[Python-checkins] CVS: python/dist/src/Python future.c,NONE,2.1 compile.c,2.173,2.174 symtable.c,2.3,2.4
Jeremy Hylton
jhylton@users.sourceforge.net
Tue, 27 Feb 2001 11:07:04 -0800
Update of /cvsroot/python/python/dist/src/Python
In directory usw-pr-cvs1:/tmp/cvs-serv27842/Python
Modified Files:
compile.c symtable.c
Added Files:
future.c
Log Message:
Improved __future__ parser; still more to do
Makefile.pre.in: add target future.o
Include/compile.h: define PyFutureFeaters and PyNode_Future()
add c_future slot to struct compiling
Include/symtable.h: add st_future slot to struct symtable
Python/future.c: implementation of PyNode_Future()
Python/compile.c: use PyNode_Future() for nested_scopes support
Python/symtable.c: include compile.h to pick up PyFutureFeatures decl
--- NEW FILE: future.c ---
#include "Python.h"
#include "node.h"
#include "token.h"
#include "graminit.h"
#include "compile.h"
#include "symtable.h"
#define UNDEFINED_FUTURE_FEATURE "future feature %.100s is not defined"
static int
future_check_features(PyFutureFeatures *ff, node *n)
{
int i;
char *feature;
REQ(n, import_stmt); /* must by from __future__ import ... */
for (i = 3; i < NCH(n); ++i) {
feature = STR(CHILD(CHILD(n, i), 0));
if (strcmp(feature, FUTURE_NESTED_SCOPES) == 0) {
ff->ff_nested_scopes = 1;
} else {
PyErr_Format(PyExc_SyntaxError,
UNDEFINED_FUTURE_FEATURE, feature);
return -1;
}
}
return 0;
}
/* Relevant portions of the grammar:
single_input: NEWLINE | simple_stmt | compound_stmt NEWLINE
file_input: (NEWLINE | stmt)* ENDMARKER
stmt: simple_stmt | compound_stmt
simple_stmt: small_stmt (';' small_stmt)* [';'] NEWLINE
small_stmt: expr_stmt | print_stmt | del_stmt | pass_stmt | flow_stmt | import_stmt | global_stmt | exec_stmt | assert_stmt
import_stmt: 'import' dotted_as_name (',' dotted_as_name)* | 'from' dotted_name 'import' ('*' | import_as_name (',' import_as_name)*)
import_as_name: NAME [NAME NAME]
dotted_as_name: dotted_name [NAME NAME]
dotted_name: NAME ('.' NAME)*
*/
/* future_parse() return values:
-1 indicates an error occurred, e.g. unknown feature name
0 indicates no feature was found
1 indicates a feature was found
*/
static int
future_parse(PyFutureFeatures *ff, node *n)
{
int i, r, found;
loop:
/* fprintf(stderr, "future_parse(%d, %d, %s)\n",
TYPE(n), NCH(n), (n == NULL) ? "NULL" : STR(n));
*/
switch (TYPE(n)) {
case file_input:
for (i = 0; i < NCH(n); i++) {
node *ch = CHILD(n, i);
if (TYPE(ch) == stmt) {
n = ch;
goto loop;
}
}
return 0;
case simple_stmt:
if (NCH(n) == 1) {
REQ(CHILD(n, 0), small_stmt);
n = CHILD(n, 0);
goto loop;
}
found = 0;
for (i = 0; i < NCH(n); ++i)
if (TYPE(CHILD(n, i)) == small_stmt) {
r = future_parse(ff, CHILD(n, i));
if (r < 1) {
ff->ff_last_lineno = n->n_lineno;
ff->ff_n_simple_stmt = i;
return r;
} else
found++;
}
if (found)
return 1;
else
return 0;
case stmt:
if (TYPE(CHILD(n, 0)) == simple_stmt) {
n = CHILD(n, 0);
goto loop;
} else {
REQ(CHILD(n, 0), compound_stmt);
ff->ff_last_lineno = n->n_lineno;
return 0;
}
case small_stmt:
n = CHILD(n, 0);
goto loop;
case import_stmt: {
node *name;
if (STR(CHILD(n, 0))[0] != 'f') { /* from */
ff->ff_last_lineno = n->n_lineno;
return 0;
}
name = CHILD(n, 1);
if (strcmp(STR(CHILD(name, 0)), "__future__") != 0)
return 0;
if (future_check_features(ff, n) < 0)
return -1;
return 1;
}
default:
ff->ff_last_lineno = n->n_lineno;
return 0;
}
}
PyFutureFeatures *
PyNode_Future(node *n, char *filename)
{
PyFutureFeatures *ff;
ff = (PyFutureFeatures *)PyMem_Malloc(sizeof(PyFutureFeatures));
