[X86] Implement -mfentry
Summary: Insert calls to __fentry__ at function entry.
Reviewers: hfinkel, craig.topper
Subscribers: mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D28000
llvm-svn: 293648
diff --git a/llvm/lib/CodeGen/CMakeLists.txt b/llvm/lib/CodeGen/CMakeLists.txt
index 43bca0e..a1e5fd4 100644
--- a/llvm/lib/CodeGen/CMakeLists.txt
+++ b/llvm/lib/CodeGen/CMakeLists.txt
@@ -23,6 +23,7 @@
ExpandISelPseudos.cpp
ExpandPostRAPseudos.cpp
FaultMaps.cpp
+ FEntryInserter.cpp
FuncletLayout.cpp
GCMetadata.cpp
GCMetadataPrinter.cpp
diff --git a/llvm/lib/CodeGen/CodeGen.cpp b/llvm/lib/CodeGen/CodeGen.cpp
index 4cf9b13..9fb796a 100644
--- a/llvm/lib/CodeGen/CodeGen.cpp
+++ b/llvm/lib/CodeGen/CodeGen.cpp
@@ -32,6 +32,7 @@
initializeExpandISelPseudosPass(Registry);
initializeExpandPostRAPass(Registry);
initializeFinalizeMachineBundlesPass(Registry);
+ initializeFEntryInserterPass(Registry);
initializeFuncletLayoutPass(Registry);
initializeGCMachineCodeAnalysisPass(Registry);
initializeGCModuleInfoPass(Registry);
diff --git a/llvm/lib/CodeGen/FEntryInserter.cpp b/llvm/lib/CodeGen/FEntryInserter.cpp
new file mode 100644
index 0000000..0759bf6
--- /dev/null
+++ b/llvm/lib/CodeGen/FEntryInserter.cpp
@@ -0,0 +1,55 @@
+//===-- FEntryInsertion.cpp - Patchable prologues for LLVM -------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file edits function bodies to insert fentry calls.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Target/TargetFrameLowering.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
+
+using namespace llvm;
+
+namespace {
+struct FEntryInserter : public MachineFunctionPass {
+ static char ID; // Pass identification, replacement for typeid
+ FEntryInserter() : MachineFunctionPass(ID) {
+ initializeFEntryInserterPass(*PassRegistry::getPassRegistry());
+ }
+
+ bool runOnMachineFunction(MachineFunction &F) override;
+};
+}
+
+bool FEntryInserter::runOnMachineFunction(MachineFunction &MF) {
+ const std::string FEntryName =
+ MF.getFunction()->getFnAttribute("fentry-call").getValueAsString();
+ if (FEntryName != "true")
+ return false;
+
+ auto &FirstMBB = *MF.begin();
+ auto &FirstMI = *FirstMBB.begin();
+
+ auto *TII = MF.getSubtarget().getInstrInfo();
+ BuildMI(FirstMBB, FirstMI, FirstMI.getDebugLoc(),
+ TII->get(TargetOpcode::FENTRY_CALL));
+ return true;
+}
+
+char FEntryInserter::ID = 0;
+char &llvm::FEntryInserterID = FEntryInserter::ID;
+INITIALIZE_PASS(FEntryInserter, "fentry-insert", "Insert fentry calls", false,
+ false)
diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp
index e7ea2b4..2788287 100644
--- a/llvm/lib/CodeGen/TargetPassConfig.cpp
+++ b/llvm/lib/CodeGen/TargetPassConfig.cpp
@@ -668,6 +668,9 @@
addPass(&StackMapLivenessID, false);
addPass(&LiveDebugValuesID, false);
+ // Insert before XRay Instrumentation.
+ addPass(&FEntryInserterID, false);
+
addPass(&XRayInstrumentationID, false);
addPass(&PatchableFunctionID, false);