASM_ERROR_CLASS;
}
// next test for reserved word and symbol string
if (fSymbol) {
// if possible symbol, check lowercase string in chPreSym
// for text operator or register name.
// otherwise, return symbol value from name in chSymbol.
for (index = 0; index < RESERVESIZE; index++)
if (!strcmp((PSTR)chPreSym, AsmReserved[index].pchRes)) {
*pvalue = AsmReserved[index].valueRes;
return AsmReserved[index].valueRes & ASM_CLASS_MASK;
}
// start processing string as symbol
chSymbol[cbSymbol] = '\0';
// test if symbol is a module name (with '!' after it)
// if so, get next token and treat as symbol
pImage = GetImageByName(g_CurrentProcess, (PSTR)chSymbol,
INAME_MODULE);
if (pImage && (ch = PeekAsmChar()) == '!') {
pchAsmLine++;
ch = PeekAsmChar();
pchAsmLine++;
cbSymbol = 0;
while ((ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z') ||
(ch >= '0' && ch <= '9') || (ch == '_')) {
chSymbol[cbSymbol++] = ch;
ch = *pchAsmLine++;
}
chSymbol[cbSymbol] = '\0';
pchAsmLine--;
}
if (GetOffsetFromSym((PSTR)chSymbol, &value64, NULL)) {
*pvalue = (ULONG)value64;
return ASM_SYMBOL_CLASS;
}
// symbol is undefined.
// if a possible hex number, do not set the error type
if (!fNumber)
errNumber = VARDEF;
}
// if possible number and no error, return the number
if (fNumber && !errNumber) {
if (fDigit) {
// check for possible segment specification
// "<16-bit number>:"
if (PeekAsmChar() == ':') {
pchAsmLine++;
if (value > 0xffff)
error(BADSEG);
*pvalue = value;
return ASM_SEGMENT_CLASS;
}
*pvalue = value;
return ASM_NUMBER_CLASS;
}
else
errNumber = SYNTAX;
}
// last chance, undefined symbol and illegal number,
// so test for register, will handle old format
if ((index = GetAsmReg(chPreSym, pvalue)) != 0) {
if (index == ASM_REG_SEGMENT)
if (PeekAsmChar() == ':') {
pchAsmLine++;
index = ASM_SEGOVR_CLASS;
}
return index; // class type returned by GetAsmReg
}
*pvalue = (ULONG) errNumber;
return ASM_ERROR_CLASS;
}
ULONG GetAsmReg (PUCHAR pSymbol, PULONG pValue)
{
static UCHAR vRegList[] = "axcxdxbxspbpsidi";
static UCHAR bRegList[] = "alcldlblahchdhbh";
static UCHAR sRegList[] = "ecsdfg"; // second char is 's'
// same order as seg enum
ULONG index;
UCHAR ch0 = *pSymbol;
UCHAR ch1 = *(pSymbol + 1);
UCHAR ch2 = *(pSymbol + 2);
UCHAR ch3 = *(pSymbol + 3);
// only test strings with two or three characters
if (ch0 && ch1) {
if (ch2 == '\0') {
// symbol has two characters, first test for 16-bit register
for (index = 0; index < 8; index++)
if (*(PUSHORT)pSymbol == *((PUSHORT)vRegList + index)) {
*pValue = index;
return ASM_REG_WORD;
}
// next test for 8-bit register
for (index = 0; index < 8; index++)
if (*(PUSHORT)pSymbol == *((PUSHORT)bRegList + index)) {
*pValue = index;
return ASM_REG_BYTE;
}
// test for segment register
if (ch1 == 's')
for (index = 0; index < 6; index++)
if (ch0 == *(sRegList + index)) {
*pValue = index + 1; // list offset is 1
return ASM_REG_SEGMENT;
}
// finally test for floating register "st" or "st(n)"
// parse the arg here as '(', <octal value>, ')'
// return value for "st" is REG_FLOAT,
// for "st(n)" is REG_INDFLT with value 0-7
if (ch0 == 's' && ch1 == 't') {
if (PeekAsmChar() != '(')
