[clang] [lld] [llvm] [RFC] Initial reference pass-plugin in LLVM (PR #171111)

[Stefan Gränitz via llvm-commits]

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@@ -0,0 +1,464 @@
+//===- tools/plugins-shlib/pypass.cpp -------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/ScopeExit.h"
+#include "llvm/Passes/PassBuilder.h"
+#include "llvm/Passes/PassPlugin.h"
+#include "llvm/Support/DynamicLibrary.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <algorithm>
+#include <cstdlib>
+#include <filesystem>
+#include <memory>
+#include <optional>
+#include <string>
+
+using namespace llvm;
+
+static cl::opt<std::string>
+    DylibPath("pypass-dylib", cl::desc("Path to the Python shared library"),
+              cl::init(""));
+
+static cl::opt<std::string>
+    ScriptPath("pypass-script", cl::desc("Path to the Python script to run"),
+               cl::init(""));
+
+static std::string findPython() {
+  if (!DylibPath.empty())
+    return DylibPath;
+  if (const char *Path = std::getenv("LLVM_PYPASS_DYLIB"))
+    return std::string(Path);
+  // TODO: Run Python from PATH and use a script to query the shared lib
+  return std::string{};
+}
+
+static std::string findScript() {
+  if (!ScriptPath.empty())
+    return ScriptPath;
+  if (const char *Path = std::getenv("LLVM_PYPASS_SCRIPT"))
+    return std::string(Path);
+  return std::string{};
+}
+
+struct PythonAPI {
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weliveindetail wrote:

The patch doesn't use pybind, because I was aiming for a minimal explicit interface that won't pull in more API calls than necessary. It will be sufficient for the plugin to forward pointers to C-API types and it shouldn't require many more Python API calls.

https://github.com/llvm/llvm-project/pull/171111