Add blame server experiment (#898)

* Add blame server experiment

* Adjustments to blame server experiment

* Add blame server experiment to docs

* Fix return type annotation

* Don't return in finally block

* Cleanup

---------

Co-authored-by: Sebastian Böhm <boehmseb@cs.uni-saarland.de>

docs/source/vara-ts-api/experiments/blame_report_experiments.rst

@@ -28,3 +28,13 @@ Module: BlameExperiment
     :members:
     :undoc-members:
     :show-inheritance:
+
+------
+
+Module: BlameServerExperiment
+-----------------------------
+
+.. automodule:: varats.experiments.vara.blame_server_experiment
+    :members:
+    :undoc-members:
+    :show-inheritance:

varats/varats/experiments/vara/blame_server_experiment.py

@@ -0,0 +1,103 @@
+"""
+Implements blame experiment using a blame cache server.
+
+The experiment starts the blame server, compiles with blame annotations and
+kills the server at the end.
+"""
+import socket
+import typing as tp
+
+from benchbuild import Project
+from benchbuild.utils import actions
+from plumbum import local
+from plumbum.cmd import kill
+
+import varats.experiments.vara.blame_experiment as BE
+from varats.data.reports.blame_annotations import BlameAnnotations as BA
+from varats.experiment.experiment_util import (
+    VersionExperiment,
+    create_default_compiler_error_handler,
+)
+from varats.experiment.wllvm import BCFileExtensions, Extract
+from varats.experiments.vara.blame_ast_experiment import (
+    BlameAnnotationGeneration,
+)
+from varats.report.report import ReportSpecification
+
+
+class CompileWithBlameServer(actions.Compile):  # type: ignore
+    """Start blame server before and kill server after compilation."""
+
+    NAME = "BlameServerSteps"
+    DESCRIPTION = "Start server before and kill server after compilation."
+
+    def __init__(self, project: Project, port: int):
+        super().__init__(project)
+        self.__port = port
+
+    def __call__(self) -> actions.StepResult:
+        server_cmd = local["vara-blamed"][
+            f"--blame-server=0.0.0.0:{self.__port}"]
+        server_proc = server_cmd.popen()
+        step_result = actions.StepResult.ERROR
+        try:
+            step_result = super().__call__()
+        finally:
+            kill[str(server_proc.pid)]()
+
+        return step_result
+
+    @staticmethod
+    def find_open_port() -> tp.Any:
+        """Finds and returns an available port on the local machine."""
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+            s.bind(('', 0))  # Bind to a free port provided by the OS
+            s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+            return s.getsockname()[1]
+
+
+class BlameServerExperiment(VersionExperiment, shorthand="BSE"):
+    """Generate a blame annotation report using blame server."""
+
+    NAME = "RunBlameServer"
+
+    REPORT_SPEC = ReportSpecification(BA)
+
+    def actions_for_project(
+        self, project: Project
+    ) -> tp.MutableSequence[actions.Step]:
+        """
+        Returns the specified steps to run the project(s) specified in the call
+        in a fixed order.
+
+        Args:
+            project: to analyze
+        """
+        project.cflags += ["-O1", "-Xclang", "-disable-llvm-optzns", "-g"]
+        bc_file_extensions = [
+            BCFileExtensions.NO_OPT,
+            BCFileExtensions.TBAA,
+            BCFileExtensions.BLAME
+        ]
+
+        BE.setup_basic_blame_experiment(self, project, BA)
+        open_port = CompileWithBlameServer.find_open_port()
+        project.cflags += [f"-fvara-blame-server=0.0.0.0:{open_port}"]
+        analysis_actions = []
+        analysis_actions.append(CompileWithBlameServer(project, open_port))
+        analysis_actions.append(
+            Extract(
+                project,
+                bc_file_extensions,
+                handler=create_default_compiler_error_handler(
+                    self.get_handle(), project, self.REPORT_SPEC.main_report
+                )
+            )
+        )
+        analysis_actions.append(
+            BlameAnnotationGeneration(
+                project, self.get_handle(), bc_file_extensions
+            )
+        )
+
+        return analysis_actions

varats/varats/tools/bb_config.py

@@ -114,6 +114,7 @@ def update_experiments(bb_cfg: s.Configuration) -> None:
         'varats.experiments.vara.agg_region_interaction_perf_runner',
         'varats.experiments.vara.blame_ast_experiment',
         'varats.experiments.vara.blame_report_experiment',
+        'varats.experiments.vara.blame_server_experiment',
         'varats.experiments.vara.blame_verifier_experiment',
         'varats.experiments.vara.commit_report_experiment',
         'varats.experiments.vara.feature_perf_runner',