Modify pylint/flake8 path helper to add lldb python module to path.

It was adding all the test infrastructure paths properly, but it
was not adding the lldb module.  The current approach only adds the
lldb from the path.  That can be improved (in the comments) to add
the one from the related build directory if it can be ascertained.

With this change, lldb tests can be run through pylint/flake8
and have the lldb module found and used as part of the checks.

llvm-svn: 250453

lldb/test/lldb_pylint_helper.py

@@ -12,10 +12,13 @@ and multiple OS types, verifying changes across all.
 Provides helper support for adding lldb test paths to the python path.
 """
 import os
+import platform
+import subprocess
 import sys
 
 
 def add_lldb_test_paths(check_dir):
+    # pylint: disable=line-too-long
     """Adds lldb test-related paths to the python path.
 
     Starting with the given directory and working upward through
@@ -67,6 +70,72 @@ def add_lldb_test_paths(check_dir):
     @param check_dir specifies a directory that will be used to start
     looking for the lldb test infrastructure python library paths.
     """
+    # Add the test-related packages themselves.
+    add_lldb_test_package_paths(check_dir)
+
+    # Add the lldb directory itself
+    add_lldb_module_directory()
+
+
+def add_lldb_module_directory():
+    """
+    Desired Approach:
+
+    Part A: find an lldb
+
+    1. Walk up the parent chain from the current directory, looking for
+    a directory matching *build*.  If we find that, use it as the
+    root of a directory search for an lldb[.exe] executable.
+
+    2. If 1 fails, use the path and look for an lldb[.exe] in there.
+
+    If Part A ends up with an lldb, go to part B.  Otherwise, give up
+    on the lldb python module path.
+
+    Part B: use the output from 'lldb[.exe] -P' to find the lldb dir.
+
+    Current approach:
+    If Darwin, use 'xcrun lldb -P'; others: find lldb on path.
+
+    Drawback to current approach:
+    If the tester is changing the SB API (adding new methods), pylint
+    will not know about them as it is using the wrong lldb python module.
+    In practice, this should be minor.
+    """
+    try:
+        lldb_module_path = None
+
+        if platform.system() == 'Darwin':
+            # Use xcrun to find the selected lldb.
+            lldb_module_path = subprocess.check_output(["xcrun", "lldb", "-P"])
+        elif platform.system() == 'Windows':
+            lldb_module_path = subprocess.check_output(
+                ["lldb.exe", "-P"], shell=True)
+        else:
+            # Use the shell to run lldb from the path.
+            lldb_module_path = subprocess.check_output(
+                ["lldb", "-P"], shell=True)
+
+        # Trim the result.
+        if lldb_module_path is not None:
+            lldb_module_path = lldb_module_path.rtrim()
+
+        # If we have a result, add it to the path
+        if lldb_module_path is not None and len(lldb_module_path) > 0:
+            sys.path.insert(0, lldb_module_path)
+    # pylint: disable=broad-except
+    except Exception as exception:
+        print "failed to find python path: {}".format(exception)
+    elif platform.system() != 'Windows':
+        
+
+def add_lldb_test_package_paths(check_dir):
+    """Adds the lldb test infrastructure modules to the python path.
+
+    See add_lldb_test_paths for more details.
+
+    @param check_dir the directory of the test.
+    """
     check_dir = os.path.realpath(check_dir)
     while check_dir and len(check_dir) > 0:
         # If the current directory is test, it might be the lldb/test