VASM - Question on conditional assembly

[RoC]

Good Sunday!

I have been trying to compile in VASM 1.9d the Blueberry's DemoStartup.s with the additional Lemon changes from the ExampleDemo of https://aminet.net/package/dev/cross...DemoToolchain5

I know this is supposed to work as such in VASM, but I am not sure whether this is true because the VASM returns errors on the IFs.

The DemoStartup.s relies on a number of conditional IFs. According to my noob reading of the VASM/MOT docs, "IF" should be able to conditionally assemble when the following lines are non-zero. So I tried to use the IFC, IFEQ, IFNE and IFGT to adjust them. The constats are defined in the main demo.s file and not in this included startup one - e.g. COMPATIBILITY and others.

I list a single instance of each of them to check whether these changes are needed or possible (coudn't find examples of ifc applied, so hope that syntax would be okay)

• There are many "if COMPATIBILITY=1" or other values. Changed them to "ifc COMPATIBILITY,1" or the relevant value
• There are "if MUSICPLAYER=0||MUSICPLAYER=2". I have changed it into "ifc MUSICPLAYER,0||MUSICPLAYER,2"
• "if MUSICPLAYERUSEVBLANK>=1" has been changed into "ifgt MUSICPLAYERUSEVBLANK"
• I could have changed "if MUSICPLAYERUSEVBLANK<>1" to "ifc MUSICPLAYERUSEVBLANK,0||MUSICPLAYERUSEVBLANK,2" but eventually I have cheated and changed the digit order (also for the IFGT cases..)
• "if COMPATIBILITY<2" changed to "ifc COMPATIBILITY,0||COMPATIBILITY,1"
• "if MUSICPLAYER=1 && MUSICPLAYERUSEVBLANK=2" changed to "ifc MUSICPLAYER,1 && MUSICPLAYERUSEVBLANK,2"

It might well possibile that this is not required altogether, so bear with me if the question is a little stupid. The modified compiles without errors, but it is not actually working because the object file does not include the selected music player and binary

For the ease of reference, please find the original demostartup.s and the changed one.

Thank you in advance for any info you could be able to share

[phx]

Originally Posted by RoC

I know this is supposed to work as such in VASM, but I am not sure whether this is true because the VASM returns errors on the IFs.

The errors tell you

expression must be constant

, because the symbols you are using are nowhere defined. So they cannot be evaluated.

According to my noob reading of the VASM/MOT docs, "IF" should be able to conditionally assemble when the following lines are non-zero.

Not the following lines, but the expression in the

IF

directive's operand field.

So I tried to use the IFC, IFEQ, IFNE and IFGT to adjust them.

Doesn't make sense.

IFC

compares strings and doesn't evaluate symbols.

IFNE

is the same as

IF

.

The constats are defined in the main demo.s file and not in this included startup one - e.g. COMPATIBILITY and others.

You need to define them. Otherwise you cannot assemble the startup source alone.

The modified compiles without errors

I get the same errors, except for

IFC

, which simply doesn't work the way you think.

IFC

is mostly used for checking whether a macro argument was empty. For example:

        ifc     "\1",""
        ...argument missing...
        endc

[a/b]

I prefer IFB/IFNB for that (blank, not blank), and IFC for straight up string compares. Just make sure you don't have a trailing comment, if could be interpreted as it's not blank and the expression is always true.

[RoC]

@phx and @a/b

I feared I was doing something wonky and indeed I did :-)

I must have completely misunderstood the if and thanks for bringing me on the right track.

I resume from the original ;-)