Invoking makefile in the project root directory from subdirectory Emacs - C++

Question

I have a makefile in the project root directory. If I am editing a file in a subdirectory, how do I invoke make from EMACS? M-x compile make will not work as it looks for the makefile in the current directory. But I have the makefile in the project root directory.

Any thoughts?

Edit

As suggested, *make -f fullpath_to_makefile* did the trick. But I have some includes in the makefile like include "tests/module.mk" which failed. It is looking for "tests" directory in the subdirectory. This can be solved by specifying fully qualified path in the makefile. But I don't think that is a good solution. Any better approaches?

Answer 1

Hi

When I use Emacs to compile the minibuffer looks something like this;

make -k

and I just add any text I like, such as -f ../../root/Makefile. This might work for you.

Mark

Answer 2

I'm not much of an emacs user, but could you pass make -C ../ or however many directories up you need to go?

Answer 3

The M-x compile function looks up the compile-command-variable which you can override on the promt -- so just replace it with something like

(cd ../.. && make && cd -)

and let that run.

I also often use a file header (in line 1) such as

// -*- compile-command: "g++ -o myprog myprog.ccc -lfoo -lbar && ./myprog"; -*-

which you can generalize at will with different options. After reloading the file, M-x compile will execute your custom compile command which I find quite useful.

Answer 4

I use EDE (from CEDET) to define projects, and store compilation commands in the project definition. Look to my config for examples: lines 105-133 -- examples of projects, lines 135-165 -- code, that defines compilation functions, and lines 168-189 -- functions for different kinds of projects -- standard (compile from root directory), and cmake (compilation in separate directory)

Answer 5

This should do it:

make -f path_to_rootdir/Makefile -I path_to_rootdir/tests

The -f tells it what makefile to use, the -I tells it where to look for files to be included in the makefile (that aren't in the local directory).

Answer 6

Start with M-x compile RET. When it prompts for a command, just enter cd /path/to/root && make and hit return. This command works for all variants of make and handles the "included makefile" problem without any extra flags.

The next time you type M-x compile RET, this new string will be presented as the default, so you only have to hit return. On the off chance that you're actively compiling multiple projects within emacs, you can use M-p and M-n to move backwards and forwards through the history of compile comamnds.

Answer 7

After a while of different attempts to make EDE work the way I wanted, I went for .dir-locals.el:

((c++-mode . ((compile-command . "make -C ../build -j2 whatever"))))

I found it slightly better for me than having a // -*- -*- in a header of every file, and a whole lot better than specifying in my init.el (or any other config) those ede-cpp-root-project with full paths to projects, which I either create too often or move all of a sudden :)

Nice addition to the scheme was cmake which makes compile errors to be 'properly jumpable' since it uses full paths in generated makefiles.

Answer 8

(I use scons, but the principle is the same. Change SConstruct to Makefile and scons to make...)

I've customized by .emacs so that it always compiles the project containing the current buffer's file, however deeply nested; it searches upwards for the first SConstruct and uses that as it's project root directory.

Here's a couple of functions which search up the directory hierarchy looking for SConstruct.

;; inspired by jds-find-tags-file in http://www.emacswiki.org/emacs/EmacsTags
(defun find-sconstruct ()
"recursively searches upwards from buffer's current dir for file named SConstruct and returns that dir. Or nil if not found or if buffer is not visiting a file"
  (labels
      ((find-sconstruct-r (path)
           (let* ((parent (file-name-directory path))    
            (possible-file (concat parent "SConstruct")))
          (cond
           ((file-exists-p possible-file)
            (throw 'found-it possible-file))
           ((string= "/SConstruct" possible-file)
            (error "No SConstruct found"))
           (t (find-sconstruct-r (directory-file-name parent)))))))
    (if (buffer-file-name)
     (catch 'found-it
       (find-sconstruct-r (buffer-file-name)))
      (error "Buffer is not visiting a file"))))


(defun project-root ()    
  (file-name-directory (find-sconstruct)))

You can then change your compile-command to use project-root e.g.

(concat "cd " (project-root) " && scons")

Answer 9

Another alternative is to set the variable compilation-process-setup-function which is documented as:

*Function to call to customize the compilation process. This function is called immediately before the compilation process is started. It can be used to set any variables or functions that are used while processing the output of the compilation process. The function is called with variables compilation-buffer' and compilation-window' bound to the compilation buffer and window, respectively.

I use Maven alot and wrote this library to support your issue for a Maven context. In the following, change the value of the variable compile-search-file as appropriate:

;;; Support for Maven 2

(require 'compile)

(setq compile-search-file "pom.xml")

(defun find-search-file ()
  ;; Search for the pom file traversing up the directory tree.
  (setq dir (expand-file-name default-directory))
  (let ((parent (file-name-directory (directory-file-name dir))))
    (while (and (not (file-readable-p (concat dir compile-search-file)))
     (not (string= parent dir)))
      (setq dir parent
        parent (file-name-directory (directory-file-name dir))))
    (if (string= dir parent)
    (error "Search file %s is missing" compile-search-file)
      (with-current-buffer compilation-last-buffer
    (message "Test %s %s." compilation-buffer compilation-window)
    (setq default-directory dir)))))

;; Add the following to support Emacs' compile mode:
(add-to-list
 'compilation-error-regexp-alist-alist
 '(mvn "^\\(.*\\):\\[\\([0-9]*\\),\\([0-9]*\\)\\]" 1 2 3))
(add-to-list 'compilation-error-regexp-alist 'mvn)

(setq compilation-process-setup-function 'find-search-file)

(provide 'maven-support)