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pycore_code.h
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671 lines (546 loc) · 20.6 KB
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#ifndef Py_INTERNAL_CODE_H
#define Py_INTERNAL_CODE_H
#ifdef __cplusplus
extern "C" {
#endif
#ifndef Py_BUILD_CORE
# error "this header requires Py_BUILD_CORE define"
#endif
#include "pycore_backoff.h" // _Py_BackoffCounter
#include "pycore_structs.h" // _Py_CODEUNIT
#include "pycore_tstate.h" // _PyThreadStateImpl
#define _PyCode_CODE(CO) _Py_RVALUE((_Py_CODEUNIT *)(CO)->co_code_adaptive)
#define _PyCode_NBYTES(CO) (Py_SIZE(CO) * (Py_ssize_t)sizeof(_Py_CODEUNIT))
/* These macros only remain defined for compatibility. */
#define _Py_OPCODE(word) ((word).op.code)
#define _Py_OPARG(word) ((word).op.arg)
static inline _Py_CODEUNIT
_py_make_codeunit(uint8_t opcode, uint8_t oparg)
{
// No designated initialisers because of C++ compat
_Py_CODEUNIT word;
word.op.code = opcode;
word.op.arg = oparg;
return word;
}
static inline void
_py_set_opcode(_Py_CODEUNIT *word, uint8_t opcode)
{
word->op.code = opcode;
}
#define _Py_MAKE_CODEUNIT(opcode, oparg) _py_make_codeunit((opcode), (oparg))
#define _Py_SET_OPCODE(word, opcode) _py_set_opcode(&(word), (opcode))
// We hide some of the newer PyCodeObject fields behind macros.
// This helps with backporting certain changes to 3.12.
#define _PyCode_HAS_EXECUTORS(CODE) \
(CODE->co_executors != NULL)
#define _PyCode_HAS_INSTRUMENTATION(CODE) \
(CODE->_co_instrumentation_version > 0)
extern PyStatus _PyCode_Init(PyInterpreterState *interp);
extern void _PyCode_Fini(PyInterpreterState *interp);
/* PEP 659
* Specialization and quickening structs and helper functions
*/
// Inline caches. If you change the number of cache entries for an instruction,
// you must *also* update the number of cache entries in Lib/opcode.py and bump
// the magic number in Lib/importlib/_bootstrap_external.py!
#define CACHE_ENTRIES(cache) (sizeof(cache)/sizeof(_Py_CODEUNIT))
typedef struct {
_Py_BackoffCounter counter;
uint16_t module_keys_version;
uint16_t builtin_keys_version;
uint16_t index;
} _PyLoadGlobalCache;
#define INLINE_CACHE_ENTRIES_LOAD_GLOBAL CACHE_ENTRIES(_PyLoadGlobalCache)
typedef struct {
_Py_BackoffCounter counter;
uint16_t external_cache[4];
} _PyBinaryOpCache;
#define INLINE_CACHE_ENTRIES_BINARY_OP CACHE_ENTRIES(_PyBinaryOpCache)
typedef struct {
_Py_BackoffCounter counter;
} _PyUnpackSequenceCache;
#define INLINE_CACHE_ENTRIES_UNPACK_SEQUENCE \
CACHE_ENTRIES(_PyUnpackSequenceCache)
typedef struct {
_Py_BackoffCounter counter;
} _PyCompareOpCache;
#define INLINE_CACHE_ENTRIES_COMPARE_OP CACHE_ENTRIES(_PyCompareOpCache)
typedef struct {
_Py_BackoffCounter counter;
} _PySuperAttrCache;
#define INLINE_CACHE_ENTRIES_LOAD_SUPER_ATTR CACHE_ENTRIES(_PySuperAttrCache)
typedef struct {
_Py_BackoffCounter counter;
uint16_t version[2];
uint16_t index;
} _PyAttrCache;
typedef struct {
_Py_BackoffCounter counter;
uint16_t type_version[2];
union {
uint16_t keys_version[2];
uint16_t dict_offset;
};
uint16_t descr[4];
} _PyLoadMethodCache;
// MUST be the max(_PyAttrCache, _PyLoadMethodCache)
#define INLINE_CACHE_ENTRIES_LOAD_ATTR CACHE_ENTRIES(_PyLoadMethodCache)
