Clang plugin with Xcode

Creating and using Clang plugin with Xcode

  • 环境设置
  • plugin 设置
  • Xcode 工程设置
  • warnning
  • error
  • Xcode 集成
  • 与 error/warning 的交互

环境设置

  1. 需要 llvm/clang，源码
1
2
3
4
5
cd /opt
sudo mkdir llvm
sudo chown `whoami` llvm
cd llvm
export LLVM_HOME=`pwd`
  1. 根据本机的 clang 版本来编译,本机3.3.1 为例
1
2
3
4
5
6
7
8
9
git clone -b release_33 https://github.com/llvm-mirror/llvm.git llvm
git clone -b release_33 https://github.com/llvm-mirror/clang.git llvm/tools/clang
git clone -b release_33 https://github.com/llvm-mirror/clang-tools-extra.git llvm/tools/clang/tools/extra
git clone -b release_33 https://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`

plugin 设置

  1. 创建 plugin 的文件夹
1
2
cd $LLVM_HOME
mkdir toy_clang_plugin; cd toy_clang_plugin

基于 plugin 的例子结构如下
ToyClangPlugin.exports
CMakeLists.txt
ToyClangPlugin.cpp

  1. 文件内容
  • ToyClangPlugin.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
#include "clang/Frontend/FrontendPluginRegistry.h"
#include "clang/AST/AST.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/Frontend/CompilerInstance.h"
 
using namespace clang;
 
namespace
{
    class ToyConsumer : public ASTConsumer
    {
    };
    
    class ToyASTAction : public PluginASTAction
    {
    public:
        virtual clang::ASTConsumer *CreateASTConsumer(CompilerInstance &Compiler,
                                                      llvm::StringRef InFile)
        {
            return new ToyConsumer;
        }
        
        bool ParseArgs(const CompilerInstance &CI, const
                       std::vector<std::string>& args) {
            return true;
        }
    };
}
 
static clang::FrontendPluginRegistry::Add<ToyASTAction>
X("ToyClangPlugin", "Toy Clang Plugin");
  • CMakeLists.txt
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
cmake_minimum_required (VERSION 2.6)
project (ToyClangPlugin)
 
set( CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin )
set( CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib )
set( CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib )
 
set( LLVM_HOME /opt/llvm )
set( LLVM_SRC_DIR ${LLVM_HOME}/llvm )
set( CLANG_SRC_DIR ${LLVM_HOME}/llvm/tools/clang )
set( LLVM_BUILD_DIR ${LLVM_HOME}/llvm_build )
set( CLANG_BUILD_DIR ${LLVM_HOME}/llvm_build/tools/clang)
 
add_definitions (-D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS)
add_definitions (-D_GNU_SOURCE -DHAVE_CLANG_CONFIG_H)
 
set (CMAKE_CXX_COMPILER "${LLVM_BUILD_DIR}/bin/clang++")
set (CMAKE_CC_COMPILER "${LLVM_BUILD_DIR}/bin/clang")
 
set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}
  -fPIC
  -fno-common
  -Woverloaded-virtual
  -Wcast-qual
  -fno-strict-aliasing
  -pedantic
  -Wno-long-long
  -Wall
  -Wno-unused-parameter
  -Wwrite-strings
  -fno-exceptions 
  -fno-rtti")
 
set (CMAKE_MODULE_LINKER_FLAGS "-Wl,-flat_namespace -Wl,-undefined -Wl,suppress")
 
set (LLVM_LIBS
  LLVMJIT
  LLVMX86CodeGen
  LLVMX86AsmParser
  LLVMX86Disassembler
  LLVMExecutionEngine
  LLVMAsmPrinter
  LLVMSelectionDAG
  LLVMX86AsmPrinter
  LLVMX86Info
  LLVMMCParser
  LLVMCodeGen
  LLVMX86Utils
  LLVMScalarOpts
  LLVMInstCombine
  LLVMTransformUtils
  LLVMipa
  LLVMAnalysis
  LLVMTarget
  LLVMCore
  LLVMMC
  LLVMSupport
  LLVMBitReader
  LLVMOption
)
 
macro(add_clang_plugin name)
  set (srcs ${ARGN})
 
  include_directories( "${LLVM_SRC_DIR}/include"
    "${CLANG_SRC_DIR}/include"
    "${LLVM_BUILD_DIR}/include"
    "${CLANG_BUILD_DIR}/include" )
  link_directories( "${LLVM_BUILD_DIR}/lib" )
 
  add_library( ${name} SHARED ${srcs} )
  
  if (SYMBOL_FILE)
    set_target_properties( ${name} PROPERTIES LINK_FlAGS
      "-exported_symbols_list ${SYMBOL_FILE}")
  endif()
 
  foreach (clang_lib ${CLANG_LIBS})
    target_link_libraries( ${name} ${clang_lib} )  
  endforeach()
  
  foreach (llvm_lib ${LLVM_LIBS})
    target_link_libraries( ${name} ${llvm_lib} )
  endforeach()
  
  foreach (user_lib ${USER_LIBS})
    target_link_libraries( ${name} ${user_lib} )
  endforeach()
 
