view Include/symtable.h @ 87690:66c1c9f32567 default tip

Add use_weakref option to functools.lru_cache The use_weakref option makes lru_cache create weak references to the function arguments when creating the cache key, which prevents them from staying in the memory forever even after all other references to them are gone. This is a proof of concept for http://bugs.python.org/issue19859
author Radomir Dopieralski <devel@sheep.art.pl>
date Tue, 03 Dec 2013 16:02:48 +0100
parents df2fdd42b375
children
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#ifndef Py_LIMITED_API
#ifndef Py_SYMTABLE_H
#define Py_SYMTABLE_H

#ifdef __cplusplus
extern "C" {
#endif

/* XXX(ncoghlan): This is a weird mix of public names and interpreter internal
 *                names.
 */

typedef enum _block_type { FunctionBlock, ClassBlock, ModuleBlock }
    _Py_block_ty;

struct _symtable_entry;

struct symtable {
    PyObject *st_filename;          /* name of file being compiled,
                                       decoded from the filesystem encoding */
    struct _symtable_entry *st_cur; /* current symbol table entry */
    struct _symtable_entry *st_top; /* symbol table entry for module */
    PyObject *st_blocks;            /* dict: map AST node addresses
                                     *       to symbol table entries */
    PyObject *st_stack;             /* list: stack of namespace info */
    PyObject *st_global;            /* borrowed ref to st_top->ste_symbols */
    int st_nblocks;                 /* number of blocks used. kept for
                                       consistency with the corresponding
                                       compiler structure */
    PyObject *st_private;           /* name of current class or NULL */
    PyFutureFeatures *st_future;    /* module's future features that affect
                                       the symbol table */
    int recursion_depth;            /* current recursion depth */
    int recursion_limit;            /* recursion limit */
};

typedef struct _symtable_entry {
    PyObject_HEAD
    PyObject *ste_id;        /* int: key in ste_table->st_blocks */
    PyObject *ste_symbols;   /* dict: variable names to flags */
    PyObject *ste_name;      /* string: name of current block */
    PyObject *ste_varnames;  /* list of function parameters */
    PyObject *ste_children;  /* list of child blocks */
    PyObject *ste_directives;/* locations of global and nonlocal statements */
    _Py_block_ty ste_type;   /* module, class, or function */
    int ste_unoptimized;     /* false if namespace is optimized */
    int ste_nested;      /* true if block is nested */
    unsigned ste_free : 1;        /* true if block has free variables */
    unsigned ste_child_free : 1;  /* true if a child block has free vars,
                                     including free refs to globals */
    unsigned ste_generator : 1;   /* true if namespace is a generator */
    unsigned ste_varargs : 1;     /* true if block has varargs */
    unsigned ste_varkeywords : 1; /* true if block has varkeywords */
    unsigned ste_returns_value : 1;  /* true if namespace uses return with
                                        an argument */
    unsigned ste_needs_class_closure : 1; /* for class scopes, true if a
                                             closure over __class__
                                             should be created */
    int ste_lineno;          /* first line of block */
    int ste_col_offset;      /* offset of first line of block */
    int ste_opt_lineno;      /* lineno of last exec or import * */
    int ste_opt_col_offset;  /* offset of last exec or import * */
    int ste_tmpname;         /* counter for listcomp temp vars */
    struct symtable *ste_table;
} PySTEntryObject;

PyAPI_DATA(PyTypeObject) PySTEntry_Type;

#define PySTEntry_Check(op) (Py_TYPE(op) == &PySTEntry_Type)

PyAPI_FUNC(int) PyST_GetScope(PySTEntryObject *, PyObject *);

PyAPI_FUNC(struct symtable *) PySymtable_Build(
    mod_ty mod,
    const char *filename,       /* decoded from the filesystem encoding */
    PyFutureFeatures *future);
PyAPI_FUNC(struct symtable *) PySymtable_BuildObject(
    mod_ty mod,
    PyObject *filename,
    PyFutureFeatures *future);
PyAPI_FUNC(PySTEntryObject *) PySymtable_Lookup(struct symtable *, void *);

PyAPI_FUNC(void) PySymtable_Free(struct symtable *);

/* Flags for def-use information */

#define DEF_GLOBAL 1           /* global stmt */
#define DEF_LOCAL 2            /* assignment in code block */
#define DEF_PARAM 2<<1         /* formal parameter */
#define DEF_NONLOCAL 2<<2      /* nonlocal stmt */
#define USE 2<<3               /* name is used */
#define DEF_FREE 2<<4          /* name used but not defined in nested block */
#define DEF_FREE_CLASS 2<<5    /* free variable from class's method */
#define DEF_IMPORT 2<<6        /* assignment occurred via import */

#define DEF_BOUND (DEF_LOCAL | DEF_PARAM | DEF_IMPORT)

/* GLOBAL_EXPLICIT and GLOBAL_IMPLICIT are used internally by the symbol
   table.  GLOBAL is returned from PyST_GetScope() for either of them.
   It is stored in ste_symbols at bits 12-15.
*/
#define SCOPE_OFFSET 11
#define SCOPE_MASK (DEF_GLOBAL | DEF_LOCAL | DEF_PARAM | DEF_NONLOCAL)

#define LOCAL 1
#define GLOBAL_EXPLICIT 2
#define GLOBAL_IMPLICIT 3
#define FREE 4
#define CELL 5

/* The following two names are used for the ste_unoptimized bit field */
#define OPT_IMPORT_STAR 1
#define OPT_TOPLEVEL 2  /* top-level names, including eval and exec */

#define GENERATOR 1
#define GENERATOR_EXPRESSION 2

#ifdef __cplusplus
}
#endif
#endif /* !Py_SYMTABLE_H */
#endif /* Py_LIMITED_API */