<tscreen><verb>
Op Description Precedence
-------------------------------------------------------------------
- .CONCAT Builtin function 0
- .LEFT Builtin function 0
- .MID Builtin function 0
- .RIGHT Builtin function 0
- .STRING Builtin function 0
-
- * Builtin pseudo variable (r/o) 1
- .BLANK Builtin function 1
- .CONST Builtin function 1
- .CPU Builtin pseudo variable (r/o) 1
- .DEFINED Builtin function 1
- .MATCH Builtin function 1
- .TCOUNT Builtin function 1
- .TIME Builtin function 1
- .VERSION Builtin function 1
- .XMATCH Builtin function 1
- .PARAMCOUNT Builtin pseudo variable (r/o) 1
- .REFERENCED Builtin function 1
+ Builtin string functions 0
+
+ Builtin pseudo variables 1
+ Builtin pseudo functions 1
+ Unary plus 1
- Unary minus 1
~ Unary bitwise not 1
To force a specific order of evaluation, braces may be used as usual.
-Some of the pseudo variables mentioned above need some more explanation:
-
-<tscreen><verb>
- * This symbol is replaced by the value of the program
- counter at start of the current instruction. Note, that
- '*' yields a rvalue, that means, you cannot assign to it.
- Use .ORG to set the program counter in sections with
- absolute code.
-</verb></tscreen>
<p>
scope named <tt/inner/, this would be an error, even if such a pair does exist
(one level up in global scope).
-Ambiguities that may be introduced by this search algorithm may be removed by
-anchoring the scope specification in the global scope. In the example above,
-if you want to access the "other" symbol <tt/bar/, you would have to write:
+Ambiguities that may be introduced by this search algorithm may be removed by
+anchoring the scope specification in the global scope. In the example above,
+if you want to access the "other" symbol <tt/bar/, you would have to write:
+
+<tscreen><verb>
+ .scope foo
+ .scope outer
+ .scope inner
+ bar = 1
+ .endscope
+ .endscope
+ .scope another
+ .scope nested
+ lda #::outer::inner::bar ; 2
+ .endscope
+ .endscope
+ .endscope
+
+ .scope outer
+ .scope inner
+ bar = 2
+ .endscope
+ .endscope
+</verb></tscreen>
+
+
+<sect>Address sizes<label id="address-sizes"><p>
+
+
+
+<sect>Pseudo variables<label id="pseudo-variables"><p>
+
+Pseudo variables are readable in all cases, and in some special cases also
+writable.
+
+<sect1><tt>*</tt><p>
+
+ Reading this pseudo variable will return the program counter at the start
+ of the current input line.
+
+ Assignment to this variable is possible when <tt/<ref id=".FEATURE"
+ name=".FEATURE pc_assignment">/ is used. Note: You should not use
+ assignments to <tt/*/, use <tt/<ref id=".ORG" name=".ORG">/ instead.
+
+
+<sect1><tt>.CPU</tt><label id=".CPU"><p>
+
+ Reading this pseudo variable will give a constant integer value that
+ tells which CPU is currently enabled. It can also tell which instruction
+ set the CPU is able to translate. The value read from the pseudo variable
+ should be further examined by using one of the constants defined by the
+ "cpu" macro package (see <tt/<ref id=".MACPACK" name=".MACPACK">/).
+
+ It may be used to replace the .IFPxx pseudo instructions or to construct
+ even more complex expressions.
+
+ Example:
+
+ <tscreen><verb>
+ .macpack cpu
+ .if (.cpu .bitand CPU_ISET_65816)
+ phx
+ phy
+ .else
+ txa
+ pha
+ tya
+ pha
+ .endif
+ </verb></tscreen>
+
+
+<sect1><tt>.PARAMCOUNT</tt><label id=".PARAMCOUNT"><p>
+
+ This builtin pseudo variable is only available in macros. It is replaced by
+ the actual number of parameters that were given in the macro invocation.
+
+ Example:
+
+ <tscreen><verb>
+ .macro foo arg1, arg2, arg3
+ .if .paramcount <> 3
+ .error "Too few parameters for macro foo"
+ .endif
+ ...
+ .endmacro
+ </verb></tscreen>
+
+ See section <ref id="macros" name="Macros">.
+
+
+<sect1><tt>.TIME</tt><label id=".TIME"><p>
+
+ Reading this pseudo variable will give a constant integer value that
+ represents the current time in POSIX standard (as seconds since the
+ Epoch).
