view docs/manual/x187.html @ 235:e3741cf53e00

Fix error messages related to undefined symbols in lwlink Make lwlink not complain about seciton base and length symbols. Also silence duplicate complaints about undefined symbols. There is no need to complain about undefined symbols during the file/section resolution stage! If they are truly undefined, they'll still be undefined at the reference resolution stage.
author William Astle <lost@l-w.ca>
date Sat, 11 Aug 2012 15:18:58 -0600
parents 2cc599f1bebf
children
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="c45.html"><LINK
REL="PREVIOUS"
TITLE="Source Format"
HREF="x177.html"><LINK
REL="NEXT"
TITLE="Numbers and Expressions"
HREF="x192.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="x177.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="x192.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="SECTION"
><H1
CLASS="SECTION"
><A
NAME="AEN187"
>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="x177.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="x192.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="c45.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>Numbers and Expressions</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>