endmacro(add_clang_plugin)
 
set(SYMBOL_FILE ToyClangPlugin.exports)
 
set (CLANG_LIBS
  clang
  clangFrontend
  clangAST
  clangAnalysis
  clangBasic
  clangCodeGen
  clangDriver
  clangFrontendTool
  clangLex
  clangParse
  clangSema
  clangEdit
  clangSerialization
  clangStaticAnalyzerCheckers
  clangStaticAnalyzerCore
  clangStaticAnalyzerFrontend
)
 
set (USER_LIBS
  pthread
  curses
)
 
add_clang_plugin(ToyClangPlugin 
  ToyClangPlugin.cpp
)
 
set_target_properties(ToyClangPlugin PROPERTIES
  LINKER_LANGUAGE CXX
  PREFIX "")
  • ToyClangPlugin.exports
1
__ZN4llvm8Registry*

现在我们能够基于 CMakeLists.txt 生成 Xcode-project，

1
2
3
mkdir build; cd build
cmake -G Xcode ..
open ToyClangPlugin.xcodeproj

运行 ALL_BUILD target ，然后就能看到动态库：lib/Debug/ToyClangPlugin.dylib

RecuresiveASTVisitor

Clang 的 AST 模块提供了RecuresiveASTVisitor，他能够让你编译整个 AST，我们只需要创建一个子类并且实现我们感兴趣的方法就行。为了测试一下，现在只是打印所有发现的类名。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
class ToyClassVisitor : public RecursiveASTVisitor<ToyClassVisitor>
{
public:
    bool VisitObjCInterfaceDecl(ObjCInterfaceDecl *declaration)
    {
        printf("ObjClass: %s\n", declaration->getNameAsString().c_str());
        return true;
    }
};
 
class ToyConsumer : public ASTConsumer
{
public:
    void HandleTranslationUnit(ASTContext &context) {
        visitor.TraverseDecl(context.getTranslationUnitDecl());
    }
private:
    ToyClassVisitor visitor;
};

下面我们就来创建测试的文件并且看看 plugin 是如何工作的。

1
2
3
4
5
6
7
8
9
#import <Foundation/Foundation.h>
 
@interface ToyObject : NSObject
 
@end
 
@implementation ToyObject
 
@end

rebuild & 运行 插件

1
2
3
4
5
/opt/llvm/toy_clang_plugin/build $ $LLVM_HOME/llvm_build/bin/clang ../test.m \
  -Xclang -load \
  -Xclang lib/Debug/ToyClangPlugin.dylib \
  -Xclang -plugin \
  -Xclang ToyClangPlugin

报警告

下面我们试试这个情况：类名是以小写字母开始。

  • 在 ToyClassVisitor 中增加 ASTContext
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
class ToyClassVisitor : public RecursiveASTVisitor<ToyClassVisitor>
{
private:
    ASTContext *context;
public:
    void setContext(ASTContext &context)
    {
        this->context = &context;
    }
// ...
};
 
// ...
void HandleTranslationUnit(ASTContext &context) {
    visitor.setContext(context);
    visitor.TraverseDecl(context.getTranslationUnitDecl());
}
    // ...
  • 增加检测
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
bool VisitObjCInterfaceDecl(ObjCInterfaceDecl *declaration)
{
    checkForLowercasedName(declaration);
    return true;
}
//  ...
void checkForLowercasedName(ObjCInterfaceDecl *declaration)
{
    StringRef name = declaration->getName();
    char c = name[0];
    if (isLowercase(c)) {
        DiagnosticsEngine &diagEngine = context->getDiagnostics();
        unsigned diagID = diagEngine.getCustomDiagID(DiagnosticsEngine::Warning, "Class name should not start with lowercase letter");
        SourceLocation location = declaration->getLocation();
        diagEngine.Report(location, diagID);
    }
}
  • 测一下
1
2
3
4
5
6
7
@interface bad_ToyObject : NSObject
 
@end
 
@implementation bad_ToyObject
 
@end
  • rebuild & run
1
2
3
4
5
6
7
8
9
10
/opt/llvm/toy_clang_plugin/build $ $LLVM_HOME/llvm_build/bin/clang ../test.m \
  -Xclang -load \
  -Xclang lib/Debug/ToyClangPlugin.dylib \
  -Xclang -plugin \
  -Xclang ToyClangPlugin
 
../test.m:11:12: warning: Class name should not start with lowercase letter
@interface bad_ToyObject : NSObject
           ^
1 warning generated.