return ASM_REG_FLOAT;
else {
pchAsmLine++;
index = (ULONG)(PeekAsmChar() - '0');
if (index < 8) {
pchAsmLine++;
if (PeekAsmChar() == ')') {
pchAsmLine++;
*pValue = index;
return ASM_REG_INDFLT;
}
}
}
}
}
else if (ch3 == '\0') {
// if three-letter symbol, test for leading 'e' and
// second and third character being in the 16-bit list
if (ch0 == 'e') {
for (index = 0; index < 8; index++)
if (*(UNALIGNED USHORT *)(pSymbol + 1) ==
*((PUSHORT)vRegList + index)) {
*pValue = index;
return ASM_REG_DWORD;
}
}
// test for control, debug, and test registers
else if (ch1 == 'r') {
ch2 -= '0';
*pValue = ch2;
// legal control registers are CR0, CR2, CR3, CR4
if (ch0 == 'c') {
if (ch2 >= 0 && ch2 <= 4)
return ASM_REG_CONTROL;
}
// legal debug registers are DR0 - DR3, DR6, DR7
else if (ch0 == 'd') {
if (ch2 <= 3 || ch2 == 6 || ch2 == 7)
return ASM_REG_DEBUG;
}
// legal trace registers are TR3 - TR7
else if (ch0 == 't') {
if (ch2 >= 3 && ch2 <= 7)
return ASM_REG_TRACE;
}
}
}
}
return 0;
}
// Operand parser - recursive descent
//
// Grammar productions:
//
// <Operand> ::= <register> | <Expr>
// <Expr> ::= <orTerm> [(XOR | OR) <orTerm>]*
// <orTerm> ::= <andTerm> [AND <andTerm>]*
// <andTerm> ::= [NOT]* <notTerm>
// <notTerm> ::= <relTerm> [(EQ | NE | GE | GT | LE | LT) <relTerm>]*
// <relTerm> ::= <addTerm> [(- | +) <addTerm>]*
// <addTerm> ::= <mulTerm> [(* | / | MOD | SHL | SHR) <mulTerm>]*
// <mulTerm> ::= [(- | +)]* <signTerm>
// <signTerm> ::= [(HIGH | LOW)]* <byteTerm>
// <byteTerm> ::= [(OFFSET | <type> PTR)]* <offTerm>
// <offTerm> ::= [<segovr>] <colnTerm>
// <colnTerm> ::= <dotTerm> [.<dotTerm>]*
// <dotTerm> ::= <indxTerm> ['['<Expr>']']*
// <indxTerm> ::= <index-reg> | <symbol> | <number> | '('<Expr>')'
// | '['<Expr>']'
// <Operand> ::= <register> | <Expr>
void GetAsmOperand (PASM_VALUE pavExpr)
{
ULONG tokenvalue;
ULONG classvalue;
classvalue = PeekAsmToken(&tokenvalue);
if ((classvalue & ASM_CLASS_MASK) == ASM_REG_CLASS) {
AcceptAsmToken();
classvalue &= ASM_TYPE_MASK;
pavExpr->flags = fREG;
pavExpr->base = (UCHAR)tokenvalue; // index within reg group
pavExpr->index = regType[classvalue - 1];
pavExpr->size = regSize[classvalue - 1];
}
else {
GetAsmExpr(pavExpr, FALSE);
if (pavExpr->reloc > 1) // only 0 and 1 are allowed
error(OPERAND);
}
}
// <Expr> ::= <orTerm> [(XOR | OR) <orTerm>]*
void GetAsmExpr (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
ASM_VALUE avTerm;
dprintf("enter GetAsmExpr\n");
GetAsmOrTerm(pavValue, fBracket);
while (PeekAsmToken(&tokenvalue) == ASM_OROP_CLASS) {
AcceptAsmToken();
GetAsmOrTerm(&avTerm, fBracket);
if (!(pavValue->flags & avTerm.flags & fIMM))
error(OPERAND);
if (tokenvalue == ASM_OROP_OR)
pavValue->value |= avTerm.value;
else
pavValue->value ^= avTerm.value;
}
dprintf("exit GetAsmExpr with %lx\n", pavValue->value);
}
// <orTerm> ::= <andTerm> [AND <andTerm>]*
void GetAsmOrTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
ASM_VALUE avTerm;
dprintf("enter GetAsmOrTerm\n");
GetAsmAndTerm(pavValue, fBracket);
while (PeekAsmToken(&tokenvalue) == ASM_ANDOP_CLASS) {
AcceptAsmToken();
GetAsmAndTerm(&avTerm, fBracket);
if (!(pavValue->flags & avTerm.flags & fIMM))
