clang

iOS中常见警告及处理方法

杀马特。学长 韩版系。学妹 提交于 2020-03-02 17:19:29
1 警告:PerformSelector may cause a leak because its selector is unknown 原因:是因为你使用控制器来加载performSelector:方法导致,由于ios运行时在arc下的消息机制是根据方法的返回值来处理的,而使用performSelector:不确定返回值是什么类型的,因此会有警告。 处理方法: #pragma clang diagnostic push #pragma clang diagnostic ignored "-Warc-performSelector-leaks" [self performSelector:funcName]; #pragma clang diagnostic pop 未完待续 来源: oschina 链接: https://my.oschina.net/u/2682077/blog/706204

Understanding the difference between ++i and i++ at the Assembly Level

▼魔方 西西 提交于 2020-03-01 14:37:27
问题 I know that variations of this question has been asked here multiple times, but I'm not asking what is the difference between the two. Just would like some help understanding the assembly behind both forms. I think my question is more related to the whys than to the what of the difference. I'm reading Prata's C Primer Plus and in the part dealing with the increment operator ++ and the difference between using i++ or ++i the author says that if the operator is used by itself, such as ego++; it

Understanding the difference between ++i and i++ at the Assembly Level

最后都变了- 提交于 2020-03-01 14:35:07
问题 I know that variations of this question has been asked here multiple times, but I'm not asking what is the difference between the two. Just would like some help understanding the assembly behind both forms. I think my question is more related to the whys than to the what of the difference. I'm reading Prata's C Primer Plus and in the part dealing with the increment operator ++ and the difference between using i++ or ++i the author says that if the operator is used by itself, such as ego++; it

如何通过WASI SDK 在Linux上编译ZXing C++

余生颓废 提交于 2020-03-01 13:48:54
Mozilla在今年三月份的时候公布了 WASI 。WASI的目标就是让WebAssembly在任何地方都可以运行,而不仅仅像现在这样只能运行在Node.js和Web浏览器中。WASI目前依然处于初级阶段,这篇文章分享下如何把ZXing C++通过WASI Libc编译成wasm文件。 支持WASI运行时的工具 现在可以用 wasmer 和 wasmtime 通过命令行来运行支持wasi的wasm文件。wasmer提供了安装包,而wasmtime只能通过源码来编译。两个工具都支持windows, Linux和macOS。 编译ZXing C++ 下载最新的 WASI-SDK 。这个安装包中已经自带了clang,所以不需要单独安装clang。 设置环境变量: sudo dpkg -i wasi-sdk_7.0_amd64.deb export PATH=/opt/wasi-sdk/bin:$PATH export CC=/opt/wasi-sdk/bin/clang export CXX=/opt/wasi-sdk/bin/clang++ 从GitHub上下载一份 ZXing C++的源码 。 接下来要对工程结构做一些修改。首先在example中的CMakeLists.txt文件里设置sysroot: set (CMAKE_SYSROOT /opt/wasi-sdk/share

Windows 10: Clang, “stdio.h” not found [duplicate]

◇◆丶佛笑我妖孽 提交于 2020-03-01 03:08:41
问题 This question already has answers here : clang/clang++ doesn't find C/C++ headers in windows? (3 answers) Closed 3 years ago . I have installed LLVM and Clang-3.9.0 on Win10. I have MinGW installed as well. I have put my C code in 'D:' drive. I can use gcc and g++ to compile my code. But when I use clang I get: clang -cc1 version 3.9.0 based upon LLVM 3.9.0 default target x86_64-pc-windows-msvc ignoring duplicate directory "C:\Program Files (x86)\Microsoft SDKs\Windows\v8.1A" ignoring

Windows 10: Clang, “stdio.h” not found [duplicate]

爱⌒轻易说出口 提交于 2020-03-01 03:07:36
问题 This question already has answers here : clang/clang++ doesn't find C/C++ headers in windows? (3 answers) Closed 3 years ago . I have installed LLVM and Clang-3.9.0 on Win10. I have MinGW installed as well. I have put my C code in 'D:' drive. I can use gcc and g++ to compile my code. But when I use clang I get: clang -cc1 version 3.9.0 based upon LLVM 3.9.0 default target x86_64-pc-windows-msvc ignoring duplicate directory "C:\Program Files (x86)\Microsoft SDKs\Windows\v8.1A" ignoring