if (ff == NULL)
return NULL;
ff->ff_last_lineno = 0;
ff->ff_n_simple_stmt = -1;
ff->ff_nested_scopes = 0;
if (future_parse(ff, n) < 0) {
PyMem_Free((void *)ff);
return NULL;
}
return ff;
}
Index: compile.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Python/compile.c,v
retrieving revision 2.173
retrieving revision 2.174
diff -C2 -r2.173 -r2.174
*** compile.c 2001/02/27 05:15:57 2.173
--- compile.c 2001/02/27 19:07:02 2.174
***************
*** 56,62 ****
"%.100s: exec or 'import *' makes names ambiguous in nested scope"
- #define UNDEFINED_FUTURE_FEATURE \
- "future feature %.100s is not defined"
-
#define GLOBAL_AFTER_ASSIGN \
"name '%.400s' is assigned to before global declaration"
--- 56,59 ----
***************
*** 369,372 ****
--- 366,370 ----
int c_closure; /* Is nested w/freevars? */
struct symtable *c_symtable; /* pointer to module symbol table */
+ PyFutureFeatures *c_future; /* pointer to module's __future__ */
};
***************
*** 3865,3869 ****
} else {
sc.c_private = NULL;
! if (symtable_build(&sc, n) < 0) {
com_free(&sc);
return NULL;
--- 3863,3868 ----
} else {
sc.c_private = NULL;
! sc.c_future = PyNode_Future(n, filename);
! if (sc.c_future == NULL || symtable_build(&sc, n) < 0) {
com_free(&sc);
return NULL;
***************
*** 3997,4000 ****
--- 3996,4001 ----
if ((c->c_symtable = symtable_init()) == NULL)
return -1;
+ if (c->c_future->ff_nested_scopes)
+ c->c_symtable->st_nested_scopes = 1;
c->c_symtable->st_filename = c->c_filename;
symtable_enter_scope(c->c_symtable, TOP, TYPE(n), n->n_lineno);
***************
*** 4281,4322 ****
}
- /* XXX this code is a placeholder for correct code.
- from __future__ import name set language options */
-
- static int
- symtable_check_future(struct symtable *st, node *n)
- {
- int i;
- node *name = CHILD(n, 1);
-
- if (strcmp(STR(CHILD(name, 0)), "__future__") != 0)
- return 0;
- /* It is only legal to define __future__ features at the top
- of a module. If the current scope is not the module level
- or if there are any symbols defined, it is too late. */
- if (st->st_cur->ste_symbols != st->st_global
- || PyDict_Size(st->st_cur->ste_symbols) != 0) {
- PyErr_SetString(PyExc_SyntaxError,
- "imports from __future__ are only legal at the beginning of a module");
- return -1;
- }
- for (i = 3; i < NCH(n); ++i) {
- char *feature = STR(CHILD(CHILD(n, i), 0));
- /* Do a linear search through the defined features,
- assuming there aren't very many of them. */
- if (strcmp(feature, FUTURE_NESTED_SCOPES) == 0) {
- st->st_nested_scopes = 1;
- } else {
- PyErr_Format(PyExc_SyntaxError,
- UNDEFINED_FUTURE_FEATURE, feature);
- set_error_location(st->st_filename,
- st->st_cur->ste_lineno);
- st->st_errors++;
- return -1;
- }
- }
- return 1;
- }
-
/* When the compiler exits a scope, it must should update the scope's
free variable information with the list of free variables in its
--- 4282,4285 ----
***************
*** 4911,4915 ****
*/
if (STR(CHILD(n, 0))[0] == 'f') { /* from */
- symtable_check_future(st, n);
if (TYPE(CHILD(n, 3)) == STAR) {
st->st_cur->ste_optimized |= OPT_IMPORT_STAR;
--- 4874,4877 ----
Index: symtable.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Python/symtable.c,v
retrieving revision 2.3
retrieving revision 2.4
diff -C2 -r2.3 -r2.4
*** symtable.c 2001/02/27 04:23:34 2.3
--- symtable.c 2001/02/27 19:07:02 2.4
***************
*** 1,3 ****
--- 1,4 ----
#include "Python.h"
+ #include "compile.h"
#include "symtable.h"
#include "graminit.h"