1 /* Definitions for bytecode */
2 
3 #ifndef Py_LIMITED_API
4 #ifndef Py_CODE_H
5 #define Py_CODE_H
6 #ifdef __cplusplus
7 extern "C" {
8 #endif
9 
10 typedef uint16_t _Py_CODEUNIT;
11 
12 #ifdef WORDS_BIGENDIAN
13 #  define _Py_OPCODE(word) ((word) >> 8)
14 #  define _Py_OPARG(word) ((word) & 255)
15 #else
16 #  define _Py_OPCODE(word) ((word) & 255)
17 #  define _Py_OPARG(word) ((word) >> 8)
18 #endif
19 
20 typedef struct _PyOpcache _PyOpcache;
21 
22 /* Bytecode object */
23 typedef struct {
24     PyObject_HEAD
25     int co_argcount;            /* #arguments, except *args */
26     int co_posonlyargcount;     /* #positional only arguments */
27     int co_kwonlyargcount;      /* #keyword only arguments */
28     int co_nlocals;             /* #local variables */
29     int co_stacksize;           /* #entries needed for evaluation stack */
30     int co_flags;               /* CO_..., see below */
31     int co_firstlineno;         /* first source line number */
32     PyObject *co_code;          /* instruction opcodes */
33     PyObject *co_consts;        /* list (constants used) */
34     PyObject *co_names;         /* list of strings (names used) */
35     PyObject *co_varnames;      /* tuple of strings (local variable names) */
36     PyObject *co_freevars;      /* tuple of strings (free variable names) */
37     PyObject *co_cellvars;      /* tuple of strings (cell variable names) */
38     /* The rest aren't used in either hash or comparisons, except for co_name,
39        used in both. This is done to preserve the name and line number
40        for tracebacks and debuggers; otherwise, constant de-duplication
41        would collapse identical functions/lambdas defined on different lines.
42     */
43     Py_ssize_t *co_cell2arg;    /* Maps cell vars which are arguments. */
44     PyObject *co_filename;      /* unicode (where it was loaded from) */
45     PyObject *co_name;          /* unicode (name, for reference) */
46     PyObject *co_lnotab;        /* string (encoding addr<->lineno mapping) See
47                                    Objects/lnotab_notes.txt for details. */
48     void *co_zombieframe;       /* for optimization only (see frameobject.c) */
49     PyObject *co_weakreflist;   /* to support weakrefs to code objects */
50     /* Scratch space for extra data relating to the code object.
51        Type is a void* to keep the format private in codeobject.c to force
52        people to go through the proper APIs. */
53     void *co_extra;
54 
55     /* Per opcodes just-in-time cache
56      *
57      * To reduce cache size, we use indirect mapping from opcode index to
58      * cache object:
59      *   cache = co_opcache[co_opcache_map[next_instr - first_instr] - 1]
60      */
61 
62     // co_opcache_map is indexed by (next_instr - first_instr).
63     //  * 0 means there is no cache for this opcode.
64     //  * n > 0 means there is cache in co_opcache[n-1].
65     unsigned char *co_opcache_map;
66     _PyOpcache *co_opcache;
67     int co_opcache_flag;  // used to determine when create a cache.
68     unsigned char co_opcache_size;  // length of co_opcache.
69 } PyCodeObject;
70 
71 /* Masks for co_flags above */
72 #define CO_OPTIMIZED    0x0001
73 #define CO_NEWLOCALS    0x0002
74 #define CO_VARARGS      0x0004
75 #define CO_VARKEYWORDS  0x0008
76 #define CO_NESTED       0x0010
77 #define CO_GENERATOR    0x0020
78 /* The CO_NOFREE flag is set if there are no free or cell variables.
79    This information is redundant, but it allows a single flag test
80    to determine whether there is any extra work to be done when the
81    call frame it setup.