+
+ It may be used to encode the time of translation somewhere in the created
+ code.
+
+ Example:
+
+ <tscreen><verb>
+ .dword .time ; Place time here
+ </verb></tscreen>
+
+
+<sect1><tt>.VERSION</tt><label id=".VERSION"><p>
+
+ Reading this pseudo variable will give the assembler version according to
+ the following formula:
+
+ VER_MAJOR*$100 + VER_MINOR*$10 + VER_PATCH
+
+ It may be used to encode the assembler version or check the assembler for
+ special features not available with older versions.
+
+ Example:
+
+ Version 2.11.1 of the assembler will return $2B1 as numerical constant when
+ reading the pseudo variable <tt/.VERSION/.
+
+
+
+<sect>Pseudo functions<label id="pseudo-functions"><p>
+
+Pseudo functions expect their arguments in parenthesis, and they have a result,
+either a string or an expression.
+
+
+<sect1><tt>.BANKBYTE</tt><label id=".BANKBYTE"><p>
+
+ The function returns the bank byte (that is, bits 16-23) of its argument.
+ It works identical to the '^' operator.
+
+ See: <tt><ref id=".HIBYTE" name=".HIBYTE"></tt>,
+ <tt><ref id=".LOBYTE" name=".LOBYTE"></tt>
+
+
+<sect1><tt>.BLANK</tt><label id=".BLANK"><p>
+
+ Builtin function. The function evaluates its argument in braces and
+ yields "false" if the argument is non blank (there is an argument), and
+ "true" if there is no argument. As an example, the <tt/.IFBLANK/ statement
+ may be replaced by
+
+ <tscreen><verb>
+ .if .blank(arg)
+ </verb></tscreen>
+
+
+<sect1><tt>.CONCAT</tt><label id=".CONCAT"><p>
+
+ Builtin string function. The function allows to concatenate a list of string
+ constants separated by commas. The result is a string constant that is the
+ concatentation of all arguments. This function is most useful in macros and
+ when used together with the <tt/.STRING/ builtin function. The function may
+ be used in any case where a string constant is expected.
+
+ Example:
+
+ <tscreen><verb>
+ .include .concat ("myheader", ".", "inc")
+ </verb></tscreen>
+
+ This is the same as the command
+
+ <tscreen><verb>
+ .include "myheader.inc"
+ </verb></tscreen>
+
+
+<sect1><tt>.CONST</tt><label id=".CONST"><p>
+
+ Builtin function. The function evaluates its argument in braces and
+ yields "true" if the argument is a constant expression (that is, an
+ expression that yields a constant value at assembly time) and "false"
+ otherwise. As an example, the .IFCONST statement may be replaced by
+
+ <tscreen><verb>
+ .if .const(a + 3)
+ </verb></tscreen>
+
+
+<sect1><tt>.HIBYTE</tt><label id=".HIBYTE"><p>
+
+ The function returns the high byte (that is, bits 8-15) of its argument.
+ It works identical to the '>' operator.
+
+ See: <tt><ref id=".LOBYTE" name=".LOBYTE"></tt>,
+ <tt><ref id=".BANKBYTE" name=".BANKBYTE"></tt>
+
+
+<sect1><tt>.HIWORD</tt><label id=".HIWORD"><p>
+
+ The function returns the high word (that is, bits 16-31) of its argument.
+
+ See: <tt><ref id=".LOWORD" name=".LOWORD"></tt>
+
+
+<sect1><tt>.LEFT</tt><label id=".LEFT"><p>
+
+ Builtin function. Extracts the left part of a given token list.
+
+ Syntax:
+
+ <tscreen><verb>
+ .LEFT (<int expr>, <token list>)
+ </verb></tscreen>
+
+ The first integer expression gives the number of tokens to extract from
+ the token list. The second argument is the token list itself.
+
+ Example:
+
+ To check in a macro if the given argument has a '#' as first token
+ (immidiate addressing mode), use something like this:
+
+ <tscreen><verb>
+ .macro ldax arg
+ ...
+ .if (.match (.left (1, arg), #))
+
+ ; ldax called with immidiate operand
+ ...
+
+ .endif
+ ...
+ .endmacro
+ </verb></tscreen>
+
+ See also the <tt><ref id=".MID" name=".MID"></tt> and <tt><ref id=".RIGHT"
+ name=".RIGHT"></tt> builtin functions.
