<article>
<title>ca65 Users Guide
-<author><url url="mailto:uz@cc65.org" name="Ullrich von Bassewitz">
-<date>2015-08-01
+<author><url url="mailto:uz@cc65.org" name="Ullrich von Bassewitz">,<newline>
+<url url="mailto:greg.king5@verizon.net" name="Greg King">
+<date>2015-11-17
<abstract>
ca65 is a powerful macro assembler for the 6502, 65C02, and 65816 CPUs. It is
<sect1><tt>.ADDRSIZE</tt><label id=".ADDRSIZE"><p>
- The <tt/.ADDRSIZE/ function is used to return the interal address size
- associated with a symbol. This can be helpful in macros when knowing the address
+ The <tt/.ADDRSIZE/ function is used to return the interal address size
+ associated with a symbol. This can be helpful in macros when knowing the address
size of symbol can help with custom instructions.
Example:
<sect1><tt>.DEFINEDMACRO</tt><label id=".DEFINEDMACRO"><p>
Builtin function. The function expects an identifier as argument in braces.
- The argument is evaluated, and the function yields "true" if the identifier
- has already been defined as the name of a macro. Otherwise the function yields
+ The argument is evaluated, and the function yields "true" if the identifier
+ has already been defined as the name of a macro. Otherwise the function yields
false. Example:
<tscreen><verb>
clc
adc foo
.endmacro
-
+
.if .definedmacro(add)
add #$01
.else
example:
<tscreen><verb>
- .macro asr ; Arithmetic shift right
- cmp #$80 ; Put bit 7 into carry
- ror ; Rotate right with carry
- .endmacro
+.macro asr ; Arithmetic shift right
+ cmp #$80 ; Put bit 7 into carry
+ ror ; Rotate right with carry
+.endmacro
</verb></tscreen>
The macro above consists of two real instructions, that are inserted into
by using the name, like this:
<tscreen><verb>
- lda $2010
- asr
- sta $2010
+ lda $2010
+ asr
+ sta $2010
</verb></tscreen>
When using macro parameters, macros can be even more useful:
<tscreen><verb>
- .macro inc16 addr
- clc
- lda addr
- adc #$01
- sta addr
- lda addr+1
- adc #$00
- sta addr+1
- .endmacro
+.macro inc16 addr
+ clc
+ lda addr
+ adc #<$0001
+ sta addr
+ lda addr+1
+ adc #>$0001
+ sta addr+1
+.endmacro
</verb></tscreen>
When calling the macro, you may give a parameter, and each occurrence of
parameter. So
<tscreen><verb>
- inc16 $1000
+ inc16 $1000
</verb></tscreen>
will be expanded to
<tscreen><verb>
- clc
- lda $1000
- adc #$01
- sta $1000
- lda $1000+1
- adc #$00
- sta $1000+1
+ clc
+ lda $1000
+ adc #<$0001
+ sta $1000
+ lda $1000+1
+ adc #>$0001
+ sta $1000+1
</verb></tscreen>
A macro may have more than one parameter, in this case, the parameters
Look at this example:
<tscreen><verb>
- .macro ldaxy a, x, y
- .ifnblank a
- lda #a
- .endif
- .ifnblank x
- ldx #x
- .endif
- .ifnblank y
- ldy #y
- .endif
- .endmacro
+.macro ldaxy a, x, y
+.ifnblank a
+ lda #a
+.endif
+.ifnblank x
+ ldx #x
+.endif
+.ifnblank y
+ ldy #y
+.endif
+.endmacro
</verb></tscreen>
-This macro may be called as follows:
+That macro may be called as follows:
<tscreen><verb>
- ldaxy 1, 2, 3 ; Load all three registers
+ ldaxy 1, 2, 3 ; Load all three registers
- ldaxy 1, , 3 ; Load only a and y
+ ldaxy 1, , 3 ; Load only a and y
- ldaxy , , 3 ; Load y only
+ ldaxy , , 3 ; Load y only
</verb></tscreen>
-There's another helper command for determining, which macro parameters are
-valid: <tt><ref id=".PARAMCOUNT" name=".PARAMCOUNT"></tt> This command is
-replaced by the parameter count given, <em/including/ intermediate empty macro
+There's another helper command for determining which macro parameters are
+valid: <tt><ref id=".PARAMCOUNT" name=".PARAMCOUNT"></tt>. That command is
+replaced by the parameter count given, <em/including/ explicitly empty
parameters:
<tscreen><verb>
- ldaxy 1 ; .PARAMCOUNT = 1
- ldaxy 1,,3 ; .PARAMCOUNT = 3
- ldaxy 1,2 ; .PARAMCOUNT = 2
- ldaxy 1, ; .PARAMCOUNT = 2
- ldaxy 1,2,3 ; .PARAMCOUNT = 3
+ ldaxy 1 ; .PARAMCOUNT = 1
+ ldaxy 1,,3 ; .PARAMCOUNT = 3
+ ldaxy 1,2 ; .PARAMCOUNT = 2
+ ldaxy 1, ; .PARAMCOUNT = 2
+ ldaxy 1,2,3 ; .PARAMCOUNT = 3
</verb></tscreen>
Macro parameters may optionally be enclosed into curly braces. This allows the
case of a macro parameter).
