compile.c

python s60 1.4.5版本的源代码

	node *m;
	REQ(n, argument); /* [test '='] test; really [keyword '='] test */
	if (NCH(n) == 1) {
		if (*pkeywords != NULL) {
			com_error(c, PyExc_SyntaxError,
				  "non-keyword arg after keyword arg");
		}
		else {
			com_node(c, CHILD(n, 0));
		}
		return;
	}
	m = n;
	do {
		m = CHILD(m, 0);
	} while (NCH(m) == 1);
	if (TYPE(m) != NAME) {
		/* f(lambda x: x[0] = 3) ends up getting parsed with
		 * LHS test = lambda x: x[0], and RHS test = 3.
		 * SF bug 132313 points out that complaining about a keyword
		 * then is very confusing.
		 */
		com_error(c, PyExc_SyntaxError,
			  TYPE(m) == lambdef ?
				  "lambda cannot contain assignment" :
				  "keyword can't be an expression");
	}
	else {
		PyObject *v = PyString_InternFromString(STR(m));
		if (v != NULL && *pkeywords == NULL)
			*pkeywords = PyDict_New();
		if (v == NULL)
			c->c_errors++;
		else if (*pkeywords == NULL) {
			c->c_errors++;
			Py_DECREF(v);
		} else {
			if (PyDict_GetItem(*pkeywords, v) != NULL)
				com_error(c, PyExc_SyntaxError,
					  "duplicate keyword argument");
			else
				if (PyDict_SetItem(*pkeywords, v, v) != 0)
					c->c_errors++;
			com_addoparg(c, LOAD_CONST, com_addconst(c, v));
			com_push(c, 1);
			Py_DECREF(v);
		}
	}
	com_node(c, CHILD(n, 2));
}

static void
com_call_function(struct compiling *c, node *n)
{
	if (TYPE(n) == RPAR) {
		com_addoparg(c, CALL_FUNCTION, 0);
	}
	else {
		PyObject *keywords = NULL;
		int i, na, nk;
		int lineno = n->n_lineno;
		int star_flag = 0;
		int starstar_flag = 0;
		int opcode;
		REQ(n, arglist);
		na = 0;
		nk = 0;
		for (i = 0; i < NCH(n); i += 2) {
			node *ch = CHILD(n, i);
			if (TYPE(ch) == STAR ||
			    TYPE(ch) == DOUBLESTAR)
			  break;
			if (ch->n_lineno != lineno) {
				lineno = ch->n_lineno;
				com_addoparg(c, SET_LINENO, lineno);
			}
			com_argument(c, ch, &keywords);
			if (keywords == NULL)
				na++;
			else
				nk++;
		}
		Py_XDECREF(keywords);
		while (i < NCH(n)) {
		    node *tok = CHILD(n, i);
		    node *ch = CHILD(n, i+1);
		    i += 3;
		    switch (TYPE(tok)) {
		    case STAR:       star_flag = 1;     break;
		    case DOUBLESTAR: starstar_flag = 1;	break;
		    }
		    com_node(c, ch);
		}
		if (na > 255 || nk > 255) {
			com_error(c, PyExc_SyntaxError,
				  "more than 255 arguments");
		}
		if (star_flag || starstar_flag)
		    opcode = CALL_FUNCTION_VAR - 1 +
			star_flag + (starstar_flag << 1);
		else
		    opcode = CALL_FUNCTION;
		com_addoparg(c, opcode, na | (nk << 8));
		com_pop(c, na + 2*nk + star_flag + starstar_flag);
	}
}

static void
com_select_member(struct compiling *c, node *n)
{
	com_addopname(c, LOAD_ATTR, n);
}

static void
com_sliceobj(struct compiling *c, node *n)
{
	int i=0;
	int ns=2; /* number of slice arguments */
	node *ch;