error(OPERAND);
pavValue->value &= avTerm.value;
}
dprintf("exit GetAsmOrTerm with %lx\n", pavValue->value);
}
// <andTerm> ::= [NOT]* <notTerm>
void GetAsmAndTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
dprintf("enter GetAsmAndTerm\n");
if (PeekAsmToken(&tokenvalue) == ASM_NOTOP_CLASS) {
AcceptAsmToken();
GetAsmAndTerm(pavValue, fBracket);
if (!(pavValue->flags & fIMM))
error(OPERAND);
pavValue->value = ~pavValue->value;
}
else
GetAsmNotTerm(pavValue, fBracket);
dprintf("exit GetAsmAndTerm with %lx\n", pavValue->value);
}
// <notTerm> ::= <relTerm> [(EQ | NE | GE | GT | LE | LT) <relTerm>]*
void GetAsmNotTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
ULONG fTest;
ULONG fAddress;
ASM_VALUE avTerm;
dprintf("enter GetAsmNotTerm\n");
GetAsmRelTerm(pavValue, fBracket);
while (PeekAsmToken(&tokenvalue) == ASM_RELOP_CLASS) {
AcceptAsmToken();
GetAsmRelTerm(&avTerm, fBracket);
if (!(pavValue->flags & avTerm.flags & fIMM) ||
pavValue->reloc > 1 || avTerm.reloc > 1)
error(OPERAND);
fAddress = pavValue->reloc | avTerm.reloc;
switch (tokenvalue) {
case ASM_RELOP_EQ:
fTest = pavValue->value == avTerm.value;
break;
case ASM_RELOP_NE:
fTest = pavValue->value != avTerm.value;
break;
case ASM_RELOP_GE:
if (fAddress)
fTest = pavValue->value >= avTerm.value;
else
fTest = (LONG)pavValue->value >= (LONG)avTerm.value;
break;
case ASM_RELOP_GT:
if (fAddress)
fTest = pavValue->value > avTerm.value;
else
fTest = (LONG)pavValue->value > (LONG)avTerm.value;
break;
case ASM_RELOP_LE:
if (fAddress)
fTest = pavValue->value <= avTerm.value;
else
fTest = (LONG)pavValue->value <= (LONG)avTerm.value;
break;
case ASM_RELOP_LT:
if (fAddress)
fTest = pavValue->value < avTerm.value;
else
fTest = (LONG)pavValue->value < (LONG)avTerm.value;
break;
default:
printf("bad RELOP type\n");
}
pavValue->value = (ULONG)(-((LONG)fTest)); // FALSE = 0; TRUE = -1
pavValue->reloc = 0;
pavValue->size = sizeB; // immediate value is byte
}
dprintf("exit GetAsmNotTerm with %lx\n", pavValue->value);
}
// <relTerm> ::= <addTerm> [(- | +) <addTerm>]*
void GetAsmRelTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
ASM_VALUE avTerm;
dprintf("enter GetAsmRelTerm\n");
GetAsmAddTerm(pavValue, fBracket);
while (PeekAsmToken(&tokenvalue) == ASM_ADDOP_CLASS) {
AcceptAsmToken();
GetAsmAddTerm(&avTerm, fBracket);
if (tokenvalue == ASM_ADDOP_MINUS) {
if (!(avTerm.flags & (fIMM | fPTR)))
error(OPERAND);
avTerm.value = (ULONG)(-((LONG)avTerm.value));
avTerm.reloc = (UCHAR)(-avTerm.reloc);
}
AddAsmValues(pavValue, &avTerm);
}
dprintf("exit GetAsmRelTerm with %lx\n", pavValue->value);
}
// <addTerm> ::= <mulTerm> [(* | / | MOD | SHL | SHR) <mulTerm>]*
void GetAsmAddTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
ASM_VALUE avTerm;
dprintf("enter GetAsmAddTerm\n");
GetAsmMulTerm(pavValue, fBracket);
while (PeekAsmToken(&tokenvalue) == ASM_MULOP_CLASS) {
AcceptAsmToken();
GetAsmMulTerm(&avTerm, fBracket);
if (tokenvalue == ASM_MULOP_MULT) {
if (pavValue->flags & fIMM)
SwapPavs(pavValue, &avTerm);
if (!(avTerm.flags & fIMM))
error(OPERAND);
if (pavValue->flags & fIMM)
pavValue->value *= avTerm.value;
