vendor/llvm/llvm-trunk-r321017

1 files changed, 163 insertions, 0 deletions

diff --git a/lib/Transforms/Utils/EntryExitInstrumenter.cpp b/lib/Transforms/Utils/EntryExitInstrumenter.cpp
new file mode 100644
index 000000000000..421663f82565
--- /dev/null
+++ b/lib/Transforms/Utils/EntryExitInstrumenter.cpp
@@ -0,0 +1,163 @@
+//===- EntryExitInstrumenter.cpp - Function Entry/Exit Instrumentation ----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Utils/EntryExitInstrumenter.h"
+#include "llvm/Analysis/GlobalsModRef.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/IR/DebugInfoMetadata.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Type.h"
+#include "llvm/Pass.h"
+#include "llvm/Transforms/Scalar.h"
+using namespace llvm;
+
+static void insertCall(Function &CurFn, StringRef Func,
+                       Instruction *InsertionPt, DebugLoc DL) {
+  Module &M = *InsertionPt->getParent()->getParent()->getParent();
+  LLVMContext &C = InsertionPt->getParent()->getContext();
+
+  if (Func == "mcount" ||
+      Func == ".mcount" ||
+      Func == "\01__gnu_mcount_nc" ||
+      Func == "\01_mcount" ||
+      Func == "\01mcount" ||
+      Func == "__mcount" ||
+      Func == "_mcount" ||
+      Func == "__cyg_profile_func_enter_bare") {
+    Constant *Fn = M.getOrInsertFunction(Func, Type::getVoidTy(C));
+    CallInst *Call = CallInst::Create(Fn, "", InsertionPt);
+    Call->setDebugLoc(DL);
+    return;
+  }
+
+  if (Func == "__cyg_profile_func_enter" || Func == "__cyg_profile_func_exit") {
+    Type *ArgTypes[] = {Type::getInt8PtrTy(C), Type::getInt8PtrTy(C)};
+
+    Constant *Fn = M.getOrInsertFunction(
+        Func, FunctionType::get(Type::getVoidTy(C), ArgTypes, false));
+
+    Instruction *RetAddr = CallInst::Create(
+        Intrinsic::getDeclaration(&M, Intrinsic::returnaddress),
+        ArrayRef<Value *>(ConstantInt::get(Type::getInt32Ty(C), 0)), "",
+        InsertionPt);
+    RetAddr->setDebugLoc(DL);
+
+    Value *Args[] = {ConstantExpr::getBitCast(&CurFn, Type::getInt8PtrTy(C)),
+                     RetAddr};
+
+    CallInst *Call =
+        CallInst::Create(Fn, ArrayRef<Value *>(Args), "", InsertionPt);
+    Call->setDebugLoc(DL);
+    return;
+  }
+
+  // We only know how to call a fixed set of instrumentation functions, because
+  // they all expect different arguments, etc.
+  report_fatal_error(Twine("Unknown instrumentation function: '") + Func + "'");
+}
+
+static bool runOnFunction(Function &F, bool PostInlining) {
+  StringRef EntryAttr = PostInlining ? "instrument-function-entry-inlined"
+                                     : "instrument-function-entry";
+
+  StringRef ExitAttr = PostInlining ? "instrument-function-exit-inlined"
+                                    : "instrument-function-exit";
+
+  StringRef EntryFunc = F.getFnAttribute(EntryAttr).getValueAsString();
+  StringRef ExitFunc = F.getFnAttribute(ExitAttr).getValueAsString();
+
+  bool Changed = false;
+
+  // If the attribute is specified, insert instrumentation and then "consume"
+  // the attribute so that it's not inserted again if the pass should happen to
+  // run later for some reason.
+
+  if (!EntryFunc.empty()) {
+    DebugLoc DL;
+    if (auto SP = F.getSubprogram())
+      DL = DebugLoc::get(SP->getScopeLine(), 0, SP);
+
+    insertCall(F, EntryFunc, &*F.begin()->getFirstInsertionPt(), DL);
+    Changed = true;
+    F.removeAttribute(AttributeList::FunctionIndex, EntryAttr);
+  }
+
+  if (!ExitFunc.empty()) {
+    for (BasicBlock &BB : F) {
+      TerminatorInst *T = BB.getTerminator();
+      DebugLoc DL;
+      if (DebugLoc TerminatorDL = T->getDebugLoc())
+        DL = TerminatorDL;
+      else if (auto SP = F.getSubprogram())
+        DL = DebugLoc::get(0, 0, SP);
+
+      if (isa<ReturnInst>(T)) {
+        insertCall(F, ExitFunc, T, DL);
+        Changed = true;
+      }
+    }
+    F.removeAttribute(AttributeList::FunctionIndex, ExitAttr);
+  }
+
+  return Changed;
+}
+
+namespace {
+struct EntryExitInstrumenter : public FunctionPass {
+  static char ID;
+  EntryExitInstrumenter() : FunctionPass(ID) {
+    initializeEntryExitInstrumenterPass(*PassRegistry::getPassRegistry());
+  }
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addPreserved<GlobalsAAWrapperPass>();
+  }
+  bool runOnFunction(Function &F) override { return ::runOnFunction(F, false); }
+};
+char EntryExitInstrumenter::ID = 0;
+
+struct PostInlineEntryExitInstrumenter : public FunctionPass {
+  static char ID;
+  PostInlineEntryExitInstrumenter() : FunctionPass(ID) {
+    initializePostInlineEntryExitInstrumenterPass(
+        *PassRegistry::getPassRegistry());
+  }
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addPreserved<GlobalsAAWrapperPass>();
+  }
+  bool runOnFunction(Function &F) override { return ::runOnFunction(F, true); }
+};
+char PostInlineEntryExitInstrumenter::ID = 0;
+}
+
+INITIALIZE_PASS(
+    EntryExitInstrumenter, "ee-instrument",
+    "Instrument function entry/exit with calls to e.g. mcount() (pre inlining)",
+    false, false)
+INITIALIZE_PASS(PostInlineEntryExitInstrumenter, "post-inline-ee-instrument",
+                "Instrument function entry/exit with calls to e.g. mcount() "
+                "(post inlining)",
+                false, false)
+
+FunctionPass *llvm::createEntryExitInstrumenterPass() {
+  return new EntryExitInstrumenter();
+}
+
+FunctionPass *llvm::createPostInlineEntryExitInstrumenterPass() {
+  return new PostInlineEntryExitInstrumenter();
+}
+
+PreservedAnalyses
+llvm::EntryExitInstrumenterPass::run(Function &F, FunctionAnalysisManager &AM) {
+  runOnFunction(F, PostInlining);
+  PreservedAnalyses PA;
+  PA.preserveSet<CFGAnalyses>();
+  return PA;
+}