#define INLINE_CACHE_ENTRIES_STORE_ATTR CACHE_ENTRIES(_PyAttrCache)
typedef struct {
_Py_BackoffCounter counter;
uint16_t func_version[2];
} _PyCallCache;
#define INLINE_CACHE_ENTRIES_CALL CACHE_ENTRIES(_PyCallCache)
#define INLINE_CACHE_ENTRIES_CALL_KW CACHE_ENTRIES(_PyCallCache)
typedef struct {
_Py_BackoffCounter counter;
} _PyStoreSubscrCache;
#define INLINE_CACHE_ENTRIES_STORE_SUBSCR CACHE_ENTRIES(_PyStoreSubscrCache)
typedef struct {
_Py_BackoffCounter counter;
} _PyForIterCache;
#define INLINE_CACHE_ENTRIES_FOR_ITER CACHE_ENTRIES(_PyForIterCache)
typedef struct {
_Py_BackoffCounter counter;
} _PySendCache;
#define INLINE_CACHE_ENTRIES_SEND CACHE_ENTRIES(_PySendCache)
typedef struct {
_Py_BackoffCounter counter;
uint16_t version[2];
} _PyToBoolCache;
#define INLINE_CACHE_ENTRIES_TO_BOOL CACHE_ENTRIES(_PyToBoolCache)
typedef struct {
_Py_BackoffCounter counter;
} _PyContainsOpCache;
#define INLINE_CACHE_ENTRIES_CONTAINS_OP CACHE_ENTRIES(_PyContainsOpCache)
/* "Locals plus" for a code object is the set of locals + cell vars +
* free vars. This relates to variable names as well as offsets into
* the "fast locals" storage array of execution frames. The compiler
* builds the list of names, their offsets, and the corresponding
* kind of local.
*
* Those kinds represent the source of the initial value and the
* variable's scope (as related to closures). A "local" is an
* argument or other variable defined in the current scope. A "free"
* variable is one that is defined in an outer scope and comes from
* the function's closure. A "cell" variable is a local that escapes
* into an inner function as part of a closure, and thus must be
* wrapped in a cell. Any "local" can also be a "cell", but the
* "free" kind is mutually exclusive with both.
*/
// Note that these all fit within a byte, as do combinations.
#define CO_FAST_ARG_POS (0x02) // pos-only, pos-or-kw, varargs
#define CO_FAST_ARG_KW (0x04) // kw-only, pos-or-kw, varkwargs
#define CO_FAST_ARG_VAR (0x08) // varargs, varkwargs
#define CO_FAST_ARG (CO_FAST_ARG_POS | CO_FAST_ARG_KW | CO_FAST_ARG_VAR)
#define CO_FAST_HIDDEN (0x10)
#define CO_FAST_LOCAL (0x20)
#define CO_FAST_CELL (0x40)
#define CO_FAST_FREE (0x80)
typedef unsigned char _PyLocals_Kind;
static inline _PyLocals_Kind
_PyLocals_GetKind(PyObject *kinds, int i)
{
assert(PyBytes_Check(kinds));
assert(0 <= i && i < PyBytes_GET_SIZE(kinds));
char *ptr = PyBytes_AS_STRING(kinds);
return (_PyLocals_Kind)(ptr[i]);
}
static inline void
_PyLocals_SetKind(PyObject *kinds, int i, _PyLocals_Kind kind)
{
assert(PyBytes_Check(kinds));
assert(0 <= i && i < PyBytes_GET_SIZE(kinds));
char *ptr = PyBytes_AS_STRING(kinds);
ptr[i] = (char) kind;
}
struct _PyCodeConstructor {
/* metadata */
PyObject *filename;
PyObject *name;
PyObject *qualname;
int flags;
/* the code */
PyObject *code;
int firstlineno;
PyObject *linetable;
/* used by the code */
PyObject *consts;
PyObject *names;
/* mapping frame offsets to information */
PyObject *localsplusnames; // Tuple of strings
PyObject *localspluskinds; // Bytes object, one byte per variable
/* args (within varnames) */
int argcount;
int posonlyargcount;
// XXX Replace argcount with posorkwargcount (argcount - posonlyargcount).