报错误

  • 试一下如果类名里面包含下划线
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
void checkForUnderscoreInName(ObjCInterfaceDecl *declaration)
{
    size_t underscorePos = declaration->getName().find('_');
    if (underscorePos != StringRef::npos) {
        DiagnosticsEngine &diagEngine = context->getDiagnostics();
        unsigned diagID = diagEngine.getCustomDiagID(DiagnosticsEngine::Error, "Class name with `_` forbidden");
        SourceLocation location = declaration->getLocation().getLocWithOffset(underscorePos);
        diagEngine.Report(location, diagID);
    }
}
 
bool VisitObjCInterfaceDecl(ObjCInterfaceDecl *declaration)
{
    // disable this check temporary
    // checkForLowercasedName(declaration);
    checkForUnderscoreInName(declaration);
    return true;
}
  • 看看运行后的输出
1
2
3
4
5
6
7
8
9
10
/opt/llvm/toy_clang_plugin/build $ $LLVM_HOME/llvm_build/bin/clang ../test.m \
  -Xclang -load \
  -Xclang lib/Debug/ToyClangPlugin.dylib \
  -Xclang -plugin \
  -Xclang ToyClangPlugin
 
../test.m:11:15: error: Class name with `_` forbidden
@interface bad_ToyObject : NSObject
              ^
1 error generated.
  • 我们试试两个监测都打开的时候的样子
1
2
3
4
5
6
7
8
9
10
11
12
13
/opt/llvm/toy_clang_plugin/build $ $LLVM_HOME/llvm_build/bin/clang ../test.m \
  -Xclang -load \
  -Xclang lib/Debug/ToyClangPlugin.dylib \
  -Xclang -plugin \
  -Xclang ToyClangPlugin
 
../test.m:11:12: warning: Class name should not start with lowercase letter
@interface bad_ToyObject : NSObject
           ^
../test.m:11:15: error: Class name with `_` forbidden
@interface bad_ToyObject : NSObject
              ^
1 warning and 1 error generated.

Xcode 集成

很遗憾，Xcode 的 clang 并不支持插件，所以我们要这么做。

  • 在 Xcode 中启用自定义编译工具
1
2
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`/Platforms/iPhoneSimulator.platform/Developer/Library/Xcode/Specifications
  • 这样就能在 build option 里面找到编译器了
  • 在 OTHER_CFLAGS 中增加
1
-Xclang -load -Xclang /opt/llvm/toy_clang_plugin/build/lib/Debug/ToyClangPlugin.dylib -Xclang -add-plugin -Xclang ToyClangPlugin

注意：这个地方使用 -add-plugin，因为我们想用自己的 ASTAction，而不是替换掉现存的

  • 在 Module - CLANG_ENABLE_MODULES 设置为 NO

  • 把之前新建的 test.m 增加到工程中。即可见到

增加交互

  • 针对 warning & error 增加 FixItHints
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
void checkForLowercasedName(ObjCInterfaceDecl *declaration)
{
    StringRef name = declaration->getName();
    char c = name[0];
    if (isLowercase(c)) {
        std::string tempName = name;
        tempName[0] = toUppercase(c);
        StringRef replacement(tempName);
        
        SourceLocation nameStart = declaration->getLocation();
        SourceLocation nameEnd = nameStart.getLocWithOffset(name.size());
        
        FixItHint fixItHint = FixItHint::CreateReplacement(SourceRange(nameStart, nameEnd), replacement);
        
        DiagnosticsEngine &diagEngine = context->getDiagnostics();
        unsigned diagID = diagEngine.getCustomDiagID(DiagnosticsEngine::Warning, "Class name should not start with lowercase letter");
        SourceLocation location = declaration->getLocation();
        diagEngine.Report(location, diagID).AddFixItHint(fixItHint);
    }
}
 
void checkForUnderscoreInName(ObjCInterfaceDecl *declaration)
{
    StringRef name = declaration->getName();
    size_t underscorePos = name.find('_');
    if (underscorePos != StringRef::npos) {
        std::string tempName = name;
        std::string::iterator end_pos = std::remove(tempName.begin(), tempName.end(), '_');
        tempName.erase(end_pos, tempName.end());
        StringRef replacement(tempName);
        
        SourceLocation nameStart = declaration->getLocation();
        SourceLocation nameEnd = nameStart.getLocWithOffset(name.size());
        
        FixItHint fixItHint = FixItHint::CreateReplacement(SourceRange(nameStart, nameEnd), replacement);
        
        DiagnosticsEngine &diagEngine = context->getDiagnostics();
        unsigned diagID = diagEngine.getCustomDiagID(DiagnosticsEngine::Error, "Class name with `_` forbidden");
        SourceLocation location = declaration->getLocation().getLocWithOffset(underscorePos);
        diagEngine.Report(location, diagID).AddFixItHint(fixItHint);
    }
}

Clang plugin with Xcode

https://bapuqln-blog.pages.dev/back/Creating_and_using_Clang_plugin_with_Xcode.html

作者

shouyi.www

发布于

2019-12-04

更新于

2025-01-30

许可协议

#

喜欢这篇文章？打赏一下作者吧

评论

关注我

链接

分类

最新文章

归档

标签

Algorithm3
Bit Manupulate1
C++1
Dynamic Programming1
Easy1
FishHook1
Hard7
LeetCode24
Mac Develop2
Medium14
NSDictionary1
SuperSign1
Swift2
VSCode1
Weakly Contest1
educative.io1
iOS5
单例1
启动速度1
背包问题1
超级签名1

订阅更新

广告

Your browser is out-of-date!

Update your browser to view this website correctly.&npsb;Update my browser now

×

×