/*

* This file compiles an abstract syntax tree (AST) into Python bytecode.

*

* The primary entry point is _PyAST_Compile(), which returns a

* PyCodeObject. The compiler makes several passes to build the code

* object:

* 1. Checks for future statements. See future.c

* 2. Builds a symbol table. See symtable.c.

* 3. Generate an instruction sequence. See compiler_mod() in this file.

* 4. Generate a control flow graph and run optimizations on it. See flowgraph.c.

* 5. Assemble the basic blocks into final code. See optimize_and_assemble() in

* this file, and assembler.c.

*

* Note that compiler_mod() suggests module, but the module ast type

* (mod_ty) has cases for expressions and interactive statements.

*

* CAUTION: The VISIT_* macros abort the current function when they

* encounter a problem. So don't invoke them when there is memory

* which needs to be released. Code blocks are OK, as the compiler

* structure takes care of releasing those. Use the arena to manage

* objects.

*/

#include <stdbool.h>

#include "Python.h"

#include "opcode.h"

#include "pycore_ast.h" // _PyAST_GetDocString()

#define NEED_OPCODE_TABLES

#include "pycore_opcode_utils.h"

#undef NEED_OPCODE_TABLES

#include "pycore_code.h" // _PyCode_New()

#include "pycore_compile.h"

#include "pycore_flowgraph.h"

#include "pycore_instruction_sequence.h" // _PyInstructionSequence_New()

#include "pycore_intrinsics.h"

#include "pycore_long.h" // _PyLong_GetZero()

#include "pycore_pystate.h" // _Py_GetConfig()

#include "pycore_setobject.h" // _PySet_NextEntry()

#include "pycore_symtable.h" // PySTEntryObject, _PyFuture_FromAST()

#define NEED_OPCODE_METADATA

#include "pycore_opcode_metadata.h" // _PyOpcode_opcode_metadata, _PyOpcode_num_popped/pushed

#undef NEED_OPCODE_METADATA

#define COMP_GENEXP 0

#define COMP_LISTCOMP 1

#define COMP_SETCOMP 2

#define COMP_DICTCOMP 3

/* A soft limit for stack use, to avoid excessive

* memory use for large constants, etc.

*

* The value 30 is plucked out of thin air.

* Code that could use more stack than this is

* rare, so the exact value is unimportant.

*/

#define STACK_USE_GUIDELINE 30

#undef SUCCESS

#undef ERROR

#define SUCCESS 0

#define ERROR -1

#define RETURN_IF_ERROR(X) \

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

return ERROR; \

}

#define IS_TOP_LEVEL_AWAIT(C) ( \

((C)->c_flags.cf_flags & PyCF_ALLOW_TOP_LEVEL_AWAIT) \

&& ((C)->u->u_ste->ste_type == ModuleBlock))

struct compiler;

typedef _PyInstruction instruction;

typedef _PyInstructionSequence instr_sequence;

static instr_sequence *compiler_instr_sequence(struct compiler *c);

static int compiler_future_features(struct compiler *c);

static struct symtable *compiler_symtable(struct compiler *c);

static PySTEntryObject *compiler_symtable_entry(struct compiler *c);

#define INSTR_SEQUENCE(C) compiler_instr_sequence(C)

#define FUTURE_FEATURES(C) compiler_future_features(C)

#define SYMTABLE(C) compiler_symtable(C)

#define SYMTABLE_ENTRY(C) compiler_symtable_entry(C)

typedef _Py_SourceLocation location;

typedef struct _PyCfgBuilder cfg_builder;

static PyObject *compiler_maybe_mangle(struct compiler *c, PyObject *name);

#define LOCATION(LNO, END_LNO, COL, END_COL) \

((const _Py_SourceLocation){(LNO), (END_LNO), (COL), (END_COL)})

#define LOC(x) SRC_LOCATION_FROM_AST(x)

typedef _PyJumpTargetLabel jump_target_label;

static jump_target_label NO_LABEL = {-1};

#define SAME_LABEL(L1, L2) ((L1).id == (L2).id)

#define IS_LABEL(L) (!SAME_LABEL((L), (NO_LABEL)))

#define NEW_JUMP_TARGET_LABEL(C, NAME) \

jump_target_label NAME = _PyInstructionSequence_NewLabel(INSTR_SEQUENCE(C)); \

if (!IS_LABEL(NAME)) { \

return ERROR; \

}

#define USE_LABEL(C, LBL) \

RETURN_IF_ERROR(_PyInstructionSequence_UseLabel(INSTR_SEQUENCE(C), (LBL).id))

/* fblockinfo tracks the current frame block.

