/*

* This file implements a data structure representing a sequence of

* instructions, which is used by different parts of the compilation

* pipeline.

*/

#include "Python.h"

#include "pycore_c_array.h" // _Py_CArray_EnsureCapacity

#include "pycore_compile.h" // _PyInstruction

#include "pycore_opcode_utils.h"

#include "pycore_opcode_metadata.h" // OPCODE_HAS_ARG, etc

typedef _PyInstruction instruction;

typedef _PyInstructionSequence instr_sequence;

typedef _Py_SourceLocation location;

#define INITIAL_INSTR_SEQUENCE_SIZE 100

#define INITIAL_INSTR_SEQUENCE_LABELS_MAP_SIZE 10

#include "clinic/instruction_sequence.c.h"

#include <stdbool.h>

#undef SUCCESS

#undef ERROR

#define SUCCESS 0

#define ERROR -1

#define RETURN_IF_ERROR(X) \

if ((X) == -1) { \

return ERROR; \

}

static int

instr_sequence_next_inst(instr_sequence *seq) {

assert(seq->s_instrs != NULL || seq->s_used == 0);

_Py_c_array_t array = {

.array = (void*)seq->s_instrs,

.allocated_entries = seq->s_allocated,

.item_size = sizeof(instruction),

.initial_num_entries = INITIAL_INSTR_SEQUENCE_SIZE,

};

RETURN_IF_ERROR(_Py_CArray_EnsureCapacity(&array, seq->s_used + 1));

seq->s_instrs = array.array;

seq->s_allocated = array.allocated_entries;

assert(seq->s_allocated >= 0);

assert(seq->s_used < seq->s_allocated);

return seq->s_used++;

}

_PyJumpTargetLabel

_PyInstructionSequence_NewLabel(instr_sequence *seq)

{

_PyJumpTargetLabel lbl = {++seq->s_next_free_label};

return lbl;

}

int

_PyInstructionSequence_UseLabel(instr_sequence *seq, int lbl)

{

int old_size = seq->s_labelmap_size;

_Py_c_array_t array = {

.array = (void*)seq->s_labelmap,

.allocated_entries = seq->s_labelmap_size,

.item_size = sizeof(int),

.initial_num_entries = INITIAL_INSTR_SEQUENCE_LABELS_MAP_SIZE,

};

RETURN_IF_ERROR(_Py_CArray_EnsureCapacity(&array, lbl));

seq->s_labelmap = array.array;

seq->s_labelmap_size = array.allocated_entries;

for(int i = old_size; i < seq->s_labelmap_size; i++) {

seq->s_labelmap[i] = -111; /* something weird, for debugging */

}

seq->s_labelmap[lbl] = seq->s_used; /* label refers to the next instruction */

return SUCCESS;

}

int

_PyInstructionSequence_ApplyLabelMap(instr_sequence *instrs)

{

if (instrs->s_labelmap == NULL) {

/* Already applied - nothing to do */

return SUCCESS;

}

/* Replace labels by offsets in the code */

for (int i=0; i < instrs->s_used; i++) {

instruction *instr = &instrs->s_instrs[i];

if (HAS_TARGET(instr->i_opcode)) {

assert(instr->i_oparg < instrs->s_labelmap_size);

instr->i_oparg = instrs->s_labelmap[instr->i_oparg];

}

_PyExceptHandlerInfo *hi = &instr->i_except_handler_info;

if (hi->h_label >= 0) {

assert(hi->h_label < instrs->s_labelmap_size);

hi->h_label = instrs->s_labelmap[hi->h_label];

}

}

/* Clear label map so it's never used again */

PyMem_Free(instrs->s_labelmap);

instrs->s_labelmap = NULL;

instrs->s_labelmap_size = 0;

return SUCCESS;

}

#define MAX_OPCODE 511

int

_PyInstructionSequence_Addop(instr_sequence *seq, int opcode, int oparg,

location loc)

{

assert(0 <= opcode && opcode <= MAX_OPCODE);

assert(IS_WITHIN_OPCODE_RANGE(opcode));

assert(OPCODE_HAS_ARG(opcode) || HAS_TARGET(opcode) || oparg == 0);

assert(0 <= oparg && oparg < (1 << 30));

int idx = instr_sequence_next_inst(seq);

RETURN_IF_ERROR(idx);

instruction *ci = &seq->s_instrs[idx];

ci->i_opcode = opcode;

ci->i_oparg = oparg;

ci->i_loc = loc;

return SUCCESS;

}

int

_PyInstructionSequence_InsertInstruction(instr_sequence *seq, int pos,

int opcode, int oparg, location loc)

{

assert(pos >= 0 && pos <= seq->s_used);

int last_idx = instr_sequence_next_inst(seq);

RETURN_IF_ERROR(last_idx);

for (int i=last_idx-1; i >= pos; i--) {

seq->s_instrs[i+1] = seq->s_instrs[i];

}

instruction *ci = &seq->s_instrs[pos];

ci->i_opcode = opcode;

ci->i_oparg = oparg;

ci->i_loc = loc;

