* lisp/progmodes/hideif.el: Undo last change which should only go to trunk

(do not merge).

2 files changed, 51 insertions, 577 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 34d057c10f1..8cc59d88615 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2014-06-26  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * progmodes/hideif.el: Undo last change which should only go to trunk
+        (do not merge).
+
 2014-06-26  Glenn Morris  <rgm@gnu.org>
 
         * emacs-lisp/cl-macs.el (help-add-fundoc-usage):
diff --git a/lisp/progmodes/hideif.el b/lisp/progmodes/hideif.el
index b0ca4f0cdd0..39ad676f593 100644
--- a/lisp/progmodes/hideif.el
+++ b/lisp/progmodes/hideif.el
@@ -36,8 +36,6 @@
 ;;
 ;; Hide-ifdef suppresses the display of code that the preprocessor wouldn't
 ;; pass through.  Support complete C/C++ expression and precedence.
-;; It will automatically scans for new #define symbols and macros on the way
-;; parsing.
 ;;
 ;; The hidden code is marked by ellipses (...).  Be
 ;; cautious when editing near ellipses, since the hidden text is
@@ -99,12 +97,11 @@
 ;; Extensively modified by Daniel LaLiberte (while at Gould).
 ;;
 ;; Extensively modified by Luke Lee in 2013 to support complete C expression
-;; evaluation and argumented macro expansion.
+;; evaluation.
 
 ;;; Code:
 
 (require 'cc-mode)
-(require 'cl-lib)
 
 (defgroup hide-ifdef nil
   "Hide selected code within `ifdef'."
@@ -136,9 +133,6 @@
   :group 'hide-ifdef
   :version "23.1")
 
-(defcustom hide-ifdef-exclude-define-regexp nil
-  "Ignore #define names if those names match this exclusion pattern."
-  :type 'string)
 
 (defvar hide-ifdef-mode-submap
   ;; Set up the submap that goes after the prefix key.
@@ -362,32 +356,12 @@ that form should be displayed.")
 ;;;  The code that understands what ifs and ifdef in files look like.
 
 (defconst hif-cpp-prefix "\\(^\\|\r\\)[ \t]*#[ \t]*")
-(defconst hif-ifxdef-regexp (concat hif-cpp-prefix "if\\(n\\)?def"))
 (defconst hif-ifndef-regexp (concat hif-cpp-prefix "ifndef"))
 (defconst hif-ifx-regexp (concat hif-cpp-prefix "if\\(n?def\\)?[ \t]+"))
-(defconst hif-elif-regexp   (concat hif-cpp-prefix "elif"))
 (defconst hif-else-regexp (concat hif-cpp-prefix "else"))
 (defconst hif-endif-regexp (concat hif-cpp-prefix "endif"))
 (defconst hif-ifx-else-endif-regexp
-  (concat hif-ifx-regexp "\\|" hif-elif-regexp "\\|" hif-else-regexp "\\|"
-          hif-endif-regexp))
-(defconst hif-macro-expr-prefix-regexp
-  (concat hif-cpp-prefix "\\(if\\(n?def\\)?\\|elif\\|define\\)[ \t]+"))
-
-(defconst hif-white-regexp         "[ \t]*")
-(defconst hif-define-regexp
-  (concat hif-cpp-prefix "\\(define\\|undef\\)"))
-(defconst hif-id-regexp
-  (concat "[[:alpha:]_][[:alnum:]_]*"))
-(defconst hif-macroref-regexp
-  (concat hif-white-regexp "\\(" hif-id-regexp "\\)" hif-white-regexp
-          "\\("
-          "(" hif-white-regexp
-          "\\(" hif-id-regexp "\\)?" hif-white-regexp
-          "\\(" "," hif-white-regexp hif-id-regexp hif-white-regexp "\\)*"
-          "\\(\\.\\.\\.\\)?" hif-white-regexp
-          ")"
-          "\\)?" ))
+  (concat hif-ifx-regexp "\\|" hif-else-regexp "\\|" hif-endif-regexp))
 
 ;; Used to store the current token and the whole token list during parsing.
 ;; Only bound dynamically.
@@ -423,12 +397,7 @@ that form should be displayed.")
     ("/"   . hif-divide)
     ("%"   . hif-modulo)
     ("?"  . hif-conditional)
-    (":"   . hif-colon)
-    (","   . hif-comma)
-    ("#"   . hif-stringify)
-    ("..." . hif-etc)))
-
-(defconst hif-valid-token-list (mapcar 'cdr hif-token-alist))
+    (":"  . hif-colon)))
 
 (defconst hif-token-regexp
   (concat (regexp-opt (mapcar 'car hif-token-alist))
@@ -438,29 +407,10 @@ that form should be displayed.")
 
