| #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; |
| } |
| |