/* fix the labels map */

for(int lbl=0; lbl < seq->s_labelmap_size; lbl++) {

if (seq->s_labelmap[lbl] >= pos) {

seq->s_labelmap[lbl]++;

}

}

return SUCCESS;

}

_PyInstruction

_PyInstructionSequence_GetInstruction(instr_sequence *seq, int pos)

{

assert(pos >= 0 && pos < seq->s_used);

return seq->s_instrs[pos];

}

int

_PyInstructionSequence_SetAnnotationsCode(instr_sequence *seq,

instr_sequence *annotations)

{

assert(seq->s_annotations_code == NULL);

seq->s_annotations_code = annotations;

return SUCCESS;

}

int

_PyInstructionSequence_AddNested(instr_sequence *seq, instr_sequence *nested)

{

if (seq->s_nested == NULL) {

seq->s_nested = PyList_New(0);

if (seq->s_nested == NULL) {

return ERROR;

}

}

if (PyList_Append(seq->s_nested, (PyObject*)nested) < 0) {

return ERROR;

}

return SUCCESS;

}

void

PyInstructionSequence_Fini(instr_sequence *seq) {

Py_XDECREF(seq->s_nested);

PyMem_Free(seq->s_labelmap);

seq->s_labelmap = NULL;

PyMem_Free(seq->s_instrs);

seq->s_instrs = NULL;

if (seq->s_annotations_code != NULL) {

PyInstructionSequence_Fini(seq->s_annotations_code);

Py_CLEAR(seq->s_annotations_code);

}

}

/*[clinic input]

class InstructionSequenceType "_PyInstructionSequence *" "&_PyInstructionSequence_Type"

[clinic start generated code]*/

/*[clinic end generated code: output=da39a3ee5e6b4b0d input=589963e07480390f]*/

static _PyInstructionSequence*

inst_seq_create(void)

{

_PyInstructionSequence *seq;

seq = PyObject_GC_New(_PyInstructionSequence, &_PyInstructionSequence_Type);

if (seq == NULL) {

return NULL;

}

seq->s_instrs = NULL;

seq->s_allocated = 0;

seq->s_used = 0;

seq->s_next_free_label = 0;

seq->s_labelmap = NULL;

seq->s_labelmap_size = 0;

seq->s_nested = NULL;

seq->s_annotations_code = NULL;

PyObject_GC_Track(seq);

return seq;

}

PyObject*

_PyInstructionSequence_New(void)

{

_PyInstructionSequence *seq = inst_seq_create();

if (seq == NULL) {

return NULL;

}

return (PyObject*)seq;

}

/*[clinic input]

@classmethod

InstructionSequenceType.__new__ as inst_seq_new

Create a new InstructionSequence object.

[clinic start generated code]*/

static PyObject *

inst_seq_new_impl(PyTypeObject *type)

/*[clinic end generated code: output=98881de92c8876f6 input=b393150146849c74]*/

{

return (PyObject*)inst_seq_create();

}

/*[clinic input]

InstructionSequenceType.use_label

label: int

Place label at current location.

[clinic start generated code]*/

static PyObject *

InstructionSequenceType_use_label_impl(_PyInstructionSequence *self,

int label)

/*[clinic end generated code: output=4c06bbacb2854755 input=da55f49bb91841f3]*/

{

if (_PyInstructionSequence_UseLabel(self, label) < 0) {

return NULL;

}

Py_RETURN_NONE;

}

/*[clinic input]

InstructionSequenceType.addop

opcode: int

oparg: int

lineno: int

col_offset: int

end_lineno: int

end_col_offset: int

Append an instruction.

[clinic start generated code]*/

static PyObject *

InstructionSequenceType_addop_impl(_PyInstructionSequence *self, int opcode,

int oparg, int lineno, int col_offset,

int end_lineno, int end_col_offset)

/*[clinic end generated code: output=af0cc22c048dfbf3 input=012762ac88198713]*/

{

_Py_SourceLocation loc = {lineno, col_offset, end_lineno, end_col_offset};

if (_PyInstructionSequence_Addop(self, opcode, oparg, loc) < 0) {

return NULL;

}

Py_RETURN_NONE;

}

/*[clinic input]

InstructionSequenceType.new_label -> int

Return a new label.

[clinic start generated code]*/

static int

InstructionSequenceType_new_label_impl(_PyInstructionSequence *self)

/*[clinic end generated code: output=dcb0589e4f5bf4bd input=c66040b9897bc327]*/

{

_PyJumpTargetLabel lbl = _PyInstructionSequence_NewLabel(self);

return lbl.id;

}

/*[clinic input]

InstructionSequenceType.add_nested

nested: object

Add a nested sequence.

[clinic start generated code]*/

static PyObject *

InstructionSequenceType_add_nested_impl(_PyInstructionSequence *self,

PyObject *nested)

/*[clinic end generated code: output=14540fad459f7971 input=f2c482568b3b3c0f]*/

{

if (!_PyInstructionSequence_Check(nested)) {

PyErr_Format(PyExc_TypeError,

"expected an instruction sequence, not %T",

Py_TYPE(nested));

return NULL;

}

if (_PyInstructionSequence_AddNested(self, (_PyInstructionSequence*)nested) < 0) {

return NULL;

}

Py_RETURN_NONE;

}

/*[clinic input]

InstructionSequenceType.get_nested

Add a nested sequence.

