NAME

Parrot::OpTrans - Transform Ops to C Code

DESCRIPTION

Parrot::OpTrans is the abstract superclass for the Parrot op to C transforms. Each transform contains various bits of information needed to generate the C code, and creates a different type of run loop. The methods defined here supply various default values and behaviour common to all transforms.

The subclass hierarchy is as follows:

OpTrans
   |_________________________
   |           |             |
   C         CGoto       Compiled
   |           |
CPrederef      |
   | |         |
   | |_________|
   |           |
CSwitch       CGP

Class Methods

new()

Returns a new instance.

Instance Methods

prefix()

Returns the default 'Parrot_' prefix.

Used by Parrot::Op's func_name() to individuate op function names.

suffix()

Implemented in subclasses to return a suffix with which to individuate variable names. This default implementation returns an empty string.

defines()

Implemented in subclasses to return the C #define macros required.

opsarraytype()

Returns the type for the array of opcodes. By default here it's an array opcode_t, but the prederef runops core uses an array of void* to do its clever tricks.

core_type()

Implemented in subclasses to return the type of core created by the transform. This default implementation raises an exception indicating that the core type is missing. See the Parrot_Run_core_t enum in include/parrot/interpreter.h for a list of the core types.

core_prefix()

Implemented in subclasses to return a short prefix indicating the core type used to individuate core function names.

run_core_func_decl($base)

Optionally implemented in subclasses to return the C code for the run core function declaration. $base is the name of the main ops file minus the .ops extension.

ops_addr_decl($base_suffix)

Optionally implemented in subclasses to return the C code for the ops address declaration. $base_suffix is the name of the main ops file minus the .ops extension with suffix() and an underscore appended.

run_core_func_decl($base)

Optionally implemented in subclasses to return the C code for the run core function declaration. $base is the same as for run_core_func_decl().

run_core_func_start()

Implemented in subclasses, if run_core_func_decl() is implemented, to return the C code prior to the run core function.

run_core_after_addr_table($base_suffix)

Optionally implemented in subclasses to return the run core C code for section after the address table. $base_suffix is the same as for ops_addr_decl().

run_core_finish($base)

Implemented in subclasses to return the C code following the run core function. $base is the same as for run_core_func_decl().

init_func_init1($base)

Optionally implemented in subclasses to return the C code for the core's init function. $base is the same as for run_core_func_decl().

init_set_dispatch($base_suffix)

Optionally implemented in subclasses to return the C code for initializing the dispatch mechanism within the core's init function. $base_suffix is the same as for ops_addr_decl().

Macro Substitutions

The following methods are called by Parrot::OpFile to perform ops file macro substitutions.

access_arg($type, $value, $op)

Implemented in subclasses to return the C code for the specified op argument type and value. $op is an instance of Parrot::Op.

gen_goto($where)

The various goto_X methods below call this method with the return value of an expr_X method (implemented in subclass).

restart_address($address)

Implemented in subclasses to return the C code for restart ADDRESS($address).

restart_offset($offset)

Implemented in subclasses to return the C code for restart OFFSET($offset).

goto_address($address)

Transforms the goto ADDRESS($address) macro in an ops file into the relevant C code.

goto_offset($offset)

Transforms the goto OFFSET($offset) macro in an ops file into the relevant C code.

goto_pop()

Transforms the goto POP($address) macro in an ops file into the relevant C code.

expr_offset($offset)

Implemented in subclasses to return the C code for OFFSET($offset). Called by goto_offset().

expr_address($address)

Implemented in subclasses to return the C code for ADDRESS($address). Called by goto_address().

SEE ALSO

Parrot::OpTrans::C

Parrot::OpTrans::CGP

Parrot::OpTrans::CGoto

Parrot::OpTrans::CPrederef

Parrot::OpTrans::CSwitch

Parrot::OpTrans::Compiled