1) Go to Build Settings -> Build Options -> Debug Information Format
2) Change the Debug setting from "DWARF with dSYM File" to "DWARF"
3) Leave the Release setting at "DWARF with dSYM File"

LLVM Core:包含一个现在的源代码/目标设备无关的优化器，一集一个针对很多主流(甚至于一些非主流)的CPU的汇编代码生成支持。
Clang:一个C/C++/Objective-C编译器，致力于提供令人惊讶的快速编译，极其有用的错误和警告信息，提供一个可用于构建很棒的源代码级别的工具.
dragonegg: gcc插件，可将GCC的优化和代码生成器替换为LLVM的相应工具。
LLDB:基于LLVM提供的库和Clang构建的优秀的本地调试器。
libc++、libc++ ABI: 符合标准的，高性能的C++标准库实现，以及对C++11的完整支持。
compiler-rt:针对__fixunsdfdi和其他目标机器上没有一个核心IR(intermediate representation)对应的短原生指令序列时，提供高度调优过的底层代码生成支持。
OpenMP: Clang中对多平台并行编程的runtime支持。
vmkit:基于LLVM的Java和.NET虚拟机实
polly: 支持高级别的循环和数据本地化优化支持的LLVM框架。
libclc: OpenCL标准库的实现
klee: 基于LLVM编译基础设施的符号化虚拟机
SAFECode:内存安全的C/C++编译器
lld: clang/llvm内置的链接器

1.自定义继承自
	clang::PluginASTAction(基于consumer的AST前端Action抽象基类)
	clang::ASTConsumer(用于客户读取AST的抽象基类)，
	clang::RecursiveASTVisitor(前序或后续地深度优先搜索整个    	   AST，并访问每一个节点的基类)等基类，
2.根据自身需要重载
	PluginASTAction::CreateASTConsumer，
	PluginASTAction::ParseArgs,
  ASTConsumer::HandleTranslationUnit
  RecursiveASTVisitor::VisitDecl
	RecursiveASTVisitor::VisitStmt
  等方法，实现自定义的分析逻辑。
3.注册插件
	static FrontendPluginRegistry::Add<MyPlugin> X("my-plugin-name", "my-plugin-description");
4.编译时载入插件
	clang++ *** -Xclang -load -Xclang path-of-your-plugin.dylib -Xclang -add-plugin -Xclang your-pluginName -Xclang -plugin-arg-your-pluginName -Xclang your-pluginName-param

#include <iostream>
#include "clang/Frontend/FrontendPluginRegistry.h"
#include "clang/AST/AST.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/Frontend/CompilerInstance.h"
#include "clang/AST/RecursiveASTVisitor.h"
using namespace clang;
using namespace std;
using namespace llvm;
namespace ClangPlugin
{
    class ClangPluginASTVisitor : public RecursiveASTVisitor<ClangPluginASTVisitor>
    {
    private:
        ASTContext *context;
    public:
        void setContext(ASTContext &context){
            this->context = &context;
        }
        bool VisitDecl(Decl *decl){
            if(isa<ObjCImplDecl>(decl)){
                ObjCImplDecl *interDecl = (ObjCImplDecl*)decl;
                cout<<"[KWLM]Class Implementation Found:"<<interDecl->getNameAsString()<<endl;
            }
            return true;
        }
    };
    class ClangPluginASTConsumer : public ASTConsumer
    {
    private:
        ClangPluginASTVisitor visitor;
        void HandleTranslationUnit(ASTContext &context){
            visitor.setContext(context);
            visitor.TraverseDecl(context.getTranslationUnitDecl());
        }
    };
    class ClangPluginASTAction : public PluginASTAction
    {
    public:
        unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &Compiler,StringRef InFile){
            return unique_ptr<ClangPluginASTConsumer>(new ClangPluginASTConsumer);
        }
        bool ParseArgs(const CompilerInstance &CI, const std::vector<std::string>& args){
            return true;
        }
    };
}
static clang::FrontendPluginRegistry::Add<ClangPlugin::ClangPluginASTAction>X("ClangPlugin", "ClangPlugin");