<tscreen><verb>
- .macro foo arg1, arg2
- ...
- .endmacro
+.macro foo arg1, arg2
+ ...
+.endmacro
- foo ($00,x) ; Two parameters passed
- foo {($00,x)} ; One parameter passed
+ foo ($00,x) ; Two parameters passed
+ foo {($00,x)} ; One parameter passed
</verb></tscreen>
In the first case, the macro is called with two parameters: '<tt/($00/'
-and 'x)'. The comma is not passed to the macro, since it is part of the
+and '<tt/x)/'. The comma is not passed to the macro, because it is part of the
calling sequence, not the parameters.
-In the second case, '($00,x)' is passed to the macro, this time
+In the second case, '<tt/($00,x)/' is passed to the macro; this time,
including the comma.
functions will allow you to do exactly this:
<tscreen><verb>
- .macro ldax arg
- .if (.match (.left (1, {arg}), #))
- ; immediate mode
- lda #<(.right (.tcount ({arg})-1, {arg}))
- ldx #>(.right (.tcount ({arg})-1, {arg}))
- .else
- ; assume absolute or zero page
- lda arg
- ldx 1+(arg)
- .endif
- .endmacro
+.macro ldax arg
+ .if (.match (.left (1, {arg}), #))
+ ; immediate mode
+ lda #<(.right (.tcount ({arg})-1, {arg}))
+ ldx #>(.right (.tcount ({arg})-1, {arg}))
+ .else
+ ; assume absolute or zero page
+ lda arg
+ ldx 1+(arg)
+ .endif
+.endmacro
</verb></tscreen>
Using the <tt/<ref id=".MATCH" name=".MATCH">/ function, the macro is able to
The macro can be used as
<tscreen><verb>
- foo: .word $5678
- ...
- ldax #$1234 ; X=$12, A=$34
- ...
- ldax foo ; X=$56, A=$78
+foo: .word $5678
+...
+ ldax #$1234 ; X=$12, A=$34
+...
