code.h
#ifndef Py_CPYTHON_CODE_H
# error "this header file must not be included directly"
#endif
/* Each instruction in a code object is a fixed-width value,
* currently 2 bytes: 1-byte opcode + 1-byte oparg. The EXTENDED_ARG
* opcode allows for larger values but the current limit is 3 uses
* of EXTENDED_ARG (see Python/wordcode_helpers.h), for a maximum
* 32-bit value. This aligns with the note in Python/compile.c
* (compiler_addop_i_line) indicating that the max oparg value is
* 2**32 - 1, rather than INT_MAX.
*/
typedef uint16_t _Py_CODEUNIT;
#ifdef WORDS_BIGENDIAN
# define _Py_OPCODE(word) ((word) >> 8)
# define _Py_OPARG(word) ((word) & 255)
# define _Py_MAKECODEUNIT(opcode, oparg) (((opcode)<<8)|(oparg))
#else
# define _Py_OPCODE(word) ((word) & 255)
# define _Py_OPARG(word) ((word) >> 8)
# define _Py_MAKECODEUNIT(opcode, oparg) ((opcode)|((oparg)<<8))
#endif
/* Bytecode object */
struct PyCodeObject {
PyObject_HEAD
/* Note only the following fields are used in hash and/or comparisons
*
* - co_name
* - co_argcount
* - co_posonlyargcount
* - co_kwonlyargcount
* - co_nlocals
* - co_stacksize
* - co_flags
* - co_firstlineno
* - co_code
* - co_consts
* - co_names
* - co_varnames
* - co_freevars
* - co_cellvars
*
* This is done to preserve the name and line number for tracebacks
* and debuggers; otherwise, constant de-duplication would collapse
* identical functions/lambdas defined on different lines.
*/
/* These fields are set with provided values on new code objects. */
// The hottest fields (in the eval loop) are grouped here at the top.
PyObject *co_consts; /* list (constants used) */
PyObject *co_names; /* list of strings (names used) */
_Py_CODEUNIT *co_firstinstr; /* Pointer to first instruction, used for quickening.
Unlike the other "hot" fields, this one is
actually derived from co_code. */
PyObject *co_exceptiontable; /* Byte string encoding exception handling table */
int co_flags; /* CO_..., see below */
int co_warmup; /* Warmup counter for quickening */
// The rest are not so impactful on performance.
int co_argcount; /* #arguments, except *args */
int co_posonlyargcount; /* #positional only arguments */
int co_kwonlyargcount; /* #keyword only arguments */
int co_stacksize; /* #entries needed for evaluation stack */
int co_firstlineno; /* first source line number */
PyObject *co_code; /* instruction opcodes */
PyObject *co_localsplusnames; /* tuple mapping offsets to names */
PyObject *co_localspluskinds; /* Bytes mapping to local kinds (one byte per variable) */
PyObject *co_filename; /* unicode (where it was loaded from) */
PyObject *co_name; /* unicode (name, for reference) */
PyObject *co_qualname; /* unicode (qualname, for reference) */
PyObject *co_linetable; /* bytes (encoding addr<->lineno mapping) See
Objects/lnotab_notes.txt for details. */
PyObject *co_endlinetable; /* bytes object that holds end lineno for
instructions separated across different
lines */
PyObject *co_columntable; /* bytes object that holds start/end column
offset each instruction */
/* These fields are set with computed values on new code objects. */
// redundant values (derived from co_localsplusnames and co_localspluskinds)
int co_nlocalsplus; /* number of local + cell + free variables */
int co_nlocals; /* number of local variables */
int co_nplaincellvars; /* number of non-arg cell variables */
int co_ncellvars; /* total number of cell variables */
int co_nfreevars; /* number of free variables */
// lazily-computed values
PyObject *co_varnames; /* tuple of strings (local variable names) */
PyObject *co_cellvars; /* tuple of strings (cell variable names) */
PyObject *co_freevars; /* tuple of strings (free variable names) */
/* The remaining fields are zeroed out on new code objects. */
PyObject *co_weakreflist; /* to support weakrefs to code objects */
/* Scratch space for extra data relating to the code object.
