Udon Extended Assembly

This project adds the ability to construct and fill the heap from UASM alone through the use of a preprocessor.

How to use:

Drop the folder ExtendedUASM into \Assets\Udon\Editor

Then right click, Create->VRChat->Udon->Extended Udon Assembly Program Asset

Add that new file to the "Program Source" slot on a UdonBehaviour

Paste your UASM code in the Assembly Code box.

Alternativly you can create a .euasm file and it will be automatically turned into an EUASM asset. This allows you to edit the source code inside any editor you want.

What does Udon Extended Assembly add?

By adding comments to the top of the uasm source code, you can construct types at compile time.

Example:

#.INIT_START
#PUSH SystemSingle 1
#PUSH SystemSingle 5
#CONSTRUCT UnityEngineVector2 2
#SETHEAP "test"
#PUSH SystemString "This should work"
#SETHEAP "str"
#.INIT_END
.data_start
	test: %UnityEngineVector2, null
	str: %SystemString, null
.data_end

.code_start
    .export _start
    
    _start:
        PUSH, test
        EXTERN, "UnityEngineDebug.__Log__SystemObject__SystemVoid"
	PUSH, str
        EXTERN, "UnityEngineDebug.__Log__SystemObject__SystemVoid"
        JUMP, 0xFFFFFF
.code_end

Above you can see comments which look very similar to udon assembly. Don't worry there's only 5 instructions.

PUSH

• Usage: #PUSH TypeName LiteralValue. Example: #PUSH SystemString "This is a string" #PUSH SystemSingle 123.456
• Supported literals that can be pushed include SystemSingle, SystemDouble, SystemInt64, SystemInt32, SystemInt16, SystemUInt64, SystemUInt32, SystemUInt16, SystemString, SystemBoolean, SystemChar, SystemByte, SystemSByte, and SystemType
• Strings should look like 'PUSH SystemString "This is a string"'

PUSHENUM

• Usage: #PUSHENUM TypeName EnumValueName. Example: #PUSHENUM UnityEngineFFTWindow Hamming
• Attempts to find the enum value EnumValueName in the type TypeName

PUSHLABEL

• Usage: #PUSHLABEL "LabelName". Example: #PUSHENUM "testing"
• Finds the label LabelName and pushes the address of that label onto the stack as a SystemUInt32

CONSTRUCT

• Usage: #CONSTRUCT TypeName ArgCount. Example: #CONSTRUCT UnityEngineVector2 2
• Pops ArgCount arguments off the stack and attempts to construct the type TypeName with those arguments. It will attempt to call the constructor that the arguments fit into. The result is automatically pushed back onto the stack.

SETHEAP

• Usage: #SETHEAP "variableName". Example: #SETHEAP "test"
• Finds the variable named variableName in the assmebly and sets the value of that variable on the heap to the first object on the stack which is popped off.

Comments start with #//

Place any of these instructions in between #.INIT_START and #.INIT_END at the top of the file.