int kwonlyargcount;
/* needed to create the frame */
int stacksize;
/* used by the eval loop */
PyObject *exceptiontable;
};
// Using an "arguments struct" like this is helpful for maintainability
// in a case such as this with many parameters. It does bear a risk:
// if the struct changes and callers are not updated properly then the
// compiler will not catch problems (like a missing argument). This can
// cause hard-to-debug problems. The risk is mitigated by the use of
// check_code() in codeobject.c. However, we may decide to switch
// back to a regular function signature. Regardless, this approach
// wouldn't be appropriate if this weren't a strictly internal API.
// (See the comments in https://github.com/python/cpython/pull/26258.)
extern int _PyCode_Validate(struct _PyCodeConstructor *);
extern PyCodeObject* _PyCode_New(struct _PyCodeConstructor *);
/* Private API */
/* Getters for internal PyCodeObject data. */
extern PyObject* _PyCode_GetVarnames(PyCodeObject *);
extern PyObject* _PyCode_GetCellvars(PyCodeObject *);
extern PyObject* _PyCode_GetFreevars(PyCodeObject *);
extern PyObject* _PyCode_GetCode(PyCodeObject *);
/** API for initializing the line number tables. */
extern int _PyCode_InitAddressRange(PyCodeObject* co, PyCodeAddressRange *bounds);
/** Out of process API for initializing the location table. */
extern void _PyLineTable_InitAddressRange(
const char *linetable,
Py_ssize_t length,
int firstlineno,
PyCodeAddressRange *range);
/** API for traversing the line number table. */
extern int _PyLineTable_NextAddressRange(PyCodeAddressRange *range);
extern int _PyLineTable_PreviousAddressRange(PyCodeAddressRange *range);
// Similar to PyCode_Addr2Line(), but return -1 if the code object is invalid
// and can be called without an attached tstate. Used by dump_frame() in
// Python/traceback.c. The function uses heuristics to detect freed memory,
// it's not 100% reliable.
extern int _PyCode_SafeAddr2Line(PyCodeObject *co, int addr);
/** API for executors */
extern void _PyCode_Clear_Executors(PyCodeObject *code);
#ifdef Py_GIL_DISABLED
// gh-115999 tracks progress on addressing this.
#define ENABLE_SPECIALIZATION 0
// Use this to enable specialization families once they are thread-safe. All
// uses will be replaced with ENABLE_SPECIALIZATION once all families are
// thread-safe.