82 */
83 #define CO_NOFREE       0x0040
84 
85 /* The CO_COROUTINE flag is set for coroutine functions (defined with
86    ``async def`` keywords) */
87 #define CO_COROUTINE            0x0080
88 #define CO_ITERABLE_COROUTINE   0x0100
89 #define CO_ASYNC_GENERATOR      0x0200
90 
91 /* bpo-39562: These constant values are changed in Python 3.9
92    to prevent collision with compiler flags. CO_FUTURE_ and PyCF_
93    constants must be kept unique. PyCF_ constants can use bits from
94    0x0100 to 0x10000. CO_FUTURE_ constants use bits starting at 0x20000. */
95 #define CO_FUTURE_DIVISION      0x20000
96 #define CO_FUTURE_ABSOLUTE_IMPORT 0x40000 /* do absolute imports by default */
97 #define CO_FUTURE_WITH_STATEMENT  0x80000
98 #define CO_FUTURE_PRINT_FUNCTION  0x100000
99 #define CO_FUTURE_UNICODE_LITERALS 0x200000
100 
101 #define CO_FUTURE_BARRY_AS_BDFL  0x400000
102 #define CO_FUTURE_GENERATOR_STOP  0x800000
103 #define CO_FUTURE_ANNOTATIONS    0x1000000
104 
105 /* This value is found in the co_cell2arg array when the associated cell
106    variable does not correspond to an argument. */
107 #define CO_CELL_NOT_AN_ARG (-1)
108 
109 /* This should be defined if a future statement modifies the syntax.
110    For example, when a keyword is added.
111 */
112 #define PY_PARSER_REQUIRES_FUTURE_KEYWORD
113 
114 #define CO_MAXBLOCKS 20 /* Max static block nesting within a function */
115 
116 PyAPI_DATA(PyTypeObject) PyCode_Type;
117 
118 #define PyCode_Check(op) (Py_TYPE(op) == &PyCode_Type)
119 #define PyCode_GetNumFree(op) (PyTuple_GET_SIZE((op)->co_freevars))
120 
121 /* Public interface */
122 PyAPI_FUNC(PyCodeObject *) PyCode_New(
123         int, int, int, int, int, PyObject *, PyObject *,
124         PyObject *, PyObject *, PyObject *, PyObject *,
125         PyObject *, PyObject *, int, PyObject *);
126 
127 PyAPI_FUNC(PyCodeObject *) PyCode_NewWithPosOnlyArgs(
128         int, int, int, int, int, int, PyObject *, PyObject *,
129         PyObject *, PyObject *, PyObject *, PyObject *,
130         PyObject *, PyObject *, int, PyObject *);
131         /* same as struct above */
132 
133 /* Creates a new empty code object with the specified source location. */
134 PyAPI_FUNC(PyCodeObject *)
135 PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno);
136 
137 /* Return the line number associated with the specified bytecode index
138    in this code object.  If you just need the line number of a frame,
139    use PyFrame_GetLineNumber() instead. */
140 PyAPI_FUNC(int) PyCode_Addr2Line(PyCodeObject *, int);
141 
142 /* for internal use only */
143 typedef struct _addr_pair {
144         int ap_lower;
145         int ap_upper;
146 } PyAddrPair;
147 
148 #ifndef Py_LIMITED_API
149 /* Update *bounds to describe the first and one-past-the-last instructions in the
150    same line as lasti.  Return the number of that line.
151 */
152 PyAPI_FUNC(int) _PyCode_CheckLineNumber(PyCodeObject* co,
153                                         int lasti, PyAddrPair *bounds);
154 
155 /* Create a comparable key used to compare constants taking in account the
156  * object type. It is used to make sure types are not coerced (e.g., float and
157  * complex) _and_ to distinguish 0.0 from -0.0 e.g. on IEEE platforms
158  *
159  * Return (type(obj), obj, ...): a tuple with variable size (at least 2 items)
160  * depending on the type and the value. The type is the first item to not
161  * compare bytes and str which can raise a BytesWarning exception. */
162 PyAPI_FUNC(PyObject*) _PyCode_ConstantKey(PyObject *obj);
163 #endif
164 
165 PyAPI_FUNC(PyObject*) PyCode_Optimize(PyObject *code, PyObject* consts,
166                                       PyObject *names, PyObject *lnotab);
167 
168 
169 #ifndef Py_LIMITED_API
170 PyAPI_FUNC(int) _PyCode_GetExtra(PyObject *code, Py_ssize_t index,
171                                  void **extra);
172 PyAPI_FUNC(int) _PyCode_SetExtra(PyObject *code, Py_ssize_t index,
173                                  void *extra);
174 #endif
175 
176 #ifdef __cplusplus
177 }
178 #endif
179 #endif /* !Py_CODE_H */
180 #endif /* Py_LIMITED_API */
181