Linux系统编程ppt课件

编程工具包
GNU CC (GNU Compiler Collection) GNU make 管理项目 GDB (GNU DeBugger)调试
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GNU CC
GCC的特性
面向多种语言 C，C++，Objective C，Pascal，Ada，Fortran 能够对编译过程有更多的控制 可以控制嵌入在二进制执行文件中调试代码的数量和类型 可以优化执行代码 有30多个警告和3个一般警告级 可以进行交叉编译 对C和C++进行了大量扩展
Possible values for language are:
c c-header
cpp-output
c++ c++-header
c++-cpp-output
assembler assembler-with-cpp
-x none
Turn off any specification of a language, so that subsequent files are handled according to their file name suffixes (as they are if -x has not been used at all).
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GNU CC
C程序的编译过程
头文件 *.h
源代码 *.c
预处理器（cpp）
编译器(cc)
可执行文件
引导代码 链接器（ld）
库代码
目标代码 *.o
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GNU CC
实例
4
GNU CC
实例
在预处理后停止编译过程
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GNU CC
从指定的步骤开始编译
实例
只编译不链接
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GNU CC
对文件扩展名的解释
, file.cp, file.cxx, file.cpp, file.CPP, file.c++, file.C C++ source code which must be preprocessed. Note that
in .cxx, the last two letters must both be literally x. Likewise, .C refers to a literal capital C.
file.hh, file.H C++ header file to be turned into a precompiled header. file.s Assembler code. file.S Assembler code which must be preprocessed.
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GNU CC
常用的命令行项
-x language
Specify explicitly the language for the following input files (rather than letting the compiler choose a default based on the file name suffix). This option applies to all following input files until the next -x option.
——For any given input file, the file name surfix determines what kind of compilation is done.
file.c C source code which must be preprocessed. file.i C source code which should not be preprocessed. file.ii C++ source code which should not be preprocessed. file.h C or C++ header le to be turned into a precompiled header.
-E
Stop after the preprocessing stage; do not run the compiler
proper.
-o file Place output in file file.
If -o is not specified, the default is to put an executable le in a.out, the object file for source.suffix in source.o, its assembler file in source.s, and all preprocessed C source on standard output.
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GNU CC
常用的命令行选项
——-x和下述几个选项结合实现分步编译
-c
Compile or assemble the source files, but do not link.
-S
Stop after the stage of compilation proper; do not assemble.
-v
Print (on standard error output) the commands executed to run
the stages of compilation.
-### Like -v except the commands are not executed and all command arguments are quoted. This is useful for shell scripts to capture the driver-generated command lines.
Note that some combinations (for example, -x cpp-output -E) instruct gcc to do nothing at all.
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GNU CC
常用的命令行选项
——下述选项控制C(C++)的“方言”
-ansi In C mode, support all ISO C89 programs. In C++ mode, remove GNU extensions that conflict with ISO C++.