	/* first argument */
	if (TYPE(CHILD(n,i)) == COLON) {
		com_addoparg(c, LOAD_CONST, com_addconst(c, Py_None));
		com_push(c, 1);
		i++;
	}
	else {
		com_node(c, CHILD(n,i));
		i++;
		REQ(CHILD(n,i),COLON);
		i++;
	}
	/* second argument */
	if (i < NCH(n) && TYPE(CHILD(n,i)) == test) {
		com_node(c, CHILD(n,i));
		i++;
	}
	else {
		com_addoparg(c, LOAD_CONST, com_addconst(c, Py_None));
		com_push(c, 1);
	}
	/* remaining arguments */
	for (; i < NCH(n); i++) {
		ns++;
		ch=CHILD(n,i);
		REQ(ch, sliceop);
		if (NCH(ch) == 1) {
			/* right argument of ':' missing */
			com_addoparg(c, LOAD_CONST, com_addconst(c, Py_None));
			com_push(c, 1);
		}
		else
			com_node(c, CHILD(ch,1));
	}
	com_addoparg(c, BUILD_SLICE, ns);
	com_pop(c, 1 + (ns == 3));
}

static void
com_subscript(struct compiling *c, node *n)
{
	node *ch;
	REQ(n, subscript);
	ch = CHILD(n,0);
	/* check for rubber index */
	if (TYPE(ch) == DOT && TYPE(CHILD(n,1)) == DOT) {
		com_addoparg(c, LOAD_CONST, com_addconst(c, Py_Ellipsis));
		com_push(c, 1);
	}
	else {
		/* check for slice */
		if ((TYPE(ch) == COLON || NCH(n) > 1))
			com_sliceobj(c, n);
		else {
			REQ(ch, test);
			com_node(c, ch);
		}
	}
}

static void
com_subscriptlist(struct compiling *c, node *n, int assigning, node *augn)
{
	int i, op;
	REQ(n, subscriptlist);
	/* Check to make backward compatible slice behavior for '[i:j]' */
	if (NCH(n) == 1) {
		node *sub = CHILD(n, 0); /* subscript */
		/* 'Basic' slice, should have exactly one colon. */
		if ((TYPE(CHILD(sub, 0)) == COLON
		     || (NCH(sub) > 1 && TYPE(CHILD(sub, 1)) == COLON))
		    && (TYPE(CHILD(sub,NCH(sub)-1)) != sliceop))
		{
			switch (assigning) {
			case OP_DELETE:
				op = DELETE_SLICE;
				break;
			case OP_ASSIGN:
				op = STORE_SLICE;
				break;
			case OP_APPLY:
				op = SLICE;
				break;
			default:
				com_augassign_slice(c, sub, assigning, augn);
				return;
			}
			com_slice(c, sub, op);
			if (op == STORE_SLICE)
				com_pop(c, 2);
			else if (op == DELETE_SLICE)
				com_pop(c, 1);
			return;
		}
	}
	/* Else normal subscriptlist.  Compile each subscript. */
	for (i = 0; i < NCH(n); i += 2)
		com_subscript(c, CHILD(n, i));
	/* Put multiple subscripts into a tuple */
	if (NCH(n) > 1) {
		i = (NCH(n)+1) / 2;
		com_addoparg(c, BUILD_TUPLE, i);
		com_pop(c, i-1);
	}
	switch (assigning) {
	case OP_DELETE:
		op = DELETE_SUBSCR;
		i = 2;
		break;
	default:
	case OP_ASSIGN:
		op = STORE_SUBSCR;
		i = 3;
		break;
	case OP_APPLY:
		op = BINARY_SUBSCR;
		i = 1;
		break;
	}
	if (assigning > OP_APPLY) {
		com_addoparg(c, DUP_TOPX, 2);
		com_push(c, 2);
		com_addbyte(c, BINARY_SUBSCR);
		com_pop(c, 1);
		com_node(c, augn);
		com_addbyte(c, assigning);
		com_pop(c, 1);
		com_addbyte(c, ROT_THREE);
	}
	com_addbyte(c, op);
	com_pop(c, i);
}