A frame block is used to handle loops, try/except, and try/finally.

It's called a frame block to distinguish it from a basic block in the

compiler IR.

*/

enum fblocktype { WHILE_LOOP, FOR_LOOP, TRY_EXCEPT, FINALLY_TRY, FINALLY_END,

WITH, ASYNC_WITH, HANDLER_CLEANUP, POP_VALUE, EXCEPTION_HANDLER,

EXCEPTION_GROUP_HANDLER, ASYNC_COMPREHENSION_GENERATOR,

STOP_ITERATION };

struct fblockinfo {

enum fblocktype fb_type;

jump_target_label fb_block;

location fb_loc;

/* (optional) type-specific exit or cleanup block */

jump_target_label fb_exit;

/* (optional) additional information required for unwinding */

void *fb_datum;

};

enum {

COMPILER_SCOPE_MODULE,

COMPILER_SCOPE_CLASS,

COMPILER_SCOPE_FUNCTION,

COMPILER_SCOPE_ASYNC_FUNCTION,

COMPILER_SCOPE_LAMBDA,

COMPILER_SCOPE_COMPREHENSION,

COMPILER_SCOPE_ANNOTATIONS,

};

static const int compare_masks[] = {

[Py_LT] = COMPARISON_LESS_THAN,

[Py_LE] = COMPARISON_LESS_THAN | COMPARISON_EQUALS,

[Py_EQ] = COMPARISON_EQUALS,

[Py_NE] = COMPARISON_NOT_EQUALS,

[Py_GT] = COMPARISON_GREATER_THAN,

[Py_GE] = COMPARISON_GREATER_THAN | COMPARISON_EQUALS,

};

/*

* Resize the array if index is out of range.

*

* idx: the index we want to access

* arr: pointer to the array

* alloc: pointer to the capacity of the array

* default_alloc: initial number of items

* item_size: size of each item

*

*/

int

_PyCompile_EnsureArrayLargeEnough(int idx, void **array, int *alloc,

int default_alloc, size_t item_size)

{

void *arr = *array;

if (arr == NULL) {

int new_alloc = default_alloc;

if (idx >= new_alloc) {

new_alloc = idx + default_alloc;

}

arr = PyMem_Calloc(new_alloc, item_size);

if (arr == NULL) {

PyErr_NoMemory();

return ERROR;

}

*alloc = new_alloc;

}

else if (idx >= *alloc) {

size_t oldsize = *alloc * item_size;

int new_alloc = *alloc << 1;

if (idx >= new_alloc) {

new_alloc = idx + default_alloc;

}

size_t newsize = new_alloc * item_size;

if (oldsize > (SIZE_MAX >> 1)) {

PyErr_NoMemory();

return ERROR;

}

assert(newsize > 0);

void *tmp = PyMem_Realloc(arr, newsize);

if (tmp == NULL) {

PyErr_NoMemory();

return ERROR;

}

*alloc = new_alloc;

arr = tmp;

memset((char *)arr + oldsize, 0, newsize - oldsize);

}

*array = arr;

return SUCCESS;

}

/* The following items change on entry and exit of code blocks.

They must be saved and restored when returning to a block.

*/

struct compiler_unit {

PySTEntryObject *u_ste;

int u_scope_type;

PyObject *u_private; /* for private name mangling */

PyObject *u_static_attributes; /* for class: attributes accessed via self.X */

PyObject *u_deferred_annotations; /* AnnAssign nodes deferred to the end of compilation */

instr_sequence *u_instr_sequence; /* codegen output */

int u_nfblocks;

int u_in_inlined_comp;

struct fblockinfo u_fblock[CO_MAXBLOCKS];

_PyCompile_CodeUnitMetadata u_metadata;

};

/* This struct captures the global state of a compilation.

The u pointer points to the current compilation unit, while units

for enclosing blocks are stored in c_stack. The u and c_stack are

managed by compiler_enter_scope() and compiler_exit_scope().

