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 /* Each instruction in a code object is a fixed-width value,
11  * currently 2 bytes: 1-byte opcode + 1-byte oparg.  The EXTENDED_ARG
12  * opcode allows for larger values but the current limit is 3 uses
13  * of EXTENDED_ARG (see Python/compile.c), for a maximum
14  * 32-bit value.  This aligns with the note in Python/compile.c
15  * (compiler_addop_i_line) indicating that the max oparg value is
16  * 2**32 - 1, rather than INT_MAX.
17  */
18 
19 typedef uint16_t _Py_CODEUNIT;
20 
21 #ifdef WORDS_BIGENDIAN
22 #  define _Py_OPCODE(word) ((word) >> 8)
23 #  define _Py_OPARG(word) ((word) & 255)
24 #  define _Py_MAKECODEUNIT(opcode, oparg) (((opcode)<<8)|(oparg))
25 #else
26 #  define _Py_OPCODE(word) ((word) & 255)
27 #  define _Py_OPARG(word) ((word) >> 8)
28 #  define _Py_MAKECODEUNIT(opcode, oparg) ((opcode)|((oparg)<<8))
29 #endif
30 
31 // Use "unsigned char" instead of "uint8_t" here to avoid illegal aliasing:
32 #define _Py_SET_OPCODE(word, opcode) (((unsigned char *)&(word))[0] = (opcode))
33 
34 // To avoid repeating ourselves in deepfreeze.py, all PyCodeObject members are
35 // defined in this macro:
36 #define _PyCode_DEF(SIZE) {                                                    \
37     PyObject_VAR_HEAD                                                          \
38                                                                                \
39     /* Note only the following fields are used in hash and/or comparisons      \
40      *                                                                         \
41      * - co_name                                                               \
42      * - co_argcount                                                           \
43      * - co_posonlyargcount                                                    \
44      * - co_kwonlyargcount                                                     \
45      * - co_nlocals                                                            \
46      * - co_stacksize                                                          \
47      * - co_flags                                                              \
48      * - co_firstlineno                                                        \
49      * - co_consts                                                             \
50      * - co_names                                                              \
51      * - co_localsplusnames                                                    \
52      * This is done to preserve the name and line number for tracebacks        \
53      * and debuggers; otherwise, constant de-duplication would collapse        \
54      * identical functions/lambdas defined on different lines.                 \
55      */                                                                        \
56                                                                                \
57     /* These fields are set with provided values on new code objects. */       \
58                                                                                \
59     /* The hottest fields (in the eval loop) are grouped here at the top. */   \
60     PyObject *co_consts;           /* list (constants used) */                 \
61     PyObject *co_names;            /* list of strings (names used) */          \
62     PyObject *co_exceptiontable;   /* Byte string encoding exception handling  \
63                                       table */                                 \
64     int co_flags;                  /* CO_..., see below */                     \
65     short co_warmup;                 /* Warmup counter for quickening */       \
66     short _co_linearray_entry_size;  /* Size of each entry in _co_linearray */ \
67                                                                                \
68     /* The rest are not so impactful on performance. */                        \
69     int co_argcount;              /* #arguments, except *args */               \
70     int co_posonlyargcount;       /* #positional only arguments */             \
71     int co_kwonlyargcount;        /* #keyword only arguments */                \
72     int co_stacksize;             /* #entries needed for evaluation stack */   \
73     int co_firstlineno;           /* first source line number */               \
74                                                                                \
75     /* redundant values (derived from co_localsplusnames and                   \
76        co_localspluskinds) */                                                  \
77     int co_nlocalsplus;           /* number of local + cell + free variables   \
78                                   */                                           \
79     int co_nlocals;               /* number of local variables */              \
80     int co_nplaincellvars;        /* number of non-arg cell variables */       \
81     int co_ncellvars;             /* total number of cell variables */         \