 (defconst hif-string-literal-regexp  "\\(\"\\(?:[^\"\\]\\|\\\\.\\)*\"\\)")
 
-(defun hif-string-to-number (string &optional base)
-  "Like `string-to-number', but it understands non-decimal floats."
-  (if (or (not base) (= base 10))
-      (string-to-number string base)
-    (let* ((parts (split-string string "\\." t "[ \t]+"))
-           (frac (cadr parts))
-           (fraclen (length frac))
-           (quot (expt (if (zerop fraclen)
-                           base
-                           (* base 1.0)) fraclen)))
-      (/ (string-to-number (concat (car parts) frac) base) quot))))
-
-;; The dynamic binding variable `hif-simple-token-only' is shared only by
-;; `hif-tokenize' and `hif-find-define'. The purpose is to prevent `hif-tokenize'
-;; from returning one more value to indicate a simple token is scanned. This help
-;; speeding up macro evaluation on those very simple cases like integers or
-;; literals.
-;; Check the long comments before `hif-find-define' for more details. [lukelee]
 
 (defun hif-tokenize (start end)
   "Separate string between START and END into a list of tokens."
   (let ((token-list nil))
-    (setq hif-simple-token-only t)
     (with-syntax-table hide-ifdef-syntax-table
       (save-excursion
         (goto-char start)
@@ -473,10 +423,8 @@ that form should be displayed.")
            ((looking-at hif-string-literal-regexp)
             (push (substring-no-properties (match-string 1)) token-list)
             (goto-char (match-end 0)))
-
            ((looking-at hif-token-regexp)
-            (let ((token (buffer-substring-no-properties
-                          (point) (match-end 0))))
+            (let ((token (buffer-substring (point) (match-end 0))))
               (goto-char (match-end 0))
               ;; (message "token: %s" token) (sit-for 1)
               (push
@@ -484,22 +432,22 @@ that form should be displayed.")
                    (if (string-equal token "defined") 'hif-defined)
                    ;; TODO:
                    ;; 1. postfix 'l', 'll', 'ul' and 'ull'
-                   ;; 2. floating number formats (like 1.23e4)
-                   ;; 3. 098 is interpreted as octal conversion error
+                   ;; 2. floating number formats
+                   ;; 3. hexadecimal/octal floats
+                   ;; 4. 098 is interpreted as octal conversion error
+                   ;; FIXME: string-to-number does not convert hex floats
                    (if (string-match "0x\\([0-9a-fA-F]+\\.?[0-9a-fA-F]*\\)"
                                      token)
-                       (hif-string-to-number (match-string 1 token) 16)) ;; hex
+                       (string-to-number (match-string 1 token) 16)) ;; hex
+                   ;; FIXME: string-to-number does not convert octal floats
                    (if (string-match "\\`0[0-9]+\\(\\.[0-9]+\\)?\\'" token)
-                       (hif-string-to-number token 8)) ;; octal
+                       (string-to-number token 8)) ;; octal
                    (if (string-match "\\`[1-9][0-9]*\\(\\.[0-9]+\\)?\\'"
                                      token)
                        (string-to-number token)) ;; decimal
-                   (prog1 (intern token)
-                     (setq hif-simple-token-only nil)))
+                   (intern token))
                token-list)))
-
            (t (error "Bad #if expression: %s" (buffer-string)))))))
-
     (nreverse token-list)))
 
 ;;------------------------------------------------------------------------
@@ -534,115 +482,9 @@ that form should be displayed.")
   "Pop the next token from token-list into the let variable `hif-token'."
   (setq hif-token (pop hif-token-list)))
 
