dt_parser.c

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		bzero(&idn, sizeof (dt_node_t));
		idp = dt_idhash_lookup(dhp, dsp->ds_ident);

		if (idp != NULL)
			(void) dt_ident_cook(&idn, idp, NULL);

		/*
		 * Cache some attributes of the decl to make the rest of this
		 * code simpler: if the decl is an array which is subscripted
		 * by a type rather than an integer, then it's an associative
		 * array (assc).  We then expect to match either DT_IDENT_ARRAY
		 * for associative arrays or DT_IDENT_SCALAR for anything else.
		 */
		assc = ddp->dd_kind == CTF_K_ARRAY &&
		    ddp->dd_node->dn_kind == DT_NODE_TYPE;

		idkind = assc ? DT_IDENT_ARRAY : DT_IDENT_SCALAR;

		if (assc) {
			if (class == DT_DC_THIS) {
				xyerror(D_DECL_LOCASSC, "associative arrays "
				    "may not be declared as local variables:"
				    " %s\n", dsp->ds_ident);
			}

			if (dt_decl_type(ddp->dd_next, &dtt) != 0)
				longjmp(yypcb->pcb_jmpbuf, EDT_COMPILER);
		}

		if (idp != NULL && (idp->di_kind != idkind ||
		    ctf_type_cmp(dtt.dtt_ctfp, dtt.dtt_type,
		    idn.dn_ctfp, idn.dn_type) != 0)) {
			xyerror(D_DECL_IDRED, "identifier redeclared: %s\n"
			    "\t current: %s %s\n\tprevious: %s %s\n",
			    dsp->ds_ident, dt_idkind_name(idkind),
			    dt_type_name(dtt.dtt_ctfp,
			    dtt.dtt_type, n1, sizeof (n1)),
			    dt_idkind_name(idp->di_kind),
			    dt_node_type_name(&idn, n2, sizeof (n2)));

		} else if (idp != NULL && assc) {
			const dt_idsig_t *isp = idp->di_data;
			dt_node_t *dnp = ddp->dd_node;
			int argc = 0;

			for (; dnp != NULL; dnp = dnp->dn_list, argc++) {
				const dt_node_t *pnp = &isp->dis_args[argc];

				if (ctf_type_cmp(dnp->dn_ctfp, dnp->dn_type,
				    pnp->dn_ctfp, pnp->dn_type) == 0)
					continue;

				xyerror(D_DECL_IDRED,
				    "identifier redeclared: %s\n"
				    "\t current: %s, key #%d of type %s\n"
				    "\tprevious: %s, key #%d of type %s\n",
				    dsp->ds_ident,
				    dt_idkind_name(idkind), argc + 1,
				    dt_node_type_name(dnp, n1, sizeof (n1)),
				    dt_idkind_name(idp->di_kind), argc + 1,
				    dt_node_type_name(pnp, n2, sizeof (n2)));
			}

			if (isp->dis_argc != argc) {
				xyerror(D_DECL_IDRED,
				    "identifier redeclared: %s\n"
				    "\t current: %s of %s, tuple length %d\n"
				    "\tprevious: %s of %s, tuple length %d\n",
				    dsp->ds_ident, dt_idkind_name(idkind),
				    dt_type_name(dtt.dtt_ctfp, dtt.dtt_type,
				    n1, sizeof (n1)), argc,
				    dt_idkind_name(idp->di_kind),
				    dt_node_type_name(&idn, n2, sizeof (n2)),
				    isp->dis_argc);
			}

		} else if (idp == NULL) {
			type = ctf_type_resolve(dtt.dtt_ctfp, dtt.dtt_type);
			kind = ctf_type_kind(dtt.dtt_ctfp, type);

			switch (kind) {
			case CTF_K_INTEGER:
				if (ctf_type_encoding(dtt.dtt_ctfp, type,
				    &cte) == 0 && IS_VOID(cte)) {
					xyerror(D_DECL_VOIDOBJ, "cannot have "
					    "void object: %s\n", dsp->ds_ident);
				}
				break;
			case CTF_K_STRUCT:
			case CTF_K_UNION:
				if (ctf_type_size(dtt.dtt_ctfp, type) != 0)
					break; /* proceed to declaring */
				/*FALLTHRU*/
			case CTF_K_FORWARD:
				xyerror(D_DECL_INCOMPLETE,
				    "incomplete struct/union/enum %s: %s\n",
				    dt_type_name(dtt.dtt_ctfp, dtt.dtt_type,
				    n1, sizeof (n1)), dsp->ds_ident);
				/*NOTREACHED*/
			}