Note that we don't track recursion levels during compilation - the

task of detecting and rejecting excessive levels of nesting is

handled by the symbol analysis pass.

*/

struct compiler {

PyObject *c_filename;

struct symtable *c_st;

_PyFutureFeatures c_future; /* module's __future__ */

PyCompilerFlags c_flags;

int c_optimize; /* optimization level */

int c_interactive; /* true if in interactive mode */

int c_nestlevel;

PyObject *c_const_cache; /* Python dict holding all constants,

including names tuple */

struct compiler_unit *u; /* compiler state for current block */

PyObject *c_stack; /* Python list holding compiler_unit ptrs */

PyArena *c_arena; /* pointer to memory allocation arena */

bool c_save_nested_seqs; /* if true, construct recursive instruction sequences

* (including instructions for nested code objects)

*/

};

typedef struct {

// A list of strings corresponding to name captures. It is used to track:

// - Repeated name assignments in the same pattern.

// - Different name assignments in alternatives.

// - The order of name assignments in alternatives.

PyObject *stores;

// If 0, any name captures against our subject will raise.

int allow_irrefutable;

// An array of blocks to jump to on failure. Jumping to fail_pop[i] will pop

// i items off of the stack. The end result looks like this (with each block

// falling through to the next):

// fail_pop[4]: POP_TOP

// fail_pop[3]: POP_TOP

// fail_pop[2]: POP_TOP

// fail_pop[1]: POP_TOP

// fail_pop[0]: NOP

jump_target_label *fail_pop;

// The current length of fail_pop.

Py_ssize_t fail_pop_size;

// The number of items on top of the stack that need to *stay* on top of the

// stack. Variable captures go beneath these. All of them will be popped on

// failure.

Py_ssize_t on_top;

} pattern_context;

static int codegen_addop_i(instr_sequence *seq, int opcode, Py_ssize_t oparg, location loc);

static void compiler_free(struct compiler *);

static int compiler_error(struct compiler *, location loc, const char *, ...);

static int compiler_warn(struct compiler *, location loc, const char *, ...);

static int compiler_nameop(struct compiler *, location, identifier, expr_context_ty);

static PyCodeObject *compiler_mod(struct compiler *, mod_ty);

static int compiler_visit_stmt(struct compiler *, stmt_ty);

static int compiler_visit_keyword(struct compiler *, keyword_ty);

static int compiler_visit_expr(struct compiler *, expr_ty);

static int compiler_augassign(struct compiler *, stmt_ty);

static int compiler_annassign(struct compiler *, stmt_ty);

static int compiler_subscript(struct compiler *, expr_ty);

static int compiler_slice(struct compiler *, expr_ty);

static bool are_all_items_const(asdl_expr_seq *, Py_ssize_t, Py_ssize_t);

static int compiler_with(struct compiler *, stmt_ty, int);

static int compiler_async_with(struct compiler *, stmt_ty, int);

static int compiler_async_for(struct compiler *, stmt_ty);

static int compiler_call_simple_kw_helper(struct compiler *c,

location loc,

asdl_keyword_seq *keywords,

Py_ssize_t nkwelts);

static int compiler_call_helper(struct compiler *c, location loc,

int n, asdl_expr_seq *args,

asdl_keyword_seq *keywords);

static int compiler_try_except(struct compiler *, stmt_ty);

static int compiler_try_star_except(struct compiler *, stmt_ty);

static int compiler_sync_comprehension_generator(

struct compiler *c, location loc,

asdl_comprehension_seq *generators, int gen_index,

int depth,

expr_ty elt, expr_ty val, int type,

int iter_on_stack);

static int compiler_async_comprehension_generator(

struct compiler *c, location loc,

asdl_comprehension_seq *generators, int gen_index,

int depth,

expr_ty elt, expr_ty val, int type,

int iter_on_stack);

static int compiler_pattern(struct compiler *, pattern_ty, pattern_context *);

static int compiler_match(struct compiler *, stmt_ty);

static int compiler_pattern_subpattern(struct compiler *,

pattern_ty, pattern_context *);

static int compiler_make_closure(struct compiler *c, location loc,

PyCodeObject *co, Py_ssize_t flags);

static PyCodeObject *optimize_and_assemble(struct compiler *, int addNone);

