对LLVM的Pass进行调试的vscode配置

文件夹结构

安装LLVM的过程省去，假设当前目录下有:

• CMakeLists.txt文件；编译pass
• include文件夹：pass的头文件
• src文件夹；pass的源码
• test文件夹：用于静态分析pass的测试代码（.c文件）

以下是CMakeLists.txt的内容，需要设置模式为Debug：

cmake_minimum_required(VERSION 3.10)

find_package(LLVM 8 REQUIRED CONFIG)
list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_DIR}")
include(HandleLLVMOptions)
include(AddLLVM)

message(STATUS "Found LLVM ${LLVM_PACKAGE_VERSION}")

add_definitions(${LLVM_DEFINITIONS})
include_directories(${LLVM_INCLUDE_DIRS} include)
link_directories(${LLVM_LIBRARY_DIRS} ${CMAKE_CURRENT_BINARY_DIR})

set(CMAKE_BUILD_TYPE Debug)

add_llvm_library(DivZeroPass MODULE
  src/PointerAnalysis.cpp
  src/DivZeroAnalysis.cpp
  src/Transfer.cpp
  src/ChaoticIteration.cpp
  src/Domain.cpp
  src/Utils.cpp
)

安装必要软件

安装lldb

sudo apt update
sudo apt install lldb

配置vscode

填写json文件

在.vscode文件夹下新建launch.json文件，填写如下内容：

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Debug LLVM Pass",
            "type": "cppdbg",
            "request": "launch",
            "program": "/usr/bin/opt",
            "args": [
                "-load", "${workspaceFolder}/build/DivZeroPass.so",
                "-DivZero", "${fileDirname}/${fileBasenameNoExtension}.ll",
                "-disable-output"
            ],
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}",
            "environment": [],
            "externalConsole": false,
            "MIMode": "lldb",
            "preLaunchTask": "compile-llvm"
        }
    ]
}

在.vscode文件夹下新建tasks.json文件，填写如下内容：

{
    "version": "2.0.0",
    "tasks": [
        {
            "label": "compile-llvm",
            "type": "shell",
            "command": "clang",
            "args": [
                "-g", "-emit-llvm", "-S", "-fno-discard-value-names", "-Xclang", "-disable-O0-optnone", "-c", "-o", "${fileDirname}/${fileBasenameNoExtension}.ll", "${file}"
            ],
            "group": {
                "kind": "build",
                "isDefault": true
            }
        }
    ]
}

调试

因为有设置prelaunch task，在test目录下打开一个.c文件，按下F5即可开始调试当前活动的.c文件，调试前会自动编译。断点要设置在pass的源码中。