ExprDesc* ED_MakeConstAbs (ExprDesc* Expr, long Value, Type* Type)
/* Make Expr an absolute const with the given value and type. */
{
Expr->Sym = 0;
Expr->Type = Type;
Expr->Flags = E_LOC_ABS | E_RTYPE_RVAL | (Expr->Flags & E_HAVE_MARKS);
Expr->Name = 0;
Expr->IVal = Value;
Expr->FVal = FP_D_Make (0.0);
return Expr;
}
ExprDesc* ED_MakeConstAbsInt (ExprDesc* Expr, long Value)
/* Make Expr a constant integer expression with the given value */
{
Expr->Sym = 0;
Expr->Type = type_int;
Expr->Flags = E_LOC_ABS | E_RTYPE_RVAL | (Expr->Flags & E_HAVE_MARKS);
Expr->Name = 0;
Expr->IVal = Value;
Expr->FVal = FP_D_Make (0.0);
return Expr;
}
ExprDesc* ED_MakeLValExpr (ExprDesc* Expr)
/* Convert Expr into a lvalue which is in the primary register without an
* offset.
*/
{
Expr->Sym = 0;
Expr->Flags &= ~(E_MASK_LOC | E_MASK_RTYPE | E_BITFIELD | E_NEED_TEST | E_CC_SET);
Expr->Flags |= (E_LOC_EXPR | E_RTYPE_LVAL);
Expr->Name = 0;
Expr->IVal = 0; /* No offset */
Expr->FVal = FP_D_Make (0.0);
return Expr;
}
ExprDesc* ED_Init (ExprDesc* Expr)
/* Initialize an ExprDesc */
{
Expr->Sym = 0;
Expr->Type = 0;
Expr->Flags = 0;
Expr->Name = 0;
Expr->IVal = 0;
Expr->FVal = FP_D_Make (0.0);
Expr->LVal = 0;
Expr->BitOffs = 0;
Expr->BitWidth = 0;
return Expr;
}
static void NumericConst (void)
/* Parse a numeric constant */
{
unsigned Base; /* Temporary number base */
unsigned Prefix; /* Base according to prefix */
StrBuf S = STATIC_STRBUF_INITIALIZER;
int IsFloat;
char C;
unsigned DigitVal;
unsigned long IVal; /* Value */
/* Check for a leading hex or octal prefix and determine the possible
** integer types.
*/
if (CurC == '0') {
/* Gobble 0 and examine next char */
NextChar ();
if (toupper (CurC) == 'X') {
Base = Prefix = 16;
NextChar (); /* gobble "x" */
} else {
Base = 10; /* Assume 10 for now - see below */
Prefix = 8; /* Actual prefix says octal */
}
} else {
Base = Prefix = 10;
}
/* Because floating point numbers don't have octal prefixes (a number
** with a leading zero is decimal), we first have to read the number
** before converting it, so we can determine if it's a float or an
** integer.
*/
while (IsXDigit (CurC) && HexVal (CurC) < Base) {
SB_AppendChar (&S, CurC);
NextChar ();
}
SB_Terminate (&S);
/* The following character tells us if we have an integer or floating
** point constant. Note: Hexadecimal floating point constants aren't
** supported in C89.
*/
IsFloat = (CurC == '.' ||
(Base == 10 && toupper (CurC) == 'E') ||
(Base == 16 && toupper (CurC) == 'P' && IS_Get (&Standard) >= STD_C99));
/* If we don't have a floating point type, an octal prefix results in an
** octal base.
*/
if (!IsFloat && Prefix == 8) {
Base = 8;