82     int co_nfreevars;             /* number of free variables */               \
83                                                                                \
84     PyObject *co_localsplusnames; /* tuple mapping offsets to names */         \
85     PyObject *co_localspluskinds; /* Bytes mapping to local kinds (one byte    \
86                                      per variable) */                          \
87     PyObject *co_filename;        /* unicode (where it was loaded from) */     \
88     PyObject *co_name;            /* unicode (name, for reference) */          \
89     PyObject *co_qualname;        /* unicode (qualname, for reference) */      \
90     PyObject *co_linetable;       /* bytes object that holds location info */  \
91     PyObject *co_weakreflist;     /* to support weakrefs to code objects */    \
92     PyObject *_co_code;           /* cached co_code object/attribute */        \
93     char *_co_linearray;          /* array of line offsets */                  \
94     int _co_firsttraceable;       /* index of first traceable instruction */   \
95     /* Scratch space for extra data relating to the code object.               \
96        Type is a void* to keep the format private in codeobject.c to force     \
97        people to go through the proper APIs. */                                \
98     void *co_extra;                                                            \
99     char co_code_adaptive[(SIZE)];                                             \
100 }
101 
102 /* Bytecode object */
103 struct PyCodeObject _PyCode_DEF(1);
104 
105 /* Masks for co_flags above */
106 #define CO_OPTIMIZED    0x0001
107 #define CO_NEWLOCALS    0x0002
108 #define CO_VARARGS      0x0004
109 #define CO_VARKEYWORDS  0x0008
110 #define CO_NESTED       0x0010
111 #define CO_GENERATOR    0x0020
112 
113 /* The CO_COROUTINE flag is set for coroutine functions (defined with
114    ``async def`` keywords) */
115 #define CO_COROUTINE            0x0080
116 #define CO_ITERABLE_COROUTINE   0x0100
117 #define CO_ASYNC_GENERATOR      0x0200
118 
119 /* bpo-39562: These constant values are changed in Python 3.9
120    to prevent collision with compiler flags. CO_FUTURE_ and PyCF_
121    constants must be kept unique. PyCF_ constants can use bits from
122    0x0100 to 0x10000. CO_FUTURE_ constants use bits starting at 0x20000. */
123 #define CO_FUTURE_DIVISION      0x20000
124 #define CO_FUTURE_ABSOLUTE_IMPORT 0x40000 /* do absolute imports by default */
125 #define CO_FUTURE_WITH_STATEMENT  0x80000
126 #define CO_FUTURE_PRINT_FUNCTION  0x100000
127 #define CO_FUTURE_UNICODE_LITERALS 0x200000
128 
129 #define CO_FUTURE_BARRY_AS_BDFL  0x400000
130 #define CO_FUTURE_GENERATOR_STOP  0x800000
131 #define CO_FUTURE_ANNOTATIONS    0x1000000
132 
133 /* This should be defined if a future statement modifies the syntax.
134    For example, when a keyword is added.
135 */
136 #define PY_PARSER_REQUIRES_FUTURE_KEYWORD
137 
138 #define CO_MAXBLOCKS 20 /* Max static block nesting within a function */
139 
140 PyAPI_DATA(PyTypeObject) PyCode_Type;
141 
142 #define PyCode_Check(op) Py_IS_TYPE(op, &PyCode_Type)
143 #define PyCode_GetNumFree(op) ((op)->co_nfreevars)
144 #define _PyCode_CODE(CO) ((_Py_CODEUNIT *)(CO)->co_code_adaptive)
145 #define _PyCode_NBYTES(CO) (Py_SIZE(CO) * (Py_ssize_t)sizeof(_Py_CODEUNIT))
146 
147 /* Public interface */
148 PyAPI_FUNC(PyCodeObject *) PyCode_New(
149         int, int, int, int, int, PyObject *, PyObject *,
150         PyObject *, PyObject *, PyObject *, PyObject *,
151         PyObject *, PyObject *, PyObject *, int, PyObject *,
152         PyObject *);
153 
154 PyAPI_FUNC(PyCodeObject *) PyCode_NewWithPosOnlyArgs(
155         int, int, int, int, int, int, PyObject *, PyObject *,
156         PyObject *, PyObject *, PyObject *, PyObject *,
157         PyObject *, PyObject *, PyObject *, int, PyObject *,
158         PyObject *);
159         /* same as struct above */
160 
161 /* Creates a new empty code object with the specified source location. */
162 PyAPI_FUNC(PyCodeObject *)
163 PyCode_NewEmpty(const char *filename, const char *funcname, int firstlineno);
164 
165 /* Return the line number associated with the specified bytecode index
166    in this code object.  If you just need the line number of a frame,
167    use PyFrame_GetLineNumber() instead. */
168 PyAPI_FUNC(int) PyCode_Addr2Line(PyCodeObject *, int);
169 
170 PyAPI_FUNC(int) PyCode_Addr2Location(PyCodeObject *, int, int *, int *, int *, int *);
171 
172 /* for internal use only */
173 struct _opaque {
174     int computed_line;
175     const uint8_t *lo_next;
176     const uint8_t *limit;
177 };
178 
179 typedef struct _line_offsets {
180     int ar_start;
181     int ar_end;
182     int ar_line;
183     struct _opaque opaque;
184 } PyCodeAddressRange;
185 
186 /* Update *bounds to describe the first and one-past-the-last instructions in the
187    same line as lasti.  Return the number of that line.