#define CAPSULE_NAME "compile.c compiler unit"

static int

compiler_setup(struct compiler *c, mod_ty mod, PyObject *filename,

PyCompilerFlags *flags, int optimize, PyArena *arena)

{

PyCompilerFlags local_flags = _PyCompilerFlags_INIT;

c->c_const_cache = PyDict_New();

if (!c->c_const_cache) {

return ERROR;

}

c->c_stack = PyList_New(0);

if (!c->c_stack) {

return ERROR;

}

c->c_filename = Py_NewRef(filename);

c->c_arena = arena;

if (!_PyFuture_FromAST(mod, filename, &c->c_future)) {

return ERROR;

}

if (!flags) {

flags = &local_flags;

}

int merged = c->c_future.ff_features | flags->cf_flags;

c->c_future.ff_features = merged;

flags->cf_flags = merged;

c->c_flags = *flags;

c->c_optimize = (optimize == -1) ? _Py_GetConfig()->optimization_level : optimize;

c->c_nestlevel = 0;

c->c_save_nested_seqs = false;

if (!_PyAST_Optimize(mod, arena, c->c_optimize, merged)) {

return ERROR;

}

c->c_st = _PySymtable_Build(mod, filename, &c->c_future);

if (c->c_st == NULL) {

if (!PyErr_Occurred()) {

PyErr_SetString(PyExc_SystemError, "no symtable");

}

return ERROR;

}

return SUCCESS;

}

static struct compiler*

new_compiler(mod_ty mod, PyObject *filename, PyCompilerFlags *pflags,

int optimize, PyArena *arena)

{

struct compiler *c = PyMem_Calloc(1, sizeof(struct compiler));

if (c == NULL) {

return NULL;

}

if (compiler_setup(c, mod, filename, pflags, optimize, arena) < 0) {

compiler_free(c);

return NULL;

}

return c;

}

PyCodeObject *

_PyAST_Compile(mod_ty mod, PyObject *filename, PyCompilerFlags *pflags,

int optimize, PyArena *arena)

{

assert(!PyErr_Occurred());

struct compiler *c = new_compiler(mod, filename, pflags, optimize, arena);

if (c == NULL) {

return NULL;

}

PyCodeObject *co = compiler_mod(c, mod);

compiler_free(c);

assert(co || PyErr_Occurred());

return co;

}

int

_PyCompile_AstOptimize(mod_ty mod, PyObject *filename, PyCompilerFlags *cf,

int optimize, PyArena *arena)

{

_PyFutureFeatures future;

if (!_PyFuture_FromAST(mod, filename, &future)) {

return -1;

}

int flags = future.ff_features | cf->cf_flags;

if (optimize == -1) {

optimize = _Py_GetConfig()->optimization_level;

}

if (!_PyAST_Optimize(mod, arena, optimize, flags)) {

return -1;

}

return 0;

}

static void

compiler_free(struct compiler *c)

{

if (c->c_st)

_PySymtable_Free(c->c_st);

Py_XDECREF(c->c_filename);

Py_XDECREF(c->c_const_cache);

Py_XDECREF(c->c_stack);

PyMem_Free(c);

}

static PyObject *

list2dict(PyObject *list)

{

Py_ssize_t i, n;

PyObject *v, *k;

PyObject *dict = PyDict_New();

if (!dict) return NULL;

n = PyList_Size(list);

for (i = 0; i < n; i++) {

v = PyLong_FromSsize_t(i);

if (!v) {

Py_DECREF(dict);

return NULL;

}

k = PyList_GET_ITEM(list, i);

if (PyDict_SetItem(dict, k, v) < 0) {

Py_DECREF(v);

Py_DECREF(dict);

return NULL;

}

Py_DECREF(v);

}

return dict;

}

/* Return new dict containing names from src that match scope(s).

src is a symbol table dictionary. If the scope of a name matches

either scope_type or flag is set, insert it into the new dict. The

values are integers, starting at offset and increasing by one for

each key.

