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More .sizeof explanations

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git-svn-id: svn://svn.cc65.org/cc65/trunk@2721 b7a2c559-68d2-44c3-8de9-860c34a00d81
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cuz 2003-12-06 14:46:12 +00:00
parent 87857eced3
commit 855fdbfcb0
1 changed files with 39 additions and 10 deletions
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49
doc/ca65.sgml
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@ -2625,7 +2625,7 @@ Here's a list of all control commands and a description, what they do:
of a name represents both, a scope and a symbol, the scope is choosen over the
symbol.
Usage examples:
After the following code:
<tscreen><verb>
.struct Point ; Struct size = 4
@ -2634,26 +2634,55 @@ Here's a list of all control commands and a description, what they do:
.endstruct
P: .tag Point ; Declare a point
@P: .tag Point ; Declare another point
.code
.proc Code ; 3 bytes
nop
.proc Code
nop
.proc Inner
nop
.endproc
nop
.endproc
.proc Data ; 4 bytes
.proc Data
.data ; Segment switch!!!
.res 4
.endproc
lda #.sizeof(Point) ; Loads 4
lda #.sizeof(Point::xcoord) ; Loads 2
lda #.sizeof(P) ; Loads 4
lda #.sizeof(Code) ; Loads 3
lda #.sizeof(Data) ; Loads 0
</verb></tscreen>
<descrip>
<tag><tt/.sizeof(Point)/</tag>
will have the value 4, because this is the size of struct <tt/Point/.
<tag><tt/.sizeof(Point::xcoord)/</tag>
will have the value 2, because this is the size of the member <tt/xcoord/
in struct <tt/Point/.
<tag><tt/.sizeof(P)/</tag>
will have the value 4, this is the size of the data declared on the same
source line as the label <tt/P/, which is in the same segment that <tt/P/
is relative to.
<tag><tt/.sizeof(@P)/</tag>
will have the value 4, see above. The example demonstrates that <tt/.SIZEOF/
does also work for cheap local symbols.
<tag><tt/.sizeof(Code)/</tag>
will have the value 3, since this is amount of data emitted into the code
segment, the segment that was active when <tt/Code/ was entered. Note that
this value includes the amount of data emitted in child scopes (in this
case <tt/Code::Inner/).
<tag><tt/.sizeof(Code::Inner)/</tag>
will have the value 1 as expected.
<tag><tt/.sizeof(Data)/</tag>
will have the value 0. Data is emitted within the scope <tt/Data/, but since
the segment is switched after entry, this data is emitted into another
segment.
</descrip>
<sect1><tt>.SMART</tt><label id=".SMART"><p>