#define ENABLE_SPECIALIZATION_FT 1
#else
#define ENABLE_SPECIALIZATION 1
#define ENABLE_SPECIALIZATION_FT ENABLE_SPECIALIZATION
#endif
/* Specialization functions */
extern void _Py_Specialize_LoadSuperAttr(_PyStackRef global_super, _PyStackRef cls,
_Py_CODEUNIT *instr, int load_method);
extern void _Py_Specialize_LoadAttr(_PyStackRef owner, _Py_CODEUNIT *instr,
PyObject *name);
extern void _Py_Specialize_StoreAttr(_PyStackRef owner, _Py_CODEUNIT *instr,
PyObject *name);
extern void _Py_Specialize_LoadGlobal(PyObject *globals, PyObject *builtins,
_Py_CODEUNIT *instr, PyObject *name);
extern void _Py_Specialize_StoreSubscr(_PyStackRef container, _PyStackRef sub,
_Py_CODEUNIT *instr);
extern void _Py_Specialize_Call(_PyStackRef callable, _Py_CODEUNIT *instr,
int nargs);
extern void _Py_Specialize_CallKw(_PyStackRef callable, _Py_CODEUNIT *instr,
int nargs);
extern void _Py_Specialize_BinaryOp(_PyStackRef lhs, _PyStackRef rhs, _Py_CODEUNIT *instr,
int oparg, _PyStackRef *locals);
extern void _Py_Specialize_CompareOp(_PyStackRef lhs, _PyStackRef rhs,
_Py_CODEUNIT *instr, int oparg);
extern void _Py_Specialize_UnpackSequence(_PyStackRef seq, _Py_CODEUNIT *instr,
int oparg);
extern void _Py_Specialize_ForIter(_PyStackRef iter, _Py_CODEUNIT *instr, int oparg);
extern void _Py_Specialize_Send(_PyStackRef receiver, _Py_CODEUNIT *instr);
extern void _Py_Specialize_ToBool(_PyStackRef value, _Py_CODEUNIT *instr);
extern void _Py_Specialize_ContainsOp(_PyStackRef value, _Py_CODEUNIT *instr);
extern void _Py_GatherStats_GetIter(_PyStackRef iterable);
// Utility functions for reading/writing 32/64-bit values in the inline caches.
// Great care should be taken to ensure that these functions remain correct and
// performant! They should compile to just "move" instructions on all supported
// compilers and platforms.
// We use memcpy to let the C compiler handle unaligned accesses and endianness
// issues for us. It also seems to produce better code than manual copying for
// most compilers (see https://blog.regehr.org/archives/959 for more info).
static inline void
write_u32(uint16_t *p, uint32_t val)
{
memcpy(p, &val, sizeof(val));
}
static inline void
write_u64(uint16_t *p, uint64_t val)
{
memcpy(p, &val, sizeof(val));
}
static inline void
write_ptr(uint16_t *p, void *val)
{
memcpy(p, &val, sizeof(val));
}
static inline uint16_t
read_u16(uint16_t *p)
{
return *p;
}
static inline uint32_t
read_u32(uint16_t *p)
{
uint32_t val;
memcpy(&val, p, sizeof(val));
return val;
}
static inline uint64_t
read_u64(uint16_t *p)
{
uint64_t val;
memcpy(&val, p, sizeof(val));
return val;
}
static inline PyObject *
read_obj(uint16_t *p)
{
PyObject *val;
memcpy(&val, p, sizeof(val));
return val;
}
/* See InternalDocs/exception_handling.md for details.
*/
static inline unsigned char *
parse_varint(unsigned char *p, int *result) {
int val = p[0] & 63;
while (p[0] & 64) {
p++;
val = (val << 6) | (p[0] & 63);
}
*result = val;
return p+1;
}
static inline int
write_varint(uint8_t *ptr, unsigned int val)
{
int written = 1;
while (val >= 64) {
*ptr++ = 64 | (val & 63);
val >>= 6;
written++;
}
*ptr = (uint8_t)val;
return written;
}
static inline int
write_signed_varint(uint8_t *ptr, int val)
{
unsigned int uval;
if (val < 0) {
// (unsigned int)(-val) has an undefined behavior for INT_MIN
uval = ((0 - (unsigned int)val) << 1) | 1;
}
else {
uval = (unsigned int)val << 1;
}
return write_varint(ptr, uval);
}
static inline int
write_location_entry_start(uint8_t *ptr, int code, int length)
{
assert((code & 15) == code);
*ptr = 128 | (uint8_t)(code << 3) | (uint8_t)(length - 1);
return 1;
}
/** Counters
* The first 16-bit value in each inline cache is a counter.
*
* When counting executions until the next specialization attempt,
* exponential backoff is used to reduce the number of specialization failures.
* See pycore_backoff.h for more details.
* On a specialization failure, the backoff counter is restarted.
