NAME
core.ops - Core Opcodes
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)
- 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__).
- load_bytecode(in STR) Load Parrot bytecode from file $1, and search the library path to locate the file.
- load_language(in STR) Load the compiler libraries for a language $1. Search the library path to locate the main compiler file in the standard locations.
Control flow
The control flow opcodes check conditions and manage program flow.
- branch(in LABEL) Branch forward or backward by the amount in $1.
- local_branch(invar PMC, in LABEL) Go to the location specified by the label in $2. Push the current location onto the stack passed in $1 for later returning.
- local_return(invar PMC) Pop the location off the top of the call stack and go there.
- jump(in LABEL) 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(invar INT, inconst LABEL)
- if(invar NUM, inconst LABEL)
- if(invar PMC, inconst LABEL)
- if(invar STR, inconst LABEL) Check register $1. If true, branch by $2.
- unless(invar INT, inconst LABEL)
- unless(invar NUM, inconst LABEL)
- unless(invar PMC, inconst LABEL)
- unless(invar STR, inconst LABEL) Check register $1. If false, branch by $2.
Subroutine operations
These operations are used to generate and call subroutines and continuations.
- invokecc(invar PMC) Call the subroutine in $1 and generate a new return continuation, if needed. For example, a NCI subroutine which executes code in some C library will not create a continuation, nor will anything but the first call to a coroutine.
- invoke(invar PMC, invar PMC) Call the subroutine in $1 and use continuation $2.
- yield() Yield results from a coroutine.
- tailcall(invar 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.
- capture_lex(invar PMC) Capture the current lexical state of the inner subroutine PMC.
- newclosure(out PMC, invar 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 invar PMC constant is the string representation of a FixedIntegerArray with one flag word per argument. The flags are documented currently in include/parrot/enums.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 get_results signature PMC of the caller. This PMC is a FixedIntegerPMCArray. The number of elements of this PMC is equal to the number of return values that are expected. The individual bits per entry are specified in docs/pdds/pdd03_calling_conventions.pod.
Address manipulation
- set_addr(out INT, inconst LABEL) Sets register $1 to the current address plus the offset $2.
- set_addr(invar PMC, inconst LABEL) Sets PMC in register $1 to the current address plus the offset $2.
- set_addr(invar PMC, invar LABEL) Sets PMC in register $1 to the absolute address $2 obtained from get_addr.
- get_addr(out INT, invar PMC) Sets $1 to the absolute address of the Sub PMC $2.
Concurrency operations
- schedule(invar PMC) Register a task with the concurrency scheduler. Details about the task are stored within the task PMC.
- addhandler(invar PMC) Add an event or exception handler to the concurrency scheduler. Details about the handler are stored within the handler PMC.
Exception handling
- push_eh(inconst LABEL) Create an exception handler for the given catch label and push it onto the exception handler stack.
- push_eh(invar PMC) Push an invokable PMC onto the exception handler stack.
- pop_eh() Pop the most recently placed exception off the handler stack.
- throw(invar PMC) Throw the exception in $1 with current continuation.
- throw(invar PMC, invar PMC) Throw the exception in $1 with continuation from $2.
- rethrow(invar PMC) Only valid inside an exception handler. Rethrow the exception $1.
- count_eh(out INT) Get a count of currently active exception handlers on the stack.
- die(in STR)
- die(in PMC) Die with message $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 dynamic environment.
- popmark(in INT) Pop all items off the dynamic environment to the given mark.
- pushaction(invar PMC) Push the given Sub PMC $1 onto the dynamic environment. If the dynamic environment is unwound due to a
popmark,
subroutine return,
or an exception,
the subroutine will be invoked with an integer argument: 0 means a normal return; 1 means an exception has been raised.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 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. The valid constants for each return value are:
- interpinfo(out INT, in INT) .TOTAL_MEM_ALLOC, .GC_MARK_RUNS, .GC_COLLECT_RUNS, .ACTIVE_PMCS, .ACTIVE_BUFFERS, .TOTAL_PMCS, .TOTAL_BUFFERS, .HEADER_ALLOCS_SINCE_COLLECT, .MEM_ALLOCS_SINCE_COLLECT, .TOTAL_COPIED, .IMPATIENT_PMCS, .GC_LAZY_MARK_RUNS, .EXTENDED_PMCS, .RUNCORE
- interpinfo(out PMC, in INT) .CURRENT_SUB, .CURRENT_CONT, .CURRENT_OBJECT, .CURRENT_LEXPAD
- interpinfo(out STR, in INT) .EXECUTABLE_FULLNAME, .EXECUTABLE_BASENAME, .RUNTIME_PREFIX
- warningson(in INT) Turns on warnings categories. Categories already turned on will stay on. Initial setting is currently all warnings off. Include warnings.pasm to access the categories. Refer to that file for the current list of warnings available.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. To access these from PASM, include errors.pasm. The current categories are:
- .PARROT_ERRORS_GLOBALS_FLAG Throw an exception if global doesn't exist. Default: on.
- .PARROT_ERRORS_OVERFLOW_FLAG Throw math overflow instead of promoting to BigInt. Default: off.
- .PARROT_ERRORS_PARAM_COUNT_FLAG Throw exception on argument <-> param count mismatch. Default: off.
- .PARROT_ERRORS_RESULT_COUNT_FLAG Throw exception on return <-> result count mismatch. Default: off.
- .PARROT_ERRORS_ALL_FLAG
- errorsoff(in INT) Turns off errors categories. Categories already turned off will stay off. See the documentation for errorson for category numbers.
- runinterp(invar PMC, in LABEL) Run the code starting at offset $2 within interpreter $1.
- getinterp(out PMC) Get the current ParrotInterpreter.
Garbage Collection
Opcodes that interact with the GC subsystem.
- sweep(inconst INT) Triggers a GC run, based on the value of $1, where:
- Trigger a GC run only if there are things that have flagged themselves as really needing to be collected.
- 1
- collect() Trigger a garbage collection.
- sweepoff() Disable GC runs. (Nestable)
- sweepon() Re-enable GC runs.
- collectoff() Disable GC runs (nestable).
- collecton() Re-enable GC.
- needs_destroy(invar PMC) Mark the PMC wanting destruction as soon as possible, for example when unused during the lazy sweep, triggered by
Trigger a GC run unconditionally.
sweep 0.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, invar 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, invar 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.
- compreg(out PMC, in STR) Get the compiler object for source type $2. The returned compiler object should provide a
- compreg(in STR, invar PMC) Register $2 as the compiler object for source type $1.
- new_callback(out PMC, invar PMC, invar PMC, in STR) Create a callback stub $1 for PASM subroutine $2 with userdata $3 and callback function signature $4. Only 2 argument signatures with signature chars U[1iscpt] or [1iscpt]U are handled currently. But these cover a lot of callback signatures. Please note that the userdata PMC U has to be handled transparently by the caller of the callback function.
compile method for translating code in the source type.
However,
some Parrot compilers such as PIR and PASM currently return a sub that is to be invoked directly on the source.
Annotations operations
These operations relate to bytecode annotations.
- annotations(out PMC) Gets all bytecode annotations in effect at the current point, in a Hash. If there are none, returns an empty Hash.
- annotations(out PMC, in STR) Gets the bytecode annotation with the given name that is in effect at the current point. Returns PMCNULL if there is none.
COPYRIGHT
Copyright (C) 2001-2008, Parrot Foundation.
LICENSE
This program is free software. It is subject to the same license as the Parrot interpreter itself.