else if ((pavValue->flags & fPTR32)
&& pavValue->value == 0
&& pavValue->base != indSP
&& pavValue->index == 0xff) {
pavValue->index = pavValue->base;
pavValue->base = 0xff;
pavValue->scale = 0xff;
if (avTerm.value == 1)
pavValue->scale = 0;
if (avTerm.value == 2)
pavValue->scale = 1;
if (avTerm.value == 4)
pavValue->scale = 2;
if (avTerm.value == 8)
pavValue->scale = 3;
if (pavValue->scale == 0xff)
error(OPERAND);
}
else
error(OPERAND);
}
else if (!(pavValue->flags & avTerm.flags & fIMM))
error(OPERAND);
else if (tokenvalue == ASM_MULOP_DIVIDE
|| tokenvalue == ASM_MULOP_MOD) {
if (avTerm.value == 0)
error(DIVIDE);
if (tokenvalue == ASM_MULOP_DIVIDE)
pavValue->value /= avTerm.value;
else
pavValue->value %= avTerm.value;
}
else if (tokenvalue == ASM_MULOP_SHL)
pavValue->value <<= avTerm.value;
else
pavValue->value >>= avTerm.value;
}
dprintf("exit GetAsmAddTerm with %lx\n", pavValue->value);
}
// <mulTerm> ::= [(- | +)]* <signTerm>
void GetAsmMulTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
dprintf("enter GetAsmMulTerm\n");
if (PeekAsmToken(&tokenvalue) == ASM_ADDOP_CLASS) { // BY WO DW POI UNDN
AcceptAsmToken();
GetAsmMulTerm(pavValue, fBracket);
if (tokenvalue == ASM_ADDOP_MINUS) {
if (!(pavValue->flags & (fIMM | fPTR)))
error(OPERAND);
pavValue->value = (ULONG)(-((LONG)pavValue->value));
pavValue->reloc = (UCHAR)(-pavValue->reloc);
}
}
else
GetAsmSignTerm(pavValue, fBracket);
dprintf("exit GetAsmMulTerm with %lx\n", pavValue->value);
}
// <signTerm> ::= [(HIGH | LOW)]* <byteTerm>
void GetAsmSignTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
dprintf("enter GetAsmSignTerm\n");
if (PeekAsmToken(&tokenvalue) == ASM_LOWOP_CLASS) {
AcceptAsmToken();
GetAsmSignTerm(pavValue, fBracket);
if (!(pavValue->flags & (fIMM | fPTR)))
error(OPERAND);
if (tokenvalue == ASM_LOWOP_LOW)
pavValue->value = pavValue->value & 0xff;
else
pavValue->value = (pavValue->value & ~0xff) >> 8;
pavValue->flags = fIMM; // make an immediate value
pavValue->reloc = 0;
pavValue->segment = segX;
pavValue->size = sizeB; // byte value
}
else
GetAsmByteTerm(pavValue, fBracket);
dprintf("exit GetAsmSignTerm with %lx\n", pavValue->value);
}
// <byteTerm> ::= [(OFFSET | <size> PTR)]* <offTerm>
void GetAsmByteTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
ULONG classvalue;
dprintf("enter GetAsmByteTerm\n");
classvalue = PeekAsmToken(&tokenvalue);
if (classvalue == ASM_OFFOP_CLASS) {
AcceptAsmToken();
GetAsmByteTerm(pavValue, fBracket);
if (!(pavValue->flags & (fIMM | fPTR)) || pavValue->reloc > 1)
error(OPERAND);
pavValue->flags = fIMM; // make offset an immediate value
pavValue->reloc = 0;
pavValue->size = sizeX;
pavValue->segment = segX;
}
else if (classvalue == ASM_SIZE_CLASS) {
AcceptAsmToken();
if (GetAsmToken(&classvalue) != ASM_PTROP_CLASS) // dummy token
error(SYNTAX);
GetAsmByteTerm(pavValue, fBracket);
if (!(pavValue->flags & (fIMM | fPTR | fPTR16 | fPTR32))
|| pavValue->reloc > 1
|| pavValue->size != sizeX)
error(OPERAND);
pavValue->reloc = 1; // make ptr a relocatable value
if (pavValue->flags & fIMM)
pavValue->flags = fPTR;
pavValue->size = (UCHAR)(tokenvalue & ASM_TYPE_MASK);
// value has "size?"