+
+
+<sect1><tt>.LOBYTE</tt><label id=".LOBYTE"><p>
+
+ The function returns the low byte (that is, bits 0-7) of its argument.
+ It works identical to the '<' operator.
+
+ See: <tt><ref id=".HIBYTE" name=".HIBYTE"></tt>,
+ <tt><ref id=".BANKBYTE" name=".BANKBYTE"></tt>
+
+
+<sect1><tt>.LOWORD</tt><label id=".LOWORD"><p>
+
+ The function returns the low word (that is, bits 0-15) of its argument.
+
+ See: <tt><ref id=".HIWORD" name=".HIWORD"></tt>
+
+
+<sect1><tt>.MATCH</tt><label id=".MATCH"><p>
+
+ Builtin function. Matches two token lists against each other. This is
+ most useful within macros, since macros are not stored as strings, but
+ as lists of tokens.
+
+ The syntax is
+
+ <tscreen><verb>
+ .MATCH(<token list #1>, <token list #2>)
+ </verb></tscreen>
+
+ Both token list may contain arbitrary tokens with the exception of the
+ terminator token (comma resp. right parenthesis) and
+
+ <itemize>
+ <item>end-of-line
+ <item>end-of-file
+ </itemize>
+
+ Often a macro parameter is used for any of the token lists.
+
+ Please note that the function does only compare tokens, not token
+ attributes. So any number is equal to any other number, regardless of the
+ actual value. The same is true for strings. If you need to compare tokens
+ <em/and/ token attributes, use the <tt><ref id=".XMATCH"
+ name=".XMATCH"></tt> function.
+
+ Example:
+
+ Assume the macro <tt/ASR/, that will shift right the accumulator by one,
+ while honoring the sign bit. The builtin processor instructions will allow
+ an optional "A" for accu addressing for instructions like <tt/ROL/ and
+ <tt/ROR/. We will use the <tt><ref id=".MATCH" name=".MATCH"></tt> function
+ to check for this and print and error for invalid calls.
+
+ <tscreen><verb>
+ .macro asr arg
+
+ .if (.not .blank(arg)) .and (.not .match (arg, a))
+ .error "Syntax error"
+ .endif
+
+ cmp #$80 ; Bit 7 into carry
+ lsr a ; Shift carry into bit 7
+
+ .endmacro
+ </verb></tscreen>
+
+ The macro will only accept no arguments, or one argument that must be the
+ reserved keyword "A".
+
+ See: <tt><ref id=".XMATCH" name=".XMATCH"></tt>
+
+
+<sect1><tt>.MID</tt><label id=".MID"><p>
+
+ Builtin function. Takes a starting index, a count and a token list as
+ arguments. Will return part of the token list.
+
+ Syntax:
+
+ <tscreen><verb>
+ .MID (<int expr>, <int expr>, <token list>)
+ </verb></tscreen>
+
+ The first integer expression gives the starting token in the list (the
+ first token has index 0). The second integer expression gives the number
+ of tokens to extract from the token list. The third argument is the
+ token list itself.
+
+ Example:
+
+ To check in a macro if the given argument has a '<tt/#/' as first token
+ (immidiate addressing mode), use something like this:
+
+ <tscreen><verb>
+ .macro ldax arg
+ ...
+ .if (.match (.mid (0, 1, arg), #))
+
+ ; ldax called with immidiate operand
+ ...
+
+ .endif
+ ...
+ .endmacro
+ </verb></tscreen>
+
+ See also the <tt><ref id=".LEFT" name=".LEFT"></tt> and <tt><ref id=".RIGHT"
+ name=".RIGHT"></tt> builtin functions.
+
+
+<sect1><tt>.REF, .REFERENCED</tt><label id=".REFERENCED"><p>
+
+ Builtin function. The function expects an identifier as argument in braces.
+ The argument is evaluated, and the function yields "true" if the identifier
+ is a symbol that has already been referenced somewhere in the source file up
+ to the current position. Otherwise the function yields false. As an example,
+ the <tt><ref id=".IFREF" name=".IFREF"></tt> statement may be replaced by
+
+ <tscreen><verb>
+ .if .referenced(a)
+ </verb></tscreen>
+
+ See: <tt><ref id=".DEFINED" name=".DEFINED"></tt>
+
+
+<sect1><tt>.RIGHT</tt><label id=".RIGHT"><p>
+
+ Builtin function. Extracts the right part of a given token list.
