Describe initialized void variables

git-svn-id: svn://svn.cc65.org/cc65/trunk@569 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/doc/cc65.sgml b/doc/cc65.sgml
index 42b2b0be38c130f0858249d3134fa106eacbe2ff..234ce16f89e10ed1655208cbb124adb7714892a1 100644 (file)
--- a/doc/cc65.sgml
+++ b/doc/cc65.sgml
@@ -429,6 +429,32 @@ This cc65 version has some extensions to the ISO C standard.
        The macro will print the name of the current function plus a given
        string.
        <p>
+
+<item>         cc65 allows the initialization of <tt/void/ variables. This may be 
+       used to create variable structures that are more compatible with 
+       interfaces written for assembler languages. Here is an example:
+
+       <tscreen><verb>
+       void GCmd = {   (char)3, (unsigned)0x2000, (unsigned)0x3000 };
+       </verb></tscreen>
+
+       This will be translated as follows:
+
+       <tscreen><verb>
+       _GCmd:
+               .byte   3
+               .word   $2000
+               .word   $3000
+       </verb></tscreen>
+
+       Since the variable is of type <tt/void/ you may not use it as is. 
+       However, taking the address of the variable results in a <tt/void*/
+       which may be passed to any function expecting a pointer.
+
+       See the <htmlurl url="geos.html" name="GEOS library"> for examples on
+       how to use this feature.
+       <p>
+
 </itemize>
 <p>