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Improved __future__ parser; still more to do

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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
This commit is contained in:
Jeremy Hylton 2001-02-27 19:07:02 +00:00
parent ed5e8234d7
commit 4db62b1e14
6 changed files with 167 additions and 46 deletions
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48
Python/compile.c
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@ -55,9 +55,6 @@ int Py_OptimizeFlag = 0;
#define ILLEGAL_DYNAMIC_SCOPE \
"%.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"
@ -368,6 +365,7 @@ struct compiling {
int c_nested; /* Is block nested funcdef or lamdef? */
int c_closure; /* Is nested w/freevars? */
struct symtable *c_symtable; /* pointer to module symbol table */
PyFutureFeatures *c_future; /* pointer to module's __future__ */
};
int is_free(int v)
@ -3864,7 +3862,8 @@ jcompile(node *n, char *filename, struct compiling *base)
sc.c_nested = 1;
} else {
sc.c_private = NULL;
if (symtable_build(&sc, n) < 0) {
sc.c_future = PyNode_Future(n, filename);
if (sc.c_future == NULL || symtable_build(&sc, n) < 0) {
com_free(&sc);
return NULL;
}
@ -3996,6 +3995,8 @@ symtable_build(struct compiling *c, node *n)
{
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);
if (c->c_symtable->st_errors > 0)
@ -4280,44 +4281,6 @@ PySymtable_Free(struct symtable *st)
PyMem_Free((void *)st);
}
/* 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
children.
@ -4910,7 +4873,6 @@ symtable_import(struct symtable *st, node *n)
import_as_name: NAME [NAME NAME]
*/
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;
} else {