}
/* Since we do now know the correct base, convert the remembered input
** into a number.
*/
SB_Reset (&S);
IVal = 0;
while ((C = SB_Get (&S)) != '\0') {
DigitVal = HexVal (C);
if (DigitVal >= Base) {
Error ("Numeric constant contains digits beyond the radix");
}
IVal = (IVal * Base) + DigitVal;
}
/* We don't need the string buffer any longer */
SB_Done (&S);
/* Distinguish between integer and floating point constants */
if (!IsFloat) {
unsigned Types;
int HaveSuffix;
/* Check for a suffix and determine the possible types */
HaveSuffix = 1;
if (toupper (CurC) == 'U') {
/* Unsigned type */
NextChar ();
if (toupper (CurC) != 'L') {
Types = IT_UINT | IT_ULONG;
} else {
NextChar ();
Types = IT_ULONG;
}
} else if (toupper (CurC) == 'L') {
/* Long type */
NextChar ();
if (toupper (CurC) != 'U') {
Types = IT_LONG | IT_ULONG;
} else {
NextChar ();
Types = IT_ULONG;
}
} else {
HaveSuffix = 0;
if (Prefix == 10) {
/* Decimal constants are of any type but uint */
Types = IT_INT | IT_LONG | IT_ULONG;
} else {
/* Octal or hex constants are of any type */
Types = IT_INT | IT_UINT | IT_LONG | IT_ULONG;
}
}
/* Check the range to determine the type */
if (IVal > 0x7FFF) {
/* Out of range for int */
Types &= ~IT_INT;
/* If the value is in the range 0x8000..0xFFFF, unsigned int is not
** allowed, and we don't have a type specifying suffix, emit a
** warning, because the constant is of type long.
*/
if (IVal <= 0xFFFF && (Types & IT_UINT) == 0 && !HaveSuffix) {
Warning ("Constant is long");
}
}
if (IVal > 0xFFFF) {
/* Out of range for unsigned int */
Types &= ~IT_UINT;
}
if (IVal > 0x7FFFFFFF) {
/* Out of range for long int */
Types &= ~IT_LONG;
}
/* Now set the type string to the smallest type in types */
if (Types & IT_INT) {
NextTok.Type = type_int;
} else if (Types & IT_UINT) {
NextTok.Type = type_uint;
} else if (Types & IT_LONG) {
NextTok.Type = type_long;
} else {
NextTok.Type = type_ulong;
}
/* Set the value and the token */
NextTok.IVal = IVal;
NextTok.Tok = TOK_ICONST;
} else {
/* Float constant */
Double FVal = FP_D_FromInt (IVal); /* Convert to double */
/* Check for a fractional part and read it */
if (CurC == '.') {
Double Scale;
/* Skip the dot */
NextChar ();
/* Read fractional digits */
Scale = FP_D_Make (1.0);
while (IsXDigit (CurC) && (DigitVal = HexVal (CurC)) < Base) {
/* Get the value of this digit */
Double FracVal = FP_D_Div (FP_D_FromInt (DigitVal * Base), Scale);
/* Add it to the float value */
FVal = FP_D_Add (FVal, FracVal);
/* Scale base */
Scale = FP_D_Mul (Scale, FP_D_FromInt (DigitVal));
/* Skip the digit */
NextChar ();
}
}
/* Check for an exponent and read it */
if ((Base == 16 && toupper (CurC) == 'F') ||
(Base == 10 && toupper (CurC) == 'E')) {
unsigned Digits;
unsigned Exp;
/* Skip the exponent notifier */
NextChar ();
/* Read an optional sign */
if (CurC == '-') {
NextChar ();
} else if (CurC == '+') {
NextChar ();
}
/* Read exponent digits. Since we support only 32 bit floats
** with a maximum exponent of +-/127, we read the exponent
** part as integer with up to 3 digits and drop the remainder.
** This avoids an overflow of Exp. The exponent is always
** decimal, even for hex float consts.
*/
Digits = 0;
Exp = 0;
while (IsDigit (CurC)) {
if (++Digits <= 3) {
Exp = Exp * 10 + HexVal (CurC);
}
NextChar ();
}
/* Check for errors: We must have exponent digits, and not more
** than three.
*/
if (Digits == 0) {
Error ("Floating constant exponent has no digits");
} else if (Digits > 3) {
Warning ("Floating constant exponent is too large");
}
/* Scale the exponent and adjust the value accordingly */
if (Exp) {
FVal = FP_D_Mul (FVal, FP_D_Make (pow (10, Exp)));
}
}
/* Check for a suffix and determine the type of the constant */
if (toupper (CurC) == 'F') {
NextChar ();
NextTok.Type = type_float;
} else {
NextTok.Type = type_double;
}
/* Set the value and the token */
NextTok.FVal = FVal;
NextTok.Tok = TOK_FCONST;
}
}
