view docs/manual/x227.html @ 389:2d9b7ae6c329

Throw error if address overflows in extended mode This may or may not cause extra problems due to sloppiness in dealing with calculations that overflow in 16 bits. However, presumably it is a good idea so unless something major pops up, it seems like a good idea. Thanks to Erik G <erik@6809.org> for the patch.
author William Astle <lost@l-w.ca>
date Mon, 13 Jul 2015 21:37:49 -0600
parents 682524a1f32f
children fc166b3bbae3
line wrap: on
line source

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd">
<HTML
><HEAD
><TITLE
>Symbols</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK
REL="HOME"
TITLE="LW Tool Chain"
HREF="index.html"><LINK
REL="UP"
TITLE="LWASM"
HREF="c62.html"><LINK
REL="PREVIOUS"
TITLE="Source Format"
HREF="x217.html"><LINK
REL="NEXT"
TITLE="Numbers and Expressions"
HREF="x232.html"></HEAD
><BODY
CLASS="SECTION"
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#840084"
ALINK="#0000FF"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>LW Tool Chain</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="x217.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
>Chapter 3. LWASM</TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="x232.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECTION"
><H1
CLASS="SECTION"
><A
NAME="AEN227"
>3.4. Symbols</A
></H1
><P
>Symbols have no length restriction. They may contain letters, numbers, dots,
dollar signs, and underscores. They must start with a letter, dot, or
underscore.</P
><P
>LWASM also supports the concept of a local symbol. A local symbol is one
which contains either a "?" or a "@", which can appear anywhere in the symbol.
The scope of a local symbol is determined by a number of factors. First,
each included file gets its own local symbol scope. A blank line will also
be considered a local scope barrier. Macros each have their own local symbol
scope as well (which has a side effect that you cannot use a local symbol
as an argument to a macro). There are other factors as well. In general,
a local symbol is restricted to the block of code it is defined within.</P
><P
>By default, unless assembling to the os9 target, a "$" in the symbol will
also make it local.  This can be controlled by the "dollarlocal" and
"nodollarlocal" pragmas.  In the absence of a pragma to the contrary, for
the os9 target, a "$" in the symbol will not make it considered local while
for all other targets it will.</P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="x217.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="x232.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>Source Format</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="c62.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Numbers and Expressions</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>