Don't automtically try to import pexpect in lldbpexpect.

Since pexpect doesn't exist on Windows, tests which are xfail'ed
are not being run at all because they are failing when the file
is imported due to the `import pexpect`.  This puts the import
behind a conditional and makes an empty base class in the case
where pexpect is not present.

llvm-svn: 258965

lldb/packages/Python/lldbsuite/test/lldbpexpect.py

@@ -6,58 +6,64 @@ import os
 import sys
 
 # Third-party modules
-import pexpect
+import six
 
 # LLDB Modules
 import lldb
 from .lldbtest import *
 from . import lldbutil
 
-class PExpectTest(TestBase):
-    
-    mydir = TestBase.compute_mydir(__file__)
-
-    def setUp(self):
-        TestBase.setUp(self)
-
-    def launchArgs(self):
+if sys.platform.startswith('win32'):
+    class PExpectTest(TestBase):
         pass
+else:
+    import pexpect
 
-    def launch(self, timeout=None):
-        if timeout is None: timeout = 30
-        logfile = sys.stdout if self.TraceOn() else None
-        self.child = pexpect.spawn('%s %s' % (lldbtest_config.lldbExec, self.launchArgs()), logfile=logfile)
-        self.child.timeout = timeout
-        self.timeout = timeout
+    class PExpectTest(TestBase):
+    
+        mydir = TestBase.compute_mydir(__file__)
 
-    def expect(self, patterns=None, timeout=None, exact=None):
-        if patterns is None: return None
-        if timeout is None: timeout = self.timeout
-        if exact is None: exact = False
-        if exact:
-            return self.child.expect_exact(patterns, timeout=timeout)
-        else:
-            return self.child.expect(patterns, timeout=timeout)
+        def setUp(self):
+            TestBase.setUp(self)
 
-    def expectall(self, patterns=None, timeout=None, exact=None):
-        if patterns is None: return None
-        if timeout is None: timeout = self.timeout
-        if exact is None: exact = False
-        for pattern in patterns:
-            self.expect(pattern, timeout=timeout, exact=exact)
+        def launchArgs(self):
+            pass
 
-    def sendimpl(self, sender, command, patterns=None, timeout=None, exact=None):
-        sender(command)
-        return self.expect(patterns=patterns, timeout=timeout, exact=exact)
+        def launch(self, timeout=None):
+            if timeout is None: timeout = 30
+            logfile = sys.stdout if self.TraceOn() else None
+            self.child = pexpect.spawn('%s %s' % (lldbtest_config.lldbExec, self.launchArgs()), logfile=logfile)
+            self.child.timeout = timeout
+            self.timeout = timeout
 
-    def send(self, command, patterns=None, timeout=None, exact=None):
-        return self.sendimpl(self.child.send, command, patterns, timeout, exact)
+        def expect(self, patterns=None, timeout=None, exact=None):
+            if patterns is None: return None
+            if timeout is None: timeout = self.timeout
+            if exact is None: exact = False
+            if exact:
+                return self.child.expect_exact(patterns, timeout=timeout)
+            else:
+                return self.child.expect(patterns, timeout=timeout)
 
-    def sendline(self, command, patterns=None, timeout=None, exact=None):
-        return self.sendimpl(self.child.sendline, command, patterns, timeout, exact)
+        def expectall(self, patterns=None, timeout=None, exact=None):
+            if patterns is None: return None
+            if timeout is None: timeout = self.timeout
+            if exact is None: exact = False
+            for pattern in patterns:
+                self.expect(pattern, timeout=timeout, exact=exact)
 
-    def quit(self, gracefully=None):
-        if gracefully is None: gracefully = True
-        self.child.sendeof()
-        self.child.close(force=not gracefully)
-        self.child = None
+        def sendimpl(self, sender, command, patterns=None, timeout=None, exact=None):
+            sender(command)
+            return self.expect(patterns=patterns, timeout=timeout, exact=exact)
+
+        def send(self, command, patterns=None, timeout=None, exact=None):
+            return self.sendimpl(self.child.send, command, patterns, timeout, exact)
+
+        def sendline(self, command, patterns=None, timeout=None, exact=None):
+            return self.sendimpl(self.child.sendline, command, patterns, timeout, exact)
+
+        def quit(self, gracefully=None):
+            if gracefully is None: gracefully = True
+            self.child.sendeof()
+            self.child.close(force=not gracefully)
+            self.child = None