cc65/src/cc65/datatype.c

/*****************************************************************************/
/*                                                                           */
/*				  datatype.c				     */
/*                                                                           */
/*		 Type string handling for the cc65 C compiler		     */
/*                                                                           */
/*                                                                           */
/*                                                                           */
/* (C) 1998-2006 Ullrich von Bassewitz                                       */
/*               R<>merstra<72>e 52                                              */
/*               D-70794 Filderstadt                                         */
/* EMail:        uz@cc65.org                                                 */
/*                                                                           */
/*                                                                           */
/* This software is provided 'as-is', without any expressed or implied       */
/* warranty.  In no event will the authors be held liable for any damages    */
/* arising from the use of this software.                                    */
/*                                                                           */
/* Permission is granted to anyone to use this software for any purpose,     */
/* including commercial applications, and to alter it and redistribute it    */
/* freely, subject to the following restrictions:                            */
/*                                                                           */
/* 1. The origin of this software must not be misrepresented; you must not   */
/*    claim that you wrote the original software. If you use this software   */
/*    in a product, an acknowledgment in the product documentation would be  */
/*    appreciated but is not required.                                       */
/* 2. Altered source versions must be plainly marked as such, and must not   */
/*    be misrepresented as being the original software.                      */
/* 3. This notice may not be removed or altered from any source              */
/*    distribution.                                                          */
/*                                                                           */
/*****************************************************************************/



#include <string.h>

/* common */
#include "check.h"
#include "xmalloc.h"

/* cc65 */
#include "codegen.h"
#include "datatype.h"
#include "error.h"
#include "funcdesc.h"
#include "global.h"
#include "symtab.h"



/*****************************************************************************/
/*		    	  	     Data	    			     */
/*****************************************************************************/



/* Predefined type strings */
Type type_schar[]       = { TYPE(T_SCHAR),  TYPE(T_END) };
Type type_uchar[]       = { TYPE(T_UCHAR),  TYPE(T_END) };
Type type_int[]         = { TYPE(T_INT),    TYPE(T_END) };
Type type_uint[]        = { TYPE(T_UINT),   TYPE(T_END) };
Type type_long[]        = { TYPE(T_LONG),   TYPE(T_END) };
Type type_ulong[]       = { TYPE(T_ULONG),  TYPE(T_END) };
Type type_void[]        = { TYPE(T_VOID),   TYPE(T_END) };
Type type_size_t[]      = { TYPE(T_SIZE_T), TYPE(T_END) };
Type type_float[]       = { TYPE(T_FLOAT),  TYPE(T_END) };
Type type_double[]      = { TYPE(T_DOUBLE), TYPE(T_END) };



/*****************************************************************************/
/*		 		     Code				     */
/*****************************************************************************/



unsigned TypeLen (const Type* T)
/* Return the length of the type string */
{
    const Type* Start = T;
    while (T->C != T_END) {
	++T;
    }
    return T - Start;
}



Type* TypeCpy (Type* Dest, const Type* Src)
/* Copy a type string */
{
    Type* Orig = Dest;
    while (1) {
      	*Dest = *Src;
        if (Src->C == T_END) {
            break;
        }
      	Src++;
        Dest++;
    }
    return Orig;
}



Type* TypeDup (const Type* T)
/* Create a copy of the given type on the heap */
{
    unsigned Len = (TypeLen (T) + 1) * sizeof (Type);
    return memcpy (xmalloc (Len), T, Len);
}



Type* TypeAlloc (unsigned Len)
/* Allocate memory for a type string of length Len. Len *must* include the
 * trailing T_END.
 */
{
    return xmalloc (Len * sizeof (Type));
}



void TypeFree (Type* T)
/* Free a type string */
{
    xfree (T);
}



int SignExtendChar (int C)
/* Do correct sign extension of a character */
{
    if (IS_Get (&SignedChars) && (C & 0x80) != 0) {
       	return C | ~0xFF;
    } else {
       	return C & 0xFF;
    }
}



TypeCode GetDefaultChar (void)
/* Return the default char type (signed/unsigned) depending on the settings */
{
    return IS_Get (&SignedChars)? T_SCHAR : T_UCHAR;
}



Type* GetCharArrayType (unsigned Len)
/* Return the type for a char array of the given length */
{
    /* Allocate memory for the type string */
    Type* T = TypeAlloc (3);    /* array/char/terminator */

    /* Fill the type string */
    T[0].C   = T_ARRAY;
    T[0].A.L = Len;             /* Array length is in the L attribute */
    T[1].C   = GetDefaultChar ();
    T[2].C   = T_END;