+
+ Syntax:
+
+ <tscreen><verb>
+ .RIGHT (<int expr>, <token list>)
+ </verb></tscreen>
+
+ The first integer expression gives the number of tokens to extract from
+ the token list. The second argument is the token list itself.
+
+ See also the <tt><ref id=".LEFT" name=".LEFT"></tt> and <tt><ref id=".MID"
+ name=".MID"></tt> builtin functions.
+
+
+<sect1><tt>.SIZEOF</tt><label id=".SIZEOF"><p>
+
+ <tt/.SIZEOF/ is a pseudo function that returns the size of its argument. The
+ argument can be a struct/union, a struct member, a procedure, or a label. In
+ case of a procedure or label, its size is defined by the amount of data
+ placed in the segment where the label is relative to. If a line of code
+ switches segments (for example in a macro) data placed in other segments
+ does not count for the size.
+
+ Please note that a symbol or scope must exist, before it is used together with
+ <tt/.SIZEOF/ (this may get relaxed later, but will always be true for scopes).
+ A scope has preference over a symbol with the same name, so if the last part
+ of a name represents both, a scope and a symbol, the scope is choosen over the
+ symbol.
+
+ After the following code:
+
+ <tscreen><verb>
+ .struct Point ; Struct size = 4
+ xcoord .word
+ xcoord .word
+ .endstruct
+
+ P: .tag Point ; Declare a point
+ @P: .tag Point ; Declare another point
+
+ .code
+ .proc Code
+ nop
+ .proc Inner
+ nop
+ .endproc
+ nop
+ .endproc
+
+ .proc Data
+ .data ; Segment switch!!!
+ .res 4
+ .endproc
+ </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>.STRAT</tt><label id=".STRAT"><p>
+
+ Builtin function. The function accepts a string and an index as
+ arguments and returns the value of the character at the given position
+ as an integer value. The index is zero based.
+
+ Example:
+
+ <tscreen><verb>
+ .macro M Arg
+ ; Check if the argument string starts with '#'
+ .if (.strat (Arg, 0) = '#')
+ ...
+ .endif
+ .endmacro
+ </verb></tscreen>
+
+
+<sect1><tt>.STRING</tt><label id=".STRING"><p>
+
+ Builtin function. The function accepts an argument in braces and converts
+ this argument into a string constant. The argument may be an identifier, or
+ a constant numeric value.
+
+ Since you can use a string in the first place, the use of the function may
+ not be obvious. However, it is useful in macros, or more complex setups.
+
+ Example:
+
+ <tscreen><verb>
+ ; Emulate other assemblers:
+ .macro section name
+ .segment .string(name)
+ .endmacro
+ </verb></tscreen>
+
+
+<sect1><tt>.STRLEN</tt><label id=".STRLEN"><p>
+
+ Builtin function. The function accepts a string argument in braces and
+ eveluates to the length of the string.
+
+ Example:
+
+ The following macro encodes a string as a pascal style string with
+ a leading length byte.
+
+ <tscreen><verb>
+ .macro PString Arg
+ .byte .strlen(Arg), Arg
+ .endmacro
+ </verb></tscreen>
+
+
+<sect1><tt>.TCOUNT</tt><label id=".TCOUNT"><p>
+
+ Builtin function. The function accepts a token list in braces. The
+ function result is the number of tokens given as argument.
+
+ Example:
+
+ The <tt/ldax/ macro accepts the '#' token to denote immidiate addressing (as
+ with the normal 6502 instructions). To translate it into two separate 8 bit
+ load instructions, the '#' token has to get stripped from the argument:
+
+ <tscreen><verb>
+ .macro ldax arg
+ .if (.match (.mid (0, 1, arg), #))
+ ; ldax called with immidiate operand
+ lda #<(.right (.tcount (arg)-1, arg))
+ ldx #>(.right (.tcount (arg)-1, arg))
+ .else
+ ...
+ .endif
+ .endmacro
+ </verb></tscreen>
+
+
+<sect1><tt>.XMATCH</tt><label id=".XMATCH"><p>
-<tscreen><verb>
- .scope foo
- .scope outer
- .scope inner
- bar = 1
- .endscope
- .endscope
- .scope another
- .scope nested
- lda #::outer::inner::bar ; 2
- .endscope
- .endscope
- .endscope
+ Builtin function. Matches two token lists against each other. This is
+ most useful within macros, since macros are not stored as strings, but
+ as lists of tokens.
