bpo-31955: Fix distutils CCompiler.set_executable() for Unicode (GH-4316)

Fix CCompiler.set_executable() of distutils to handle properly Unicode strings.

Lib/distutils/ccompiler.py

@@ -160,7 +160,7 @@ class CCompiler:
             self.set_executable(key, args[key])
 
     def set_executable(self, key, value):
-        if isinstance(value, str):
+        if isinstance(value, basestring):
             setattr(self, key, split_quoted(value))
         else:
             setattr(self, key, value)

Lib/distutils/tests/test_ccompiler.py

@@ -24,6 +24,30 @@ class FakeCompiler(object):
 
 class CCompilerTestCase(support.EnvironGuard, unittest.TestCase):
 
+    def test_set_executables(self):
+        class MyCCompiler(CCompiler):
+            executables = {'compiler': '', 'compiler_cxx': '', 'linker': ''}
+
+        compiler = MyCCompiler()
+
+        # set executable as list
+        compiler.set_executables(compiler=['env', 'OMPI_MPICC=clang', 'mpicc'])
+        self.assertEqual(compiler.compiler, ['env',
+                                             'OMPI_MPICC=clang',
+                                             'mpicc'])
+
+        # set executable as string
+        compiler.set_executables(compiler_cxx='env OMPI_MPICXX=clang++ mpicxx')
+        self.assertEqual(compiler.compiler_cxx, ['env',
+                                                 'OMPI_MPICXX=clang++',
+                                                 'mpicxx'])
+
+        # set executable as unicode string
+        compiler.set_executables(linker=u'env OMPI_MPICXX=clang++ mpiCC')
+        self.assertEqual(compiler.linker, [u'env',
+                                           u'OMPI_MPICXX=clang++',
+                                           u'mpiCC'])
+
     def test_gen_lib_options(self):
         compiler = FakeCompiler()
         libdirs = ['lib1', 'lib2']

Misc/NEWS.d/next/Library/2017-11-07-19-12-25.bpo-31955.1DWu-S.rst

@@ -0,0 +1 @@
+Fix CCompiler.set_executable() of distutils to handle properly Unicode strings.