    /* Return the new type */
    return T;
}



Type* GetImplicitFuncType (void)
/* Return a type string for an inplicitly declared function */
{
    /* Get a new function descriptor */
    FuncDesc* F = NewFuncDesc ();

    /* Allocate memory for the type string */
    Type* T = TypeAlloc (3);    /* func/returns int/terminator */

    /* Prepare the function descriptor */
    F->Flags  = FD_EMPTY | FD_VARIADIC;
    F->SymTab = &EmptySymTab;
    F->TagTab = &EmptySymTab;

    /* Fill the type string */
    T[0].C   = T_FUNC;
    T[0].A.P = F;
    T[1].C   = T_INT;
    T[2].C   = T_END;

    /* Return the new type */
    return T;
}



Type* PointerTo (const Type* T)
/* Return a type string that is "pointer to T". The type string is allocated
 * on the heap and may be freed after use.
 */
{
    /* Get the size of the type string including the terminator */
    unsigned Size = TypeLen (T) + 1;

    /* Allocate the new type string */
    Type* P = TypeAlloc	(Size + 1);

    /* Create the return type... */
    P[0].C = T_PTR;
    memcpy (P+1, T, Size * sizeof (Type));

    /* ...and return it */
    return P;
}



static TypeCode PrintTypeComp (FILE* F, TypeCode C, TypeCode Mask, const char* Name)
/* Check for a specific component of the type. If it is there, print the
 * name and remove it. Return the type with the component removed.
 */
{
    if ((C & Mask) == Mask) {
      	fprintf (F, "%s ", Name);
	C &= ~Mask;
    }
    return C;
}



void PrintType (FILE* F, const Type* T)
/* Output translation of type array. */
{
    /* Walk over the type string */
    while (T->C != T_END) {

        /* Get the type code */
        TypeCode C = T->C;

	/* Print any qualifiers */
       	C = PrintTypeComp (F, C, T_QUAL_CONST, "const");
	C = PrintTypeComp (F, C, T_QUAL_VOLATILE, "volatile");
        C = PrintTypeComp (F, C, T_QUAL_RESTRICT, "restrict");

    	/* Signedness. Omit the signedness specifier for long and int */
       	if ((C & T_MASK_TYPE) != T_TYPE_INT && (C & T_MASK_TYPE) != T_TYPE_LONG) {
	    C = PrintTypeComp (F, C, T_SIGN_SIGNED, "signed");
	}
    	C = PrintTypeComp (F, C, T_SIGN_UNSIGNED, "unsigned");

    	/* Now check the real type */
     	switch (C & T_MASK_TYPE) {
    	    case T_TYPE_CHAR:
    	  	fprintf (F, "char");
    	  	break;
	    case T_TYPE_SHORT:
		fprintf (F, "short");
		break;
    	    case T_TYPE_INT:
    	  	fprintf (F, "int");
    	  	break;
	    case T_TYPE_LONG:
		fprintf (F, "long");
		break;
	    case T_TYPE_LONGLONG:
		fprintf (F, "long long");
		break;
    	    case T_TYPE_FLOAT:
    	     	fprintf (F, "float");
    	     	break;
    	    case T_TYPE_DOUBLE:
    	     	fprintf (F, "double");
    	     	break;
     	    case T_TYPE_VOID:
     	  	fprintf (F, "void");
    	  	break;
    	    case T_TYPE_STRUCT:
    	     	fprintf (F, "struct %s", ((SymEntry*) T->A.P)->Name);
	     	break;
	    case T_TYPE_UNION:
	     	fprintf (F, "union %s", ((SymEntry*) T->A.P)->Name);
	     	break;
	    case T_TYPE_ARRAY:
		/* Recursive call */
		PrintType (F, T + 1);
		if (T->A.L == UNSPECIFIED) {
		    fprintf (F, "[]");
		} else {
		    fprintf (F, "[%ld]", T->A.L);
		}
	     	return;
	    case T_TYPE_PTR:
 		/* Recursive call */
		PrintType (F, T + 1);
		fprintf (F, "*");
	     	return;
	    case T_TYPE_FUNC:
	     	fprintf (F, "function returning ");
	     	break;
	    default:
	     	fprintf (F, "unknown type: %04lX", T->C);
	}

        /* Next element */
        ++T;
    }
}



void PrintFuncSig (FILE* F, const char* Name, Type* T)
/* Print a function signature. */
{
    /* Get the function descriptor */
    const FuncDesc* D = GetFuncDesc (T);

    /* Print a comment with the function signature */
    PrintType (F, GetFuncReturn (T));
    if (D->Flags & FD_NEAR) {
        fprintf (F, " __near__");
    }
    if (D->Flags & FD_FAR) {
        fprintf (F, " __far__");
    }
    if (D->Flags & FD_FASTCALL) {
     	fprintf (F, " __fastcall__");
    }
    fprintf (F, " %s (", Name);

