Introduce CompilerConfig.

CompilerConfig defines the "attributes" of a Compiler. It contains
target information, configuration, etc. to setup an instance of
Compiler (more specifically, a instance of LLVM TargetMachine used by
the compiler.)

CompilerConfig together with bcc::init::Initialize() will replace
current Compiler::GlobalInitialization().
diff --git a/lib/ExecutionEngine/CompilerConfig.cpp b/lib/ExecutionEngine/CompilerConfig.cpp
new file mode 100644
index 0000000..faaaa97
--- /dev/null
+++ b/lib/ExecutionEngine/CompilerConfig.cpp
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2012, The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "CompilerConfig.h"
+
+#include <llvm/CodeGen/SchedulerRegistry.h>
+#include <llvm/MC/SubtargetFeature.h>
+#include <llvm/Support/TargetRegistry.h>
+
+#include "DebugHelper.h"
+#include "TargetCompilerConfigs.h"
+
+using namespace bcc;
+
+CompilerConfig::CompilerConfig(const std::string &pTriple)
+  : mTriple(pTriple), mTarget(NULL) {
+  //===--------------------------------------------------------------------===//
+  // Default setting of register sheduler
+  //===--------------------------------------------------------------------===//
+  llvm::RegisterScheduler::setDefault(llvm::createDefaultScheduler);
+
+  //===--------------------------------------------------------------------===//
+  // Default setting of target options
+  //===--------------------------------------------------------------------===//
+  // Use hardfloat ABI by default.
+  //
+  // TODO(all): Need to detect the CPU capability and decide whether to use
+  // softfp. To use softfp, change the following 2 lines to
+  //
+  // options.FloatABIType = llvm::FloatABI::Soft;
+  // options.UseSoftFloat = true;
+  mTargetOpts.FloatABIType = llvm::FloatABI::Soft;
+  mTargetOpts.UseSoftFloat = false;
+
+  // Enable frame pointer elimination optimization by default.
+  mTargetOpts.NoFramePointerElim = false;
+
+  //===--------------------------------------------------------------------===//
+  // Default setting for code model
+  //===--------------------------------------------------------------------===//
+  mCodeModel = llvm::CodeModel::Small;
+
+  //===--------------------------------------------------------------------===//
+  // Default setting for relocation model
+  //===--------------------------------------------------------------------===//
+  mRelocModel = llvm::Reloc::Default;
+
+  //===--------------------------------------------------------------------===//
+  // Default setting for optimization level (-O2)
+  //===--------------------------------------------------------------------===//
+  mOptLevel = llvm::CodeGenOpt::Default;
+
+  //===--------------------------------------------------------------------===//
+  // Default setting for architecture type
+  //===--------------------------------------------------------------------===//
+  mArchType = llvm::Triple::UnknownArch;
+
+  initializeTarget();
+  initializeArch();
+
+  return;
+}
+
+bool CompilerConfig::initializeTarget() {
+  std::string error;
+  mTarget = llvm::TargetRegistry::lookupTarget(mTriple, error);
+  if (mTarget != NULL) {
+    return true;
+  } else {
+    ALOGE("Cannot initialize llvm::Target for given triple '%s'! (%s)",
+          mTriple.c_str(), error.c_str());
+    return false;
+  }
+}
+
+void CompilerConfig::initializeArch() {
+  if (mTarget != NULL) {
+    mArchType = llvm::Triple::getArchTypeForLLVMName(mTarget->getName());
+  } else {
+    mArchType = llvm::Triple::UnknownArch;
+  }
+  return;
+}
+
+void CompilerConfig::setFeatureString(const std::vector<std::string> &pAttrs) {
+  llvm::SubtargetFeatures f;
+
+  for (std::vector<std::string>::const_iterator attr_iter = pAttrs.begin(),
+           attr_end = pAttrs.end();
+       attr_iter != attr_end; attr_iter++) {
+    f.AddFeature(*attr_iter);
+  }
+
+  mFeatureString = f.getString();
+  return;
+}