[llvm] [LLVM][rtsan] Add RealtimeSanitizer transform pass (PR #101232)

[Florian Mayer via llvm-commits]

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@@ -0,0 +1,61 @@
+//===- RealtimeSanitizer.cpp - RealtimeSanitizer instrumentation *- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of the RealtimeSanitizer, an LLVM transformation for
+// detecting and reporting realtime safety violations.
+//
+// See also: llvm-project/compiler-rt/lib/rtsan/
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/Analysis.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Module.h"
+
+#include "llvm/Transforms/Instrumentation/RealtimeSanitizer.h"
+
+using namespace llvm;
+
+static void insertCallBeforeInstruction(Function &Fn, Instruction &Instruction,
+                                        const char *FunctionName) {
+  LLVMContext &Context = Fn.getContext();
+  FunctionType *FuncType = FunctionType::get(Type::getVoidTy(Context), false);
+  FunctionCallee Func =
+      Fn.getParent()->getOrInsertFunction(FunctionName, FuncType);
+  IRBuilder<> Builder{&Instruction};
+  Builder.CreateCall(Func, {});
+}
+
+static void insertCallAtFunctionEntryPoint(Function &Fn,
+                                           const char *InsertFnName) {
+
+  insertCallBeforeInstruction(Fn, Fn.front().front(), InsertFnName);
+}
+
+static void insertCallAtAllFunctionExitPoints(Function &Fn,
+                                              const char *InsertFnName) {
+  for (auto &BB : Fn)
+    for (auto &I : BB)
+      if (auto *RI = dyn_cast<ReturnInst>(&I))
+        insertCallBeforeInstruction(Fn, I, InsertFnName);
+}
+
+RealtimeSanitizerPass::RealtimeSanitizerPass(
+    const RealtimeSanitizerOptions &Options)
+    : Options{Options} {}
+
+PreservedAnalyses RealtimeSanitizerPass::run(Function &F,
+                                             AnalysisManager<Function> &AM) {
+  if (F.hasFnAttribute(Attribute::SanitizeRealtime)) {
+    insertCallAtFunctionEntryPoint(F, "__rtsan_realtime_enter");
+    insertCallAtAllFunctionExitPoints(F, "__rtsan_realtime_exit");
+    return PreservedAnalyses::none();
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fmayer wrote:

Yes, that sounds correct.

https://github.com/llvm/llvm-project/pull/101232