- .scope outer
- .scope inner
- bar = 2
- .endscope
- .endscope
-</verb></tscreen>
+ The syntax is
+ <tscreen><verb>
+ .XMATCH(<token list #1>, <token list #2>)
+ </verb></tscreen>
-<sect>Address sizes<label id="address-sizes"><p>
+ Both token list may contain arbitrary tokens with the exception of the
+ terminator token (comma resp. right parenthesis) and
+
+ <itemize>
+ <item>end-of-line
+ <item>end-of-file
+ </itemize>
+ Often a macro parameter is used for any of the token lists.
+ The function compares tokens <em/and/ token values. If you need a function
+ that just compares the type of tokens, have a look at the <tt><ref
+ id=".MATCH" name=".MATCH"></tt> function.
+ See: <tt><ref id=".MATCH" name=".MATCH"></tt>
-<sect>Control commands<label id="control-commands">
+<sect>Control commands<label id="control-commands"><p>
-<p>
Here's a list of all control commands and a description, what they do:
</verb></tscreen>
-<sect1><tt>.BLANK</tt><label id=".BLANK"><p>
-
- Builtin function. The function evaluates its argument in braces and
- yields "false" if the argument is non blank (there is an argument), and
- "true" if there is no argument. As an example, the <tt/.IFBLANK/ statement
- may be replaced by
-
- <tscreen><verb>
- .if .blank(arg)
- </verb></tscreen>
-
-
<sect1><tt>.BSS</tt><label id=".BSS"><p>
Switch to the BSS segment. The name of the BSS segment is always "BSS",
feature in more detail.
-<sect1><tt>.CONCAT</tt><label id=".CONCAT"><p>
-
- Builtin function. The function allows to concatenate a list of string
- constants separated by commas. The result is a string constant that
- is the concatentation of all arguments. This function is most useful
- in macros and when used together with the <tt/.STRING/ builtin function.
- The function may be used in any case where a string constant is
- expected.
-
- Example:
-
- <tscreen><verb>
- .include .concat ("myheader", ".", "inc")
- </verb></tscreen>
-
- This is the same as the command
-
- <tscreen><verb>
- .include "myheader.inc"
- </verb></tscreen>
-
-
-<sect1><tt>.CONST</tt><label id=".CONST"><p>
-
- Builtin function. The function evaluates its argument in braces and
- yields "true" if the argument is a constant expression (that is, an
- expression that yields a constant value at assembly time) and "false"
- otherwise. As an example, the .IFCONST statement may be replaced by
-
- <tscreen><verb>
- .if .const(a + 3)
- </verb></tscreen>
-
-
<sect1><tt>.CONSTRUCTOR</tt><label id=".CONSTRUCTOR"><p>
Export a symbol and mark it as a module constructor. This may be used
feature in more detail.
-<sect1><tt>.CPU</tt><label id=".CPU"><p>
-
- Reading this pseudo variable will give a constant integer value that
- tells which CPU is currently enabled. It can also tell which instruction
- set the CPU is able to translate. The value read from the pseudo variable
- should be further examined by using one of the constants defined by the
- "cpu" macro package (see <tt/<ref id=".MACPACK" name=".MACPACK">/).
-
- It may be used to replace the .IFPxx pseudo instructions or to construct
- even more complex expressions.
-
- Example:
-
- <tscreen><verb>
- .macpack cpu
- .if (.cpu .bitand CPU_ISET_65816)
- phx
- phy
- .else
- txa
- pha
- tya
- pha
- .endif
- </verb></tscreen>
-
-
<sect1><tt>.DATA</tt><label id=".DATA"><p>
Switch to the DATA segment. The name of the DATA segment is always
<sect1><tt>.ENDSTRUCT</tt><label id=".ENDSTRUCT"><p>
- Ends a struct definition. See the section named <ref id="structs"
- name="Structs and unions">.
+ Ends a struct definition. See the <tt/<ref id=".STRUCT" name=".STRUCT">/
+ command and the separate section named <ref id="structs" name=""Structs
+ and unions"">.
<sect1><tt>.ENUM</tt><label id=".ENUM"><p>
</verb></tscreen>
-<sect1><tt>.LEFT</tt><label id=".LEFT"><p>
-
- Builtin function. Extracts the left part of a given token list.
-
- Syntax:
-
- <tscreen><verb>
- .LEFT (<int expr>, <token list>)
- </verb></tscreen>
-
- The first integer expression gives the number of tokens to extract from
- the token list. The second argument is the token list itself.