			if ((kind == CTF_K_STRUCT || kind == CTF_K_UNION ||
			    kind == CTF_K_ARRAY) && class == DT_DC_THIS) {
				xyerror(D_VAR_UNSUP, "clause-local variable"
				    " cannot be used with struct/union/array"
				    " type: %s\n", dsp->ds_ident);
			}

			if (dt_idhash_nextid(dhp, &id) == -1) {
				xyerror(D_ID_OFLOW, "cannot create %s: limit "
				    "on number of %s variables exceeded\n",
				    dsp->ds_ident, dt_idhash_name(dhp));
			}

			dt_dprintf("declare %s %s variable %s, id=%u\n",
			    dt_idhash_name(dhp), dt_idkind_name(idkind),
			    dsp->ds_ident, id);

			idp = dt_idhash_insert(dhp, dsp->ds_ident, idkind,
			    idflags | DT_IDFLG_WRITE | DT_IDFLG_DECL, id,
			    _dtrace_defattr, 0, assc ? &dt_idops_assc :
			    &dt_idops_thaw, NULL, dtp->dt_gen);

			if (idp == NULL)
				longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM);

			dt_ident_type_assign(idp, dtt.dtt_ctfp, dtt.dtt_type);

			/*
			 * If we are declaring an associative array, use our
			 * fake parse node to cook the new assoc identifier.
			 * This will force the ident code to instantiate the
			 * array type signature corresponding to the list of
			 * types pointed to by ddp->dd_node.  We also reset
			 * the identifier's attributes based upon the result.
			 */
			if (assc) {
				idp->di_attr =
				    dt_ident_cook(&idn, idp, &ddp->dd_node);
			}
		}
	}

	} /* end of switch */

	free(dsp->ds_ident);
	dsp->ds_ident = NULL;

	return (NULL);
}

dt_node_t *
dt_node_func(dt_node_t *dnp, dt_node_t *args)
{
	dt_ident_t *idp;

	if (dnp->dn_kind != DT_NODE_IDENT) {
		xyerror(D_FUNC_IDENT,
		    "function designator is not of function type\n");
	}

	idp = dt_idhash_lookup(yypcb->pcb_hdl->dt_globals, dnp->dn_string);

	if (idp == NULL) {
		xyerror(D_FUNC_UNDEF,
		    "undefined function name: %s\n", dnp->dn_string);
	}

	if (idp->di_kind != DT_IDENT_FUNC &&
	    idp->di_kind != DT_IDENT_AGGFUNC &&
	    idp->di_kind != DT_IDENT_ACTFUNC) {
		xyerror(D_FUNC_IDKIND, "%s '%s' may not be referenced as a "
		    "function\n", dt_idkind_name(idp->di_kind), idp->di_name);
	}

	free(dnp->dn_string);
	dnp->dn_string = NULL;

	dnp->dn_kind = DT_NODE_FUNC;
	dnp->dn_flags &= ~DT_NF_COOKED;
	dnp->dn_ident = idp;
	dnp->dn_args = args;
	dnp->dn_list = NULL;

	return (dnp);
}

/*
 * The offsetof() function is special because it takes a type name as an
 * argument.  It does not actually construct its own node; after looking up the
 * structure or union offset, we just return an integer node with the offset.
 */
dt_node_t *
dt_node_offsetof(dt_decl_t *ddp, char *s)
{
	dtrace_typeinfo_t dtt;
	dt_node_t dn;
	char *name;
	int err;

	ctf_membinfo_t ctm;
	ctf_id_t type;
	uint_t kind;

	name = alloca(strlen(s) + 1);
	(void) strcpy(name, s);
	free(s);

	err = dt_decl_type(ddp, &dtt);
	dt_decl_free(ddp);

	if (err != 0)
		longjmp(yypcb->pcb_jmpbuf, EDT_COMPILER);

	type = ctf_type_resolve(dtt.dtt_ctfp, dtt.dtt_type);
	kind = ctf_type_kind(dtt.dtt_ctfp, type);

	if (kind != CTF_K_STRUCT && kind != CTF_K_UNION) {
		xyerror(D_OFFSETOF_TYPE,
		    "offsetof operand must be a struct or union type\n");
	}

	if (ctf_member_info(dtt.dtt_ctfp, type, name, &ctm) == CTF_ERR) {
		xyerror(D_UNKNOWN, "failed to determine offset of %s: %s\n",
		    name, ctf_errmsg(ctf_errno(dtt.dtt_ctfp)));
	}

	bzero(&dn, sizeof (dn));
	dt_node_type_assign(&dn, dtt.dtt_ctfp, ctm.ctm_type);

	if (dn.dn_flags & DT_NF_BITFIELD) {
		xyerror(D_OFFSETOF_BITFIELD,
		    "cannot take offset of a bit-field: %s\n", name);
	}

