feat(build): Also support python3

Author: Aurélien 'Bubu' Busi

CMakeLists.txt

@@ -7,10 +7,7 @@ INCLUDE(version)
 
 SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=gnu++11")
 
-FIND_PACKAGE(PythonInterp 2 REQUIRED)
-IF (NOT PYTHON_VERSION_MAJOR EQUAL 2)
-  MESSAGE(FATAL_ERROR "Python 2 is required.")
-ENDIF()
+FIND_PACKAGE(PythonInterp 2)
 
 FIND_PROGRAM(CTYPESGEN_FOUND ctypesgen.py)
 

ast/ast.py

@@ -54,6 +54,13 @@ def print_ast(lang_module, input_file):
 if __name__ == '__main__':
   import sys
   lang = sys.argv[1]
+
+  try:
+      if sys.version_info >= (3,0):
+        lang = "%s_py3" % lang
+  except:
+      pass
+
   filename = sys.argv[2]
 
   lang_module = load_lang(lang)

ast/c_impl_py3.py

@@ -0,0 +1,61 @@
+# Copyright (c) 2015-present, Facebook, Inc.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+from c_py3 import field_prototype, return_type, struct_name
+from casing import title
+from license import C_LICENSE_COMMENT
+
+class Printer(object):
+  '''Printer for the implementation of the pure C interface to the AST.
+  '''
+
+  def __init__(self):
+    self._current_type = None
+
+  def start_file(self):
+    print(C_LICENSE_COMMENT + '''/** @generated */
+
+#include "GraphQLAst.h"
+#include "../Ast.h"
+
+using namespace facebook::graphql::ast;  // NOLINT
+''')
+
+  def end_file(self):
+    pass
+
+  def start_type(self, name):
+    self._current_type = name
+
+  def field(self, type, name, nullable, plural):
+    print(field_prototype(self._current_type, type, name, nullable, plural) + ' {')
+    print('  const auto *realNode = reinterpret_cast<const %s *>(node);' % self._current_type)
+    title_name = title(name)
+    call_get = 'realNode->get%s()' % title_name
+    if plural:
+      if nullable:
+        print('  return %s ? %s->size() : 0;' % (call_get, call_get))
+      else:
+        print('  return %s.size();' % call_get)
+    else:
+      if type in ['string', 'OperationKind', 'boolean']:
+        print('  return %s;' % call_get)
+      else:
+        fmt = '  return reinterpret_cast<const struct %s *>(%s%s);'
+        print(fmt % (struct_name(type), '' if nullable else '&', call_get))
+
+    print('}')
+
+  def end_type(self, name):
+    pass
+
+  def start_union(self, name):
+    pass
+
+  def union_option(self, option):
+    pass
+
+  def end_union(self, name):
+    pass

ast/c_py3.py

@@ -0,0 +1,100 @@
+# Copyright (c) 2015-present, Facebook, Inc.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+from casing import snake
+
+from license import C_LICENSE_COMMENT
+
+def struct_name(type):
+  return 'GraphQLAst' + type
+
+
+def return_type(type):
+  if type == 'OperationKind' or type == 'string':
+    return 'const char *'
+
+  if type == 'boolean':
+    return 'int'
+
+  return 'const struct %s *' % struct_name(type)
+
+
+def field_prototype(owning_type, type, name, nullable, plural):
+  st_name = struct_name(owning_type)
+  if plural:
+    return 'int %s_get_%s_size(const struct %s *node)' % (
+      st_name, snake(name), st_name)
+  else:
+    ret_type = return_type(type)
+    return '%s %s_get_%s(const struct %s *node)' % (
+      ret_type, st_name, snake(name), st_name)
+
+
+class Printer(object):
+  '''Printer for the pure C interface to the AST.
+
+  Merely a set of wrappers around the C++ interface; makes it possible
+  to use the AST from C code and simplifies the task of writing
+  bindings for other langugages.
+
+  The mapping is as follows:
+
+  - For each concrete type, you get an opaque C struct type,
+  accessible only by pointer.
+
+  - For each singular field of a concrete type, you get an accessor
+  function, returning said field in the obvious way.
+
+  - For each plural field of a concrete type, you get an accessor
+  function telling you its size. For access to elements of a plural
+  field, you can use the visitor API.
+
+  - For each union type, you get nothing specific (REVIEW), but you
+    can use the visitor API to work around this entirely.
+
+  '''
+
+  def __init__(self):
+    self._current_type = None
+
+  def start_file(self):
+    print(C_LICENSE_COMMENT + '''/** @generated */
+
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+''')
+
+  def end_file(self):
+    print('''
+
+#ifdef __cplusplus
+}
+#endif
+''')
+
+  def start_type(self, name):
+    # Forward declarations for AST nodes.
+    st_name = struct_name(name)
+    print('struct ' + st_name + ';')
+    self._current_type = name
+
+  def field(self, type, name, nullable, plural):
+    print(field_prototype(self._current_type, type, name, nullable, plural) + ';')
+
+  def end_type(self, name):
+    print()
+
+  def start_union(self, name):
+    print('struct ' + struct_name(name) + ';')
+
+  def union_option(self, option):
+    pass
+
+  def end_union(self, name):
+    print()