-
- Example:
-
- To check in a macro if the given argument has a '#' as first token
- (immidiate addressing mode), use something like this:
-
- <tscreen><verb>
- .macro ldax arg
- ...
- .if (.match (.left (1, arg), #))
-
- ; ldax called with immidiate operand
- ...
-
- .endif
- ...
- .endmacro
- </verb></tscreen>
-
- See also the <tt><ref id=".MID" name=".MID"></tt> and <tt><ref id=".RIGHT"
- name=".RIGHT"></tt> builtin functions.
-
-
<sect1><tt>.LINECONT</tt><label id=".LINECONT"><p>
Switch on or off line continuations using the backslash character
See section <ref id="macros" name="Macros">.
-<sect1><tt>.MATCH</tt><label id=".MATCH"><p>
-
- Builtin function. Matches two token lists against each other. This is
- most useful within macros, since macros are not stored as strings, but
- as lists of tokens.
-
- The syntax is
-
- <tscreen><verb>
- .MATCH(<token list #1>, <token list #2>)
- </verb></tscreen>
-
- Both token list may contain arbitrary tokens with the exception of the
- terminator token (comma resp. right parenthesis) and
-
- <itemize>
- <item>end-of-line
- <item>end-of-file
- </itemize>
-
- Often a macro parameter is used for any of the token lists.
-
- Please note that the function does only compare tokens, not token
- attributes. So any number is equal to any other number, regardless of the
- actual value. The same is true for strings. If you need to compare tokens
- <em/and/ token attributes, use the <tt><ref id=".XMATCH"
- name=".XMATCH"></tt> function.
-
- Example:
-
- Assume the macro <tt/ASR/, that will shift right the accumulator by one,
- while honoring the sign bit. The builtin processor instructions will allow
- an optional "A" for accu addressing for instructions like <tt/ROL/ and
- <tt/ROR/. We will use the <tt><ref id=".MATCH" name=".MATCH"></tt> function
- to check for this and print and error for invalid calls.
-
- <tscreen><verb>
- .macro asr arg
-
- .if (.not .blank(arg)) .and (.not .match (arg, a))
- .error "Syntax error"
- .endif
-
- cmp #$80 ; Bit 7 into carry
- lsr a ; Shift carry into bit 7
-
- .endmacro
- </verb></tscreen>
-
- The macro will only accept no arguments, or one argument that must be the
- reserved keyword "A".
-
- See: <tt><ref id=".XMATCH" name=".XMATCH"></tt>
-
-
-<sect1><tt>.MID</tt><label id=".MID"><p>
-
- Builtin function. Takes a starting index, a count and a token list as
- arguments. Will return part of the token list.
-
- Syntax:
-
- <tscreen><verb>
- .MID (<int expr>, <int expr>, <token list>)
- </verb></tscreen>
-
- The first integer expression gives the starting token in the list (the
- first token has index 0). The second integer expression gives the number
- of tokens to extract from the token list. The third argument is the
- token list itself.
-
- Example:
-
- To check in a macro if the given argument has a '<tt/#/' as first token
- (immidiate addressing mode), use something like this:
-
- <tscreen><verb>
- .macro ldax arg
- ...
- .if (.match (.mid (0, 1, arg), #))
-
- ; ldax called with immidiate operand
- ...
-
- .endif
- ...
- .endmacro
- </verb></tscreen>
-
- See also the <tt><ref id=".LEFT" name=".LEFT"></tt> and <tt><ref id=".RIGHT"
- name=".RIGHT"></tt> builtin functions.
-
-
<sect1><tt>.ORG</tt><label id=".ORG"><p>
Start a section of absolute code. The command is followed by a constant
</verb></tscreen>
-<sect1><tt>.PARAMCOUNT</tt><label id=".PARAMCOUNT"><p>
-
- This builtin pseudo variable is only available in macros. It is replaced by
- the actual number of parameters that were given in the macro invocation.
-
- Example:
-
- <tscreen><verb>
- .macro foo arg1, arg2, arg3
- .if .paramcount <> 3
- .error "Too few parameters for macro foo"
- .endif
- ...
- .endmacro
- </verb></tscreen>
-
- See section <ref id="macros" name="Macros">.