static void
com_apply_trailer(struct compiling *c, node *n)
{
	REQ(n, trailer);
	switch (TYPE(CHILD(n, 0))) {
	case LPAR:
		com_call_function(c, CHILD(n, 1));
		break;
	case DOT:
		com_select_member(c, CHILD(n, 1));
		break;
	case LSQB:
		com_subscriptlist(c, CHILD(n, 1), OP_APPLY, NULL);
		break;
	default:
		com_error(c, PyExc_SystemError,
			  "com_apply_trailer: unknown trailer type");
	}
}

static void
com_power(struct compiling *c, node *n)
{
	int i;
	REQ(n, power);
	com_atom(c, CHILD(n, 0));
	for (i = 1; i < NCH(n); i++) {
		if (TYPE(CHILD(n, i)) == DOUBLESTAR) {
			com_factor(c, CHILD(n, i+1));
			com_addbyte(c, BINARY_POWER);
			com_pop(c, 1);
			break;
		}
		else
			com_apply_trailer(c, CHILD(n, i));
	}
}

static void
com_invert_constant(struct compiling *c, node *n)
{
	/* Compute the inverse of int and longs and use them directly,
	   but be prepared to generate code for all other
	   possibilities (invalid numbers, floats, complex).
	*/
	PyObject *num, *inv = NULL;
	int i;

	REQ(n, NUMBER);
	num = parsenumber(c, STR(n));
	if (num == NULL)
		i = 255;
	else {
		inv = PyNumber_Invert(num);
		if (inv == NULL) {
			PyErr_Clear();
			i = com_addconst(c, num);
		} else {
			i = com_addconst(c, inv);
			Py_DECREF(inv);
		}
		Py_DECREF(num);
	}
	com_addoparg(c, LOAD_CONST, i);
	com_push(c, 1);
	if (num != NULL && inv == NULL)
		com_addbyte(c, UNARY_INVERT);
}

static int
is_float_zero(const char *p)
{
	int found_radix_point = 0;
	int ch;
	while ((ch = Py_CHARMASK(*p++)) != '\0') {
		switch (ch) {
		case '0':
			/* no reason to believe it's not 0 -- continue */
			break;

		case 'e': case 'E': case 'j': case 'J':
			/* If this was a hex constant, we already would have
			   returned 0 due to the 'x' or 'X', so 'e' or 'E'
			   must be an exponent marker, and we haven't yet
			   seen a non-zero digit, and it doesn't matter what
			   the exponent is then.  For 'j' or 'J' similarly,
			   except that this is an imaginary 0 then. */
			return 1;

		case '.':
			found_radix_point = 1;
			break;

		default:
			return 0;
		}
	}
	return found_radix_point;
}

static void
com_factor(struct compiling *c, node *n)
{
	int childtype = TYPE(CHILD(n, 0));
	node *pfactor, *ppower, *patom, *pnum;
	REQ(n, factor);
	/* If the unary +, -, or ~ operator is applied to a constant,
	   don't generate a UNARY_xxx opcode.  Just store the
	   approriate value as a constant.  If the value is negative,
	   extend the string containing the constant and insert a
	   negative in the 0th position -- unless we're doing unary minus
	   of a floating zero!  In that case the sign is significant, but
	   the const dict can't distinguish +0.0 from -0.0.
	 */
	if ((childtype == PLUS || childtype == MINUS || childtype == TILDE)
	    && NCH(n) == 2
	    && TYPE((pfactor = CHILD(n, 1))) == factor
 	    && NCH(pfactor) == 1
	    && TYPE((ppower = CHILD(pfactor, 0))) == power
 	    && NCH(ppower) == 1
	    && TYPE((patom = CHILD(ppower, 0))) == atom
	    && TYPE((pnum = CHILD(patom, 0))) == NUMBER
	    && !(childtype == MINUS && is_float_zero(STR(pnum)))) {
		if (childtype == TILDE) {
			com_invert_constant(c, pnum);
			return;
		}
		if (childtype == MINUS) {
			char *s = PyMem_Malloc(strlen(STR(pnum)) + 2);
			if (s == NULL) {
				com_error(c, PyExc_MemoryError, "");
				com_addbyte(c, 255);
				return;
			}
			s[0] = '-';
			strcpy(s + 1, STR(pnum));
			PyMem_Free(STR(pnum));
			STR(pnum) = s;
		}
		com_atom(c, patom);
	}
	else if (childtype == PLUS) {
		com_factor(c, CHILD(n, 1));
		com_addbyte(c, UNARY_POSITIVE);
	}
	else if (childtype == MINUS) {
		com_factor(c, CHILD(n, 1));
		com_addbyte(c, UNARY_NEGATIVE);
	}
	else if (childtype == TILDE) {
		com_factor(c, CHILD(n, 1));
		com_addbyte(c, UNARY_INVERT);
	}
	else {
		com_power(c, CHILD(n, 0));
	}
}

