intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 158 insertions, 0 deletions

diff --git a/contrib/tools/python3/src/Python/future.c b/contrib/tools/python3/src/Python/future.c
new file mode 100644
index 0000000000..1663a38a6f
--- /dev/null
+++ b/contrib/tools/python3/src/Python/future.c
@@ -0,0 +1,158 @@
+#include "Python.h"
+#include "Python-ast.h"
+#include "node.h"
+#include "token.h"
+#include "graminit.h"
+#include "code.h"
+#include "symtable.h"
+#include "ast.h"
+
+#define UNDEFINED_FUTURE_FEATURE "future feature %.100s is not defined"
+#define ERR_LATE_FUTURE \
+"from __future__ imports must occur at the beginning of the file"
+
+static int
+future_check_features(PyFutureFeatures *ff, stmt_ty s, PyObject *filename)
+{
+    int i;
+    asdl_seq *names;
+
+    assert(s->kind == ImportFrom_kind);
+
+    names = s->v.ImportFrom.names;
+    for (i = 0; i < asdl_seq_LEN(names); i++) {
+        alias_ty name = (alias_ty)asdl_seq_GET(names, i);
+        const char *feature = PyUnicode_AsUTF8(name->name);
+        if (!feature)
+            return 0;
+        if (strcmp(feature, FUTURE_NESTED_SCOPES) == 0) {
+            continue;
+        } else if (strcmp(feature, FUTURE_GENERATORS) == 0) {
+            continue;
+        } else if (strcmp(feature, FUTURE_DIVISION) == 0) {
+            continue;
+        } else if (strcmp(feature, FUTURE_ABSOLUTE_IMPORT) == 0) {
+            continue;
+        } else if (strcmp(feature, FUTURE_WITH_STATEMENT) == 0) {
+            continue;
+        } else if (strcmp(feature, FUTURE_PRINT_FUNCTION) == 0) {
+            continue;
+        } else if (strcmp(feature, FUTURE_UNICODE_LITERALS) == 0) {
+            continue;
+        } else if (strcmp(feature, FUTURE_BARRY_AS_BDFL) == 0) {
+            ff->ff_features |= CO_FUTURE_BARRY_AS_BDFL;
+        } else if (strcmp(feature, FUTURE_GENERATOR_STOP) == 0) {
+            continue;
+        } else if (strcmp(feature, FUTURE_ANNOTATIONS) == 0) {
+            ff->ff_features |= CO_FUTURE_ANNOTATIONS;
+        } else if (strcmp(feature, "braces") == 0) {
+            PyErr_SetString(PyExc_SyntaxError,
+                            "not a chance");
+            PyErr_SyntaxLocationObject(filename, s->lineno, s->col_offset + 1);
+            return 0;
+        } else {
+            PyErr_Format(PyExc_SyntaxError,
+                         UNDEFINED_FUTURE_FEATURE, feature);
+            PyErr_SyntaxLocationObject(filename, s->lineno, s->col_offset + 1);
+            return 0;
+        }
+    }
+    return 1;
+}
+
+static int
+future_parse(PyFutureFeatures *ff, mod_ty mod, PyObject *filename)
+{
+    int i, done = 0, prev_line = 0;
+
+    if (!(mod->kind == Module_kind || mod->kind == Interactive_kind))
+        return 1;
+
+    if (asdl_seq_LEN(mod->v.Module.body) == 0)
+        return 1;
+
+    /* A subsequent pass will detect future imports that don't
+       appear at the beginning of the file.  There's one case,
+       however, that is easier to handle here: A series of imports
+       joined by semi-colons, where the first import is a future
+       statement but some subsequent import has the future form
+       but is preceded by a regular import.
+    */
+
+    i = 0;
+    if (_PyAST_GetDocString(mod->v.Module.body) != NULL)
+        i++;
+
+    for (; i < asdl_seq_LEN(mod->v.Module.body); i++) {
+        stmt_ty s = (stmt_ty)asdl_seq_GET(mod->v.Module.body, i);
+
+        if (done && s->lineno > prev_line)
+            return 1;
+        prev_line = s->lineno;
+
+        /* The tests below will return from this function unless it is
+           still possible to find a future statement.  The only things
+           that can precede a future statement are another future
+           statement and a doc string.
+        */
+
+        if (s->kind == ImportFrom_kind) {
+            identifier modname = s->v.ImportFrom.module;
+            if (modname &&
+                _PyUnicode_EqualToASCIIString(modname, "__future__")) {
+                if (done) {
+                    PyErr_SetString(PyExc_SyntaxError,
+                                    ERR_LATE_FUTURE);
+                    PyErr_SyntaxLocationObject(filename, s->lineno, s->col_offset);
+                    return 0;
+                }
+                if (!future_check_features(ff, s, filename))
+                    return 0;
+                ff->ff_lineno = s->lineno;
+            }
+            else {
+                done = 1;
+            }
+        }
+        else {
+            done = 1;
+        }
+    }
+    return 1;
+}
+
+
+PyFutureFeatures *
+PyFuture_FromASTObject(mod_ty mod, PyObject *filename)
+{
+    PyFutureFeatures *ff;
+
+    ff = (PyFutureFeatures *)PyObject_Malloc(sizeof(PyFutureFeatures));
+    if (ff == NULL) {
+        PyErr_NoMemory();
+        return NULL;
+    }
+    ff->ff_features = 0;
+    ff->ff_lineno = -1;
+
+    if (!future_parse(ff, mod, filename)) {
+        PyObject_Free(ff);
+        return NULL;
+    }
+    return ff;
+}
+
+
+PyFutureFeatures *
+PyFuture_FromAST(mod_ty mod, const char *filename_str)
+{
+    PyFutureFeatures *ff;
+    PyObject *filename;
+
+    filename = PyUnicode_DecodeFSDefault(filename_str);
+    if (filename == NULL)
+        return NULL;
+    ff = PyFuture_FromASTObject(mod, filename);
+    Py_DECREF(filename);
+    return ff;
+}