    /* Parameters */
    if (D->Flags & FD_VOID_PARAM) {
 	fprintf (F, "void");
    } else {
 	unsigned I;
 	SymEntry* E = D->SymTab->SymHead;
 	for (I = 0; I < D->ParamCount; ++I) {
 	    if (I > 0) {
 		fprintf (F, ", ");
 	    }
            if (SymIsRegVar (E)) {
                fprintf (F, "register ");
            }
 	    PrintType (F, E->Type);
 	    E = E->NextSym;
 	}
    }

    /* End of parameter list */
    fprintf (F, ")");
}



void PrintRawType (FILE* F, const Type* T)
/* Print a type string in raw format (for debugging) */
{
    while (T->C != T_END) {
       	fprintf (F, "%04lX ", T->C);
        ++T;
    }
    fprintf (F, "\n");
}



int TypeHasAttr (const Type* T)
/* Return true if the given type has attribute data */
{
    return IsClassStruct (T) || IsTypeArray (T) || IsClassFunc (T);
}



unsigned SizeOf (const Type* T)
/* Compute size of object represented by type array. */
{
    switch (UnqualifiedType (T->C)) {

    	case T_VOID:
       	    return 0;   /* Assume voids have size zero */

	case T_SCHAR:
	case T_UCHAR:
	    return SIZEOF_CHAR;

       	case T_SHORT:
    	case T_USHORT:
            return SIZEOF_SHORT;

    	case T_INT:
	case T_UINT:
            return SIZEOF_INT;

	case T_PTR:
	case T_FUNC:	/* Maybe pointer to function */
	    return SIZEOF_PTR;

        case T_LONG:
    	case T_ULONG:
	    return SIZEOF_LONG;

	case T_LONGLONG:
	case T_ULONGLONG:
	    return SIZEOF_LONGLONG;

        case T_ENUM:
	    return SIZEOF_INT;

	case T_FLOAT:
            return SIZEOF_FLOAT;

	case T_DOUBLE:
	    return SIZEOF_DOUBLE;

	case T_STRUCT:
	case T_UNION:
            return ((SymEntry*) T->A.P)->V.S.Size;

	case T_ARRAY:
            if (T->A.L == UNSPECIFIED) {
                /* Array with unspecified size */
                return 0;
            } else {
	        return T->A.L * SizeOf (T + 1);
            }

    	default:
	    Internal ("Unknown type in SizeOf: %04lX", T->C);
	    return 0;

    }
}



unsigned PSizeOf (const Type* T)
/* Compute size of pointer object. */
{
    /* We are expecting a pointer expression */
    CHECK (IsClassPtr (T));

    /* Skip the pointer or array token itself */
    return SizeOf (T + 1);
}



unsigned CheckedSizeOf (const Type* T)
/* Return the size of a data type. If the size is zero, emit an error and
 * return some valid size instead (so the rest of the compiler doesn't have
 * to work with invalid sizes).
 */
{
    unsigned Size = SizeOf (T);
    if (Size == 0) {
        Error ("Size of data type is unknown");
        Size = SIZEOF_CHAR;     /* Don't return zero */
    }
    return Size;
}



unsigned CheckedPSizeOf (const Type* T)
/* Return the size of a data type that is pointed to by a pointer. If the
 * size is zero, emit an error and return some valid size instead (so the
 * rest of the compiler doesn't have to work with invalid sizes).
 */
{
    unsigned Size = PSizeOf (T);
    if (Size == 0) {
        Error ("Size of data type is unknown");
        Size = SIZEOF_CHAR;     /* Don't return zero */
    }
    return Size;
}



unsigned TypeOf (const Type* T)
/* Get the code generator base type of the object */
{
    switch (UnqualifiedType (T->C)) {

	case T_SCHAR:
    	    return CF_CHAR;

    	case T_UCHAR:
    	    return CF_CHAR | CF_UNSIGNED;

    	case T_SHORT:
	case T_INT:
        case T_ENUM:
	    return CF_INT;

    	case T_USHORT:
	case T_UINT:
	case T_PTR:
    	case T_ARRAY:
	    return CF_INT | CF_UNSIGNED;

        case T_LONG:
	    return CF_LONG;

       	case T_ULONG:
       	    return CF_LONG | CF_UNSIGNED;

        case T_FLOAT:
        case T_DOUBLE:
            /* These two are identical in the backend */
            return CF_FLOAT;

        case T_FUNC:
	    return (((FuncDesc*) T->A.P)->Flags & FD_VARIADIC)? 0 : CF_FIXARGC;

        case T_STRUCT:
        case T_UNION:
       	    /* Address of ... */
       	    return CF_INT | CF_UNSIGNED;

       	default:
       	    Error ("Illegal type %04lX", T->C);
       	    return CF_INT;
    }
}