+ ldax foo ; X=$56, A=$78
</verb></tscreen>
Macros may be used recursively:
<tscreen><verb>
- .macro push r1, r2, r3
- lda r1
- pha
- .if .paramcount > 1
- push r2, r3
- .endif
- .endmacro
+.macro push r1, r2, r3
+ lda r1
+ pha
+.ifnblank r2
+ push r2, r3
+.endif
+.endmacro
</verb></tscreen>
-There's also a special macro to help writing recursive macros: <tt><ref
-id=".EXITMACRO" name=".EXITMACRO"></tt> This command will stop macro expansion
-immediately:
+There's also a special macro command to help with writing recursive macros:
+<tt><ref id=".EXITMACRO" name=".EXITMACRO"></tt>. That command will stop macro
+expansion immediately:
<tscreen><verb>
- .macro push r1, r2, r3, r4, r5, r6, r7
- .ifblank r1
- ; First parameter is empty
- .exitmacro
- .else
- lda r1
- pha
- .endif
- push r2, r3, r4, r5, r6, r7
- .endmacro
+.macro push r1, r2, r3, r4, r5, r6, r7
+.ifblank r1
+ ; First parameter is empty
+ .exitmacro
+.else
+ lda r1
+ pha
+.endif
+ push r2, r3, r4, r5, r6, r7
+.endmacro
</verb></tscreen>
-When expanding this macro, the expansion will push all given parameters
+When expanding that macro, the expansion will push all given parameters
until an empty one is encountered. The macro may be called like this:
<tscreen><verb>
- push $20, $21, $32 ; Push 3 ZP locations
- push $21 ; Push one ZP location
+ push $20, $21, $32 ; Push 3 ZP locations
+ push $21 ; Push one ZP location
</verb></tscreen>
Have a look at the inc16 macro above. Here is it again:
<tscreen><verb>
- .macro inc16 addr
- clc
- lda addr
- adc #$01
- sta addr
- lda addr+1
- adc #$00
- sta addr+1
- .endmacro
+.macro inc16 addr
+ clc
+ lda addr
+ adc #<$0001
+ sta addr
+ lda addr+1
+ adc #>$0001
+ sta addr+1
+.endmacro
</verb></tscreen>
If you have a closer look at the code, you will notice, that it could be
written more efficiently, like this:
<tscreen><verb>
- .macro inc16 addr
- inc addr
- bne Skip
- inc addr+1
- Skip:
- .endmacro
+.macro inc16 addr
+ inc addr
+ bne Skip
+ inc addr+1
+Skip:
+.endmacro
</verb></tscreen>
But imagine what happens, if you use this macro twice? Since the label "Skip"
expansion. So we can solve the problem above by using <tt/.LOCAL/:
<tscreen><verb>
- .macro inc16 addr
- .local Skip ; Make Skip a local symbol
- inc addr
- bne Skip
- inc addr+1
- Skip: ; Not visible outside
- .endmacro
+.macro inc16 addr
+ .local Skip ; Make Skip a local symbol
+ inc addr
+ bne Skip
+ inc addr+1
+Skip: ; Not visible outside
+.endmacro
</verb></tscreen>
Another solution is of course to start a new lexical block inside the macro
that hides any labels:
<tscreen><verb>
- .macro inc16 addr
- .proc
- inc addr
- bne Skip
- inc addr+1
- Skip:
- .endproc
- .endmacro
+.macro inc16 addr
+.proc
+ inc addr
+ bne Skip
+ inc addr+1
+Skip:
+.endproc
+.endmacro
</verb></tscreen>
be omitted.
<item> Since <tt><ref id=".DEFINE" name=".DEFINE"></tt> style macros may not
- contain end-of-line tokens, there are things that cannot be done. They
+ contain end-of-line tokens, there are things that cannot be done. They
may not contain several processor instructions for example. So, while
some things may be done with both macro types, each type has special
usages. The types complement each other.
following <tt/.DEFINE/:
<tscreen><verb>
- .define EQU =
+.define EQU =
- foo EQU $1234 ; This is accepted now
+foo EQU $1234 ; This is accepted now
</verb></tscreen>
You may use the directive to define string constants used elsewhere:
<tscreen><verb>
- ; Define the version number
- .define VERSION "12.3a"
+; Define the version number
+.define VERSION "12.3a"
- ; ... and use it
- .asciiz VERSION
+ ; ... and use it
+ .asciiz VERSION
</verb></tscreen>
Macros with parameters may also be useful:
<tscreen><verb>
- .define DEBUG(message) .out message
+.define DEBUG(message) .out message
- DEBUG "Assembling include file #3"
+ DEBUG "Assembling include file #3"
</verb></tscreen>
Note that, while formal parameters have to be placed in braces, this is
don't like that, use classic macros instead:
<tscreen><verb>
- .macro DEBUG message
- .out message
- .endmacro
+.macro DEBUG message
+ .out message
+.endmacro
</verb></tscreen>
-(This is an example where a problem can be solved with both macro types).
+(That is an example where a problem can be solved with both macro types).
