Hey, danhedron of OpenRW noticed that one of the commands had confusing descriptions.

Affected GTA III version
Affected GTA VC version

The XML portion in question is

        <Arg Type="INT" Desc="Ped type" Entity="CAR"/>
        <Arg Type="INT" Desc="Model ID" Enum="PEDTYPE"/>
        <Arg Type="INT" Desc="Car/vehicle" Enum="CARPEDMODEL"/>

where a mismatch between Desc and Entity / Enum occurs.

        <Arg Type="INT" Desc="Car/vehicle type" Entity="CAR"/>
        <Arg Type="INT" Desc="Ped" Enum="PEDTYPE"/>
        <Arg Type="INT" Desc="Model ID" Enum="CARPEDMODEL"/>

is probably better.

Note that the GTA SA version of the command is less complete so the problem doesn't exist there yet.

We currently implement alternators by some kind of overloading.

This gives us some issues:

• Producing a error message is a bit harder.
• You can't use the non-alternator command (e.g. SET_VAR_INT_TO_VAR_INT) directly, unlike in miss2.

Implement this by using a <Alternators> XML section.

If two scripts have the same SCRIPT_NAME, a error should be given.

We should have a compiler option to output the generated intermediate code, in text form. Much like what miss2 does with main_test.txt. The output must be very explicit about datatypes and such.

This will be quite useful for codegen tests, since taking the checksum of the binary every time you modify the test is annoying.

Add a switch to enable the use of arrays instead of always allowing it.

Where should the check be placed? Codegen? Or maybe once a array is declared?

Oh well #46, look at those debug prints

{1885665} 065D: NOP $7424 "OTANK_TARGET[0]" 
{1885687} 065D: NOP $7425 "OTANK_TARGET[1]" 
{1885709} 065D: NOP $7426 "OTANK_TARGET[2]" 

miss2 throws an error when trying to do something like VAR1 = THING - VAR1 because it would require an implicit temporary variable which miss2 nor gta3sc cannot do. However, gta3sc compiles this and produces invalid code in the process looking like:

VAR = THING
VAR -= VAR

There is no documentation:

• How to compile this
• How to run this
• What can this even do?

Background: I'm currently looking for a tool to disassemble a PC GTA3 main.scm on Linux.
It's important that I get a disassembled version which still includes all opcode numbers as I want to generate statistics about opcode usage etc.

You can declare more than 16/32 local variables in one scope, therefore first reusing TIMERA and TIMERB implicitly and then referencing inexistant local variables.

Allow IFNOT and WHILENOT. Pedantically only in III, but would be nice to support also in VC/SA.

See here for details.

• Arrays
• SWITCH (#32)
• TEXT_LABEL / TEXT_LABEL16 (#33)
• Streamed scripts (#34)
• CONST_INT / CONST_FLOAT / CONSTANT_INT (too risky, see #35)
• Change the amount of allowed local variables, including mission locals (#36)
• SKIP_CUTSCENE* directives (#37)

Its commands.xml also probably needs more static information? (#38)

Read IDE files so that the result of ProgramContext::is_model_from_ide is actually accurate. Also remove all the constants from constants.xml that are similar to the name of the models on IDEs.

Making this a optional switch would be a good idea.

The compiler doesn't emit any errors nor warnings when you try to use more than 8 conditions in a single IF statement.

Suggestion: Refuse to compile such file? I guess this could be exposed to a configuration file in the future, but for now hardcoding 8 conditions limit should be OK.

Because

1. ANTLR3 error messages are crypt and doesn't match the formatting of the messages in the rest of the compiler.
2. ANTLR3 is a performance bottleneck.

Keep the grammar on the header of functions in the lex/parser.

GOSUB_FILE, LAUNCH_MISSION, LOAD_AND_LAUNCH_MISSION and probably the streamed script equivalent can only be invoked from a main script or in a extension script.

Define whether

• They should be fully lower-case
• They should end with a dot
• More?

Additionally

• Make the message clear (currently it has a quick draft)
• Possibly suggest a compiler option to get rid of the error

Avoid generating ANDOR with a single condition.

A compiler switch should be added for this.

...at least using -pedantic

See TEXT_LABEL / TEXT_LABEL16 on GTAModding.

For the same purpose as SB's HEX...END

Use a XML on the directory of each configuration specifying some code generation flags, such as half float. Maybe also specifying the id of special opcodes.

This way, the configurations can have arbitrary values, not only gta3, gtavc and gtasa.

For instance

/*
   Nest Level 1
   /* Nest Level 2 */
*/

Probably depends on #5

Since Vice City the following kind of command is allowed

VAR_INT v
v = CHEETAH // 105

which compiles to a specific opcode (different from the one used in v = 105).

What are these?

Implement a very basic preprocessor which only allows the #ifdef / #ifndef directive. Any definition should be given to the compiler by the means of a -D switch.

See the TODOs in config/gta3/constants.xml

String constants may have collisions. For instance, the CAMMODE enumeration contains a SNIPER constant, same name of a CARPEDMODEL constant.

The implication of this is that the following may generate different output depending on how we evaluate the search for a constant:

VAR_INT x
x = SNIPER

In fact, this ends up using CARPEDMODEL in miss2, while it uses the CAMMODE enum here.

Specify the evaluation order of enumerations!

For instance

SWITCH n
    CASE 1
    CASE 2
        BREAK
ENDSWITCH

Add -fstreamed-scripts and only allow it with guesser mode.

Implement based on message exchanging with Wesser.

We currently allow both semantics, but pedantically this is how it works in III:

label:
{
    // code
}

and how it works in Vice City:

{
label:
    // code
}

Also the index of the timers

Entity tracking behaviour isn't following miss2 behaviour!

See SCM Language, SWITCH.

Add a -fswitch option, and when SWITCH_START / SWITCH_CONTINUED isn't available, use a IF chain.

We should probably add this to guesser mode?

Easily done on codegen.

Lots of commands (specially the ones that don't exist in III/VC) need tweaking of static information.

Some of the issues:

• Out parameters aren't marked as var-only
• Entity information is missing
• Enum information is missing

.

miss2 doesn't allow a different entity type to be assigned to a variable, for example:

VAR_INT var
CREATE_CAR 400 0.0 0.0 0.0 var
CREATE_CHAR 4 1 0.0 0.0 0.0 var   // error: Variable has already been used to create a entity of a different type
TERMINATE_THIS_SCRIPT

Implement a mechanism (a pseudo-command) to define constants.

San Andreas probably implemented it with CONST_INT, CONST_FLOAT and/or CONSTANT_INT, but it's too risky to assume anything about those commands. Better create a new one.

Everything is mostly ready for this by-design.

Add a pseudo-command (REQUIRE) which adds a extension script to the compilation process, much like GOSUB_FILE, except without generating a command or calling anything.

Add a compiler switch, and implement SKIP_CUTSCENE_START and SKIP_CUTSCENE_END directives. Only allow it's use in guesser mode.