-(defsubst hif-if-valid-identifier-p (id)
-  (not (or (numberp id)
-           (stringp id))))
-
-(defun hif-define-operator (tokens)
-  "`Upgrade' hif-define xxx to '(hif-define xxx)' so that it won't be
-subsitituted"
-  (let ((result nil)
-        (tok nil))
-    (while (setq tok (pop tokens))
-      (push
-       (if (eq tok 'hif-defined)
-           (progn
-             (setq tok (cadr tokens))
-             (if (eq (car tokens) 'hif-lparen)
-                 (if (and (hif-if-valid-identifier-p tok)
-                          (eq (caddr tokens) 'hif-rparen))
-                     (setq tokens (cdddr tokens))
-                   (error "#define followed by non-identifier: %S" tok))
-               (setq tok (car tokens)
-                     tokens (cdr tokens))
-               (unless (hif-if-valid-identifier-p tok)
-                 (error "#define followed by non-identifier: %S" tok)))
-             (list 'hif-defined 'hif-lparen tok 'hif-rparen))
-         tok)
-       result))
-    (nreverse result)))
-
-(defun hif-flatten (l)
-  "Flatten a tree"
-  (apply #'nconc
-         (mapcar (lambda (x) (if (listp x)
-                                 (hif-flatten x)
-                               (list x))) l)))
-
-(defun hif-expand-token-list (tokens &optional macroname expand_list)
-  "Perform expansion till everything expanded.  No self-reference expansion.
-  EXPAND_LIST is the list of macro names currently being expanded."
-  (catch 'self-referencing
-    (let ((expanded nil)
-          (remains (hif-define-operator
-                    (hif-token-concatenation
-                     (hif-token-stringification tokens))))
-          tok rep)
-      (if macroname
-          (setq expand_list (cons macroname expand_list)))
-      ;; Expanding all tokens till list exhausted
-      (while (setq tok (pop remains))
-        (if (memq tok expand_list)
-            ;; For self-referencing tokens, don't expand it
-            (throw 'self-referencing tokens))
-        (push
-         (cond
-          ((or (memq tok hif-valid-token-list)
-               (numberp tok)
-               (stringp tok))
-           tok)
-
-          ((setq rep (hif-lookup tok))
-           (if (and (listp rep)
-                    (eq (car rep) 'hif-define-macro)) ;; a defined macro
-               ;; Recursively expand it
-               (if (cadr rep) ;; Argument list is not nil
-                   (if (not (eq (car remains) 'hif-lparen))
-                       ;; No argument, no invocation
-                       tok
-                     ;; Argumented macro, get arguments and invoke it.
-                     ;; Dynamically bind hif-token-list and hif-token
-                     ;; for hif-macro-supply-arguments
-                     (let* ((hif-token-list (cdr remains))
-                            (hif-token nil)
-                            (parmlist (mapcar 'hif-expand-token-list
-                                              (hif-get-argument-list
-                                               tok)))
-                            (result
-                             (hif-expand-token-list
-                              (hif-macro-supply-arguments tok parmlist)
-                              tok expand_list)))
-                       (setq remains (cons hif-token hif-token-list))
-                       result))
-                 ;; Argument list is nil, direct expansion
-                 (setq rep (hif-expand-token-list
-                            (caddr rep) ;; Macro's token list
-                            tok expand_list))
-                 ;; Replace all remaining references immediately
-                 (setq remains (substitute tok rep remains))
-                 rep)
-             ;; Lookup tok returns an atom
-             rep))
-
-          ;;[2013-10-22 16:06:12 +0800] Must keep the token, removing
-          ;; this token might results in an incomplete expression that
-          ;; cannot be parsed further.
-          ;;((= 1 (hif-defined tok)) ;; defined (hif-defined tok)=1,
-          ;;  ;;but empty (hif-lookup tok)=nil, thus remove this token
-          ;; (setq remains (delete tok remains))
-          ;; nil)
-
-          (t ;; Usual IDs
-           tok))
-
-         expanded))
-
-      (hif-flatten (nreverse expanded)))))
-
-(defun hif-parse-exp (token-list &optional macroname)
-  "Parse the TOKEN-LIST.  Return translated list in prefix form.  MACRONAME
-is applied when invoking macros to prevent self-referencing macros."
-  (let ((hif-token-list (hif-expand-token-list token-list macroname)))
+(defun hif-parse-if-exp (token-list)
+  "Parse the TOKEN-LIST.  Return translated list in prefix form."
+  (let ((hif-token-list token-list))
     (hif-nexttoken)
     (prog1
         (and hif-token
@@ -732,8 +574,7 @@ is applied when invoking macros to prevent self-referencing macros."
   "Parse a comp-expr : logshift | comp-expr `<'|`>'|`>='|`<=' logshift."
   (let ((result (hif-logshift-expr))
         (comp-token nil))
-    (while (memq hif-token '(hif-greater hif-less hif-greater-equal
-                                         hif-less-equal))
+    (while (memq hif-token '(hif-greater hif-less hif-greater-equal hif-less-equal))
       (setq comp-token hif-token)
       (hif-nexttoken)
       (setq result (list comp-token result (hif-logshift-expr))))
@@ -772,8 +613,7 @@ is applied when invoking macros to prevent self-referencing macros."
   result))
 
 (defun hif-factor ()
-  "Parse a factor: '!' factor | '~' factor | '(' expr ')' |
-'defined(' id ')' | 'id(parmlist)' | strings | id."
+  "Parse a factor: '!' factor | '~' factor | '(' expr ')' | 'defined(' id ')' | 'id(parmlist)' | strings | id."
   (cond
    ((eq hif-token 'hif-not)
     (hif-nexttoken)
@@ -806,8 +646,6 @@ is applied when invoking macros to prevent self-referencing macros."
 