在Linux CentOS 6.6上安装Python 2.7.9

纵然是瞬间 提交于 2020-03-01 02:02:26
编译CoreCLR需要Clang 3.5,而CentOS上安装的是Clang 3.4.2(yum repos中最新版也是这个),只能自己手工编译LLVM的源代码进行安装。 (注:CentOS的版本是6.6) 一、安装libstdc++4.7 (注:如果是CentOS 7.0,不需要这步) wget http://people.centos.org/tru/devtools-2/devtools-2.repo -O /etc/yum.repos.d/devtools-2.repo yum install devtoolset-2-gcc devtoolset-2-binutils devtoolset-2-gcc-c++ ln -s /opt/rh/devtoolset-2/root/usr/bin/* /usr/local/bin/ 如果不安装,在configure配置编译选项时会出现下面的错误提示: We detected a missing feature in the standard C++ library that was known to be missing in libstdc++4.6 and implemented in libstdc++4.7. There are numerous C++11 problems with 4.6's library, and

Visual Studio Code 如何编写运行 C、C++ 程序?

时光怂恿深爱的人放手 提交于 2020-02-29 04:55:16
0. 前言 VS Code 是微软发布一款跨平台的源代码编辑器,其拥有强大的功能和丰富的扩展,使之能适合编写许多语言。 本文面向初学者(但不是纯小白),分享一点我配置C/C++的经验。 本文所有内容均可从VS Code的官方文档: C++ programming with Visual Studio Code 以及各个扩展的文档中获得,并且他们还会进行更新。 我的环境:64位Windows 10。VS Code的配置文件在Linux下应该也是通用的,但需要修改路径等部位配置。 1. 环境的准备 VS Code的官网和下载、安装最新的版本。VS Code只是一个编辑器,并不是IDE(集成开发环境)。不含编译器(和许多其它功能),所以编译器要自己安装好。如果想用其他工具链或单纯用官方扩展。 然后下载安装MinGW-w64,其实MinGW和MinGW-w64只是名字像,它们是两个不同的项目。为了方便,本文中的MinGW指的其实都是MinGW-w64。MinGW本身已经很久没有更新了,故 不推荐 。下载以下两个程序(都要): LLVM Download Page 在此页面下载Clang。选Pre-Built Binaries中的Clang for Windows (64-bit), 不需要下.sig文件 MinGW-w64 - for 32 and 64 bit Windows

clang 编译多个文件生成.ll 的Makefile

喜你入骨 提交于 2020-02-28 15:21:07
AR=ar LD=ld CCPATH= CC=$(CCPATH)clang CXX=$(CCPATH)clang++ INC = LIBS = -lm #-lpthread -lm -lstdc++ CFLAGS = LLVMFLAGS = -emit-llvm -S -Xclang -disable-O0-optnone #注:"\"后面不能有空格,并且该句写完后最好有个换行 #注释部分推荐在单独的一行编写 #只改下面几行变量值就够了 #动态库需要 -fPIC -shared SOFLAGS = #-O2 -fPIC -shared # Search paths VPATH = SRC_ROOT = . #这里递归遍历3级子目录 DIRS := $(shell find $(SRC_ROOT) -type d) #这里循环遍历目录的cpp文件 CPPFILES := $(foreach dir,$(DIRS),$(wildcard $(dir)/*.cpp)) CFILES += $(foreach dir,$(DIRS),$(wildcard $(dir)/*.c)) #定义宏 DEF = #-DLINUX -DENABLE_EPOLL CPPLLS := $(patsubst %.cpp,%.ll, $(CPPFILES)) CLLS := $(patsubst %.c,%

什么是clang

烈酒焚心 提交于 2020-02-28 00:54:06
clang Clang是一个 C语言 、 C++ 、 Objective-C 语言的轻量级 编译器 。 源代码 发布于 BSD 协议下。Clang将支持其普通 lambda表达式 、返回类型的简化处理以及更好的处理constexpr关键字。 简介 Clang是一个由Apple主导编写,基于LLVM的C/C++/Objective-C编译器 2013年4月,Clang已经全面支持 C++11 标准,并开始实现C++1y特性(也就是C++14,这是C++的下一个小更新版本)。Clang将支持其普通 lambda表达式 、返回类型的简化处理以及更好的处理constexpr关键字。 [2] Clang是一个C++编写、基于 LLVM 、发布于LLVM BSD许可证下的C/ C++ / Objective-C /Objective-C++编译器。它与 GNU C语言规范几乎完全兼容(当然,也有部分不兼容的内容,包括编译命令选项也会有点差异),并在此基础上增加了额外的语法特性,比如C函数重载(通过__attribute__((overloadable))来修饰函数),其目标(之一)就是超越 GCC 。 [1] Clang的官方文档: [1] 特色 终端用户特色: 快速编译和较少内存占用 [3] ;有诊断功能;兼容 GCC ; 实用工具和应用: 基础架构模块库;可满足多样的客户需求( 代码重构