;;; ob-C.el --- org-babel functions for C and similar languages

;; Copyright (C) 2010-2014 Free Software Foundation, Inc.

;; Author: Eric Schulte, Thierry Banel
;; Keywords: literate programming, reproducible research
;; Homepage: http://orgmode.org

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;; Org-Babel support for evaluating C, C++, D code.
;;
;; very limited implementation:
;; - currently only support :results output
;; - not much in the way of error feedback

;;; Code:
(eval-when-compile
  (require 'cl))
(require 'ob)
(require 'cc-mode)

(declare-function org-entry-get "org"
		  (pom property &optional inherit literal-nil))
(declare-function org-remove-indentation "org" (code &optional n))

(defvar org-babel-tangle-lang-exts)
(add-to-list 'org-babel-tangle-lang-exts '("C++" . "cpp"))
(add-to-list 'org-babel-tangle-lang-exts '("D" . "d"))

(defvar org-babel-default-header-args:C '())

(defvar org-babel-C-compiler "gcc"
  "Command used to compile a C source code file into an
executable.")

(defvar org-babel-C++-compiler "g++"
  "Command used to compile a C++ source code file into an
executable.")

(defvar org-babel-D-compiler "rdmd"
  "Command used to compile and execute a D source code file.")

(defvar org-babel-c-variant nil
  "Internal variable used to hold which type of C (e.g. C or C++ or D)
is currently being evaluated.")

(defun org-babel-execute:cpp (body params)
  "Execute BODY according to PARAMS.
This function calls `org-babel-execute:C++'."
  (org-babel-execute:C++ body params))

(defun org-babel-execute:C++ (body params)
  "Execute a block of C++ code with org-babel.
This function is called by `org-babel-execute-src-block'."
  (let ((org-babel-c-variant 'cpp)) (org-babel-C-execute body params)))

(defun org-babel-execute:D (body params)
  "Execute a block of D code with org-babel.
This function is called by `org-babel-execute-src-block'."
  (let ((org-babel-c-variant 'd)) (org-babel-C-execute body params)))

(defun org-babel-execute:C (body params)
  "Execute a block of C code with org-babel.
This function is called by `org-babel-execute-src-block'."
  (let ((org-babel-c-variant 'c)) (org-babel-C-execute body params)))

(defun org-babel-C-execute (body params)
  "This function should only be called by `org-babel-execute:C'
or `org-babel-execute:C++' or `org-babel-execute:D'."
  (let* ((tmp-src-file (org-babel-temp-file
			"C-src-"
			(case org-babel-c-variant
			 (c   ".c"  )
			 (cpp ".cpp")
			 (d   ".d"  ))))
	 (tmp-bin-file (org-babel-temp-file "C-bin-" org-babel-exeext)) ;; not used for D
	 (cmdline (cdr (assoc :cmdline params)))
	 (cmdline (if cmdline (concat " " cmdline) ""))
	 (flags (cdr (assoc :flags params)))
	 (flags (mapconcat 'identity
			   (if (listp flags) flags (list flags)) " "))
	 (full-body
	  (case org-babel-c-variant
	    (c   (org-babel-C-expand-C   body params))
	    (cpp (org-babel-C-expand-C++ body params))
	    (d   (org-babel-C-expand-D   body params)))))
    (with-temp-file tmp-src-file (insert full-body))
    (case org-babel-c-variant
      ((c cpp)
       (org-babel-eval
	(format "%s -o %s %s %s"
		(case org-babel-c-variant
		 (c   org-babel-C-compiler)
		 (cpp org-babel-C++-compiler))
		(org-babel-process-file-name tmp-bin-file)
		flags
		(org-babel-process-file-name tmp-src-file)) ""))
      (d nil)) ;; no separate compilation for D
    (let ((results
	   (org-babel-eval
	    (case org-babel-c-variant
	      ((c cpp)
	       (concat tmp-bin-file cmdline))
	      (d
	       (format "%s %s %s %s"
		       org-babel-D-compiler
		       flags
		       (org-babel-process-file-name tmp-src-file)
		       cmdline)))
	    "")))
      (when results
	(setq results (org-babel-trim (org-remove-indentation results)))
	(org-babel-reassemble-table
	 (org-babel-result-cond (cdr (assoc :result-params params))
	   (org-babel-read results t)
	   (let ((tmp-file (org-babel-temp-file "c-")))
	     (with-temp-file tmp-file (insert results))
	     (org-babel-import-elisp-from-file tmp-file)))
	 (org-babel-pick-name
	  (cdr (assoc :colname-names params)) (cdr (assoc :colnames params)))
	 (org-babel-pick-name
	  (cdr (assoc :rowname-names params)) (cdr (assoc :rownames params)))))
      )))