clang -std=c++11 -stdlib=libc++ -L/opt/local/lib -L/opt/llvm/llvm_build/lib -I/opt/llvm/llvm_build/tools/clang/include -I/opt/llvm/llvm_build/include -I/opt/llvm/llvm/tools/clang/include -I/opt/llvm/llvm/include -dynamiclib -Wl,-headerpad_max_install_names -lclang -lclangFrontend -lclangAST -lclangAnalysis -lclangBasic -lclangCodeGen -lclangDriver -lclangFrontendTool -lclangLex -lclangParse -lclangSema -lclangEdit -lclangSerialization -lclangStaticAnalyzerCheckers -lclangStaticAnalyzerCore -lclangStaticAnalyzerFrontend -lLLVMX86CodeGen -lLLVMX86AsmParser -lLLVMX86Disassembler -lLLVMExecutionEngine -lLLVMAsmPrinter -lLLVMSelectionDAG -lLLVMX86AsmPrinter -lLLVMX86Info -lLLVMMCParser -lLLVMCodeGen -lLLVMX86Utils -lLLVMScalarOpts -lLLVMInstCombine -lLLVMTransformUtils -lLLVMAnalysis -lLLVMTarget -lLLVMCore -lLLVMMC -lLLVMSupport -lLLVMBitReader -lLLVMOption -lLLVMProfileData -lpthread -lcurses -lz -lstdc++ -fPIC -fno-common -Woverloaded-virtual -Wcast-qual -fno-strict-aliasing -pedantic -Wno-long-long -Wall -Wno-unused-parameter -Wwrite-strings -fno-rtti -fPIC your-clang-plugin-source.cpp -o your-clang-plugin-name.dylib

/opt/llvm/llvm_build/bin/clang -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator10.0.sdk -I/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1 -mios-version-min=8.0 -Xclang -load -Xclang ~/Desktop/your-clang-plugin-name.dylib -Xclang -add-plugin -Xclang your-clang-plugin-name -c ./ocClsDemo.m

sudo mv HackedClang.xcplugin `xcode-select -print- path`/../PlugIns/Xcode3Core.ideplugin/Contents/SharedSupport/Developer/Library/Xcode/Plug-ins
sudo mv HackedBuildSystem.xcspec `xcode-select -print- path`/../Developer/Platforms/iPhoneSimulator.platform/Developer/Library/Xcode/Specifications

#!/bin/sh
PROJ=`find . -name '*.xib' -o -name '*.[mh]'`
for png in `find . -name '*.png'`
do
name=`basename $png`
if ! grep -qhs "$name" "$PROJ"; then
    echo "$png is not referenced"
fi
done

- (void)viewDidLoad {
    [super viewDidLoad];
    __weak typeof(self) weakSelf = self;
    self.handler = ^{
        __strong typeof(weakSelf) strongSelf = weakSelf;
        NSLog(@"self is %@", strongSelf);
    };
    NSTimeInterval interval = 6.0;
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(interval * NSEC_PER_SEC)), dispatch_get_main_queue(), weakSelf.handler);
}

static void *_Block_copy_internal(const void *arg, const int flags) {
    struct Block_layout *aBlock;
    const bool wantsOne = (WANTS_ONE & flags) == WANTS_ONE;
    // 1
    if (!arg) return NULL;
    // 2
    aBlock = (struct Block_layout *)arg;
    // 3
    if (aBlock->flags & BLOCK_NEEDS_FREE) {
        // latches on high
        latching_incr_int(&aBlock->flags);
        return aBlock;
    }
    // 4
    else if (aBlock->flags & BLOCK_IS_GLOBAL) {
        return aBlock;
    }
    // 5
    struct Block_layout *result = malloc(aBlock->descriptor->size);
    if (!result) return (void *)0;
    // 6
    memmove(result, aBlock, aBlock->descriptor->size); // bitcopy first
    // 7
    result->flags &= ~(BLOCK_REFCOUNT_MASK);    // XXX not needed
    result->flags |= BLOCK_NEEDS_FREE | 1;
    // 8
    result->isa = _NSConcreteMallocBlock;
    // 9
    if (result->flags & BLOCK_HAS_COPY_DISPOSE) {
        (*aBlock->descriptor->copy)(result, aBlock); // do fixup
    }
    return result;
}

struct __block_impl {
    void *isa;
    int Flags;
    int Reserved;
    void *FuncPtr;
};
struct __xx_block_impl_y {
    struct __block_impl impl;
    __weak OCClass *occlass;
    // ...
};
static void __xx_block_func_y(struct __xx_block_impl_y *__cself) {
    OCClass *occlass = __cself -> occlass;
    // ...
}

cd /opt
sudo mkdir llvm
sudo chown `whoami` llvm
cd llvm
export LLVM_HOME=`pwd`
git clone -b release_39 git@github.com:llvm-mirror/llvm.git llvm
git clone -b release_39 git@github.com:llvm-mirror/clang.git llvm/tools/clang
git clone -b release_39 git@github.com:llvm-mirror/clang-tools-extra.git llvm/tools/clang/tools/extra
git clone -b release_39 git@github.com:llvm-mirror/compiler-rt.git llvm/projects/compiler-rt

mkdir llvm_build
cd llvm_build
cmake ../llvm -DCMAKE_BUILD_TYPE:STRING=Release
make -j`sysctl -n hw.logicalcpu`

$ git config --global user.name luohs
$ git config --global user.email luohs@example.com

$ cat ~/.gitconfig
[user]
    name = luohs
    email = luohs@example.com

$ git config --global --unset user.name
$ git config --global --unset user.email