ast/c_visitor_impl_py3.py

@@ -0,0 +1,39 @@
+# Copyright (c) 2015-present, Facebook, Inc.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+from casing import snake
+from license import C_LICENSE_COMMENT
+
+class Printer(object):
+  '''Printer for a simple list of types to be visited by the C visitor.
+  '''
+
+  def __init__(self):
+    self._types = []
+
+  def start_file(self):
+    print(C_LICENSE_COMMENT + '/** @generated */')
+    print('#define FOR_EACH_CONCRETE_TYPE(MACRO) \\')
+
+  def start_type(self, name):
+    self._types.append(name)
+
+  def field(self, type, name, nullable, plural):
+    pass
+
+  def end_type(self, name):
+    pass
+
+  def end_file(self):
+    print(' \\\n'.join('MACRO(%s, %s)' % (name, snake(name)) for name in self._types))
+
+  def start_union(self, name):
+    pass
+
+  def union_option(self, option):
+    pass
+
+  def end_union(self, name):
+    pass

ast/cxx_impl_py3.py

@@ -0,0 +1,61 @@
+# Copyright (c) 2015-present, Facebook, Inc.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+from license import C_LICENSE_COMMENT
+
+class Printer(object):
+  def __init__(self):
+    pass
+
+  def start_file(self):
+    print(C_LICENSE_COMMENT + '''/** @generated */
+
+#include "Ast.h"
+#include "AstVisitor.h"
+
+namespace facebook {
+namespace graphql {
+namespace ast {
+''')
+
+  def end_file(self):
+    print('}  // namespace ast')
+    print('}  // namespace graphql')
+    print('}  // namespace facebook')
+
+  def start_type(self, name):
+    print('''void %s::accept(visitor::AstVisitor *visitor) const {
+  if (visitor->visit%s(*this)) {
+''' % (name, name))
+
+  def field(self, type, name, nullable, plural):
+    if type in ['OperationKind', 'string', 'boolean']:
+      return
+  
+    if plural:
+      accept = '{ for (const auto &x : *%s_) { x->accept(visitor); } }' % name
+      if nullable:
+        accept = 'if (%s_) %s' % (name, accept)
+      print('    ' + accept)
+    else:
+      accept = '%s_->accept(visitor);' % name
+      if nullable:
+        accept = 'if (%s_) { %s }' % (name, accept)
+      print('    ' + accept)
+
+  def end_type(self, name):
+    print('''  }
+  visitor->endVisit%s(*this);
+}
+''' % name)
+
+  def start_union(self, name):
+    pass
+
+  def union_option(self, option):
+    pass
+
+  def end_union(self, name):
+    pass

ast/cxx_json_visitor_header_py3.py

@@ -0,0 +1,42 @@
+# Copyright (c) 2016-present, Facebook, Inc.
+# All rights reserved.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+from casing import title
+from license import C_LICENSE_COMMENT
+
+class Printer(object):
+  def __init__(self):
+    self._anyFieldIsANode = False
+
+  def start_file(self):
+    print(C_LICENSE_COMMENT + '/** @generated */')
+
+  def end_file(self):
+    pass
+
+  def start_type(self, name):
+    self._anyFieldIsANode = False
+
+  def end_type(self, name):
+    titleName = title(name)
+    if self._anyFieldIsANode:
+      print('bool visit%s(const %s &node) override;' % (titleName, titleName))
+    print('void endVisit%s(const %s &node) override;' % (titleName, titleName))
+    print()
+
+  def field(self, type, name, nullable, plural):
+    if (not self._anyFieldIsANode and
+        type not in ('OperationKind', 'string', 'boolean')):
+      self._anyFieldIsANode = True
+
+  def start_union(self, name):
+    pass
+
+  def union_option(self, option):
+    pass
+
+  def end_union(self, name):
+    pass