[clinic start generated code]*/

static PyObject *

InstructionSequenceType_get_nested_impl(_PyInstructionSequence *self)

/*[clinic end generated code: output=f415112c292630cb input=e429e474c57b95b4]*/

{

if (self->s_nested == NULL) {

return PyList_New(0);

}

return Py_NewRef(self->s_nested);

}

/*[clinic input]

InstructionSequenceType.get_instructions

Return the instructions as a list of tuples or labels.

[clinic start generated code]*/

static PyObject *

InstructionSequenceType_get_instructions_impl(_PyInstructionSequence *self)

/*[clinic end generated code: output=23f4f3f894c301b3 input=fbadb5dadb611291]*/

{

if (_PyInstructionSequence_ApplyLabelMap(self) < 0) {

return NULL;

}

PyObject *instructions = PyList_New(0);

if (instructions == NULL) {

return NULL;

}

for (int i = 0; i < self->s_used; i++) {

instruction *instr = &self->s_instrs[i];

location loc = instr->i_loc;

PyObject *inst_tuple;

if (OPCODE_HAS_ARG(instr->i_opcode)) {

inst_tuple = Py_BuildValue(

"(iiiiii)", instr->i_opcode, instr->i_oparg,

loc.lineno, loc.end_lineno,

loc.col_offset, loc.end_col_offset);

}

else {

inst_tuple = Py_BuildValue(

"(iOiiii)", instr->i_opcode, Py_None,

loc.lineno, loc.end_lineno,

loc.col_offset, loc.end_col_offset);

}

if (inst_tuple == NULL) {

goto error;

}

int res = PyList_Append(instructions, inst_tuple);

Py_DECREF(inst_tuple);

if (res != 0) {

goto error;

}

}

return instructions;

error:

Py_XDECREF(instructions);

return NULL;

}

static PyMethodDef inst_seq_methods[] = {

INSTRUCTIONSEQUENCETYPE_ADDOP_METHODDEF

INSTRUCTIONSEQUENCETYPE_NEW_LABEL_METHODDEF

INSTRUCTIONSEQUENCETYPE_USE_LABEL_METHODDEF

INSTRUCTIONSEQUENCETYPE_ADD_NESTED_METHODDEF

INSTRUCTIONSEQUENCETYPE_GET_NESTED_METHODDEF

INSTRUCTIONSEQUENCETYPE_GET_INSTRUCTIONS_METHODDEF

{NULL, NULL, 0, NULL},

};

static PyMemberDef inst_seq_memberlist[] = {

{NULL} /* Sentinel */

};

static PyGetSetDef inst_seq_getsetters[] = {

{NULL} /* Sentinel */

};

static void

inst_seq_dealloc(PyObject *op)

{

_PyInstructionSequence *seq = (_PyInstructionSequence *)op;

PyObject_GC_UnTrack(seq);

PyInstructionSequence_Fini(seq);

PyObject_GC_Del(seq);

}

static int

inst_seq_traverse(PyObject *op, visitproc visit, void *arg)

{

_PyInstructionSequence *seq = (_PyInstructionSequence *)op;

Py_VISIT(seq->s_nested);

Py_VISIT((PyObject *)seq->s_annotations_code);

return 0;

}

static int

inst_seq_clear(PyObject *op)

{

_PyInstructionSequence *seq = (_PyInstructionSequence *)op;

Py_CLEAR(seq->s_nested);

Py_CLEAR(seq->s_annotations_code);

return 0;

}

PyTypeObject _PyInstructionSequence_Type = {

PyVarObject_HEAD_INIT(&PyType_Type, 0)

"InstructionSequence",

sizeof(_PyInstructionSequence),

0,

inst_seq_dealloc, /*tp_dealloc*/

0, /*tp_vectorcall_offset*/

0, /*tp_getattr*/

0, /*tp_setattr*/

0, /*tp_as_async*/

0, /*tp_repr*/

0, /*tp_as_number*/

0, /*tp_as_sequence*/

0, /*tp_as_mapping*/

0, /* tp_hash */

0, /* tp_call */

0, /* tp_str */

PyObject_GenericGetAttr, /* tp_getattro */

0, /* tp_setattro */

0, /* tp_as_buffer */

Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,/* tp_flags */

inst_seq_new__doc__, /* tp_doc */

inst_seq_traverse, /* tp_traverse */

inst_seq_clear, /* tp_clear */

0, /* tp_richcompare */

0, /* tp_weaklistoffset */

0, /* tp_iter */

0, /* tp_iternext */

inst_seq_methods, /* tp_methods */

inst_seq_memberlist, /* tp_members */

inst_seq_getsetters, /* tp_getset */

0, /* tp_base */

0, /* tp_dict */

0, /* tp_descr_get */

0, /* tp_descr_set */

0, /* tp_dictoffset */

0, /* tp_init */

0, /* tp_alloc */

inst_seq_new, /* tp_new */

};