-
-
<sect1><tt>.PC02</tt><label id=".PC02"><p>
Enable the 65C02 instructions set. This instruction set includes all
See: <tt><ref id=".POPSEG" name=".POPSEG"></tt>
-<sect1><tt>.REF, .REFERENCED</tt><label id=".REFERENCED"><p>
-
- Builtin function. The function expects an identifier as argument in braces.
- The argument is evaluated, and the function yields "true" if the identifier
- is a symbol that has already been referenced somewhere in the source file up
- to the current position. Otherwise the function yields false. As an example,
- the <tt><ref id=".IFREF" name=".IFREF"></tt> statement may be replaced by
-
- <tscreen><verb>
- .if .referenced(a)
- </verb></tscreen>
-
- See: <tt><ref id=".DEFINED" name=".DEFINED"></tt>
-
-
<sect1><tt>.REPEAT</tt><label id=".REPEAT"><p>
Repeat all commands between <tt/.REPEAT/ and <tt><ref id=".ENDREPEAT"
</verb></tscreen>
-<sect1><tt>.RIGHT</tt><label id=".RIGHT"><p>
-
- Builtin function. Extracts the right part of a given token list.
-
- Syntax:
-
- <tscreen><verb>
- .RIGHT (<int expr>, <token list>)
- </verb></tscreen>
-
- The first integer expression gives the number of tokens to extract from
- the token list. The second argument is the token list itself.
-
- See also the <tt><ref id=".LEFT" name=".LEFT"></tt> and <tt><ref id=".MID"
- name=".MID"></tt> builtin functions.
-
-
<sect1><tt>.RODATA</tt><label id=".RODATA"><p>
Switch to the RODATA segment. The name of the RODATA segment is always
<tt><ref id=".PSC02" name=".PSC02"></tt>
-<sect1><tt>.SIZEOF</tt><label id=".SIZEOF"><p>
-
- <tt/.SIZEOF/ is a pseudo function that returns the size of its argument. The
- argument can be a struct/union, a struct member, a procedure, or a label. In
- case of a procedure or label, its size is defined by the amount of data
- placed in the segment where the label is relative to. If a line of code
- switches segments (for example in a macro) data placed in other segments
- does not count for the size.
-
- Please note that a symbol or scope must exist, before it is used together with
- <tt/.SIZEOF/ (this may get relaxed later, but will always be true for scopes).
- A scope has preference over a symbol with the same name, so if the last part
- of a name represents both, a scope and a symbol, the scope is choosen over the
- symbol.
-
- After the following code:
-
- <tscreen><verb>
- .struct Point ; Struct size = 4
- xcoord .word
- xcoord .word
- .endstruct
-
- P: .tag Point ; Declare a point
- @P: .tag Point ; Declare another point
-
- .code
- .proc Code
- nop
- .proc Inner
- nop
- .endproc
- nop
- .endproc
-
- .proc Data
- .data ; Segment switch!!!
- .res 4
- .endproc
- </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>
Switch on or off smart mode. The command must be followed by a '+' or
<tt><ref id=".I8" name=".I8"></tt>
-<sect1><tt>.STRAT</tt><label id=".STRAT"><p>
-
- Builtin function. The function accepts a string and an index as
- arguments and returns the value of the character at the given position
- as an integer value. The index is zero based.
-
- Example:
-
- <tscreen><verb>
- .macro M Arg
- ; Check if the argument string starts with '#'
- .if (.strat (Arg, 0) = '#')
- ...
- .endif
- .endmacro
- </verb></tscreen>
-
-
-<sect1><tt>.STRING</tt><label id=".STRING"><p>
-
- Builtin function. The function accepts an argument in braces and converts
- this argument into a string constant. The argument may be an identifier, or
- a constant numeric value.
-
- Since you can use a string in the first place, the use of the function may
- not be obvious. However, it is useful in macros, or more complex setups.
-
- Example:
-
- <tscreen><verb>
- ; Emulate other assemblers:
- .macro section name
- .segment .string(name)
- .endmacro
- </verb></tscreen>
-
-
-<sect1><tt>.STRLEN</tt><label id=".STRLEN"><p>
-
- Builtin function. The function accepts a string argument in braces and
- eveluates to the length of the string.
-
- Example:
-
- The following macro encodes a string as a pascal style string with
- a leading length byte.
-
- <tscreen><verb>
- .macro PString Arg
- .byte .strlen(Arg), Arg
- .endmacro
- </verb></tscreen>
-
-
<sect1><tt>.STRUCT</tt><label id=".STRUCT"><p>
- Starts a struct definition. See the section named <ref id="structs"
- name="Structs and unions">.
