NAME

core.ops - Parrot Core Ops

DESCRIPTION

Parrot's core library of ops.

Core operations are primarily flow control and interpreter introspection.

Basic ops

These are the fundamental operations. Please note: These opcodes must not be moved; they must have exactly these opcode numbers. Opcodes ending with underscores are for internal use only, don't emit these opcodes.

end(): Halts the interpreter. (Must be op #0, CORE_OPS_end). See also exit.
noop(): Does nothing other than waste an iota of time and 32 bits of bytecode space. (Must be op #1, CORE_OPS_noop)
cpu_ret(): Emit a cpu return instruction. This is used to return from CGP core to JIT code. Note: Do not use this opcode. It is for internal use only. (Must be op #2, CORE_OPS_cpu_ret)
check_events(): Check the event queue and run event handlers if there are unhandled events. Note: This opcode is mainly for testing. It should not be necessary to ever use it explicitly. (Must be op #3, CORE_OPS_check_events).
check_events__(): Check the event queue and run event handlers if there are unhandled events. Note: Do not use this opcode. It is for internal use only. (Must be op #4, CORE_OPS_check_events__).
wrapper__(): Internal opcode to wrap unknown ops from loaded opcode libs. Don't use. (Must be op #5, CORE_OPS_wrapper__).
prederef__(): Internal opcode to prederef opcodes on the fly. Don't use. (Must be op #6, CORE_OPS_prederef__ ).
reserved(inconst INT): Reserve 1 more fix entry.
load_bytecode(in STR): Load Parrot bytecode from file $1, and (TODO) search the library path, to locate the file.

Control flow

The control flow opcodes check conditions and manage program flow.

branch(label INT): Branch forward or backward by the amount in $1.
branch_cs(in STR): Intersegment branch to location in fixup table named $1.
bsr(label INT): Branch to the location specified by $1. Push the current location onto the call stack for later returning.
ret(): Pop the location off the top of the call stack and go there.
jsr(label INT): Jump to the location specified by register $1. Push the current location onto the call stack for later returning.
jump(label INT): Jump to the address held in register $1.
enternative(): Internal opcode used to jump from normal bytecode into a JITted version.

Conditional branch operations

These operations perform a conditional relative branch. If the condition is met, the branch happens, otherwise control falls to the next operation.

if(in INT, labelconst INT)
if(in NUM, labelconst INT)
if(in PMC, labelconst INT)
if(in STR, labelconst INT): Check register $1. If true, branch by $2.
unless(in INT, labelconst INT)
unless(in NUM, labelconst INT)
unless(in PMC, labelconst INT)
unless(in STR, labelconst INT): Check register $1. If false, branch by $2.

Subroutine operations

These operations are used to generate and call subroutines and continuations.

invokecc(in PMC): Call the subroutine in $1 and generate a new return continuation, if needed. E.g. a NCI subroutine, which executes code in some C library will not create a continuation, neither the not-first call to a coroutine.
invoke(in PMC, in PMC): Call the subroutine in $1 and use continuation $2.
yield(): Yield results from a coroutine.
tailcall(in PMC): Call the subroutine in $1 and use the current continuation as the subs continuation.
returncc(): Return from the sub or method via the current continuation.
newclosure(out PMC, in PMC): Create a closure of the given subroutine PMC by cloning the sub's state.

Function argument opcode

Implementations of function argument and params handling

set_args(inconst PMC /* , ... */): Define arguments for the next function call.
get_results(inconst PMC /* , ... */): Define return values for the next function call.
get_params(inconst PMC /* , ... */): Define function parameters for this subroutine.
set_returns(inconst PMC /* , ... */): Define return results for the subroutine return statement.; For all of these opcodes the passed in PMC constant is the string representation of a fixed integer array with one flag word per argument. The flags are documented currently in include/parrrot/enum.h only.; After this argument a variable amount of arguments must follow according to the elements of the signature array.
result_info(out PMC): Returns the results PMC of the caller. The number of elements of this PMC is equal to the number of return values that are expected.

Address manipulation

########################################

set_addr(out INT, labelconst INT): Sets register $1 to the current address plus the offset $2.
set_addr(in PMC, labelconst INT): Sets PMC in register $1 to the current address plus the offset $2.
set_addr(in PMC, labelvar INT): Sets PMC in register $1 to the absolute address $2 obtained from get_addr.
get_addr(out INT, in PMC): Sets $1 to the absolute address of the Sub PMC $2.

