[lldb] [llvm] [BoundsSafety][LLDB] Implement instrumentation plugin for -fbounds-safety soft traps (PR #169117)

[Jonas Devlieghere via llvm-commits]

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@@ -0,0 +1,491 @@
+//===-- InstrumentationRuntimeBoundsSafety.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 "InstrumentationRuntimeBoundsSafety.h"
+
+#include "Plugins/Process/Utility/HistoryThread.h"
+#include "lldb/Breakpoint/StoppointCallbackContext.h"
+#include "lldb/Core/Debugger.h"
+#include "lldb/Core/Module.h"
+#include "lldb/Core/PluginManager.h"
+#include "lldb/Symbol/Block.h"
+#include "lldb/Symbol/Symbol.h"
+#include "lldb/Symbol/SymbolContext.h"
+#include "lldb/Symbol/Variable.h"
+#include "lldb/Symbol/VariableList.h"
+#include "lldb/Target/InstrumentationRuntimeStopInfo.h"
+#include "lldb/Target/RegisterContext.h"
+#include "lldb/Target/SectionLoadList.h"
+#include "lldb/Target/StopInfo.h"
+#include "lldb/Target/Target.h"
+#include "lldb/Target/Thread.h"
+#include "lldb/Utility/RegisterValue.h"
+#include "lldb/Utility/RegularExpression.h"
+#include "clang/CodeGen/ModuleBuilder.h"
+
+#include <memory>
+
+using namespace lldb;
+using namespace lldb_private;
+
+LLDB_PLUGIN_DEFINE(InstrumentationRuntimeBoundsSafety)
+
+#define BOUNDS_SAFETY_SOFT_TRAP_MINIMAL "__bounds_safety_soft_trap"
+#define BOUNDS_SAFETY_SOFT_TRAP_S "__bounds_safety_soft_trap_s"
+
+const std::vector<std::string> &getBoundsSafetySoftTrapRuntimeFuncs() {
+  static std::vector<std::string> Funcs = {BOUNDS_SAFETY_SOFT_TRAP_MINIMAL,
+                                           BOUNDS_SAFETY_SOFT_TRAP_S};
+
+  return Funcs;
+}
+
+#define SOFT_TRAP_CATEGORY_PREFIX "Soft "
+#define SOFT_TRAP_FALLBACK_CATEGORY                                            \
+  SOFT_TRAP_CATEGORY_PREFIX "Bounds check failed"
+
+class InstrumentationBoundsSafetyStopInfo : public StopInfo {
+public:
+  ~InstrumentationBoundsSafetyStopInfo() override = default;
+
+  lldb::StopReason GetStopReason() const override {
+    return lldb::eStopReasonInstrumentation;
+  }
+
+  std::optional<uint32_t>
+  GetSuggestedStackFrameIndex(bool inlined_stack) override {
+    return m_value;
+  }
+
+  const char *GetDescription() override { return m_description.c_str(); }
+
+  bool DoShouldNotify(Event *event_ptr) override { return true; }
+
+  static lldb::StopInfoSP
+  CreateInstrumentationBoundsSafetyStopInfo(Thread &thread) {
+    return StopInfoSP(new InstrumentationBoundsSafetyStopInfo(thread));
+  }
+
+private:
+  InstrumentationBoundsSafetyStopInfo(Thread &thread);
+
+  std::pair<std::optional<std::string>, std::optional<uint32_t>>
+  ComputeStopReasonAndSuggestedStackFrame(bool &warning_emitted_for_failure);
+
+  std::pair<std::string, std::optional<uint32_t>>
+  ComputeStopReasonAndSuggestedStackFrameWithDebugInfo(
+      lldb::StackFrameSP parent_sf, lldb::user_id_t debugger_id,
+      bool &warning_emitted_for_failure);
+
+  std::pair<std::optional<std::string>, std::optional<uint32_t>>
+  ComputeStopReasonAndSuggestedStackFrameWithoutDebugInfo(
+      ThreadSP thread_sp, lldb::user_id_t debugger_id,
+      bool &warning_emitted_for_failure);
+};
+
+InstrumentationBoundsSafetyStopInfo::InstrumentationBoundsSafetyStopInfo(
+    Thread &thread)
+    : StopInfo(thread, 0) {
+  // No additional data describing the reason for stopping
+  m_extended_info = nullptr;
+  m_description = SOFT_TRAP_FALLBACK_CATEGORY;
+
+  bool warning_emitted_for_failure = false;
+  auto [Description, MaybeSuggestedStackIndex] =
+      ComputeStopReasonAndSuggestedStackFrame(warning_emitted_for_failure);
+  if (Description)
+    m_description = Description.value();
+  if (MaybeSuggestedStackIndex)
+    m_value = MaybeSuggestedStackIndex.value();
+
+  // Emit warning about the failure to compute the stop info if one wasn't
+  // already emitted
----------------
JDevlieghere wrote:

```suggestion
  // Emit warning about the failure to compute the stop info if one wasn't
  // already emitted.
```

https://github.com/llvm/llvm-project/pull/169117