*/

static PyObject *

dictbytype(PyObject *src, int scope_type, int flag, Py_ssize_t offset)

{

Py_ssize_t i = offset, num_keys, key_i;

PyObject *k, *v, *dest = PyDict_New();

PyObject *sorted_keys;

assert(offset >= 0);

if (dest == NULL)

return NULL;

/* Sort the keys so that we have a deterministic order on the indexes

saved in the returned dictionary. These indexes are used as indexes

into the free and cell var storage. Therefore if they aren't

deterministic, then the generated bytecode is not deterministic.

*/

sorted_keys = PyDict_Keys(src);

if (sorted_keys == NULL) {

Py_DECREF(dest);

return NULL;

}

if (PyList_Sort(sorted_keys) != 0) {

Py_DECREF(sorted_keys);

Py_DECREF(dest);

return NULL;

}

num_keys = PyList_GET_SIZE(sorted_keys);

for (key_i = 0; key_i < num_keys; key_i++) {

k = PyList_GET_ITEM(sorted_keys, key_i);

v = PyDict_GetItemWithError(src, k);

if (!v) {

if (!PyErr_Occurred()) {

PyErr_SetObject(PyExc_KeyError, k);

}

Py_DECREF(sorted_keys);

Py_DECREF(dest);

return NULL;

}

long vi = PyLong_AsLong(v);

if (vi == -1 && PyErr_Occurred()) {

Py_DECREF(sorted_keys);

Py_DECREF(dest);

return NULL;

}

if (SYMBOL_TO_SCOPE(vi) == scope_type || vi & flag) {

PyObject *item = PyLong_FromSsize_t(i);

if (item == NULL) {

Py_DECREF(sorted_keys);

Py_DECREF(dest);

return NULL;

}

i++;

if (PyDict_SetItem(dest, k, item) < 0) {

Py_DECREF(sorted_keys);

Py_DECREF(item);

Py_DECREF(dest);

return NULL;

}

Py_DECREF(item);

}

}

Py_DECREF(sorted_keys);

return dest;

}

static void

compiler_unit_free(struct compiler_unit *u)

{

Py_CLEAR(u->u_instr_sequence);

Py_CLEAR(u->u_ste);

Py_CLEAR(u->u_metadata.u_name);

Py_CLEAR(u->u_metadata.u_qualname);

Py_CLEAR(u->u_metadata.u_consts);

Py_CLEAR(u->u_metadata.u_names);

Py_CLEAR(u->u_metadata.u_varnames);

Py_CLEAR(u->u_metadata.u_freevars);

Py_CLEAR(u->u_metadata.u_cellvars);

Py_CLEAR(u->u_metadata.u_fasthidden);

Py_CLEAR(u->u_private);

Py_CLEAR(u->u_static_attributes);

Py_CLEAR(u->u_deferred_annotations);

PyMem_Free(u);

}

static int

compiler_maybe_add_static_attribute_to_class(struct compiler *c, expr_ty e)

{

assert(e->kind == Attribute_kind);

expr_ty attr_value = e->v.Attribute.value;

if (attr_value->kind != Name_kind ||

e->v.Attribute.ctx != Store ||

!_PyUnicode_EqualToASCIIString(attr_value->v.Name.id, "self"))

{

return SUCCESS;

}

Py_ssize_t stack_size = PyList_GET_SIZE(c->c_stack);

for (Py_ssize_t i = stack_size - 1; i >= 0; i--) {

PyObject *capsule = PyList_GET_ITEM(c->c_stack, i);

struct compiler_unit *u = (struct compiler_unit *)PyCapsule_GetPointer(

capsule, CAPSULE_NAME);

assert(u);

if (u->u_scope_type == COMPILER_SCOPE_CLASS) {

assert(u->u_static_attributes);

RETURN_IF_ERROR(PySet_Add(u->u_static_attributes, e->v.Attribute.attr));

break;

}

}

return SUCCESS;

}

static int

compiler_set_qualname(struct compiler *c)

{

Py_ssize_t stack_size;

struct compiler_unit *u = c->u;

PyObject *name, *base;

base = NULL;

stack_size = PyList_GET_SIZE(c->c_stack);

assert(stack_size >= 1);

if (stack_size > 1) {

int scope, force_global = 0;

struct compiler_unit *parent;

