cpython/Include/symtable.h
Jeremy Hylton 81e9502df6 Provisional implementation of PEP 3104.
Add nonlocal_stmt to Grammar and Nonlocal node to AST.  They both
parallel the definitions for globals.  The symbol table treats
variables declared as nonlocal just like variables that are free
implicitly.

This change is missing the language spec changes, but makes some
decisions about what the spec should say via the unittests.  The PEP
is silent on a number of decisions, so we should review those before
claiming that nonlocal is complete.

Thomas Wouters made the grammer and ast changes.  Jeremy Hylton added
the symbol table changes and the tests.  Pete Shinners and Neal
Norwitz helped review the code.
2007-02-27 06:50:52 +00:00

103 lines
3.9 KiB
C

#ifndef Py_SYMTABLE_H
#define Py_SYMTABLE_H
#ifdef __cplusplus
extern "C" {
#endif
typedef enum _block_type { FunctionBlock, ClassBlock, ModuleBlock }
_Py_block_ty;
struct _symtable_entry;
struct symtable {
const char *st_filename; /* name of file being compiled */
struct _symtable_entry *st_cur; /* current symbol table entry */
struct _symtable_entry *st_top; /* module entry */
PyObject *st_symbols; /* dictionary of symbol table entries */
PyObject *st_stack; /* stack of namespace info */
PyObject *st_global; /* borrowed ref to MODULE in st_symbols */
int st_nblocks; /* number of blocks */
PyObject *st_private; /* name of current class or NULL */
int st_tmpname; /* temporary name counter */
PyFutureFeatures *st_future; /* module's future features */
};
typedef struct _symtable_entry {
PyObject_HEAD
PyObject *ste_id; /* int: key in st_symbols */
PyObject *ste_symbols; /* dict: name to flags */
PyObject *ste_name; /* string: name of block */
PyObject *ste_varnames; /* list of variable names */
PyObject *ste_children; /* list of child ids */
_Py_block_ty ste_type; /* module, class, or function */
int ste_unoptimized; /* false if namespace is optimized */
unsigned ste_nested : 1; /* 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 */
int ste_lineno; /* first line of block */
int ste_opt_lineno; /* lineno 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) ((op)->ob_type == &PySTEntry_Type)
PyAPI_FUNC(int) PyST_GetScope(PySTEntryObject *, PyObject *);
PyAPI_FUNC(struct symtable *) PySymtable_Build(mod_ty, const char *,
PyFutureFeatures *);
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_STAR 2<<4 /* parameter is star arg */
#define DEF_DOUBLESTAR 2<<5 /* parameter is star-star arg */
#define DEF_INTUPLE 2<<6 /* name defined in tuple in parameters */
#define DEF_FREE 2<<7 /* name used but not defined in nested block */
#define DEF_FREE_GLOBAL 2<<8 /* free variable is actually implicit global */
#define DEF_FREE_CLASS 2<<9 /* free variable from class's method */
#define DEF_IMPORT 2<<10 /* 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_OFF 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 */