}
else
GetAsmOffTerm(pavValue, fBracket);
dprintf("exit GetAsmByteTerm with %lx\n", pavValue->value);
}
// <offTerm> ::= [<segovr>] <colnTerm>
void GetAsmOffTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG classvalue;
ULONG tokenvalue;
dprintf("enter GetAsmOffTerm\n");
classvalue = PeekAsmToken(&tokenvalue);
if (classvalue == ASM_SEGOVR_CLASS || classvalue == ASM_SEGMENT_CLASS) {
if (fBracket)
error(SYNTAX);
AcceptAsmToken();
}
GetAsmColnTerm(pavValue, fBracket);
if (classvalue == ASM_SEGOVR_CLASS) {
if (pavValue->reloc > 1 || pavValue->segovr != segX)
error(OPERAND);
pavValue->reloc = 1; // make ptr a relocatable value
if (pavValue->flags & fIMM)
pavValue->flags = fPTR;
pavValue->segovr = (UCHAR)tokenvalue; // has segment override
}
else if (classvalue == ASM_SEGMENT_CLASS) {
if (!(pavValue->flags & fIMM) || pavValue->reloc > 1)
error(OPERAND);
pavValue->segment = (USHORT)tokenvalue; // segment has segment value
pavValue->flags = fFPTR; // set flag for far pointer
}
dprintf("exit GetAsmOffTerm with %lx\n", pavValue->value);
}
// <colnTerm> ::= <dotTerm> [.<dotTerm>]*
void GetAsmColnTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
ASM_VALUE avTerm;
dprintf("enter GetAsmColnTerm\n");
GetAsmDotTerm(pavValue, fBracket);
while (PeekAsmToken(&tokenvalue) == ASM_DOTOP_CLASS) {
AcceptAsmToken();
GetAsmDotTerm(&avTerm, fBracket);
AddAsmValues(pavValue, &avTerm);
}
dprintf("exit GetAsmColnTerm with %lx\n", pavValue->value);
}
// <dotTerm> ::= <indxTerm> ['['<Expr>']']*
void GetAsmDotTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
ASM_VALUE avExpr;
dprintf("enter GetAsmDotTerm\n");
GetAsmIndxTerm(pavValue, fBracket);
if (pavValue->reloc > 1)
error(OPERAND);
while (PeekAsmToken(&tokenvalue) == ASM_LBRACK_CLASS) {
AcceptAsmToken();
if (fBracket)
error(SYNTAX);
GetAsmExpr(&avExpr, TRUE);
AddAsmValues(pavValue, &avExpr);
if (GetAsmToken(&tokenvalue) != ASM_RBRACK_CLASS)
error(SYNTAX);
if (pavValue->flags & fIMM)
pavValue->flags = fPTR;
}
dprintf("exit GetAsmDotTerm with %lx\n", pavValue->value);
}
// <indxTerm> ::= <index-reg> | <symbol> | <number> | '('<Expr>')'
// | '['<Expr>']'
void GetAsmIndxTerm (PASM_VALUE pavValue, UCHAR fBracket)
{
ULONG tokenvalue;
ULONG classvalue;
dprintf("enter GetAsmIndxTerm\n");
classvalue = GetAsmToken(&tokenvalue);
pavValue->segovr = segX;
pavValue->size = sizeX;
pavValue->reloc = 0;
pavValue->value = 0;
if (classvalue == ASM_LPAREN_CLASS) {
GetAsmExpr(pavValue, fBracket);
if (GetAsmToken(&tokenvalue) != ASM_RPAREN_CLASS)
error(SYNTAX);
}
else if (classvalue == ASM_LBRACK_CLASS) {
if (fBracket)
error(SYNTAX);
GetAsmExpr(pavValue, TRUE);
if (GetAsmToken(&tokenvalue) != ASM_RBRACK_CLASS)
error(SYNTAX);
if (pavValue->flags == fIMM)
pavValue->flags = fPTR;
}
else if (classvalue == ASM_SYMBOL_CLASS) {
pavValue->value = tokenvalue;
pavValue->flags = fIMM;
pavValue->reloc = 1;
}
else if (classvalue == ASM_NUMBER_CLASS) {
pavValue->value = tokenvalue;
pavValue->flags = fIMM;
}
else if (classvalue == ASM_REG_WORD) {
if (!fBracket)
error(SYNTAX);
