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1 #ifndef Py_INTERNAL_SYMTABLE_H
2 #define Py_INTERNAL_SYMTABLE_H
3 #ifdef __cplusplus
4 extern "C" {
5 #endif
6 
7 #ifndef Py_BUILD_CORE
8 #  error "this header requires Py_BUILD_CORE define"
9 #endif
10 
11 struct _mod;   // Type defined in pycore_ast.h
12 
13 typedef enum _block_type {
14     FunctionBlock, ClassBlock, ModuleBlock,
15     // Used for annotations if 'from __future__ import annotations' is active.
16     // Annotation blocks cannot bind names and are not evaluated.
17     AnnotationBlock,
18 
19     // The following blocks are used for generics and type aliases. These work
20     // mostly like functions (see PEP 695 for details). The three different
21     // blocks function identically; they are different enum entries only so
22     // that error messages can be more precise.
23 
24     // The block to enter when processing a "type" (PEP 695) construction,
25     // e.g., "type MyGeneric[T] = list[T]".
26     TypeAliasBlock,
27     // The block to enter when processing a "generic" (PEP 695) object,
28     // e.g., "def foo[T](): pass" or "class A[T]: pass".
29     TypeParametersBlock,
30     // The block to enter when processing the bound, the constraint tuple
31     // or the default value of a single "type variable" in the formal sense,
32     // i.e., a TypeVar, a TypeVarTuple or a ParamSpec object (the latter two
33     // do not support a bound or a constraint tuple).
34     TypeVariableBlock,
35 } _Py_block_ty;
36 
37 typedef enum _comprehension_type {
38     NoComprehension = 0,
39     ListComprehension = 1,
40     DictComprehension = 2,
41     SetComprehension = 3,
42     GeneratorExpression = 4 } _Py_comprehension_ty;
43 
44 /* source location information */
45 typedef struct {
46     int lineno;
47     int end_lineno;
48     int col_offset;
49     int end_col_offset;
50 } _Py_SourceLocation;
51 
52 #define SRC_LOCATION_FROM_AST(n) \
53     (_Py_SourceLocation){ \
54                .lineno = (n)->lineno, \
55                .end_lineno = (n)->end_lineno, \
56                .col_offset = (n)->col_offset, \
57                .end_col_offset = (n)->end_col_offset }
58 
59 static const _Py_SourceLocation NO_LOCATION = {-1, -1, -1, -1};
60 
61 /* __future__ information */
62 typedef struct {
63     int ff_features;                    /* flags set by future statements */
64     _Py_SourceLocation ff_location;     /* location of last future statement */
65 } _PyFutureFeatures;
66 
67 struct _symtable_entry;
68 
69 struct symtable {
70     PyObject *st_filename;          /* name of file being compiled,
71                                        decoded from the filesystem encoding */
72     struct _symtable_entry *st_cur; /* current symbol table entry */
73     struct _symtable_entry *st_top; /* symbol table entry for module */
74     PyObject *st_blocks;            /* dict: map AST node addresses
75                                      *       to symbol table entries */
76     PyObject *st_stack;             /* list: stack of namespace info */
77     PyObject *st_global;            /* borrowed ref to st_top->ste_symbols */
78     int st_nblocks;                 /* number of blocks used. kept for
79                                        consistency with the corresponding
80                                        compiler structure */
81     PyObject *st_private;           /* name of current class or NULL */
82     _PyFutureFeatures *st_future;   /* module's future features that affect
83                                        the symbol table */
84     int recursion_depth;            /* current recursion depth */
85     int recursion_limit;            /* recursion limit */
86 };
87 
88 typedef struct _symtable_entry {
89     PyObject_HEAD
90     PyObject *ste_id;        /* int: key in ste_table->st_blocks */
91     PyObject *ste_symbols;   /* dict: variable names to flags */
92     PyObject *ste_name;      /* string: name of current block */
93     PyObject *ste_varnames;  /* list of function parameters */
94     PyObject *ste_children;  /* list of child blocks */
95     PyObject *ste_directives;/* locations of global and nonlocal statements */
96     PyObject *ste_mangled_names; /* set of names for which mangling should be applied */
97 
98     _Py_block_ty ste_type;
99     // Optional string set by symtable.c and used when reporting errors.
100     // The content of that string is a description of the current "context".
101     //
102     // For instance, if we are processing the default value of the type
103     // variable "T" in "def foo[T = int](): pass", `ste_scope_info` is
104     // set to "a TypeVar default".