    ((numberp hif-token)
     (prog1 hif-token (hif-nexttoken)))
-   ((stringp hif-token)
-    (hif-string-concatenation))
 
    ;; Unary plus/minus.
    ((memq hif-token '(hif-minus hif-plus))
@@ -815,91 +653,10 @@ is applied when invoking macros to prevent self-referencing macros."
 
    (t                                   ; identifier
     (let ((ident hif-token))
+      (if (memq ident '(or and))
+          (error "Error: missing identifier"))
       (hif-nexttoken)
-      (if (eq hif-token 'hif-lparen)
-          (hif-place-macro-invocation ident)
-        `(hif-lookup (quote ,ident)))))))
-
-(defun hif-get-argument-list (ident)
-  (let ((nest 0)
-        (parmlist nil) ;; A "token" list of parameters, will later be parsed
-        (parm nil))
-
-    (while (or (not (eq (hif-nexttoken) 'hif-rparen))
-               (/= nest 0))
-      (if (eq (car (last parm)) 'hif-comma)
-          (setq parm nil))
-      (cond
-       ((eq hif-token 'hif-lparen)
-        (setq nest (1+ nest)))
-       ((eq hif-token 'hif-rparen)
-        (setq nest (1- nest)))
-       ((and (eq hif-token 'hif-comma)
-             (= nest 0))
-        (push (nreverse parm) parmlist)
-        (setq parm nil)))
-      (push hif-token parm))
-
-    (push (nreverse parm) parmlist) ;; Okay even if parm is nil
-    (hif-nexttoken) ;; Drop the hif-rparen, get next token
-    (nreverse parmlist)))
-
-(defun hif-place-macro-invocation (ident)
-  (let ((parmlist (hif-get-argument-list ident)))
-    `(hif-invoke (quote ,ident) (quote ,parmlist))))
-
-(defun hif-string-concatenation ()
-  "Parse concatenated strings: string | strings string"
-  (let ((result (substring-no-properties hif-token)))
-    (while (stringp (hif-nexttoken))
-      (setq result (concat
-                    (substring result 0 -1)    ; remove trailing '"'
-                    (substring hif-token 1)))) ; remove leading  '"'
-    result))
-
-(defun hif-define-macro (parmlist token-body)
-  "A marker for defined macro with arguments, cannot be evaluated alone with
-no parameters inputed."
-  ;;TODO: input arguments at run time, use minibuffer to query all arguments
-  (error
-   "Argumented macro cannot be evaluated without passing any parameter."))
-
-(defun hif-stringify (a)
-  "Stringify a number, string or symbol."
-  (cond
-   ((numberp a)
-    (number-to-string a))
-   ((atom a)
-    (symbol-name a))
-   ((stringp a)
-    (concat "\"" a "\""))
-   (t
-    (error "Invalid token to stringify"))))
-
-(defun intern-safe (str)
-  (if (stringp str)
-      (intern str)))
-
-(defun hif-token-concat (a b)
-  "Concatenate two tokens into a longer token, currently support only simple
-token concatenation.  Also support weird (but valid) token concatenation like
-'>' ## '>' becomes '>>'.  Here we take care only those that can be evaluated
-during preprocessing time and ignore all those that can only be evaluated at
-C(++) runtime (like '++', '--' and '+='...)."
-  (if (or (memq a hif-valid-token-list)
-          (memq b hif-valid-token-list))
-      (let* ((ra (car (rassq a hif-token-alist)))
-             (rb (car (rassq b hif-token-alist)))
-             (result (and ra rb
-                          (cdr (assoc (concat ra rb) hif-token-alist)))))
-        (or result
-            ;;(error "Invalid token to concatenate")
-            (error "Concatenating \"%s\" and \"%s\" does not give a valid \
-preprocessing token."
-                   (or ra (symbol-name a))
-                   (or rb (symbol-name b)))))
-    (intern-safe (concat (hif-stringify a)
-                         (hif-stringify b)))))
+      `(hif-lookup (quote ,ident))))))
 