<sect1>Characters in macros<p>
<sect1>Deleting macros<p>
Macros can be deleted. This will not work if the macro that should be deleted
-is currently expanded as in the following non working example:
+is currently expanded as in the following non-working example:
<tscreen><verb>
- .macro notworking
- .delmacro notworking
- .endmacro
+.macro notworking
+ .delmacro notworking
+.endmacro
notworking ; Will not work
</verb></tscreen>
id=".UNDEFINE" name=".UNDEFINE"></tt> must be used. Example:
<tscreen><verb>
- .define value 1
- .macro mac
- .byte 2
- .endmacro
+.define value 1
+.macro mac
+ .byte 2
+.endmacro
- .byte value ; Emit one byte with value 1
- mac ; Emit another byte with value 2
+ .byte value ; Emit one byte with value 1
+ mac ; Emit another byte with value 2
- .undefine value
- .delmacro mac
+.undefine value
+.delmacro mac
- .byte value ; Error: Unknown identifier
- mac ; Error: Missing ":"
+ .byte value ; Error: Unknown identifier
+ mac ; Error: Missing ":"
</verb></tscreen>
A separate command for <tt>.DEFINE</tt> style macros was necessary, because
different commands increases flexibility.
+
<sect>Macro packages<label id="macropackages"><p>
Using the <tt><ref id=".MACPACK" name=".MACPACK"></tt> directive, predefined
instruction is supported, which is the case for the 65SC02, 65C02 and 65816
CPUs (the latter two are upwards compatible to the 65SC02).
-
+
<sect1><tt>.MACPACK module</tt><p>
This macro package defines a macro named <tt/module_header/. It takes an
</article>
-
-
-
/* Counter to create local names for symbols */
static unsigned LocalName = 0;
-/* Define style macros disabled if != 0 */
+/* Define-style macros disabled if != 0 */
static unsigned DisableDefines = 0;
EnterRawTokenMode ();
NextTok ();
- /* If we have a DEFINE style macro, we may have parameters in braces,
- ** otherwise we may have parameters without braces.
+ /* If we have a DEFINE-style macro, we may have parameters in parentheses;
+ ** otherwise, we may have parameters without parentheses.
*/
if (Style == MAC_STYLE_CLASSIC) {
HaveParams = 1;
}
}
- /* For class macros, we expect a separator token, for define style macros,
+ /* For classic macros, we expect a separator token, for define-style macros,
** we expect the closing paren.
*/
if (Style == MAC_STYLE_CLASSIC) {
}
/* Preparse the macro body. We will read the tokens until we reach end of
- ** file, or a .endmacro (or end of line for DEFINE style macros) and store
- ** them into an token list internal to the macro. For classic macros, there
- ** the .LOCAL command is detected and removed at this time.
+ ** file, or a .endmacro (or end of line for DEFINE-style macros) and store
+ ** them into a token list internal to the macro. For classic macros,
+ ** the .LOCAL command is detected and removed, at this time.
*/
while (1) {
FreeTokNode (Mac->Final);
Mac->Final = 0;