static void
com_term(struct compiling *c, node *n)
{
	int i;
	int op;
	REQ(n, term);
	com_factor(c, CHILD(n, 0));
	for (i = 2; i < NCH(n); i += 2) {
		com_factor(c, CHILD(n, i));
		switch (TYPE(CHILD(n, i-1))) {
		case STAR:
			op = BINARY_MULTIPLY;
			break;
		case SLASH:
			if (c->c_flags & CO_FUTURE_DIVISION)
				op = BINARY_TRUE_DIVIDE;
			else
				op = BINARY_DIVIDE;
			break;
		case PERCENT:
			op = BINARY_MODULO;
			break;
		case DOUBLESLASH:
			op = BINARY_FLOOR_DIVIDE;
			break;
		default:
			com_error(c, PyExc_SystemError,
				  "com_term: operator not *, /, // or %");
			op = 255;
		}
		com_addbyte(c, op);
		com_pop(c, 1);
	}
}

static void
com_arith_expr(struct compiling *c, node *n)
{
	int i;
	int op;
	REQ(n, arith_expr);
	com_term(c, CHILD(n, 0));
	for (i = 2; i < NCH(n); i += 2) {
		com_term(c, CHILD(n, i));
		switch (TYPE(CHILD(n, i-1))) {
		case PLUS:
			op = BINARY_ADD;
			break;
		case MINUS:
			op = BINARY_SUBTRACT;
			break;
		default:
			com_error(c, PyExc_SystemError,
				  "com_arith_expr: operator not + or -");
			op = 255;
		}
		com_addbyte(c, op);
		com_pop(c, 1);
	}
}

static void
com_shift_expr(struct compiling *c, node *n)
{
	int i;
	int op;
	REQ(n, shift_expr);
	com_arith_expr(c, CHILD(n, 0));
	for (i = 2; i < NCH(n); i += 2) {
		com_arith_expr(c, CHILD(n, i));
		switch (TYPE(CHILD(n, i-1))) {
		case LEFTSHIFT:
			op = BINARY_LSHIFT;
			break;
		case RIGHTSHIFT:
			op = BINARY_RSHIFT;
			break;
		default:
			com_error(c, PyExc_SystemError,
				  "com_shift_expr: operator not << or >>");
			op = 255;
		}
		com_addbyte(c, op);
		com_pop(c, 1);
	}
}

static void
com_and_expr(struct compiling *c, node *n)
{
	int i;
	int op;
	REQ(n, and_expr);
	com_shift_expr(c, CHILD(n, 0));
	for (i = 2; i < NCH(n); i += 2) {
		com_shift_expr(c, CHILD(n, i));
		if (TYPE(CHILD(n, i-1)) == AMPER) {
			op = BINARY_AND;
		}
		else {
			com_error(c, PyExc_SystemError,
				  "com_and_expr: operator not &");
			op = 255;
		}
		com_addbyte(c, op);
		com_pop(c, 1);
	}
}

static void
com_xor_expr(struct compiling *c, node *n)
{
	int i;
	int op;
	REQ(n, xor_expr);
	com_and_expr(c, CHILD(n, 0));
	for (i = 2; i < NCH(n); i += 2) {
		com_and_expr(c, CHILD(n, i));