Add a --with-oprofile flag to configure, which uses OProfile's agent

library to tell it the addresses of JITted functions.  For a
particular program, this changes the opreport -l output from:

samples %    image name        symbol name
48182  98.9729 anon (tgid:19412 range:0x7f12ccaab000-0x7f12cdaab000) anon (tgid:19412 range:0x7f12ccaab000-0x7f12cdaab000)
11     0.0226  libstdc++.so.6.0.9    /usr/lib/libstdc++.so.6.0.9

to:

samples %    image name        symbol name
24565  60.7308 19814.jo        fib_left
15365  37.9861 19814.jo        fib_right
22     0.0544  ld-2.7.so       do_lookup_x



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75279 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 109 insertions, 0 deletions

diff --git a/lib/ExecutionEngine/JIT/OProfileJITEventListener.cpp b/lib/ExecutionEngine/JIT/OProfileJITEventListener.cpp
new file mode 100644
index 0000000000..1cc45139da
--- /dev/null
+++ b/lib/ExecutionEngine/JIT/OProfileJITEventListener.cpp
@@ -0,0 +1,109 @@
+//===-- OProfileJITEventListener.cpp - Tell OProfile about JITted code ----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a JITEventListener object that calls into OProfile to tell
+// it about JITted functions.  For now, we only record function names and sizes,
+// but eventually we'll also record line number information.
+//
+// See http://oprofile.sourceforge.net/doc/devel/jit-interface.html for the
+// definition of the interface we're using.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "oprofile-jit-event-listener"
+#include "llvm/Function.h"
+#include "llvm/ExecutionEngine/JITEventListener.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/System/Errno.h"
+#include "llvm/Config/config.h"
+#include <stddef.h>
+using namespace llvm;
+
+#if defined(USE_OPROFILE)
+
+#include <opagent.h>
+
+namespace {
+
+class OProfileJITEventListener : public JITEventListener {
+  op_agent_t Agent;
+public:
+  OProfileJITEventListener();
+  ~OProfileJITEventListener();
+
+  virtual void NotifyFunctionEmitted(const Function &F,
+                                     void *FnStart, size_t FnSize,
+                                     const EmittedFunctionDetails &Details);
+  virtual void NotifyFreeingMachineCode(const Function &F, void *OldPtr);
+};
+
+OProfileJITEventListener::OProfileJITEventListener()
+    : Agent(op_open_agent()) {
+  if (Agent == NULL) {
+    const std::string err_str = sys::StrError();
+    DOUT << "Failed to connect to OProfile agent: " << err_str << "\n";
+  } else {
+    DOUT << "Connected to OProfile agent.\n";
+  }
+}
+
+OProfileJITEventListener::~OProfileJITEventListener() {
+  if (Agent != NULL) {
+    if (op_close_agent(Agent) == -1) {
+      const std::string err_str = sys::StrError();
+      DOUT << "Failed to disconnect from OProfile agent: " << err_str << "\n";
+    } else {
+      DOUT << "Disconnected from OProfile agent.\n";
+    }
+  }
+}
+
+// Adds the just-emitted function to the symbol table.
+void OProfileJITEventListener::NotifyFunctionEmitted(
+    const Function &F, void *FnStart, size_t FnSize,
+    const EmittedFunctionDetails &) {
+  const char *const FnName = F.getNameStart();
+  assert(FnName != 0 && FnStart != 0 && "Bad symbol to add");
+  if (op_write_native_code(Agent, FnName,
+                           reinterpret_cast<uint64_t>(FnStart),
+                           FnStart, FnSize) == -1) {
+    DOUT << "Failed to tell OProfile about native function " << FnName
+         << " at [" << FnStart << "-" << ((char*)FnStart + FnSize) << "]\n";
+  }
+}
+
+// Removes the to-be-deleted function from the symbol table.
+void OProfileJITEventListener::NotifyFreeingMachineCode(
+    const Function &F, void *FnStart) {
+  assert(FnStart && "Invalid function pointer");
+  if (op_unload_native_code(Agent, reinterpret_cast<uint64_t>(FnStart)) == -1) {
+    DOUT << "Failed to tell OProfile about unload of native function "
+         << F.getName() << " at " << FnStart << "\n";
+  }
+}
+
+}  // anonymous namespace.
+
+namespace llvm {
+JITEventListener *createOProfileJITEventListener() {
+  return new OProfileJITEventListener;
+}
+}
+
+#else  // !defined(USE_OPROFILE)
+
+namespace llvm {
+// By defining this to return NULL, we can let clients call it unconditionally,
+// even if they haven't configured with the OProfile libraries.
+JITEventListener *createOProfileJITEventListener() {
+  return NULL;
+}
+}  // namespace llvm
+
+#endif  // defined(USE_OPROFILE)