pavValue->flags = fPTR16;
pavValue->base = tabWordReg[tokenvalue];
if (pavValue->base == 0xff)
error(OPERAND);
}
else if (classvalue == ASM_REG_DWORD) {
if (!fBracket)
error(SYNTAX);
pavValue->flags = fPTR32;
pavValue->base = (UCHAR)tokenvalue;
pavValue->index = 0xff;
}
else
error(SYNTAX);
dprintf("exit GetAsmIndxTerm with %lx\n", pavValue->value);
}
void AddAsmValues (PASM_VALUE pavLeft, PASM_VALUE pavRight)
{
// swap values if left one is a pointer
if (pavLeft->flags & fPTR)
SwapPavs(pavLeft, pavRight);
// swap values if left one is an immediate
if (pavLeft->flags & fIMM)
SwapPavs(pavLeft, pavRight);
// the above swaps reduce the cases to test.
// pairs with an immediate will have it on the right
// pairs with a pointer will have it on the right,
// except for a pointer-immediate pair
// if both values are 16-bit pointers, combine them
if (pavLeft->flags & pavRight->flags & fPTR16) {
// if either side has both registers (rm < 4), error
if (!(pavLeft->base & pavRight->base & 4))
error(OPERAND);
// use lookup table to compute new rm value
pavLeft->base = rm16Table[((pavLeft->base & 3) << 2) +
(pavRight->base & 3)];
if (pavLeft->base == 0xff)
error(OPERAND);
pavRight->flags = fPTR;
}
// if both values are 32-bit pointers, combine them
if (pavLeft->flags & pavRight->flags & fPTR32) {
// error if either side has both base and index,
// or if both have index
if (((pavLeft->base | pavLeft->index) != 0xff)
|| ((pavRight->base | pavRight->index) != 0xff)
|| ((pavLeft->index | pavRight->index) != 0xff))
error(OPERAND);
// if left side has base, swap sides
if (pavLeft->base != 0xff)
SwapPavs(pavLeft, pavRight);
// two cases remaining, index-base and base-base
if (pavLeft->base != 0xff) {
// left side has base, promote to index but swap if left
// base is ESP since it cannot be an index register
if (pavLeft->base == indSP)
SwapPavs(pavLeft, pavRight);
if (pavLeft->base == indSP)
error(OPERAND);
pavLeft->index = pavLeft->base;
pavLeft->scale = 0;
}
// finish by setting left side base to right side value
pavLeft->base = pavRight->base;
pavRight->flags = fPTR;
}
// if left side is any pointer and right is nonindex pointer,
// combine them. (above cases set right side to use this code)
if ((pavLeft->flags & (fPTR | fPTR16 | fPTR32))
&& (pavRight->flags & fPTR)) {
if (pavLeft->segovr + pavRight->segovr != segX
&& pavLeft->segovr != pavRight->segovr)
error(OPERAND);
if (pavLeft->size + pavRight->size != sizeX
&& pavLeft->size != pavRight->size)
error(OPERAND);
pavRight->flags = fIMM;
}
// if right side is immediate, add values and relocs
// (above case sets right side to use this code)
// illegal value types do not have right side set to fIMM
if (pavRight->flags & fIMM) {
pavLeft->value += pavRight->value;
pavLeft->reloc += pavRight->reloc;
}
else
error(OPERAND);
}
void SwapPavs (PASM_VALUE pavFirst, PASM_VALUE pavSecond)
{
ASM_VALUE temp;
memmove(&temp, pavFirst, sizeof(ASM_VALUE));
memmove(pavFirst, pavSecond, sizeof(ASM_VALUE));
memmove(pavSecond, &temp, sizeof(ASM_VALUE));
}