	return (dt_node_int(ctm.ctm_offset / NBBY));
}

dt_node_t *
dt_node_op1(int op, dt_node_t *cp)
{
	dt_node_t *dnp;

	if (cp->dn_kind == DT_NODE_INT) {
		switch (op) {
		case DT_TOK_INEG:
			/*
			 * If we're negating an unsigned integer, zero out any
			 * extra top bits to truncate the value to the size of
			 * the effective type determined by dt_node_int().
			 */
			cp->dn_value = -cp->dn_value;
			if (!(cp->dn_flags & DT_NF_SIGNED)) {
				cp->dn_value &= ~0ULL >>
				    (64 - dt_node_type_size(cp) * NBBY);
			}
			/*FALLTHRU*/
		case DT_TOK_IPOS:
			return (cp);
		case DT_TOK_BNEG:
			cp->dn_value = ~cp->dn_value;
			return (cp);
		case DT_TOK_LNEG:
			cp->dn_value = !cp->dn_value;
			return (cp);
		}
	}

	/*
	 * If sizeof is applied to a type_name or string constant, we can
	 * transform 'cp' into an integer constant in the node construction
	 * pass so that it can then be used for arithmetic in this pass.
	 */
	if (op == DT_TOK_SIZEOF &&
	    (cp->dn_kind == DT_NODE_STRING || cp->dn_kind == DT_NODE_TYPE)) {
		dtrace_hdl_t *dtp = yypcb->pcb_hdl;
		size_t size = dt_node_type_size(cp);

		if (size == 0) {
			xyerror(D_SIZEOF_TYPE, "cannot apply sizeof to an "
			    "operand of unknown size\n");
		}

		dt_node_type_assign(cp, dtp->dt_ddefs->dm_ctfp,
		    ctf_lookup_by_name(dtp->dt_ddefs->dm_ctfp, "size_t"));

		cp->dn_kind = DT_NODE_INT;
		cp->dn_op = DT_TOK_INT;
		cp->dn_value = size;

		return (cp);
	}

	dnp = dt_node_alloc(DT_NODE_OP1);
	assert(op <= USHRT_MAX);
	dnp->dn_op = (ushort_t)op;
	dnp->dn_child = cp;

	return (dnp);
}

dt_node_t *
dt_node_op2(int op, dt_node_t *lp, dt_node_t *rp)
{
	dtrace_hdl_t *dtp = yypcb->pcb_hdl;
	dt_node_t *dnp;

	/*
	 * First we check for operations that are illegal -- namely those that
	 * might result in integer division by zero, and abort if one is found.
	 */
	if (rp->dn_kind == DT_NODE_INT && rp->dn_value == 0 &&
	    (op == DT_TOK_MOD || op == DT_TOK_DIV ||
	    op == DT_TOK_MOD_EQ || op == DT_TOK_DIV_EQ))
		xyerror(D_DIV_ZERO, "expression contains division by zero\n");

	/*
	 * If both children are immediate values, we can just perform inline
	 * calculation and return a new immediate node with the result.
	 */
	if (lp->dn_kind == DT_NODE_INT && rp->dn_kind == DT_NODE_INT) {
		uintmax_t l = lp->dn_value;
		uintmax_t r = rp->dn_value;