PyObject *mangled, *capsule;

capsule = PyList_GET_ITEM(c->c_stack, stack_size - 1);

parent = (struct compiler_unit *)PyCapsule_GetPointer(capsule, CAPSULE_NAME);

assert(parent);

if (parent->u_scope_type == COMPILER_SCOPE_ANNOTATIONS) {

/* The parent is an annotation scope, so we need to

look at the grandparent. */

if (stack_size == 2) {

// If we're immediately within the module, we can skip

// the rest and just set the qualname to be the same as name.

u->u_metadata.u_qualname = Py_NewRef(u->u_metadata.u_name);

return SUCCESS;

}

capsule = PyList_GET_ITEM(c->c_stack, stack_size - 2);

parent = (struct compiler_unit *)PyCapsule_GetPointer(capsule, CAPSULE_NAME);

assert(parent);

}

if (u->u_scope_type == COMPILER_SCOPE_FUNCTION

|| u->u_scope_type == COMPILER_SCOPE_ASYNC_FUNCTION

|| u->u_scope_type == COMPILER_SCOPE_CLASS) {

assert(u->u_metadata.u_name);

mangled = _Py_Mangle(parent->u_private, u->u_metadata.u_name);

if (!mangled) {

return ERROR;

}

scope = _PyST_GetScope(parent->u_ste, mangled);

Py_DECREF(mangled);

RETURN_IF_ERROR(scope);

assert(scope != GLOBAL_IMPLICIT);

if (scope == GLOBAL_EXPLICIT)

force_global = 1;

}

if (!force_global) {

if (parent->u_scope_type == COMPILER_SCOPE_FUNCTION

|| parent->u_scope_type == COMPILER_SCOPE_ASYNC_FUNCTION

|| parent->u_scope_type == COMPILER_SCOPE_LAMBDA)

{

_Py_DECLARE_STR(dot_locals, ".<locals>");

base = PyUnicode_Concat(parent->u_metadata.u_qualname,

&_Py_STR(dot_locals));

if (base == NULL) {

return ERROR;

}

}

else {

base = Py_NewRef(parent->u_metadata.u_qualname);

}

}

}

if (base != NULL) {

name = PyUnicode_Concat(base, _Py_LATIN1_CHR('.'));

Py_DECREF(base);

if (name == NULL) {

return ERROR;

}

PyUnicode_Append(&name, u->u_metadata.u_name);

if (name == NULL) {

return ERROR;

}

}

else {

name = Py_NewRef(u->u_metadata.u_name);

}

u->u_metadata.u_qualname = name;

return SUCCESS;

}

static int

codegen_addop_noarg(instr_sequence *seq, int opcode, location loc)

{

assert(!OPCODE_HAS_ARG(opcode));

assert(!IS_ASSEMBLER_OPCODE(opcode));

return _PyInstructionSequence_Addop(seq, opcode, 0, loc);

}

static Py_ssize_t

dict_add_o(PyObject *dict, PyObject *o)

{

PyObject *v;

Py_ssize_t arg;

if (PyDict_GetItemRef(dict, o, &v) < 0) {

return ERROR;

}

if (!v) {

arg = PyDict_GET_SIZE(dict);

v = PyLong_FromSsize_t(arg);

if (!v) {

return ERROR;

}

if (PyDict_SetItem(dict, o, v) < 0) {

Py_DECREF(v);

return ERROR;

}

}

else

arg = PyLong_AsLong(v);

Py_DECREF(v);

return arg;

}

/* Merge const *o* and return constant key object.

* If recursive, insert all elements if o is a tuple or frozen set.

*/

static PyObject*

const_cache_insert(PyObject *const_cache, PyObject *o, bool recursive)

{

assert(PyDict_CheckExact(const_cache));

// None and Ellipsis are immortal objects, and key is the singleton.

// No need to merge object and key.

if (o == Py_None || o == Py_Ellipsis) {

return o;

}

PyObject *key = _PyCode_ConstantKey(o);

if (key == NULL) {

return NULL;

}

PyObject *t;

int res = PyDict_SetDefaultRef(const_cache, key, key, &t);

if (res != 0) {

// o was not inserted into const_cache. t is either the existing value

// or NULL (on error).

Py_DECREF(key);

return t;

}

Py_DECREF(t);

if (!recursive) {

return key;

}

// We registered o in const_cache.

