为了理解ipv6代码方便，使用codeviz，显示函数调用关系。
安装的过程比较简答：
1）apt-get install graphviz
2) 下载codeviz，不同版本对应不同的gcc。configure --help 的时候可以得知。
3）下载对应版本的gcc，cp到compiler目录下，执行make，这回对gcc打patch。
这就算安装完成了。
如果要分析哪个代码，需要设置CC为对应的gcc。会为每一个c文件生成cdepn文件。
CodeViz 使用两个脚本来生成调用图,一个是 genfull,该脚本可以生成项目的完整调
用图,因此调用图可能很大很复杂,缺省使用 cdepn 文件来创建调用图;另一个是
gengraph,该脚本可以对给定一组函数生成一个小的调用图,
genfull 的-s 选项,-s 指定了检测哪些子目录。
gengraph
-d 指定最大调用层数
-s 仅仅显示指定函数,而不对其调用进行展开
-i 忽略指定函数
gengraph - Generate a call graph for a given set of functions
Usage:
gengraph [options]
Main Options:
-f, --function Top level functions to graph, quote if more than one -t, --trim Ignore a set of Linux kernel functions (Kernel specific) -i, --ignore Functions to ignore -s, --show Show a function but not the sub-functions -d, --maxdepth Maximum depth of graph -r, --reverse Place the function at the bottom and graph callers
-g, --graph Source graph from by genfull (Default: ./full.graph)
-l, --location Show the location of the function declarations
-a, --all-locs Show the location of declarations and calls
-k, --keep Keep the sub.graph file
-o, --output Output postscript filename
-v, --verbose Verbose output
-h, --help Print this message
--no-extern Ignore functions not defined in the current source
--output-type Set the output type: ps, html png or gif (default: ps)
--output-font What font to use for output graph (default: Helvetica)
--output-fontsize Size of output font (default: 12)
--output-layout Layout direction: LR|RL|BT|TB (default TB)
--version Print the version number
HTML Options (specify --output-type=html above):
-e, --source Root of the source code being graphed
--html-fragment Generate HTML suitable for including in another page
--base-url Template URL to use for hyperlinks in the web page
--shighlight Use source-highlight for HTML links
--scss Cascading style-sheet to use for source-highlight
Regular Expression Options:
-z, --func-re Regular expressions of top-level functions to graph
-j, --ignore-re Regular expressions of functions to ignore
-y, --show-re Regular expressions of functions to show but not traverse
Post-Processing Options:
--pp-stack Show stack usage and highlight excessive usage
--pp-cstack Show cumulative usage in a given set of code paths
Daemon Options:
-p, --daemon Run gengraph as a daemon
-q, --client Run gengraph as a client to a gengraph daemon
--plain Output the dot graph file but do not use dot
--stdout Use this file as standard out instead of normal
--stderr Print errors to this file instead of STDERR
genfull [options]
Main Options:
-d, --toplevel Top level source directory (Default: current)
-f, --file Files to scan for data (Default: find all files)
-s, --subdirs Subdirectories to graph (Default: all) -g, --method Method for collecting data (Default: cdepn)
-o, --output Output graph (Default: ./full.graph)
-h, --help Print this message
--version Print the version number
Post-Processing Options:
--skip Skip collection and only post-process
--pp-stack Calculate stack usage
For Linux kernel call graphs, the following calling is recommended
genfull -s "arch/i386 net lib ipc mm fs net kernel init drivers"
使用cs模式
gengraph -p -g /usr/src/linux-2.4.20-clean/full.graph
When this returns, the daemon is running. To generate a graph using the daemon,
run
gengraph -q -t -d 2 -f alloc_pages
Note the use of the -q switch which says that gengraph should run as a client
to the daemon instance. If you are bored, compare the difference in running
times between normal gengraph and when it is used as a client :-) . To stop
the daemon, do the following
echo QUIT > /tmp/codeviz.pipe