- /* Problem: When a .define style macro is expanded within the call
+ /* Problem: When a .define-style macro is expanded within the call
** of a classic one, the latter may be terminated and removed while
- ** the expansion of the .define style macro is still active. Because
+ ** the expansion of the .define-style macro is still active. Because
** line info slots are "stacked", this runs into a CHECK FAILED. For
- ** now, we will fix that by removing the .define style macro expansion
+ ** now, we will fix that by removing the .define-style macro expansion
** immediately, once the final token is placed. The better solution
** would probably be to not require AllocLineInfoSlot/FreeLineInfoSlot
** to be called in FIFO order, but this is a bigger change.
static void StartExpClassic (MacExp* E)
/* Start expanding a classic macro */
{
- token_t Term;
+ token_t Term;
/* Skip the macro name */
NextTok ();
- /* Read the actual parameters */
- while (!TokIsSep (CurTok.Tok)) {
+ /* Does this invocation have any arguments? */
+ if (!TokIsSep (CurTok.Tok)) {
- TokNode* Last;
+ /* Read the actual parameters */
+ while (1) {
+ TokNode* Last;
- /* Check for maximum parameter count */
- if (E->ParamCount >= E->M->ParamCount) {
- ErrorSkip ("Too many macro parameters");
- break;
- }
+ /* Check for maximum parameter count */
+ if (E->ParamCount >= E->M->ParamCount) {
+ ErrorSkip ("Too many macro parameters");
+ break;
+ }
- /* The macro may optionally be enclosed in curly braces */
- Term = GetTokListTerm (TOK_COMMA);
+ /* The macro argument optionally may be enclosed in curly braces */
+ Term = GetTokListTerm (TOK_COMMA);
- /* Read tokens for one parameter, accept empty params */
- Last = 0;
- while (CurTok.Tok != Term && CurTok.Tok != TOK_SEP) {
+ /* Read tokens for one parameter, accept empty params */
+ Last = 0;
+ while (CurTok.Tok != Term && CurTok.Tok != TOK_SEP) {
+ TokNode* T;
- TokNode* T;
+ /* Check for end of file */
+ if (CurTok.Tok == TOK_EOF) {
+ Error ("Unexpected end of file");
+ FreeMacExp (E);
+ return;
+ }
- /* Check for end of file */
- if (CurTok.Tok == TOK_EOF) {
- Error ("Unexpected end of file");
- FreeMacExp (E);
- return;
- }
+ /* Get the next token in a node */
+ T = NewTokNode ();
- /* Get the next token in a node */
- T = NewTokNode ();
+ /* Insert it into the list */
+ if (Last == 0) {
+ E->Params [E->ParamCount] = T;
+ } else {
+ Last->Next = T;
+ }
+ Last = T;
- /* Insert it into the list */
- if (Last == 0) {
- E->Params [E->ParamCount] = T;
- } else {
- Last->Next = T;
+ /* And skip it... */
+ NextTok ();
}
- Last = T;
- /* And skip it... */
- NextTok ();
- }
+ /* One parameter more */
+ ++E->ParamCount;
- /* One parameter more */
- ++E->ParamCount;
+ /* If the macro argument was enclosed in curly braces, end-of-line
+ ** is an error. Skip the closing curly brace.
+ */
+ if (Term == TOK_RCURLY) {
+ if (CurTok.Tok == TOK_SEP) {
+ Error ("End of line encountered within macro argument");
+ break;
+ }
+ NextTok ();
+ }
- /* If the macro argument was enclosed in curly braces, end-of-line
- ** is an error. Skip the closing curly brace.
- */
- if (Term == TOK_RCURLY) {
- if (CurTok.Tok == TOK_SEP) {
- Error ("End of line encountered within macro argument");
+ /* Check for a comma */
+ if (CurTok.Tok == TOK_COMMA) {
+ NextTok ();
+ } else {
break;
}
- NextTok ();
- }
-
- /* Check for a comma */
- if (CurTok.Tok == TOK_COMMA) {
- NextTok ();
- } else {
- break;
}
}
static void StartExpDefine (MacExp* E)
-/* Start expanding a DEFINE style macro */
+/* Start expanding a DEFINE-style macro */
{
- /* A define style macro must be called with as many actual parameters
+ /* A define-style macro must be called with as many actual parameters
** as there are formal ones. Get the parameter count.
*/
unsigned Count = E->M->ParamCount;
/* Read the actual parameters */
while (Count--) {
+ TokNode* Last;
- TokNode* Last;
-
- /* The macro may optionally be enclosed in curly braces */
+ /* The macro argument optionally may be enclosed in curly braces */
token_t Term = GetTokListTerm (TOK_COMMA);
/* Check if there is really a parameter */
/* Read tokens for one parameter */
Last = 0;
do {
-
TokNode* T;
/* Get the next token in a node */
}
/* Macro expansion will overwrite the current token. This is a problem
- ** for define style macros since these are called from the scanner level.
+ ** for define-style macros since these are called from the scanner level.
** To avoid it, remember the current token and re-insert it, once macro
** expansion is done.
*/
Macro* FindDefine (const StrBuf* Name)
-/* Try to find the define style macro with the given name and return it. If no
-** such macro was found, return NULL.
+/* Try to find the define-style macro with the given name; and, return it.
+** If no such macro was found, return NULL.
*/
{
Macro* M;
void DisableDefineStyleMacros (void)
-/* Disable define style macros until EnableDefineStyleMacros is called */
+/* Disable define-style macros until EnableDefineStyleMacros() is called */
{
++DisableDefines;
}
void EnableDefineStyleMacros (void)
-/* Re-enable define style macros previously disabled with
-** DisableDefineStyleMacros.
+/* Re-enable define-style macros previously disabled with
+** DisableDefineStyleMacros().
*/
{
PRECONDITION (DisableDefines > 0);
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