prepare_bindings.py: enable static bindings

Added a new flag, --allow-static-binding.  When specified,
if (and only if) the swig binary cannot be found, then the
LLDBWrapPython.cpp and lldb.py from the
scripts/Python/{static-binding-dir} are copied into the place where
swig would have generated them.

{static-binding-dir} defaults to static-binding, and can be
overridden with the --static-binding-dir command line argument.

The static bindings checked in are from r253424.

llvm-svn: 253448

lldb/lldb.xcodeproj/project.pbxproj

@@ -6226,7 +6226,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/bash;
-			shellScript = "/usr/bin/python $SRCROOT/scripts/prepare_bindings.py --find-swig --framework --src-root $SRCROOT --target-dir $TARGET_BUILD_DIR --config-build-dir $CONFIGURATION_BUILD_DIR";
+			shellScript = "/usr/bin/python $SRCROOT/scripts/prepare_bindings.py --find-swig --framework --src-root $SRCROOT --target-dir $TARGET_BUILD_DIR --config-build-dir $CONFIGURATION_BUILD_DIR --allow-static-binding";
 		};
 		4959511A1A1ACE9500F6F8FC /* Install Clang compiler headers */ = {
 			isa = PBXShellScriptBuildPhase;

lldb/scripts/Python/prepare_binding_Python.py

@@ -251,6 +251,42 @@ def do_swig_rebuild(options, dependency_file, config_build_dir, settings):
             sys.exit(-10)
 
 
+def copy_static_bindings(options, config_build_dir, settings):
+    """Copies the static Python bindings over to the build dir.
+    """
+
+    # Copy the LLDBWrapPython.cpp C++ binding file impl over.
+    lldb_wrap_python_src_path = os.path.join(
+        options.src_root,
+        "scripts",
+        "Python",
+        options.static_binding_dir,
+        "LLDBWrapPython.cpp")
+    if not os.path.exists(lldb_wrap_python_src_path):
+        logging.error(
+            "failed to find static Python binding .cpp file at '%s'",
+            lldb_wrap_python_src_path)
+        sys.exit(-12)
+    shutil.copyfile(lldb_wrap_python_src_path, settings.output_file)
+
+    # Copy the lldb.py impl over.
+    lldb_py_src_path = os.path.join(
+        options.src_root,
+        "scripts",
+        "Python",
+        options.static_binding_dir,
+        "lldb.py")
+    if not os.path.exists(lldb_py_src_path):
+        logging.error(
+            "failed to find static Python binding .py file at '%s'",
+            lldb_py_src_path)
+        sys.exit(-13)
+    lldb_py_dest_path = os.path.join(
+        os.path.dirname(settings.output_file),
+        "lldb.py")
+    shutil.copyfile(lldb_py_src_path, lldb_py_dest_path)
+
+
 def run_python_script(script_and_args):
     """Runs a python script, logging appropriately.
 
@@ -418,7 +454,14 @@ def main(options):
             "Skipping Python binding generation: everything is up to date")
         return
 
-    # Generate the Python binding with swig.
+    # Generate the Python binding with swig, or use the static bindings if no swig.
+    if not options.swig_executable or not os.path.exists(options.swig_executable):
+        # Copy over the static bindings.  We capture the the modified (i.e. post-processed)
+        # binding, so we don't do the modify step here - the modifications have
+        # already been applied.
+        copy_static_bindings(options, config_build_dir, settings)
+    else:
+        # Generate the bindings with swig.
         logging.info("Python binding is out of date, regenerating")
         do_swig_rebuild(options, dependency_file, config_build_dir, settings)
         if options.generate_dependency_file:

lldb/scripts/prepare_bindings.py

@@ -158,6 +158,19 @@ def process_args(args):
             "Specifies the build dir where the language binding "
             "should be placed"))
 
+    group = parser.add_argument_group("static binding usage")
+    group.add_argument(
+        "--allow-static-binding",
+        action="store_true",
+        help=(
+            "Specify the pre-baked binding can be used if "
+            "swig cannot be found."))
+    group.add_argument(
+        "--static-binding-dir",
+        default="static-binding",
+        help="script-relative directory for appropriate static bindings"
+    )
+
     # Process args.
     options = parser.parse_args(args)
 
@@ -196,9 +209,14 @@ def find_file_in_paths(paths, exe_basename):
     return None
 
 
-def find_swig_executable(options):
+def find_swig_executable(options, must_exist):
     """Finds the swig executable in the PATH or known good locations.
 
+    :param options the command line options returned by argparse.
+
+    :param must_exist if True, this method exits the program if
+    swig is not found; otherwise, always returns whether swig is found.
+
     Replaces options.swig_executable with the full swig executable path.
     """
     # Figure out what we're looking for.
@@ -219,19 +237,27 @@ def find_swig_executable(options):
     # Add in the extra dirs
     paths_to_check.extend(extra_dirs)
     if len(paths_to_check) < 1:
+        if must_exist:
             logging.error(
                 "swig executable was not specified, PATH has no "
                 "contents, and there are no extra directories to search")
             sys.exit(-6)
+        else:
+            logging.info("failed to find swig: no paths available")
+            return
 
     # Find the swig executable
     options.swig_executable = find_file_in_paths(paths_to_check, exe_basename)
     if not options.swig_executable or len(options.swig_executable) < 1:
+        if must_exist:
             logging.error(
                 "failed to find exe='%s' in paths='%s'",
                 exe_basename,
                 paths_to_check)
             sys.exit(-6)
+        else:
+            logging.info("%s not found in paths %s", exe_basename, paths_to_check)
+    else:
         logging.info("found swig executable: %s", options.swig_executable)
 
 
@@ -247,7 +273,8 @@ def main(args):
     # Ensure we have a swig executable.
     if not options.swig_executable or len(options.swig_executable) == 0:
         if options.find_swig:
-            find_swig_executable(options)
+            must_exist = not options.allow_static_binding
+            find_swig_executable(options, must_exist)
         else:
             logging.error(
                 "The --find-swig option must be specified "