Exception handling

push_eh(labelconst INT): Create an exception handler for the given catch label and push it onto the control stack.
clear_eh(): Clear out the most recently placed exception.
throw(in PMC): Throw the exception in $1.
rethrow(in PMC): Only valid inside an exception handler. Rethrow the exception $1.
die(in INT, in INT): Die with severity $1 and error $2. If severity is .EXCEPT_DOOMED, call _exit($2). The latter isn't catchable.
exit(in INT): Exit the interpreter with exit_status $1. If you want to communicate an extended exit status, create an exception with severity EXCEPT_exit and throw it.
pushmark(in INT): Push a mark labeled $1 onto the control stack.
popmark(in INT): Pop all items off the control stack to the given mark.
pushaction(in PMC): Push the given Sub PMC $1 onto the control stack. If the control stack is unwound due to a popmark, subroutine return, or an exception, the subroutine will be invoked.

Interpreter operations

These operations inspect or modify the interpreter itself, possibly affecting its subsequent operation.

debug(in INT): If $1 is zero, turn off debugging. Otherwise turn debug flag $1 on.
bounds(in INT): If $1 is zero, turn off byte code bounds checking. Otherwise turn it on.
profile(in INT): If $1 is zero, turn off profiling. Otherwise turn it on.
trace(in INT): If $1 is zero, turn off tracing. Otherwise turn trace flag $1 on.
gc_debug(in INT): If $1 is zero, turn off GC_DEBUG. Otherwise turn it on.
interpinfo(out INT, in INT)
interpinfo(out PMC, in INT)
interpinfo(out STR, in INT): Fetch some piece of information about the interpreter and put it in $1. Possible values for $2 are defined in runtime/parrot/include/interpinfo.pasm.
warningson(in INT): Turns on warnings categories. Categories already turned on will stay on. Initial setting is currently all warnings off. Current categories are (include "warnings.pasm"):; To turn on multiple categories, OR the category numbers together.
warningsoff(in INT): Turns off warnings categories. Categories already turned off will stay off. See the documentation for warningson for category numbers.
errorson(in INT): Turns on error categories. Categories already turned on will stay on. Current categories are (include "errors.pasm"):; To turn on multiple categories, OR the category numbers together.
errorsoff(in INT): Turns off errors categories. Categories already turned off will stay off. See the documentation for errorson for category numbers.
runinterp(in PMC, label INT): Run the code starting at offset $2 within interpreter $1.
getinterp(out PMC): Get the current ParrotInterpreter.
setline(in INT): Set the line number for which we're currently executing code.
getline(out INT): Get the current line number.
setfile(in STR): Set the name of the file for which we're currently executing code.
getfile(out STR): Get the name of the current file.
setpackage(in STR): Set the name of the package for which we're currently executing code.
getpackage(out STR): Get the name of the current package.

Dead Object Detection/Garbage Collection

Opcodes that interact with the DOD and GC subsystems.

sweep(inconst INT): 0 ... Trigger a DOD run only if there are things that have flagged themselves as really needing to be collected. 1 ... Trigger a dead object detection (DOD) sweep unconditionally.
collect(): Trigger a garbage collection.
sweepoff(): Disable DOD sweeps. (Nestable)
sweepon(): Re-enable DOD sweeps.
collectoff(): Disable GC runs (nestable).
collecton(): Re-enable GC.
needs_destroy(in PMC): Mark the PMC wanting destruction as soon as possible, i.e. when unused during the lazy sweep, triggered by "sweep 0".

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Native Call Interface

Opcodes for interfacing with C functions in shared libraries.

loadlib(out PMC, in STR): Load a dynamic link library named $2 and store it in $1.
dlfunc(out PMC, in PMC, in STR, in STR): Look up symbol $3 in library $2 with signature $4, and put the corresponding sub object in $1. Note that you need the signature so we can build or find an appropriate thunking function.
dlvar(out PMC, in PMC, in STR): Look up symbol $3 in library $2. We assume that this is actually a variable address rather than a function address, and build an unmanagedstruct PMC and stick the address into its data pointer.
compile(out PMC, in PMC, in STR): Don't use compile - just invoke the compiler.
compreg(out PMC, in STR): Get a compiler for source type $2.
compreg(in STR, in PMC): Register the sub $2 as a compiler for source type $1. $2 is either a NCI PMC with signature "pIt" or a PASM Sub.
new_callback(out PMC, in PMC, in PMC, in STR): Create a callback stub $1 for PASM subroutine $2 with userdata $3 and function signature $4.

COPYRIGHT

LICENSE

This program is free software. It is subject to the same license as the Parrot interpreter itself.