[llvm-exegesis] Move native target initialization code to a separate file.

Summary: This helps building internal tools on top of the library.

Reviewers: gchatelet

Subscribers: tschuett, llvm-commits, bdb, ondrasej

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D62239

llvm-svn: 361385

2 files changed, 42 insertions, 7 deletions

diff --git a/llvm/tools/llvm-exegesis/lib/TargetSelect.h b/llvm/tools/llvm-exegesis/lib/TargetSelect.h
new file mode 100644
index 00000000000..003d12e6e7b
--- /dev/null
+++ b/llvm/tools/llvm-exegesis/lib/TargetSelect.h
@@ -0,0 +1,40 @@
+//===-- TargetSelect.h ------------------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+///
+/// Utilities to handle the creation of the native exegesis target.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TOOLS_LLVM_EXEGESIS_TARGET_SELECT_H
+#define LLVM_TOOLS_LLVM_EXEGESIS_TARGET_SELECT_H
+
+namespace llvm {
+namespace exegesis {
+
+#ifdef LLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET
+void LLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET();
+#endif
+
+// Initializes the native exegesis target, or returns false if there is no
+// native target (either because llvm-exegesis does not support the target or
+// because it's not linked in).
+inline bool InitializeNativeExegesisTarget() {
+#ifdef LLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET
+  LLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET();
+  return true;
+#else
+  return false;
+#endif
+}
+
+} // namespace exegesis
+} // namespace llvm
+
+#endif // LLVM_TOOLS_LLVM_EXEGESIS_TARGET_SELECT_H
diff --git a/llvm/tools/llvm-exegesis/llvm-exegesis.cpp b/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
index ed8ab6fc3f0..4f349555763 100644
--- a/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
+++ b/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
@@ -18,6 +18,7 @@
 #include "lib/LlvmState.h"
 #include "lib/PerfHelper.h"
 #include "lib/Target.h"
+#include "lib/TargetSelect.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/MC/MCInstBuilder.h"
@@ -145,10 +146,6 @@ static cl::opt<bool>
 
 static ExitOnError ExitOnErr;
 
-#ifdef LLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET
-void LLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET();
-#endif
-
 // Checks that only one of OpcodeNames, OpcodeIndex or SnippetsFile is provided,
 // and returns the opcode indices or {} if snippets should be read from
 // `SnippetsFile`.
@@ -370,9 +367,7 @@ void benchmarkMain() {
   llvm::InitializeNativeTarget();
   llvm::InitializeNativeTargetAsmPrinter();
   llvm::InitializeNativeTargetAsmParser();
-#ifdef LLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET
-  LLVM_EXEGESIS_INITIALIZE_NATIVE_TARGET();
-#endif
+  InitializeNativeExegesisTarget();
 
   const LLVMState State(CpuName);
   const auto Opcodes = getOpcodesOrDie(State.getInstrInfo());