188 */
189 PyAPI_FUNC(int) _PyCode_CheckLineNumber(int lasti, PyCodeAddressRange *bounds);
190 
191 /* Create a comparable key used to compare constants taking in account the
192  * object type. It is used to make sure types are not coerced (e.g., float and
193  * complex) _and_ to distinguish 0.0 from -0.0 e.g. on IEEE platforms
194  *
195  * Return (type(obj), obj, ...): a tuple with variable size (at least 2 items)
196  * depending on the type and the value. The type is the first item to not
197  * compare bytes and str which can raise a BytesWarning exception. */
198 PyAPI_FUNC(PyObject*) _PyCode_ConstantKey(PyObject *obj);
199 
200 PyAPI_FUNC(PyObject*) PyCode_Optimize(PyObject *code, PyObject* consts,
201                                       PyObject *names, PyObject *lnotab);
202 
203 
204 PyAPI_FUNC(int) _PyCode_GetExtra(PyObject *code, Py_ssize_t index,
205                                  void **extra);
206 PyAPI_FUNC(int) _PyCode_SetExtra(PyObject *code, Py_ssize_t index,
207                                  void *extra);
208 
209 /* Equivalent to getattr(code, 'co_code') in Python.
210    Returns a strong reference to a bytes object. */
211 PyAPI_FUNC(PyObject *) PyCode_GetCode(PyCodeObject *code);
212 /* Equivalent to getattr(code, 'co_varnames') in Python. */
213 PyAPI_FUNC(PyObject *) PyCode_GetVarnames(PyCodeObject *code);
214 /* Equivalent to getattr(code, 'co_cellvars') in Python. */
215 PyAPI_FUNC(PyObject *) PyCode_GetCellvars(PyCodeObject *code);
216 /* Equivalent to getattr(code, 'co_freevars') in Python. */
217 PyAPI_FUNC(PyObject *) PyCode_GetFreevars(PyCodeObject *code);
218 
219 typedef enum _PyCodeLocationInfoKind {
220     /* short forms are 0 to 9 */
221     PY_CODE_LOCATION_INFO_SHORT0 = 0,
222     /* one lineforms are 10 to 12 */
223     PY_CODE_LOCATION_INFO_ONE_LINE0 = 10,
224     PY_CODE_LOCATION_INFO_ONE_LINE1 = 11,
225     PY_CODE_LOCATION_INFO_ONE_LINE2 = 12,
226 
227     PY_CODE_LOCATION_INFO_NO_COLUMNS = 13,
228     PY_CODE_LOCATION_INFO_LONG = 14,
229     PY_CODE_LOCATION_INFO_NONE = 15
230 } _PyCodeLocationInfoKind;
231 
232 #ifdef __cplusplus
233 }
234 #endif
235 #endif  // !Py_CODE_H
236 #endif  // !Py_LIMITED_API
237