// When o is a tuple or frozenset, we want to merge its

// items too.

if (PyTuple_CheckExact(o)) {

Py_ssize_t len = PyTuple_GET_SIZE(o);

for (Py_ssize_t i = 0; i < len; i++) {

PyObject *item = PyTuple_GET_ITEM(o, i);

PyObject *u = const_cache_insert(const_cache, item, recursive);

if (u == NULL) {

Py_DECREF(key);

return NULL;

}

// See _PyCode_ConstantKey()

PyObject *v; // borrowed

if (PyTuple_CheckExact(u)) {

v = PyTuple_GET_ITEM(u, 1);

}

else {

v = u;

}

if (v != item) {

PyTuple_SET_ITEM(o, i, Py_NewRef(v));

Py_DECREF(item);

}

Py_DECREF(u);

}

}

else if (PyFrozenSet_CheckExact(o)) {

// *key* is tuple. And its first item is frozenset of

// constant keys.

// See _PyCode_ConstantKey() for detail.

assert(PyTuple_CheckExact(key));

assert(PyTuple_GET_SIZE(key) == 2);

Py_ssize_t len = PySet_GET_SIZE(o);

if (len == 0) { // empty frozenset should not be re-created.

return key;

}

PyObject *tuple = PyTuple_New(len);

if (tuple == NULL) {

Py_DECREF(key);

return NULL;

}

Py_ssize_t i = 0, pos = 0;

PyObject *item;

Py_hash_t hash;

while (_PySet_NextEntry(o, &pos, &item, &hash)) {

PyObject *k = const_cache_insert(const_cache, item, recursive);

if (k == NULL) {

Py_DECREF(tuple);

Py_DECREF(key);

return NULL;

}

PyObject *u;

if (PyTuple_CheckExact(k)) {

u = Py_NewRef(PyTuple_GET_ITEM(k, 1));

Py_DECREF(k);

}

else {

u = k;

}

PyTuple_SET_ITEM(tuple, i, u); // Steals reference of u.

i++;

}

// Instead of rewriting o, we create new frozenset and embed in the

// key tuple. Caller should get merged frozenset from the key tuple.

PyObject *new = PyFrozenSet_New(tuple);

Py_DECREF(tuple);

if (new == NULL) {

Py_DECREF(key);

return NULL;

}

assert(PyTuple_GET_ITEM(key, 1) == o);

Py_DECREF(o);

PyTuple_SET_ITEM(key, 1, new);

}

return key;

}

static PyObject*

merge_consts_recursive(PyObject *const_cache, PyObject *o)

{

return const_cache_insert(const_cache, o, true);

}

static Py_ssize_t

compiler_add_const(struct compiler *c, PyObject *o)

{

PyObject *key = merge_consts_recursive(c->c_const_cache, o);

if (key == NULL) {

return ERROR;

}

Py_ssize_t arg = dict_add_o(c->u->u_metadata.u_consts, key);

Py_DECREF(key);

return arg;

}

static int

compiler_addop_load_const(struct compiler *c, location loc, PyObject *o)

{

Py_ssize_t arg = compiler_add_const(c, o);

if (arg < 0) {

return ERROR;

}

return codegen_addop_i(INSTR_SEQUENCE(c), LOAD_CONST, arg, loc);

}

static int

compiler_addop_o(struct compiler *c, location loc,

int opcode, PyObject *dict, PyObject *o)

{

Py_ssize_t arg = dict_add_o(dict, o);

if (arg < 0) {

return ERROR;

}

return codegen_addop_i(INSTR_SEQUENCE(c), opcode, arg, loc);

}

#define LOAD_METHOD -1

#define LOAD_SUPER_METHOD -2

#define LOAD_ZERO_SUPER_ATTR -3

#define LOAD_ZERO_SUPER_METHOD -4

static int

compiler_addop_name(struct compiler *c, location loc,

int opcode, PyObject *dict, PyObject *o)

{

PyObject *mangled = compiler_maybe_mangle(c, o);

if (!mangled) {

return ERROR;

}

Py_ssize_t arg = dict_add_o(dict, mangled);

Py_DECREF(mangled);

if (arg < 0) {

return ERROR;

}

if (opcode == LOAD_ATTR) {

arg <<= 1;

}

if (opcode == LOAD_METHOD) {

opcode = LOAD_ATTR;

arg <<= 1;

arg |= 1;