(defun org-babel-expand-body:C++ (body params)
  "Expand a block of C++ code with org-babel according to it's
header arguments."
  (let ((org-babel-c-variant 'cpp)) (org-babel-C-expand-C++ body params)))

(defun org-babel-expand-body:C (body params)
  "Expand a block of C code with org-babel according to it's
header arguments."
  (let ((org-babel-c-variant 'c)) (org-babel-C-expand-C body params)))

(defun org-babel-expand-body:D (body params)
  "Expand a block of D code with org-babel according to it's
header arguments."
  (let ((org-babel-c-variant 'd)) (org-babel-C-expand-D body params)))

(defun org-babel-C-expand-C++ (body params)
  "Expand a block of C or C++ code with org-babel according to
it's header arguments."
  (org-babel-C-expand-C body params))

(defun org-babel-C-expand-C (body params)
  "Expand a block of C or C++ code with org-babel according to
it's header arguments."
  (let ((vars (mapcar #'cdr (org-babel-get-header params :var)))
	(colnames (cdar (org-babel-get-header params :colname-names)))
	(main-p (not (string= (cdr (assoc :main params)) "no")))
	(includes (or (cdr (assoc :includes params))
		      (org-babel-read (org-entry-get nil "includes" t))))
	(defines (org-babel-read
		  (or (cdr (assoc :defines params))
		      (org-babel-read (org-entry-get nil "defines" t))))))
    (unless (listp includes) (setq includes (list includes)))
    (setq includes (append includes '("<string.h>" "<stdio.h>" "<stdlib.h>")))
    (mapconcat 'identity
	       (list
		;; includes
		(mapconcat
		 (lambda (inc) (format "#include %s" inc))
		 includes "\n")
		;; defines
		(mapconcat
		 (lambda (inc) (format "#define %s" inc))
		 (if (listp defines) defines (list defines)) "\n")
		;; variables
		(mapconcat 'org-babel-C-var-to-C vars "\n")
		;; table sizes
		(mapconcat 'org-babel-C-table-sizes-to-C vars "\n")
		;; tables headers utility
		(when colnames
		  (org-babel-C-utility-header-to-C))
		;; tables headers
		(mapconcat 'org-babel-C-header-to-C colnames "\n")
		;; body
		(if main-p
		    (org-babel-C-ensure-main-wrap body)
		  body) "\n") "\n")))

(defun org-babel-C-expand-D (body params)
  "Expand a block of D code with org-babel according to
it's header arguments."
  (let ((vars (mapcar #'cdr (org-babel-get-header params :var)))
	(colnames (cdar (org-babel-get-header params :colname-names)))
	(main-p (not (string= (cdr (assoc :main params)) "no")))
	(imports (or (cdr (assoc :imports params))
		     (org-babel-read (org-entry-get nil "imports" t)))))
    (unless (listp imports) (setq imports (list imports)))
    (setq imports (append imports '("std.stdio" "std.conv")))
    (mapconcat 'identity
	       (list
		"module mmm;"
		;; imports
		(mapconcat
		 (lambda (inc) (format "import %s;" inc))
		 imports "\n")
		;; variables
		(mapconcat 'org-babel-C-var-to-C vars "\n")
		;; table sizes
		(mapconcat 'org-babel-C-table-sizes-to-C vars "\n")
		;; tables headers utility
		(when colnames
		  (org-babel-C-utility-header-to-C))
		;; tables headers
		(mapconcat 'org-babel-C-header-to-C colnames "\n")
		;; body
		(if main-p
		    (org-babel-C-ensure-main-wrap body)
		  body) "\n") "\n")))

(defun org-babel-C-ensure-main-wrap (body)
  "Wrap BODY in a \"main\" function call if none exists."
  (if (string-match "^[ \t]*[intvod]+[ \t\n\r]*main[ \t]*(.*)" body)
      body
    (format "int main() {\n%s\nreturn 0;\n}\n" body)))

(defun org-babel-prep-session:C (session params)
  "This function does nothing as C is a compiled language with no
support for sessions"
  (error "C is a compiled languages -- no support for sessions"))

(defun org-babel-load-session:C (session body params)
  "This function does nothing as C is a compiled language with no
support for sessions"
  (error "C is a compiled languages -- no support for sessions"))

;; helper functions

(defun org-babel-C-format-val (type val)
  "Handle the FORMAT part of TYPE with the data from VAL."
  (let ((format-data (cadr type)))
    (if (stringp format-data)
	(cons "" (format format-data val))
      (funcall format-data val))))

(defun org-babel-C-val-to-base-type (val)
  "Determine the base type of VAL which may be
'integerp if all base values are integers
'floatp if all base values are either floating points or integers
'stringp otherwise."
  (cond
   ((integerp val) 'integerp)
   ((floatp val) 'floatp)
   ((or (listp val) (vectorp val))
    (let ((type nil))
      (mapc (lambda (v)
	      (case (org-babel-C-val-to-base-type v)
		(stringp (setq type 'stringp))
		(floatp
		 (if (or (not type) (eq type 'integerp))
		     (setq type 'floatp)))
		(integerp
		 (unless type (setq type 'integerp)))))
	    val)
      type))
   (t 'stringp)))