 (defun hif-mathify (val)
   "Treat VAL as a number: if it's t or nil, use 1 or 0."
@@ -962,157 +719,23 @@ preprocessing token."
         (setq result (funcall hide-ifdef-evaluator e))))
     result))
 
-(defun hif-token-stringification (l)
-  "Scan token list for 'hif-stringify' ('#') token and stringify the next
-token."
-  (let (result)
-    (while l
-      (push (if (eq (car l) 'hif-stringify)
-                (prog1
-                    (if (cadr l)
-                        (hif-stringify (cadr l))
-                      (error "No token to stringify"))
-                  (setq l (cdr l)))
-              (car l))
-            result)
-      (setq l (cdr l)))
-    (nreverse result)))
-
-(defun hif-token-concatenation (l)
-  "Scan token list for 'hif-token-concat' ('##') token and concatenate two
-tokens."
-  (let ((prev nil)
-        result)
-    (while l
-      (while (eq (car l) 'hif-token-concat)
-        (unless prev
-          (error "No token before ## to concatenate"))
-        (unless (cdr l)
-          (error "No token after ## to concatenate"))
-        (setq prev (hif-token-concat prev (cadr l)))
-        (setq l (cddr l)))
-      (if prev
-        (setq result (append result (list prev))))
-      (setq prev (car l)
-            l (cdr l)))
-    (if prev
-        (append result (list prev))
-      result)))
-
-(defun hif-delimit (lis atom)
-  (nconc (mapcan (lambda (l) (list l atom))
-                 (butlast lis))
-         (last lis)))
-
-;; Perform token replacement:
-(defun hif-macro-supply-arguments (macro-name actual-parms)
-  "Expand a macro call, replace ACTUAL-PARMS in the macro body."
-  (let* ((SA                   (assoc macro-name hide-ifdef-env))
-         (macro                (and SA
-                                    (cdr SA)
-                                    (eq (cadr SA) 'hif-define-macro)
-                                    (cddr SA)))
-         (formal-parms         (and macro (car macro)))
-         (macro-body           (and macro (cadr macro)))
-         (hide-ifdef-local-env nil) ; dynamic binding local table
-         actual-count
-         formal-count
-         actual
-         formal
-         etc)
-
-    (when (and actual-parms formal-parms macro-body)
-      ;; For each actual parameter, evaluate each one and associate it
-      ;; with the associated actual parameter, put it into local table and finally
-      ;; evaluate the macro body.
-      (if (setq etc (eq (car formal-parms) 'hif-etc))
-          ;; Take care of 'hif-etc first. Prefix 'hif-comma back if needed.
-          (setq formal-parms (cdr formal-parms)))
-      (setq formal-count (length formal-parms)
-            actual-count (length actual-parms))
-
-      (if (> formal-count actual-count)
-          (error "Too few parmameter for macro %S" macro-name)
-        (if (< formal-count actual-count)
-            (or etc
-                (error "Too many parameters for macro %S" macro-name))))
-
-      ;; Perform token replacement on the macro-body on the parameters
-      (while (setq formal (pop formal-parms))
-        ;; Prevent repetitive substitutation, thus cannot use 'subst'
-        ;; for example:
-        ;; #define mac(a,b) (a+b)
-        ;; #define testmac mac(b,y)
-        ;; testmac should expand to (b+y): replace of argument a and b
-        ;; occurs simultaneously, not sequentially. If sequentially,
-        ;; according to the argument order, it will become:
-        ;; 1. formal parm #1 'a' replaced by actual parm 'b', thus (a+b)
-        ;;    becomes (b+b)
-        ;; 2. formal parm #2 'b' replaced by actual parm 'y', thus (b+b)
-        ;;    becomes (y+y).
-        (setq macro-body
-              ;; Unlike 'subst', 'substitute' replace only the top level
-              ;; instead of the whole tree; more importantly, it's not
-              ;; destructive.
-              (substitute (if (and etc (null formal-parms))
-                              (hif-delimit actual-parms 'hif-comma)
-                            (car actual-parms))
-                          formal macro-body))
-        (setq actual-parms (cdr actual-parms)))
-
-      ;; Replacement completed, flatten the whole token list
-      (setq macro-body (hif-flatten macro-body))
-
-      ;; Stringification and token concatenation happens here
-      (hif-token-concatenation (hif-token-stringification macro-body)))))
-
-(defun hif-invoke (macro-name actual-parms)
-  "Invoke a macro by first expanding it, then reparse the macro-body,
-finally invoke the macro."
-    ;; Reparse the macro body and evaluate it
-    (funcall hide-ifdef-evaluator
-             (hif-parse-exp
-              (hif-macro-supply-arguments macro-name actual-parms)
-              macro-name)))
 
