Notes on C++ development with Emacs on Ubuntu Linux

Here are my notes on setting up an Emacs C++ development environment. I'm using GNU g++ (4.3.3), GNU make (3.81), GNU gdb (3.8-debian), and GNU emacs (23.0.92.1 built from CVS 2009-04-22) on Ubuntu Linux (9.04 Jaunty Jackalope).

Install tools

If you don't already have g++, make, and gdb, install them:

sudo apt-get install g++ make gdb

Create files

• Create a project directory:

  mkdir helloworld

• Create a source file helloworld/hello.cpp:

  #include <iostream>
  
  int main(void) 
  {
     char greeting[] = "Hello World!";
     std::cout << greeting << std::endl;
     return 0;
  }

• Create a makefile helloworld/Makefile:

  # Makefile for GNU g++
  
  CC=g++
  CFLAGS=-g -Wall
  all: hello
  
  hello: hello.cpp
  	$(CC) $(CFLAGS) -o hello hello.cpp
  
  clean:
  	rm hello
  

Compile within Emacs

See also: 32 Compiling and Testing Programs in the GNU Emacs manual.

• Open hello.cpp in Emacs

• M-x compile RET

  make -k RET

  Note: The default compile command is make -k. You can change the default command by setting the compile-command variable in your .emacs file.

• Useful commands in the compilation window:
  • C-x `: Go to next error in the code
  • M-n: Go to next error message
  • M-p: Go to previous error message
  • RET: Go to the source code for the current error message

Run using Emacs shell

• M-! ./hello RET

  You should see the output in the minibuffer.

Debug with gdb in Emacs

For more information see: 32.6 Running Debuggers Under Emacs in the GNU Emacs manual.

• To show multiple debugging windows such as breakpoints, locals, etc., set the gdb-many-windows variable in ~/.emacs:

  (setq gdb-many-windows t)

  Restart Emacs.
  
  
• Start the debugger. While visiting helloworld/hello.cpp:

  M-x gdb RET --annotate=3 hello RET

• Set a breakpoint by clicking in the left margin at the desired location.
• Run the debugger by typing run at the (gdb) prompt in the *gud-hello* buffer.
• In the GUD buffer, use the following commands:
  • C-c C-s Step into
  • C-c C-n Stev over
  • C-c C-p Evaluate the expression at point.
  • C-c C-r Continue
  • C-c C-u Continue until current line
  
  
• When finished, type quit at the (gdb) prompt.

Documentation:

• GNU gcc 4.4
• GNU make
• GNU Emacs manuals
• GNU gdb

References

• Practical C++ Programming, 2nd Edition by Steve Oualine (2004)
• Learning GNU Emacs, 3rd Edition by Debra Cameron et al. (2004)
• Emacs: the Free Software IDE at the Linux Journal (2002)