Type is a void* to keep the format private in codeobject.c to force
people to go through the proper APIs. */
void *co_extra;
/* Quickened instructions and cache, or NULL
This should be treated as opaque by all code except the specializer and
interpreter. */
union _cache_or_instruction *co_quickened;
};
/* Masks for co_flags above */
#define CO_OPTIMIZED 0x0001
#define CO_NEWLOCALS 0x0002
#define CO_VARARGS 0x0004
#define CO_VARKEYWORDS 0x0008
#define CO_NESTED 0x0010
#define CO_GENERATOR 0x0020
/* The CO_COROUTINE flag is set for coroutine functions (defined with
``async def`` keywords) */
#define CO_COROUTINE 0x0080
#define CO_ITERABLE_COROUTINE 0x0100
#define CO_ASYNC_GENERATOR 0x0200
/* bpo-39562: These constant values are changed in Python 3.9
to prevent collision with compiler flags. CO_FUTURE_ and PyCF_
constants must be kept unique. PyCF_ constants can use bits from
0x0100 to 0x10000. CO_FUTURE_ constants use bits starting at 0x20000. */
#define CO_FUTURE_DIVISION 0x20000
#define CO_FUTURE_ABSOLUTE_IMPORT 0x40000 /* do absolute imports by default */
#define CO_FUTURE_WITH_STATEMENT 0x80000
#define CO_FUTURE_PRINT_FUNCTION 0x100000
#define CO_FUTURE_UNICODE_LITERALS 0x200000
#define CO_FUTURE_BARRY_AS_BDFL 0x400000
#define CO_FUTURE_GENERATOR_STOP 0x800000
#define CO_FUTURE_ANNOTATIONS 0x1000000
/* This should be defined if a future statement modifies the syntax.
For example, when a keyword is added.
*/
#define PY_PARSER_REQUIRES_FUTURE_KEYWORD
#define CO_MAXBLOCKS 20 /* Max static block nesting within a function */
PyAPI_DATA(PyTypeObject) PyCode_Type;
#define PyCode_Check(op) Py_IS_TYPE(op, &PyCode_Type)
#define PyCode_GetNumFree(op) ((op)->co_nfreevars)
/* Public interface */
PyAPI_FUNC(PyCodeObject *) PyCode_New(
int, int, int, int, int, PyObject *, PyObject *,
PyObject *, PyObject *, PyObject *, PyObject *,
PyObject *, PyObject *, PyObject *, int, PyObject *,
PyObject *, PyObject *, PyObject *);
PyAPI_FUNC(PyCodeObject *) PyCode_NewWithPosOnlyArgs(
int, int, int, int, int, int, PyObject *, PyObject *,
PyObject *, PyObject *, PyObject *, PyObject *,
PyObject *, PyObject *, PyObject *, int, PyObject *,
PyObject *, PyObject *, PyObject *);
/* same as struct above */
/* Creates a new empty code object with the specified source location. */
PyAPI_FUNC(PyCodeObject *)
PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno);
/* Return the line number associated with the specified bytecode index
in this code object. If you just need the line number of a frame,
use PyFrame_GetLineNumber() instead. */
PyAPI_FUNC(int) PyCode_Addr2Line(PyCodeObject *, int);
PyAPI_FUNC(int) PyCode_Addr2Location(PyCodeObject *, int, int *, int *, int *, int *);
/* Return the ending source code line number from a bytecode index. */
PyAPI_FUNC(int) _PyCode_Addr2EndLine(PyCodeObject *, int);
/* Return the starting source code column offset from a bytecode index. */
PyAPI_FUNC(int) _PyCode_Addr2Offset(PyCodeObject *, int);
/* Return the ending source code column offset from a bytecode index. */
PyAPI_FUNC(int) _PyCode_Addr2EndOffset(PyCodeObject *, int);
/* for internal use only */
struct _opaque {
int computed_line;
const char *lo_next;
const char *limit;
};
typedef struct _line_offsets {
int ar_start;
int ar_end;
int ar_line;
struct _opaque opaque;
} PyCodeAddressRange;
/* Update *bounds to describe the first and one-past-the-last instructions in the
same line as lasti. Return the number of that line.
*/
PyAPI_FUNC(int) _PyCode_CheckLineNumber(int lasti, PyCodeAddressRange *bounds);
/* Create a comparable key used to compare constants taking in account the
* object type. It is used to make sure types are not coerced (e.g., float and
* complex) _and_ to distinguish 0.0 from -0.0 e.g. on IEEE platforms
*
* Return (type(obj), obj, ...): a tuple with variable size (at least 2 items)
* depending on the type and the value. The type is the first item to not
* compare bytes and str which can raise a BytesWarning exception. */
PyAPI_FUNC(PyObject*) _PyCode_ConstantKey(PyObject *obj);
PyAPI_FUNC(PyObject*) PyCode_Optimize(PyObject *code, PyObject* consts,
PyObject *names, PyObject *lnotab);
PyAPI_FUNC(int) _PyCode_GetExtra(PyObject *code, Py_ssize_t index,
void **extra);
PyAPI_FUNC(int) _PyCode_SetExtra(PyObject *code, Py_ssize_t index,
void *extra);
/** API for initializing the line number tables. */
int _PyCode_InitAddressRange(PyCodeObject* co, PyCodeAddressRange *bounds);
int _PyCode_InitEndAddressRange(PyCodeObject* co, PyCodeAddressRange* bounds);
/** Out of process API for initializing the line number table. */
void PyLineTable_InitAddressRange(const char *linetable, Py_ssize_t length, int firstlineno, PyCodeAddressRange *range);
/** API for traversing the line number table. */
int PyLineTable_NextAddressRange(PyCodeAddressRange *range);
int PyLineTable_PreviousAddressRange(PyCodeAddressRange *range);