		dnp = dt_node_int(0); /* allocate new integer node for result */

		switch (op) {
		case DT_TOK_LOR:
			dnp->dn_value = l || r;
			dt_node_type_assign(dnp,
			    DT_INT_CTFP(dtp), DT_INT_TYPE(dtp));
			break;
		case DT_TOK_LXOR:
			dnp->dn_value = (l != 0) ^ (r != 0);
			dt_node_type_assign(dnp,
			    DT_INT_CTFP(dtp), DT_INT_TYPE(dtp));
			break;
		case DT_TOK_LAND:
			dnp->dn_value = l && r;
			dt_node_type_assign(dnp,
			    DT_INT_CTFP(dtp), DT_INT_TYPE(dtp));
			break;
		case DT_TOK_BOR:
			dnp->dn_value = l | r;
			dt_node_promote(lp, rp, dnp);
			break;
		case DT_TOK_XOR:
			dnp->dn_value = l ^ r;
			dt_node_promote(lp, rp, dnp);
			break;
		case DT_TOK_BAND:
			dnp->dn_value = l & r;
			dt_node_promote(lp, rp, dnp);
			break;
		case DT_TOK_EQU:
			dnp->dn_value = l == r;
			dt_node_type_assign(dnp,
			    DT_INT_CTFP(dtp), DT_INT_TYPE(dtp));
			break;
		case DT_TOK_NEQ:
			dnp->dn_value = l != r;
			dt_node_type_assign(dnp,
			    DT_INT_CTFP(dtp), DT_INT_TYPE(dtp));
			break;
		case DT_TOK_LT:
			dt_node_promote(lp, rp, dnp);
			if (dnp->dn_flags & DT_NF_SIGNED)
				dnp->dn_value = (intmax_t)l < (intmax_t)r;
			else
				dnp->dn_value = l < r;
			dt_node_type_assign(dnp,
			    DT_INT_CTFP(dtp), DT_INT_TYPE(dtp));
			break;
		case DT_TOK_LE:
			dt_node_promote(lp, rp, dnp);
			if (dnp->dn_flags & DT_NF_SIGNED)
				dnp->dn_value = (intmax_t)l <= (intmax_t)r;
			else
				dnp->dn_value = l <= r;
			dt_node_type_assign(dnp,
			    DT_INT_CTFP(dtp), DT_INT_TYPE(dtp));
			break;
		case DT_TOK_GT:
			dt_node_promote(lp, rp, dnp);
			if (dnp->dn_flags & DT_NF_SIGNED)
				dnp->dn_value = (intmax_t)l > (intmax_t)r;
			else
				dnp->dn_value = l > r;
			dt_node_type_assign(dnp,
			    DT_INT_CTFP(dtp), DT_INT_TYPE(dtp));
			break;
		case DT_TOK_GE:
			dt_node_promote(lp, rp, dnp);
			if (dnp->dn_flags & DT_NF_SIGNED)
				dnp->dn_value = (intmax_t)l >= (intmax_t)r;
			else
				dnp->dn_value = l >= r;
			dt_node_type_assign(dnp,
			    DT_INT_CTFP(dtp), DT_INT_TYPE(dtp));
			break;
		case DT_TOK_LSH:
			dnp->dn_value = l << r;
			dt_node_type_propagate(lp, dnp);
			dt_node_attr_assign(rp,
			    dt_attr_min(lp->dn_attr, rp->dn_attr));
			break;
		case DT_TOK_RSH:
			dnp->dn_value = l >> r;
			dt_node_type_propagate(lp, dnp);
			dt_node_attr_assign(rp,
			    dt_attr_min(lp->dn_attr, rp->dn_attr));
			break;
		case DT_TOK_ADD:
			dnp->dn_value = l + r;
			dt_node_promote(lp, rp, dnp);
			break;
		case DT_TOK_SUB:
			dnp->dn_value = l - r;
			dt_node_promote(lp, rp, dnp);
			break;
		case DT_TOK_MUL:
			dnp->dn_value = l * r;
			dt_node_promote(lp, rp, dnp);
			break;
		case DT_TOK_DIV:
			dt_node_promote(lp, rp, dnp);
			if (dnp->dn_flags & DT_NF_SIGNED)
				dnp->dn_value = (intmax_t)l / (intmax_t)r;
			else
				dnp->dn_value = l / r;
			break;
		case DT_TOK_MOD:
			dt_node_promote(lp, rp, dnp);
			if (dnp->dn_flags & DT_NF_SIGNED)
				dnp->dn_value = (intmax_t)l % (intmax_t)r;
			else
				dnp->dn_value = l % r;
			break;
		default:
			dt_node_free(dnp);
			dnp = NULL;
		}

		if (dnp != NULL) {
			dt_node_free(lp);
			dt_node_free(rp);
			return (dnp);
		}
	}

	/*
	 * If an integer constant is being cast to another integer type, we can
	 * perform the cast as part of integer constant folding in this pass.
	 * We must take action when the integer is being cast to a smaller type
	 * or if it is changing signed-ness.  If so, we first shift rp's bits
	 * bits high (losing excess bits if narrowing) and then shift them down
	 * with either a logical shift (unsigned) or arithmetic shift (signed).
	 */
	if (op == DT_TOK_LPAR && rp->dn_kind == DT_NODE_INT &&
	    dt_node_is_integer(lp)) {
		size_t srcsize = dt_node_type_size(rp);
		size_t dstsize = dt_node_type_size(lp);

		if ((dstsize < srcsize) || ((lp->dn_flags & DT_NF_SIGNED) ^
		    (rp->dn_flags & DT_NF_SIGNED))) {
			int n = dstsize < srcsize ?
			    (sizeof (uint64_t) * NBBY - dstsize * NBBY) :
			    (sizeof (uint64_t) * NBBY - srcsize * NBBY);

			rp->dn_value <<= n;
			if (lp->dn_flags & DT_NF_SIGNED)
				rp->dn_value = (intmax_t)rp->dn_value >> n;
			else