*/
// A value of 1 means that we attempt to specialize the *second* time each
// instruction is executed. Executing twice is a much better indicator of
// "hotness" than executing once, but additional warmup delays only prevent
// specialization. Most types stabilize by the second execution, too:
#define ADAPTIVE_WARMUP_VALUE 1
#define ADAPTIVE_WARMUP_BACKOFF 1
// A value of 52 means that we attempt to re-specialize after 53 misses (a prime
// number, useful for avoiding artifacts if every nth value is a different type
// or something). Setting the backoff to 0 means that the counter is reset to
// the same state as a warming-up instruction (value == 1, backoff == 1) after
// deoptimization. This isn't strictly necessary, but it is bit easier to reason
// about when thinking about the opcode transitions as a state machine:
#define ADAPTIVE_COOLDOWN_VALUE 52
#define ADAPTIVE_COOLDOWN_BACKOFF 0
// Can't assert this in pycore_backoff.h because of header order dependencies
#if SIDE_EXIT_INITIAL_VALUE <= ADAPTIVE_COOLDOWN_VALUE
# error "Cold exit value should be larger than adaptive cooldown value"
#endif
static inline _Py_BackoffCounter
adaptive_counter_bits(uint16_t value, uint16_t backoff) {
return make_backoff_counter(value, backoff);
}
static inline _Py_BackoffCounter
adaptive_counter_warmup(void) {
return adaptive_counter_bits(ADAPTIVE_WARMUP_VALUE,
ADAPTIVE_WARMUP_BACKOFF);
}
static inline _Py_BackoffCounter
adaptive_counter_cooldown(void) {
return adaptive_counter_bits(ADAPTIVE_COOLDOWN_VALUE,
ADAPTIVE_COOLDOWN_BACKOFF);
}
static inline _Py_BackoffCounter
adaptive_counter_backoff(_Py_BackoffCounter counter) {
return restart_backoff_counter(counter);
}
/* Specialization Extensions */
/* callbacks for an external specialization */
typedef int (*binaryopguardfunc)(PyObject *lhs, PyObject *rhs);
typedef PyObject *(*binaryopactionfunc)(PyObject *lhs, PyObject *rhs);
typedef struct {
int oparg;
binaryopguardfunc guard;
binaryopactionfunc action;
} _PyBinaryOpSpecializationDescr;
/* Comparison bit masks. */
/* Note this evaluates its arguments twice each */
#define COMPARISON_BIT(x, y) (1 << (2 * ((x) >= (y)) + ((x) <= (y))))
/*
* The following bits are chosen so that the value of
* COMPARSION_BIT(left, right)
* masked by the values below will be non-zero if the
* comparison is true, and zero if it is false */
/* This is for values that are unordered, ie. NaN, not types that are unordered, e.g. sets */
#define COMPARISON_UNORDERED 1
#define COMPARISON_LESS_THAN 2
#define COMPARISON_GREATER_THAN 4
#define COMPARISON_EQUALS 8
#define COMPARISON_NOT_EQUALS (COMPARISON_UNORDERED | COMPARISON_LESS_THAN | COMPARISON_GREATER_THAN)
extern int _Py_Instrument(PyCodeObject *co, PyInterpreterState *interp);
extern _Py_CODEUNIT _Py_GetBaseCodeUnit(PyCodeObject *code, int offset);
extern int _PyInstruction_GetLength(PyCodeObject *code, int offset);
extern PyObject *_PyInstrumentation_BranchesIterator(PyCodeObject *code);
struct _PyCode8 _PyCode_DEF(8);
PyAPI_DATA(const struct _PyCode8) _Py_InitCleanup;
#ifdef Py_GIL_DISABLED
static inline _PyCodeArray *
_PyCode_GetTLBCArray(PyCodeObject *co)
{
return _Py_STATIC_CAST(_PyCodeArray *,
_Py_atomic_load_ptr_acquire(&co->co_tlbc));
}
// Return a pointer to the thread-local bytecode for the current thread, if it
// exists.