+ Starts a struct definition. Structs are covered in a separate section named
+ <ref id="structs" name=""Structs and unions"">.
+
+ See: <tt><ref id=".ENDSTRUCT" name=".ENDSTRUCT"></tt>
<sect1><tt>.SUNPLUS</tt><label id=".SUNPLUS"><p>
</verb></tscreen>
-<sect1><tt>.TCOUNT</tt><label id=".TCOUNT"><p>
-
- Builtin function. The function accepts a token list in braces. The
- function result is the number of tokens given as argument.
-
- Example:
-
- The <tt/ldax/ macro accepts the '#' token to denote immidiate addressing (as
- with the normal 6502 instructions). To translate it into two separate 8 bit
- load instructions, the '#' token has to get stripped from the argument:
-
- <tscreen><verb>
- .macro ldax arg
- .if (.match (.mid (0, 1, arg), #))
- ; ldax called with immidiate operand
- lda #<(.right (.tcount (arg)-1, arg))
- ldx #>(.right (.tcount (arg)-1, arg))
- .else
- ...
- .endif
- .endmacro
- </verb></tscreen>
-
-
-<sect1><tt>.TIME</tt><label id=".TIME"><p>
-
- Reading this pseudo variable will give a constant integer value that
- represents the current time in POSIX standard (as seconds since the
- Epoch).
-
- It may be used to encode the time of translation somewhere in the created
- code.
-
- Example:
-
- <tscreen><verb>
- .dword .time ; Place time here
- </verb></tscreen>
-
-
-<sect1><tt>.VERSION</tt><label id=".VERSION"><p>
-
- Reading this pseudo variable will give the assembler version according to
- the following formula:
-
- VER_MAJOR*$100 + VER_MINOR*$10 + VER_PATCH
-
- It may be used to encode the assembler version or check the assembler for
- special features not available with older versions.
-
- Example:
-
- Version 2.11.1 of the assembler will return $2B1 as numerical constant when
- reading the pseudo variable <tt/.VERSION/.
-
-
<sect1><tt>.WARNING</tt><label id=".WARNING"><p>
Force an assembly warning. The assembler will output a warning message
</verb></tscreen>
-<sect1><tt>.XMATCH</tt><label id=".XMATCH"><p>
-
- Builtin function. Matches two token lists against each other. This is
- most useful within macros, since macros are not stored as strings, but
- as lists of tokens.
-
- The syntax is
-
- <tscreen><verb>
- .XMATCH(<token list #1>, <token list #2>)
- </verb></tscreen>
-
- Both token list may contain arbitrary tokens with the exception of the
- terminator token (comma resp. right parenthesis) and
-
- <itemize>
- <item>end-of-line
- <item>end-of-file
- </itemize>
-
- Often a macro parameter is used for any of the token lists.
-
- The function compares tokens <em/and/ token values. If you need a function
- that just compares the type of tokens, have a look at the <tt><ref
- id=".MATCH" name=".MATCH"></tt> function.
-
- See: <tt><ref id=".MATCH" name=".MATCH"></tt>
-
-
<sect1><tt>.ZEROPAGE</tt><label id=".ZEROPAGE"><p>
Switch to the ZEROPAGE segment and mark it as direct (zeropage) segment.
Structs and unions are special forms of <ref id="scopes" name="scopes">. They
are to some degree comparable to their C counterparts. Both have a list of
members. Each member allocates storage and may optionally have a name, which,
-in case of a struct, is the offset from the beginning and, in case of a union
+in case of a struct, is the offset from the beginning and, in case of a union,
is always zero.
Here is an example for a very simple struct with two members and a total size
.struct Circle
Origin .tag Point
- Radius .word
+ Radius .byte
.endstruct
</verb></tscreen>
Space for a struct or union may be allocated using the <ref id=".TAG"
name=".TAG"> directive.
+<tscreen><verb>
+ C: .tag Circle
+</verb></tscreen>
+
+Currently, members are just offsets from the start of the struct or union. To
+access a field of a struct, the member offset has to be added to the address
+of the struct itself:
+
+<tscreen><verb>
+ lda C+Circle::Radius ; Load circle radius into A
+</verb></tscreen>
+
+This may change in a future version of the assembler.
<sect>Module constructors/destructors<label id="condes"><p>
projects / cc65 / commitdiff