105     const char *ste_scope_info;
106 
107     int ste_nested;      /* true if block is nested */
108     unsigned ste_free : 1;        /* true if block has free variables */
109     unsigned ste_child_free : 1;  /* true if a child block has free vars,
110                                      including free refs to globals */
111     unsigned ste_generator : 1;   /* true if namespace is a generator */
112     unsigned ste_coroutine : 1;   /* true if namespace is a coroutine */
113     _Py_comprehension_ty ste_comprehension;  /* Kind of comprehension (if any) */
114     unsigned ste_varargs : 1;     /* true if block has varargs */
115     unsigned ste_varkeywords : 1; /* true if block has varkeywords */
116     unsigned ste_returns_value : 1;  /* true if namespace uses return with
117                                         an argument */
118     unsigned ste_needs_class_closure : 1; /* for class scopes, true if a
119                                              closure over __class__
120                                              should be created */
121     unsigned ste_needs_classdict : 1; /* for class scopes, true if a closure
122                                          over the class dict should be created */
123     unsigned ste_comp_inlined : 1; /* true if this comprehension is inlined */
124     unsigned ste_comp_iter_target : 1; /* true if visiting comprehension target */
125     unsigned ste_can_see_class_scope : 1; /* true if this block can see names bound in an
126                                              enclosing class scope */
127     int ste_comp_iter_expr; /* non-zero if visiting a comprehension range expression */
128     int ste_lineno;          /* first line of block */
129     int ste_col_offset;      /* offset of first line of block */
130     int ste_end_lineno;      /* end line of block */
131     int ste_end_col_offset;  /* end offset of first line of block */
132     int ste_opt_lineno;      /* lineno of last exec or import * */
133     int ste_opt_col_offset;  /* offset of last exec or import * */
134     struct symtable *ste_table;
135 } PySTEntryObject;
136 
137 extern PyTypeObject PySTEntry_Type;
138 
139 #define PySTEntry_Check(op) Py_IS_TYPE((op), &PySTEntry_Type)
140 
141 extern long _PyST_GetSymbol(PySTEntryObject *, PyObject *);
142 extern int _PyST_GetScope(PySTEntryObject *, PyObject *);
143 extern int _PyST_IsFunctionLike(PySTEntryObject *);
144 
145 extern struct symtable* _PySymtable_Build(
146     struct _mod *mod,
147     PyObject *filename,
148     _PyFutureFeatures *future);
149 extern PySTEntryObject* _PySymtable_Lookup(struct symtable *, void *);
150 
151 extern void _PySymtable_Free(struct symtable *);
152 
153 extern PyObject *_Py_MaybeMangle(PyObject *privateobj, PySTEntryObject *ste, PyObject *name);
154 extern PyObject* _Py_Mangle(PyObject *p, PyObject *name);
155 
156 /* Flags for def-use information */
157 
158 #define DEF_GLOBAL 1             /* global stmt */
159 #define DEF_LOCAL 2              /* assignment in code block */
160 #define DEF_PARAM (2<<1)         /* formal parameter */
161 #define DEF_NONLOCAL (2<<2)      /* nonlocal stmt */
162 #define USE (2<<3)               /* name is used */
163 #define DEF_FREE (2<<4)          /* name used but not defined in nested block */
164 #define DEF_FREE_CLASS (2<<5)    /* free variable from class's method */
165 #define DEF_IMPORT (2<<6)        /* assignment occurred via import */
166 #define DEF_ANNOT (2<<7)         /* this name is annotated */
167 #define DEF_COMP_ITER (2<<8)     /* this name is a comprehension iteration variable */
168 #define DEF_TYPE_PARAM (2<<9)    /* this name is a type parameter */
169 #define DEF_COMP_CELL (2<<10)    /* this name is a cell in an inlined comprehension */
170 
171 #define DEF_BOUND (DEF_LOCAL | DEF_PARAM | DEF_IMPORT)
172 
173 /* GLOBAL_EXPLICIT and GLOBAL_IMPLICIT are used internally by the symbol
174    table.  GLOBAL is returned from PyST_GetScope() for either of them.
175    It is stored in ste_symbols at bits 13-16.
176 */
177 #define SCOPE_OFFSET 12
178 #define SCOPE_MASK (DEF_GLOBAL | DEF_LOCAL | DEF_PARAM | DEF_NONLOCAL)
179 
180 #define LOCAL 1
181 #define GLOBAL_EXPLICIT 2
182 #define GLOBAL_IMPLICIT 3
183 #define FREE 4
184 #define CELL 5
185 
186 #define GENERATOR 1
187 #define GENERATOR_EXPRESSION 2
188 
189 // Used by symtablemodule.c
190 extern struct symtable* _Py_SymtableStringObjectFlags(
191     const char *str,
192     PyObject *filename,
193     int start,
194     PyCompilerFlags *flags);
195 
196 int _PyFuture_FromAST(
197     struct _mod * mod,
198     PyObject *filename,
199     _PyFutureFeatures* futures);
200 
201 #ifdef __cplusplus
202 }
203 #endif
204 #endif /* !Py_INTERNAL_SYMTABLE_H */
205