Type* Indirect (Type* T)
/* Do one indirection for the given type, that is, return the type where the
 * given type points to.
 */
{
    /* We are expecting a pointer expression */
    CHECK (IsClassPtr (T));

    /* Skip the pointer or array token itself */
    return T + 1;
}



Type* ArrayToPtr (const Type* T)
/* Convert an array to a pointer to it's first element */
{
    /* Function must only be called for an array */
    CHECK (IsTypeArray (T));

    /* Return pointer to first element */
    return PointerTo (T + 1);
}



TypeCode GetQualifier (const Type* T)
/* Get the qualifier from the given type string */
{
    /* If this is an array, look at the element type, otherwise look at the
     * type itself.
     */
    if (IsTypeArray (T)) {
     	++T;
    }
    return (T->C & T_MASK_QUAL);
}



int IsFastCallFunc (const Type* T)
/* Return true if this is a function type or pointer to function with
 * __fastcall__ calling conventions
 */
{
    FuncDesc* F	= GetFuncDesc (T);
    return (F->Flags & FD_FASTCALL) != 0;
}



int IsVariadicFunc (const Type* T)
/* Return true if this is a function type or pointer to function type with
 * variable parameter list
 */
{
    FuncDesc* F = GetFuncDesc (T);
    return (F->Flags & FD_VARIADIC) != 0;
}



FuncDesc* GetFuncDesc (const Type* T)
/* Get the FuncDesc pointer from a function or pointer-to-function type */
{
    if (UnqualifiedType (T->C) == T_PTR) {
 	/* Pointer to function */
 	++T;
    }

    /* Be sure it's a function type */
    CHECK (IsClassFunc (T));

    /* Get the function descriptor from the type attributes */
    return T->A.P;
}



void SetFuncDesc (Type* T, FuncDesc* F)
/* Set the FuncDesc pointer in a function or pointer-to-function type */
{
    if (UnqualifiedType (T->C) == T_PTR) {
 	/* Pointer to function */
 	++T;
    }

    /* Be sure it's a function type */
    CHECK (IsClassFunc (T));

    /* Set the function descriptor */
    T->A.P = F;
}



Type* GetFuncReturn (Type* T)
/* Return a pointer to the return type of a function or pointer-to-function type */
{
    if (UnqualifiedType (T->C) == T_PTR) {
 	/* Pointer to function */
 	++T;
    }

    /* Be sure it's a function type */
    CHECK (IsClassFunc (T));

    /* Return a pointer to the return type */
    return T + 1;
}



long GetElementCount (const Type* T)
/* Get the element count of the array specified in T (which must be of
 * array type).
 */
{
    CHECK (IsTypeArray (T));
    return T->A.L;
}



void SetElementCount (Type* T, long Count)
/* Set the element count of the array specified in T (which must be of
 * array type).
 */
{
    CHECK (IsTypeArray (T));
    T->A.L = Count;
}



Type* GetElementType (Type* T)
/* Return the element type of the given array type. */
{
    CHECK (IsTypeArray (T));
    return T + 1;
}



SymEntry* GetSymEntry (const Type* T)
/* Return a SymEntry pointer from a type */
{
    /* Only structs or unions have a SymEntry attribute */
    CHECK (IsClassStruct (T));

    /* Return the attribute */
    return T->A.P;
}



void SetSymEntry (Type* T, SymEntry* S)
/* Set the SymEntry pointer for a type */
{
    /* Only structs or unions have a SymEntry attribute */
    CHECK (IsClassStruct (T));

    /* Set the attribute */
    T->A.P = S;
}



Type* IntPromotion (Type* T)
/* Apply the integer promotions to T and return the result. The returned type
 * string may be T if there is no need to change it.
 */
{
    /* We must have an int to apply int promotions */
    PRECONDITION (IsClassInt (T));

    /* An integer can represent all values from either signed or unsigned char,
     * so convert chars to int and leave all other types alone.
     */
    if (IsTypeChar (T)) {
        return type_int;
    } else {
        return T;
    }
}



Type* PtrConversion (Type* T)
/* If the type is a function, convert it to pointer to function. If the
 * expression is an array, convert it to pointer to first element. Otherwise
 * return T.
 */
{
    if (IsTypeFunc (T)) {
       	return PointerTo (T);
    } else if (IsTypeArray (T)) {
        return ArrayToPtr (T);
    } else {
        return T;
    }
}