 ;;;----------- end of parser -----------------------
 
 
-(defun hif-canonicalize-tokens (regexp) ;; for debugging
-  "Return the expanded result of the scanned tokens."
+(defun hif-canonicalize ()
+  "When at beginning of #ifX, return a Lisp expression for its condition."
   (save-excursion
-    (re-search-forward regexp)
-    (let* ((curr-regexp (match-string 0))
-           (defined (string-match hif-ifxdef-regexp curr-regexp))
-           (negate (and defined
-                        (string= (match-string 2 curr-regexp) "n")))
-           (hif-simple-token-only nil) ;; Dynamic binding var for `hif-tokenize'
-           (tokens (hif-tokenize (point)
-                                 (progn (hif-end-of-line) (point)))))
-      (if defined
-          (setq tokens (list 'hif-defined tokens)))
-      (if negate
-          (setq tokens (list 'hif-not tokens)))
-      tokens)))
-
-(defun hif-canonicalize (regexp)
-  "When at beginning of `regexp' (i.e. #ifX), return a Lisp expression for
-its condition."
-  (let ((case-fold-search nil))
-    (save-excursion
-      (re-search-forward regexp)
-      (let* ((curr-regexp (match-string 0))
-             (defined (string-match hif-ifxdef-regexp curr-regexp))
-             (negate (and defined
-                          (string= (match-string 2 curr-regexp) "n")))
-             (hif-simple-token-only nil) ;; Dynamic binding for `hif-tokenize'
-             (tokens (hif-tokenize (point)
-                                   (progn (hif-end-of-line) (point)))))
-        (if defined
-            (setq tokens (list 'hif-defined tokens)))
-        (if negate
-            (setq tokens (list 'hif-not tokens)))
-        (hif-parse-exp tokens)))))
+    (let ((negate (looking-at hif-ifndef-regexp)))
+      (re-search-forward hif-ifx-regexp)
+      (let* ((tokens (hif-tokenize (point)
+                                   (progn (hif-end-of-line) (point))))
+             (expr (hif-parse-if-exp tokens)))
+        ;; (message "hif-canonicalized: %s" expr)
+        (if negate
+            (list 'hif-not expr)
+          expr)))))
+
 
 (defun hif-find-any-ifX ()
   "Move to next #if..., or #ifndef, at point or after."
@@ -1123,10 +746,10 @@ its condition."
 
 
 (defun hif-find-next-relevant ()
-  "Move to next #if..., #elif..., #else, or #endif, after the current line."
+  "Move to next #if..., #else, or #endif, after the current line."
   ;; (message "hif-find-next-relevant at %d" (point))
   (end-of-line)
-  ;; Avoid infinite recursion by only going to line-beginning if match found
+  ;; avoid infinite recursion by only going to beginning of line if match found
   (if (re-search-forward hif-ifx-else-endif-regexp (point-max) t)
       (beginning-of-line)))
 
@@ -1134,7 +757,7 @@ its condition."
   "Move to previous #if..., #else, or #endif, before the current line."
   ;; (message "hif-find-previous-relevant at %d" (point))
   (beginning-of-line)
-  ;; Avoid infinite recursion by only going to line-beginning if match found
+  ;; avoid infinite recursion by only going to beginning of line if match found
   (if (re-search-backward hif-ifx-else-endif-regexp (point-min) t)
      (beginning-of-line)))
 
@@ -1146,19 +769,15 @@ its condition."
 (defun hif-looking-at-else ()
   (looking-at hif-else-regexp))
 
-(defun hif-looking-at-elif ()
-  (looking-at hif-elif-regexp))
 
 
 (defun hif-ifdef-to-endif ()
-  "If positioned at #ifX, #elif, or #else form, skip to corresponding #endif."
+  "If positioned at #ifX or #else form, skip to corresponding #endif."
   ;; (message "hif-ifdef-to-endif at %d" (point)) (sit-for 1)
   (hif-find-next-relevant)
   (cond ((hif-looking-at-ifX)
          (hif-ifdef-to-endif) ; find endif of nested if
          (hif-ifdef-to-endif)) ; find outer endif or else
-        ((hif-looking-at-elif)
-         (hif-ifdef-to-endif))
         ((hif-looking-at-else)
          (hif-ifdef-to-endif)) ; find endif following else
         ((hif-looking-at-endif)
@@ -1331,7 +950,7 @@ Point is left unchanged."
 ;;; A bit slimy.
 