(defun org-babel-C-val-to-C-type (val)
  "Determine the type of VAL.
Return a list (TYPE-NAME FORMAT).  TYPE-NAME should be the name of the type.
FORMAT can be either a format string or a function which is called with VAL."
  (let* ((basetype (org-babel-C-val-to-base-type val))
	 (type
	  (case basetype
	    (integerp '("int" "%d"))
	    (floatp '("double" "%f"))
	    (stringp
	     (list
	      (if (equal org-babel-c-variant 'd) "string" "const char*")
	      "\"%s\""))
	    (t (error "unknown type %S" type)))))
    (cond
     ((integerp val) type) ;; an integer declared in the #+begin_src line
     ((floatp val) type) ;; a numeric declared in the #+begin_src line
     ((and (listp val) (listp (car val))) ;; a table
      `(,(car type)
	(lambda (val)
	  (cons
	   (format "[%d][%d]" (length val) (length (car val)))
	   (concat
	    (if (equal org-babel-c-variant 'd) "[\n" "{\n")
	    (mapconcat
	     (lambda (v)
	       (concat
		(if (equal org-babel-c-variant 'd) " [" " {")
		(mapconcat (lambda (w) (format ,(cadr type) w)) v ",")
		(if (equal org-babel-c-variant 'd) "]" "}")))
	     val
	     ",\n")
	    (if (equal org-babel-c-variant 'd) "\n]" "\n}"))))))
     ((or (listp val) (vectorp val)) ;; a list declared in the #+begin_src line
      `(,(car type)
	(lambda (val)
	  (cons
	   (format "[%d]" (length val))
	   (concat
	    (if (equal org-babel-c-variant 'd) "[" "{")
	    (mapconcat (lambda (v) (format ,(cadr type) v)) val ",")
	    (if (equal org-babel-c-variant 'd) "]" "}"))))))
     (t ;; treat unknown types as string
      type))))

(defun org-babel-C-var-to-C (pair)
  "Convert an elisp val into a string of C code specifying a var
of the same value."
  ;; TODO list support
  (let ((var (car pair))
	(val (cdr pair)))
    (when (symbolp val)
      (setq val (symbol-name val))
      (when (= (length val) 1)
	(setq val (string-to-char val))))
    (let* ((type-data (org-babel-C-val-to-C-type val))
	   (type (car type-data))
	   (formated (org-babel-C-format-val type-data val))
	   (suffix (car formated))
	   (data (cdr formated)))
      (format "%s %s%s = %s;"
	      type
	      var
	      suffix
	      data))))

(defun org-babel-C-table-sizes-to-C (pair)
  "Create constants of table dimensions, if PAIR is a table."
  (when (listp (cdr pair))
    (cond
     ((listp (cadr pair)) ;; a table
      (concat
       (format "const int %s_rows = %d;" (car pair) (length (cdr pair)))
       "\n"
       (format "const int %s_cols = %d;" (car pair) (length (cadr pair)))))
     (t ;; a list declared in the #+begin_src line
      (format "const int %s_cols = %d;" (car pair) (length (cdr pair)))))))

(defun org-babel-C-utility-header-to-C ()
  "Generate a utility function to convert a column name
into a column number."
  (case org-babel-c-variant
    ((c cpp)
     "int get_column_num (int nbcols, const char** header, const char* column)
{
  int c;
  for (c=0; c<nbcols; c++)
    if (strcmp(header[c],column)==0)
      return c;
  return -1;
}
"
     )
    (d
     "int get_column_num (string[] header, string column)
{
  foreach (c, h; header)
    if (h==column)
      return to!int(c);
  return -1;
}
"
     )))

(defun org-babel-C-header-to-C (head)
  "Convert an elisp list of header table into a C or D vector
specifying a variable with the name of the table."
  (let ((table (car head))
        (headers (cdr head)))
    (concat
     (format
      (case org-babel-c-variant
	((c cpp) "const char* %s_header[%d] = {%s};")
	(d       "string %s_header[%d] = [%s];"))
      table
      (length headers)
      (mapconcat (lambda (h) (format "%S" h)) headers ","))
     "\n"
     (case org-babel-c-variant
       ((c cpp)
	(format
	 "const char* %s_h (int row, const char* col) { return %s[row][get_column_num(%d,%s_header,col)]; }"
	 table table (length headers) table))
       (d
	(format
	 "string %s_h (ulong row, string col) { return %s[row][get_column_num(%s_header,col)]; }"
	 table table table))))))

(provide 'ob-C)

;;; ob-C.el ends here