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view docs/manual/x238.html @ 508:10f62dc61a75
Fix bad usage of sprintf()
Usage of sprintf() to append to a string in the form of
sprintf(buf, "%s...", buf...) is undefined, regardless whether it
worked on a lot of older systems. It was always a bad idea and it
now breaks on current glibc and gcc development environments.
The moral: if any of your code uses sprintf() in a way similar to
the above, fix it. It may not fail in a benign way.
author | William Astle <lost@l-w.ca> |
---|---|
date | Sun, 10 May 2020 22:38:24 -0600 |
parents | 52af0aa54fe5 |
children |
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Source Format</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="Dialects" HREF="x229.html"><LINK REL="NEXT" TITLE="Symbols" HREF="x248.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="x229.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="x248.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECTION" ><H1 CLASS="SECTION" ><A NAME="AEN238" >3.3. Source Format</A ></H1 ><P >LWASM accepts plain text files in a relatively free form. It can handle lines terminated with CR, LF, CRLF, or LFCR which means it should be able to assemble files on any platform on which it compiles.</P ><P >Each line may start with a symbol. If a symbol is present, there must not be any whitespace preceding it. It is legal for a line to contain nothing but a symbol.</P ><P >The op code is separated from the symbol by whitespace. If there is no symbol, there must be at least one white space character preceding it. If applicable, the operand follows separated by whitespace. Following the opcode and operand is an optional comment.</P ><P > It is important to note that operands cannot contain any whitespace except in the case of delimited strings. This is because the first whitespace character will be interpreted as the separator between the operand column and the comment. This behaviour is required for approximate source compatibility with other 6x09 assemblers. </P ><P >A comment can also be introduced with a * or a ;. The comment character is optional for end of statement comments. However, if a symbol is the only thing present on the line other than the comment, the comment character is mandatory to prevent the assembler from interpreting the comment as an opcode.</P ><P >For compatibility with the output generated by some C preprocessors, LWASM will also ignore lines that begin with a #. This should not be used as a general comment character, however.</P ><P >The opcode is not treated case sensitively. Neither are register names in the operand fields. Symbols, however, are case sensitive.</P ><P > As of version 2.6, LWASM supports files with line numbers. If line numbers are present, the line must start with a digit. The line number itself must consist only of digits. The line number must then be followed by either the end of the line or exactly one white space character. After that white space character, the lines are interpreted exactly as above. </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="x229.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="x248.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Dialects</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="c62.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Symbols</TD ></TR ></TABLE ></DIV ></BODY ></HTML >