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Chapter 23: Editing Programs
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When you are debugging C code that uses macros, sometimes it is hard to figure
out precisely how the macros expand. With this command, you don’t have to
figure it out; you can see the expansions.
C-c C-\
Insert or align ‘\’ characters at the ends of the lines of the region (c-backslashregion). This is useful after writing or editing a C macro definition.
If a line already ends in ‘\’, this command adjusts the amount of whitespace
before it. Otherwise, it inserts a new ‘\’. However, the last line in the region is
treated specially; no ‘\’ is inserted on that line, and any ‘\’ there is deleted.
M-x cpp-highlight-buffer
Highlight parts of the text according to its preprocessor conditionals. This
command displays another buffer named ‘*CPP Edit*’, which serves as a graphic
menu for selecting how to display particular kinds of conditionals and their
contents. After changing various settings, click on ‘[A]pply these settings’
(or go to that buffer and type a) to rehighlight the C mode buffer accordingly.
C-c C-s
Display the syntactic information about the current source line (cshow-syntactic-information). This information directs how the line is
indented.
M-x cwarn-mode
M-x global-cwarn-mode
CWarn minor mode highlights certain suspicious C and C++ constructions:
• Assignments inside expressions.
• Semicolon following immediately after ‘if’, ‘for’, and ‘while’ (except after
a ‘do ... while’ statement);
• C++ functions with reference parameters.
You can enable the mode for one buffer with the command M-x cwarn-mode,
or for all suitable buffers with the command M-x global-cwarn-mode or by
customizing the variable global-cwarn-mode. You must also enable Font Lock
mode to make it work.
M-x hide-ifdef-mode
Hide-ifdef minor mode hides selected code within ‘#if’ and ‘#ifdef’ preprocessor blocks. See the documentation string of hide-ifdef-mode for more
information.
M-x ff-find-related-file
Find a file “related” in a special way to the file visited by the current buffer.
Typically this will be the header file corresponding to a C/C++ source file, or
vice versa. The variable ff-related-file-alist specifies how to compute
related file names.
23.12 Asm Mode
Asm mode is a major mode for editing files of assembler code. It defines these commands:
TAB
tab-to-tab-stop.
C-j
Insert a newline and then indent using tab-to-tab-stop.