 (defun hif-hide-line (point)
-  "Hide the line containing point. Does nothing if `hide-ifdef-lines' is nil."
+  "Hide the line containing point.  Does nothing if `hide-ifdef-lines' is nil."
   (when hide-ifdef-lines
     (save-excursion
       (goto-char point)
@@ -1375,7 +994,7 @@ Point is left unchanged."
   "Called at #ifX expression, this hides those parts that should be hidden.
 It uses the judgment of `hide-ifdef-evaluator'."
   ;; (message "hif-possibly-hide") (sit-for 1)
-  (let ((test (hif-canonicalize hif-ifx-regexp))
+  (let ((test (hif-canonicalize))
         (range (hif-find-range)))
     ;; (message "test = %s" test) (sit-for 1)
 
@@ -1403,145 +1022,16 @@ It uses the judgment of `hide-ifdef-evaluator'."
     (goto-char (hif-range-end range))
     (end-of-line)))
 
-(defun hif-parse-macro-arglist (str)
-  "Parse argument list formatted as '( arg1 [ , argn] [...] )', including
-the '...'.  Return a list of the arguments, if '...' exists the first arg
-will be hif-etc."
-  (let* ((hif-simple-token-only nil) ;; Dynamic binding var for `hif-tokenize'
-         (tokenlist
-          (cdr (hif-tokenize
-                (- (point) (length str)) (point)))) ; remove hif-lparen
-         etc result token)
-    (while (not (eq (setq token (pop tokenlist)) 'hif-rparen))
-      (cond
-       ((eq token 'hif-etc)
-        (setq etc t))
-       ((eq token 'hif-comma)
-        t)
-       (t
-        (push token result))))
-    (if etc
-        (cons 'hif-etc (nreverse result))
-      (nreverse result))))
-
-;; The original version of hideif evaluates the macro early and store the
-;; final values for the defined macro into the symbol database (aka
-;; `hide-ifdef-env'). The evaluation process is "strings -> tokens -> parsed
-;; tree -> [value]". (The square bracket refers to what's stored in in our
-;; `hide-ifdef-env'.)
-;;
-;; This forbids the evaluation of an argumented macro since the parameters
-;; are applied at run time. In order to support argumented macro I then
-;; postponed the evaluation process one stage and store the "parsed tree"
-;; into symbol database. The evaluation process was then "strings -> tokens
-;; -> [parsed tree] -> value". Hideif therefore run slower since it need to
-;; evaluate the parsed tree everytime when trying to expand the symbol. These
-;; temporarily code changes are obsolete and not in Emacs source repository.
-;;
-;; Furthermore, CPP did allow partial expression to be defined in several
-;; macros and later got concatenated into a complete expression and then
-;; evaluate it. In order to match this behavior I had to postpone one stage
-;; further, otherwise those partial expression will be fail on parsing and
-;; we'll miss all macros that reference it. The evaluation process thus
-;; became "strings -> [tokens] -> parsed tree -> value." This degraded the
-;; performance since we need to parse tokens and evaluate them everytime
-;; when that symbol is referenced.
-;;
-;; In real cases I found a lot portion of macros are "simple macros" that
-;; expand to literals like integers or other symbols. In order to enhance
-;; the performance I use this `hif-simple-token-only' to notify my code and
-;; save the final [value] into symbol database. [lukelee]
 