}

if (opcode == LOAD_SUPER_ATTR) {

arg <<= 2;

arg |= 2;

}

if (opcode == LOAD_SUPER_METHOD) {

opcode = LOAD_SUPER_ATTR;

arg <<= 2;

arg |= 3;

}

if (opcode == LOAD_ZERO_SUPER_ATTR) {

opcode = LOAD_SUPER_ATTR;

arg <<= 2;

}

if (opcode == LOAD_ZERO_SUPER_METHOD) {

opcode = LOAD_SUPER_ATTR;

arg <<= 2;

arg |= 1;

}

return codegen_addop_i(INSTR_SEQUENCE(c), opcode, arg, loc);

}

/* Add an opcode with an integer argument */

static int

codegen_addop_i(instr_sequence *seq, int opcode, Py_ssize_t oparg, location loc)

{

/* oparg value is unsigned, but a signed C int is usually used to store

it in the C code (like Python/ceval.c).

Limit to 32-bit signed C int (rather than INT_MAX) for portability.

The argument of a concrete bytecode instruction is limited to 8-bit.

EXTENDED_ARG is used for 16, 24, and 32-bit arguments. */

int oparg_ = Py_SAFE_DOWNCAST(oparg, Py_ssize_t, int);

assert(!IS_ASSEMBLER_OPCODE(opcode));

return _PyInstructionSequence_Addop(seq, opcode, oparg_, loc);

}

static int

codegen_addop_j(instr_sequence *seq, location loc,

int opcode, jump_target_label target)

{

assert(IS_LABEL(target));

assert(OPCODE_HAS_JUMP(opcode) || IS_BLOCK_PUSH_OPCODE(opcode));

assert(!IS_ASSEMBLER_OPCODE(opcode));

return _PyInstructionSequence_Addop(seq, opcode, target.id, loc);

}

#define RETURN_IF_ERROR_IN_SCOPE(C, CALL) { \

if ((CALL) < 0) { \

compiler_exit_scope((C)); \

return ERROR; \

} \

}

#define ADDOP(C, LOC, OP) \

RETURN_IF_ERROR(codegen_addop_noarg(INSTR_SEQUENCE(C), (OP), (LOC)))

#define ADDOP_IN_SCOPE(C, LOC, OP) RETURN_IF_ERROR_IN_SCOPE((C), codegen_addop_noarg(INSTR_SEQUENCE(C), (OP), (LOC)))

#define ADDOP_LOAD_CONST(C, LOC, O) \

RETURN_IF_ERROR(compiler_addop_load_const((C), (LOC), (O)))

/* Same as ADDOP_LOAD_CONST, but steals a reference. */

#define ADDOP_LOAD_CONST_NEW(C, LOC, O) { \

PyObject *__new_const = (O); \

if (__new_const == NULL) { \

return ERROR; \

} \

if (compiler_addop_load_const((C), (LOC), __new_const) < 0) { \

Py_DECREF(__new_const); \

return ERROR; \

} \

Py_DECREF(__new_const); \

}

#define ADDOP_N(C, LOC, OP, O, TYPE) { \

assert(!OPCODE_HAS_CONST(OP)); /* use ADDOP_LOAD_CONST_NEW */ \

if (compiler_addop_o((C), (LOC), (OP), (C)->u->u_metadata.u_ ## TYPE, (O)) < 0) { \

Py_DECREF((O)); \

return ERROR; \

} \

Py_DECREF((O)); \

}

#define ADDOP_NAME(C, LOC, OP, O, TYPE) \

RETURN_IF_ERROR(compiler_addop_name((C), (LOC), (OP), (C)->u->u_metadata.u_ ## TYPE, (O)))

#define ADDOP_I(C, LOC, OP, O) \

RETURN_IF_ERROR(codegen_addop_i(INSTR_SEQUENCE(C), (OP), (O), (LOC)))

#define ADDOP_JUMP(C, LOC, OP, O) \

RETURN_IF_ERROR(codegen_addop_j(INSTR_SEQUENCE(C), (LOC), (OP), (O)))

#define ADDOP_COMPARE(C, LOC, CMP) \

RETURN_IF_ERROR(compiler_addcompare((C), (LOC), (cmpop_ty)(CMP)))

#define ADDOP_BINARY(C, LOC, BINOP) \