emacs+cscope/gtags/etags

README

find the files containing the obsolete: 
such as assoc:
find ~/.emacs.d/ -name "*.el" -exec grep -H "(require 'assoc)" {} \;


# for the differences of cscope ctags, etags, global(gtags, ggtags..)...:
# https://github.com/OpenGrok/OpenGrok/wiki/Comparison-with-Similar-Tools

# etags for small c;cscope for big project

etags:
find /usr/include/XXX | egrep '.h$|.hpp$|.c$|.cpp$' | etags -
or
find /usr/include/ -name "*.[cChHsS]" | etags - (using this)
or
etags -a -i /usr/include/XXX/TAGS
.emacs:
(setq tags-file-name "/usr/src/linux/TAGS")
(setq tags-table-list '("path1/TAGS" "path2/TAGS")) /* multi-TAGSs
M-. ：跳至相应的函数定义处；
M-* ：返回刚才的函数名处；
C-u M-. ：如果emacs找错了，找下一个；
M-Tab ：自动补齐函数名；


cscope: install cscope cscope-el
1:
under project path: /* it seems the files output by `make cscope` is working faster than 2 & 3
make cscope # size cscope* #2
make cscope ARCH=arm  # specific platform, size cscope* #1
---using this  *******************************use1************************
2: cscope-indexer用于处理源代码并不是在一个文件夹下面的情况
under project path:  /* to produce cscope.files & cscope.out */
cscope-indexer -v -r #cannot be -vr, if no Makefile, you can use this, size cscope* #3
or 
find . -name "*.[ch]" -print > cscope.files
find /usr/include -type f >> cscope.files
cscope -b -q -R # this file will call cscope.files , not -k for kernel mode, man cscope
3:http://cscope.sourceforge.net/large_projects.html
默认是的快捷键都是绑定到 C-c s 的前缀上面，如果嫌麻烦的话可以自己更改 快捷键绑定。这是默认的用于查找的键绑定：
C-c s s         Find symbol.
C-c s d         Find global definition.
C-c s g         Find global definition (alternate binding).
C-c s G         Find global definition without prompting.
C-c s c         Find functions calling a function.
C-c s C         Find called functions (list functions called from a function).
C-c s t         Find text string.
C-c s e         Find egrep pattern.
C-c s f         Find a file.
C-c s i         Find files #including a file.
下面是在搜索到的结果之间切换用的快捷键：
C-c s b         Display *cscope* buffer.
C-c s B         Auto display *cscope* buffer toggle.
C-c s n         Next symbol.
C-c s N         Next file.
C-c s p         Previous symbol.
C-c s P         Previous file.
C-c s u         Pop mark.
更详细的使用说明请参见 xcscope.el 文件头部的注释

global:  install global gtags 
# http://www.gnu.org/software/global/manual/global.html
# gtags can browser assembly file, should use global(gtags) and etags together, gtags are much faster than etags and generally more accurate. I did find a few issues where it was incorrectly parsing code.
# 安装好以后，有global、gtags、gtags-cscope三个命令。global是查询，gtags是生成索引文件，gtags-cscope是与cscope一样的界面。而gtags相对于cscope的优势就在这里：增量更新单个文件的速度极快，几乎是瞬间完成。可以在终端下面使用global命令行查询，详见上链接
1:
under project dir: if no Makefile, you can only use gtags of the two
gtags -v # ouput GTAGS, GRTAGS, GPATH, GSYMS  size G* #1
make gtags # size G* #3
make gtags ARCH=arm # specific platform, size G* #2

# if you have a project which is not a kernel big, and you want to include both the system include and the projects files into your G* files, then: (in the project dir)
ln -s /usr/include include_sys
gtags

*********************use2***********************
2:
read gtags.el
##
ggtags: https://github.com/leoliu/ggtags
if gtags isn't working, use ggtags, it will use the G* files above:

############### for kernel project #################### 
##use1 and use2 size comparision, linux-3.14.1 for example
make cscope 	     # 570M = cscope.files + cscope.out + cscope.out.in + cscope.out.po
make ARCH=arm cscope # 583M = ..
make gtags 	     # 390M = GPATH + GTAGS + GSYMS + GRTAGS
make ARCH=arm gtags  # 402M = ..
# sometimes, the above(no ARCH or not) will be the same, if ARCH is specific in Makefile

############### for program project ###################
check .local/bin/tag

gtags 		     # 473M = G..
cscope-indexer -r    # 358M = cscope.out + cscope.files


# after installing all the .el, do the following
1. replace the old expressions
M-x find-name-dired --> .emacs.d --> *.el* --> interactive-p --> \
called-interactively-p --> ! many times

2. recompile all the .el
C-x 0 M-x byte-recompile-directory --> .emacs.d 

3. right the wrongs, then delete all the .elc
M-x find-name-dired --> .emacs.d --> *.elc --> t to mark all --> D to \
delete all 

4. repeat step 2 once again


# if Message shows that "Warning: called-interactively-p called with 0 arguments, but requires 1"
1.
M-x igrep (called-interactively-p)
replace all  (called-interactively-p) by (called-interactively-p 'any)
2.
do step 3 and 4
(iyou can also put (setq byte-compile-warnings nil) to .emacs to avoid it)

# view code in read-only mode
# create a file called `.dir-locals.el` in the root directory you want to protect with the content:
((nil . ((eval . (view-mode 1)))))
# or just use C-x C-q in that buffer