static inline _Py_CODEUNIT *
_PyCode_GetTLBCFast(PyThreadState *tstate, PyCodeObject *co)
{
_PyCodeArray *code = _PyCode_GetTLBCArray(co);
int32_t idx = ((_PyThreadStateImpl*) tstate)->tlbc_index;
if (idx < code->size && code->entries[idx] != NULL) {
return (_Py_CODEUNIT *) code->entries[idx];
}
return NULL;
}
// Return a pointer to the thread-local bytecode for the current thread,
// creating it if necessary.
extern _Py_CODEUNIT *_PyCode_GetTLBC(PyCodeObject *co);
// Reserve an index for the current thread into thread-local bytecode
// arrays
//
// Returns the reserved index or -1 on error.
extern int32_t _Py_ReserveTLBCIndex(PyInterpreterState *interp);
// Release the current thread's index into thread-local bytecode arrays
extern void _Py_ClearTLBCIndex(_PyThreadStateImpl *tstate);
// Free all TLBC copies not associated with live threads.
//
// Returns 0 on success or -1 on error.
extern int _Py_ClearUnusedTLBC(PyInterpreterState *interp);
#endif
typedef struct {
int total;
struct co_locals_counts {
int total;
struct {
int total;
int numposonly;
int numposorkw;
int numkwonly;
int varargs;
int varkwargs;
} args;
int numpure;
struct {
int total;
// numargs does not contribute to locals.total.
int numargs;
int numothers;
} cells;
struct {
int total;
int numpure;
int numcells;
} hidden;
} locals;
int numfree; // nonlocal
struct co_unbound_counts {
int total;
struct {
int total;
int numglobal;
int numbuiltin;
int numunknown;
} globals;
int numattrs;
int numunknown;
} unbound;
} _PyCode_var_counts_t;
PyAPI_FUNC(void) _PyCode_GetVarCounts(
PyCodeObject *,
_PyCode_var_counts_t *);
PyAPI_FUNC(int) _PyCode_SetUnboundVarCounts(
PyThreadState *,
PyCodeObject *,
_PyCode_var_counts_t *,
PyObject *globalnames,
PyObject *attrnames,
PyObject *globalsns,
PyObject *builtinsns);
/* "Stateless" code is a function or code object which does not rely on
* external state or internal state. It may rely on arguments and
* builtins, but not globals or a closure. Thus it does not rely
* on __globals__ or __closure__, and a stateless function
* is equivalent to its code object.
*
* Stateless code also does not keep any persistent state
* of its own, so it can't have any executors, monitoring,
* instrumentation, or "extras" (i.e. co_extra).
*
* Stateless code may create nested functions, including closures.
* However, nested functions must themselves be stateless, except they
* *can* close on the enclosing locals.
*
* Stateless code may return any value, including nested functions and closures.
*
* Stateless code that takes no arguments and doesn't return anything
* may be treated like a script.
*
* We consider stateless code to be "portable" if it does not return
* any object that holds a reference to any of the code's locals. Thus
* generators and coroutines are not portable. Likewise a function
* that returns a closure is not portable. The concept of
* portability is useful in cases where the code is run
* in a different execution context than where
* the return value will be used. */
PyAPI_FUNC(int) _PyCode_CheckNoInternalState(PyCodeObject *, const char **);
PyAPI_FUNC(int) _PyCode_CheckNoExternalState(
PyCodeObject *,
_PyCode_var_counts_t *,
const char **);
PyAPI_FUNC(int) _PyCode_VerifyStateless(
PyThreadState *,
PyCodeObject *,
PyObject *globalnames,
PyObject *globalsns,
PyObject *builtinsns);
PyAPI_FUNC(int) _PyCode_CheckPureFunction(PyCodeObject *, const char **);
PyAPI_FUNC(int) _PyCode_ReturnsOnlyNone(PyCodeObject *);
#ifdef __cplusplus
}
#endif
#endif /* !Py_INTERNAL_CODE_H */