JAI TIDBITS
Random bits of information I'd like to remember when writing Jai programs.
Note: This information is valid as of the version 0.2.017 (August 2025).
DISASSEMBLE PROCEDURES
Procedures marked with the #dump directive will have their internal IR dumped at compile-time. Jai's IR isn't 1:1 with assembly instructions, but it does give a decent indicator for what instructions the compiler will generate.
// file.jai
AddTwoNumbers :: (x: int, y: int) -> int #dump {
return x + y;
}
ShowChecks :: (values: []u16) -> u8 #dump {
// Trigger array bounds and overflow checks
return values[0].(u8) + values[1].(u8);
}
$ jai file.jai
Disassembly of 'AddTwoNumbers' in Workspace 2 at file.jai:1
- Stack size 0
-------- Basic Block 0 -------- defines v4 --------
(no dominating)
0| binop v4, v1 + v2
1| return_value v4 -> 1
2| return
Disassembly of 'ShowChecks' in Workspace 2 at file.jai:5
- Stack size 0
-------- Basic Block 0 -------- defines v3-15 --------
(no dominating)
0| constant v3 = 0
1| mov v4, [v1] :8b
2| array_check v3, v4
3| mov v5, [v1+0x8] :8b
4| binop v7, v3 * 2
5| mov v6, [v5+v7*1] :2b
6| cast_number v8 (u8), v6 (u16)
7| cast_check v6, v8 {fatal=1}
8| constant v10 = 1
9| mov v11, [v1] :8b
10| array_check v10, v11
11| mov v12, [v1+0x8] :8b
12| binop v14, v10 * 2
13| mov v13, [v12+v14*1] :2b
14| cast_number v15 (u8), v13 (u16)
15| cast_check v13, v15 {fatal=1}
16| binop v9, v8 + v15
17| return_value v9 -> 1
18| return
DIRECTIVES
Here's a list of the current (non-deprecated) compiler directives and what they generally do. Because many of these are undocumented, it's possible some number of directives are missing.
#add_context inject declaration into the base context #align alignment of a struct field #as struct implicitly casts to this type #asm inline assembly #bake_arguments bake arguments as constants #bake_constants [todo] #body_text [todo] #bytes inline binary data #c_call c calling convention #caller_location location of calling code #char character literal #code create a Code node #compile_time check if running at compile-time #compiler internal compiler declaration #complete check that all enum cases are handled #Context type of Context (post #add_context) #cpp_method c++ calling convention #cpp_return_type_is_non_pod return type has c++ methods #deprecated display deprecation warning #discard argument is unused #dump dump procedure's IR #dynamic_specialize [todo] #exists check if symbol exists at compile-time #expand procedure is a macro #file current filename as string #filepath path of current file as string #foreign foreign procedure #if, #else compile-time if/switch #ifx compile-time ternary #import import module #insert insert code, string at location #intrinsic procedure implemented by compiler #library link to a library #line current line number as int #load import file into namespace #location source location of a symbol #modify check or assign polymorphic variables #module_parameters declare import arguments #no_abc disable array bounds checking #no_alias [todo] #no_aoc disable arithmetic overflow checking #no_context procedure is called without the context #no_debug disable debug information for a macro or macro call #no_padding disable struct field padding #no_reset global data persists from compile-time #place struct field memory offset #placeholder symbol will be filled in at compile-time #poke_name inject symbol into another namespace #procedure_name procedure name as string #run execute block or procedure at compile-time #scope_export visible to importers #scope_file visible to file only #scope_module visible to module files #specified enum fields must be given values #string multi-line string #symmetric procedure arguments are order independent #system_library link to a system library #this the type of the current block #through fall-through to next case #type proceeding expression is a type #type_info_no_size_complaint [todo] #type_info_none disable type info for type #type_info_procedures_are_void_pointers [todo]