Move BuildEnvironment out of wheel.py

2 files changed, 61 insertions, 53 deletions

diff --git a/src/pip/_internal/build_env.py b/src/pip/_internal/build_env.py
new file mode 100644
index 000000000..4ae1c4d9f
--- /dev/null
+++ b/src/pip/_internal/build_env.py
@@ -0,0 +1,60 @@
+"""Build Environment used for isolation during sdist building
+"""
+
+import os
+from sysconfig import get_paths
+
+from pip._internal.utils.temp_dir import TempDirectory
+
+
+class BuildEnvironment(object):
+    """Manages a temporary environment to install build deps
+    """
+
+    def __init__(self, no_clean):
+        self._temp_dir = TempDirectory(kind="build-env")
+        self._no_clean = no_clean
+
+    def __enter__(self):
+        self._temp_dir.create()
+
+        self.save_path = os.environ.get('PATH', None)
+        self.save_pythonpath = os.environ.get('PYTHONPATH', None)
+
+        install_scheme = 'nt' if (os.name == 'nt') else 'posix_prefix'
+        install_dirs = get_paths(install_scheme, vars={
+            'base': self._temp_dir.path,
+            'platbase': self._temp_dir.path,
+        })
+
+        scripts = install_dirs['scripts']
+        if self.save_path:
+            os.environ['PATH'] = scripts + os.pathsep + self.save_path
+        else:
+            os.environ['PATH'] = scripts + os.pathsep + os.defpath
+
+        if install_dirs['purelib'] == install_dirs['platlib']:
+            lib_dirs = install_dirs['purelib']
+        else:
+            lib_dirs = install_dirs['purelib'] + os.pathsep + \
+                install_dirs['platlib']
+        if self.save_pythonpath:
+            os.environ['PYTHONPATH'] = lib_dirs + os.pathsep + \
+                self.save_pythonpath
+        else:
+            os.environ['PYTHONPATH'] = lib_dirs
+
+        return self._temp_dir.path
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        if not self._no_clean:
+            self._temp_dir.cleanup()
+        if self.save_path is None:
+            os.environ.pop('PATH', None)
+        else:
+            os.environ['PATH'] = self.save_path
+
+        if self.save_pythonpath is None:
+            os.environ.pop('PYTHONPATH', None)
+        else:
+            os.environ['PYTHONPATH'] = self.save_pythonpath
diff --git a/src/pip/_internal/wheel.py b/src/pip/_internal/wheel.py
index c8fc21518..45a7590a9 100644
--- a/src/pip/_internal/wheel.py
+++ b/src/pip/_internal/wheel.py
@@ -17,7 +17,6 @@ import sys
 import warnings
 from base64 import urlsafe_b64encode
 from email.parser import Parser
-from sysconfig import get_paths
 
 from pip._vendor import pkg_resources, pytoml
 from pip._vendor.distlib.scripts import ScriptMaker
@@ -25,6 +24,7 @@ from pip._vendor.packaging.utils import canonicalize_name
 from pip._vendor.six import StringIO
 
 from pip._internal import pep425tags
+from pip._internal.build_env import BuildEnvironment
 from pip._internal.download import path_to_url, unpack_url
 from pip._internal.exceptions import (
     InstallationError, InvalidWheelFilename, UnsupportedWheel,
@@ -602,58 +602,6 @@ class Wheel(object):
         return bool(set(tags).intersection(self.file_tags))
 
 
-class BuildEnvironment(object):
-    """Context manager to install build deps in a simple temporary environment
-    """
-    def __init__(self, no_clean):
-        self._temp_dir = TempDirectory(kind="build-env")
-        self._no_clean = no_clean
-
-    def __enter__(self):
-        self._temp_dir.create()
-
-        self.save_path = os.environ.get('PATH', None)
-        self.save_pythonpath = os.environ.get('PYTHONPATH', None)
-
-        install_scheme = 'nt' if (os.name == 'nt') else 'posix_prefix'
-        install_dirs = get_paths(install_scheme, vars={
-            'base': self._temp_dir.path,
-            'platbase': self._temp_dir.path,
-        })
-
-        scripts = install_dirs['scripts']
-        if self.save_path:
-            os.environ['PATH'] = scripts + os.pathsep + self.save_path
-        else:
-            os.environ['PATH'] = scripts + os.pathsep + os.defpath
-
-        if install_dirs['purelib'] == install_dirs['platlib']:
-            lib_dirs = install_dirs['purelib']
-        else:
-            lib_dirs = install_dirs['purelib'] + os.pathsep + \
-                install_dirs['platlib']
-        if self.save_pythonpath:
-            os.environ['PYTHONPATH'] = lib_dirs + os.pathsep + \
-                self.save_pythonpath
-        else:
-            os.environ['PYTHONPATH'] = lib_dirs
-
-        return self._temp_dir.path
-
-    def __exit__(self, exc_type, exc_val, exc_tb):
-        if not self._no_clean:
-            self._temp_dir.cleanup()
-        if self.save_path is None:
-            os.environ.pop('PATH', None)
-        else:
-            os.environ['PATH'] = self.save_path
-
-        if self.save_pythonpath is None:
-            os.environ.pop('PYTHONPATH', None)
-        else:
-            os.environ['PYTHONPATH'] = self.save_pythonpath
-
-
 class WheelBuilder(object):
     """Build wheels from a RequirementSet."""