-(defun hif-find-define (&optional min max)
-  "Parse texts and retrieve all defines within the region MIN and MAX."
-  (interactive)
-  (and min (goto-char min))
-  (and (re-search-forward hif-define-regexp max t)
-       (or
-        (let* ((defining (string= "define" (match-string 2)))
-               (name (and (re-search-forward hif-macroref-regexp max t)
-                          (match-string 1)))
-               (parsed nil)
-               (parmlist (and (match-string 3) ;; First arg id found
-                              (hif-parse-macro-arglist (match-string 2)))))
-          (if defining
-              ;; Ignore name (still need to return 't), or define the name
-              (or (and hide-ifdef-exclude-define-regexp
-                       (string-match hide-ifdef-exclude-define-regexp
-                                     name))
-
-                  (let* ((start (point))
-                         (end   (progn (hif-end-of-line) (point)))
-                         (hif-simple-token-only nil) ;; Dynamic binding
-                         (tokens
-                          (and name
-                               ;; `hif-simple-token-only' is set/clear
-                               ;; only in this block
-                               (condition-case nil
-                                   ;; Prevent C statements like
-                                   ;; 'do { ... } while (0)'
-                                   (hif-tokenize start end)
-                                 (error
-                                  ;; We can't just return nil here since
-                                  ;; this will stop hideif from searching
-                                  ;; for more #defines.
-                                  (setq hif-simple-token-only t)
-                                  (buffer-substring-no-properties
-                                   start end)))))
-                         ;; For simple tokens we save only the parsed result;
-                         ;; otherwise we save the tokens and parse it after
-                         ;; parameter replacement
-                         (expr (and tokens
-                                    ;; `hif-simple-token-only' is checked only
-                                    ;; here.
-                                    (or (and hif-simple-token-only
-                                             (listp tokens)
-                                             (= (length tokens) 1)
-                                             (hif-parse-exp tokens))
-                                        `(hif-define-macro ,parmlist
-                                                           ,tokens))))
-                         (SA (and name
-                                  (assoc (intern name) hide-ifdef-env))))
-                    (and name
-                         (if SA
-                             (or (setcdr SA expr) t)
-                           ;; Lazy evaluation, eval only if hif-lookup find it.
-                           ;; Define it anyway, even if nil it's still in list
-                           ;; and therefore considerred defined
-                           (push (cons (intern name) expr) hide-ifdef-env)))))
-            ;; #undef
-            (and name
-                 (hif-undefine-symbol (intern name))))))
-       t))
-
-
-(defun hif-add-new-defines (&optional min max)
-  "Scan and add all #define macros between MIN and MAX"
-  (interactive)
-  (save-excursion
-    (save-restriction
-      ;; (mark-region min max) ;; for debugging
-      (while (hif-find-define min max)
-        (setf min (point)))
-      (if max (goto-char max)
-        (goto-char (point-max))))))
 
 (defun hide-ifdef-guts ()
   "Does most of the work of `hide-ifdefs'.
 It does not do the work that's pointless to redo on a recursive entry."
   ;; (message "hide-ifdef-guts")
   (save-excursion
-    (let ((case-fold-search nil)
-          min max)
     (goto-char (point-min))
-      (setf min (point))
-      (loop do
-            (setf max (hif-find-any-ifX))
-            (hif-add-new-defines min max)
-            (if max
-                (hif-possibly-hide))
-            (setf min (point))
-            while max))))
+    (while (hif-find-any-ifX)
+      (hif-possibly-hide))))
 
 ;;===%%SF%% hide-ifdef-hiding (End)  ===
 
@@ -1555,8 +1045,7 @@ It does not do the work that's pointless to redo on a recursive entry."
   (message "Hide-Read-Only %s"
            (if hide-ifdef-read-only "ON" "OFF"))
   (if hide-ifdef-hiding
-      (setq buffer-read-only (or hide-ifdef-read-only
-                                 hif-outside-read-only)))
+      (setq buffer-read-only (or hide-ifdef-read-only hif-outside-read-only)))
   (force-mode-line-update))
 
 (defun hide-ifdef-toggle-outside-read-only ()
@@ -1592,32 +1081,12 @@ It does not do the work that's pointless to redo on a recursive entry."
   (hif-set-var var 1)
   (if hide-ifdef-hiding (hide-ifdefs)))
 
-(defun hif-undefine-symbol (var)
-  (setq hide-ifdef-env
-        (delete (assoc var hide-ifdef-env) hide-ifdef-env)))
-
-;;(defun hide-ifdef-undef (var)
-;;  "Undefine a VAR so that #ifdef VAR would not be included."
-;;  (interactive "SUndefine what? ")
-;;  ;;(hif-set-var var nil);;Luke fixed: set it nil is still considered
-;;  ;;defined so #ifdef VAR is still true.
-;;  (hif-undefine-symbol var)
-;;  (if hide-ifdef-hiding (hide-ifdefs)))
-
-(defun hide-ifdef-undef (start end)
+(defun hide-ifdef-undef (var)
   "Undefine a VAR so that #ifdef VAR would not be included."
-  (interactive "r")
-  (let* ((symstr
-          (or (and mark-active
-                   (buffer-substring-no-properties start end))
-              (read-string "Undefine what? " (current-word))))
-         (sym (and symstr
-                   (intern symstr))))
-    (if (zerop (hif-defined sym))
-        (message "`%s' not defined, no need to undefine it" symstr)
-      (hif-undefine-symbol sym)
-      (if hide-ifdef-hiding (hide-ifdefs))
-      (message "`%S' undefined" sym))))
+  (interactive "SUndefine what? ")
+  (hif-set-var var nil)
+  (if hide-ifdef-hiding (hide-ifdefs)))
+
 
 (defun hide-ifdefs (&optional nomsg)
   "Hide the contents of some #ifdefs.