diff --git a/cligen_buf.c b/cligen_buf.c
index 4a1f0cd..0f78da4 100644
--- a/cligen_buf.c
+++ b/cligen_buf.c
@@ -312,7 +312,7 @@ vcprintf(cbuf       *cb,
   */
 int
 cbuf_append_str(cbuf *cb,
-                char *str)
+                const char *str)
 {
     size_t  len0;
     size_t  len;
diff --git a/cligen_buf.h b/cligen_buf.h
index f922ea0..13ccbc1 100644
--- a/cligen_buf.h
+++ b/cligen_buf.h
@@ -69,7 +69,7 @@ int      cprintf(cbuf *cb, const char *format, ...) __attribute__ ((format (prin
 int      vcprintf(cbuf *cb, const char *format, va_list ap);
 void     cbuf_reset(cbuf *cb);
 int      cbuf_append(cbuf *cb, int c);
-int      cbuf_append_str(cbuf *cb, char *str);
+int      cbuf_append_str(cbuf *cb, const char *str);
 int      cbuf_append_buf(cbuf *cb, void *src, size_t n);
 int      cbuf_trunc(cbuf *cb, size_t i);
 
diff --git a/cligen_cv.c b/cligen_cv.c
index 8c4e2fb..6281048 100644
--- a/cligen_cv.c
+++ b/cligen_cv.c
@@ -68,7 +68,7 @@
 /*
  * URL protocol strings
  */
-static char *cg_urlprotostr[] = {
+static const char *cg_urlprotostr[] = {
     NULL,
     "file",
     "flash",
@@ -1336,7 +1336,7 @@ parse_dec64(char    *str,
 
     if (n<=0 || n>18){
         if (reason != NULL)
-            if ((*reason = cligen_reason("%s: fraction-digit=%d given but should be in interval [1:18]", __FUNCTION__, n)) == NULL){
+            if ((*reason = cligen_reason("%s: fraction-digit=%d given but should be in interval [1:18]", __func__, n)) == NULL){
                 goto done;
             }
         retval = 0;
@@ -2089,7 +2089,7 @@ cv_str2type(const char *str)
 const char *
 cv_type2str(enum cv_type type)
 {
-    char *str = NULL;
+    const char *str = NULL;
     switch (type){
     case CGV_ERR:
         str="err";
@@ -2164,7 +2164,7 @@ cv_type2str(enum cv_type type)
         str="empty";
         break;
     default:
-        fprintf(stderr, "%s: invalid type: %d\n", __FUNCTION__, type);
+        fprintf(stderr, "%s: invalid type: %d\n", __func__, type);
         break;
     }
     return str;
@@ -2510,14 +2510,14 @@ cv2str(cg_var *cv,
                        cv->var_ipv4masklen);
         break;
     case CGV_IPV6ADDR:
-        if (inet_ntop(AF_INET6, &cv->var_ipv6addr, straddr, sizeof(straddr)) < 0){
+        if (NULL == inet_ntop(AF_INET6, &cv->var_ipv6addr, straddr, sizeof(straddr))){
             fprintf(stderr, "inet_ntop: %s\n", strerror(errno));
             return -1;
         }
         len = snprintf(str, size, "%s", straddr);
         break;
     case CGV_IPV6PFX:
-        if (inet_ntop(AF_INET6, &cv->var_ipv6addr, straddr, sizeof(straddr)) < 0){
+        if (NULL == inet_ntop(AF_INET6, &cv->var_ipv6addr, straddr, sizeof(straddr))){
             fprintf(stderr, "inet_ntop: %s\n", strerror(errno));
             return -1;
         }
diff --git a/cligen_cvec.c b/cligen_cvec.c
index dc1bf4a..1592324 100644
--- a/cligen_cvec.c
+++ b/cligen_cvec.c
@@ -765,7 +765,7 @@ next_token(char **s0,
 
     s = *s0;
     if (s==NULL){
-        fprintf(stderr, "%s: null string\n", __FUNCTION__);
+        fprintf(stderr, "%s: null string\n", __func__);
         return -1;
     }
     for (s=*s0; *s; s++){ /* First iterate through delimiters */
@@ -818,7 +818,7 @@ next_token(char **s0,
         }
     }
     if ((token=malloc(len+1)) == NULL){
-        fprintf(stderr, "%s: malloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s: malloc: %s\n", __func__, strerror(errno));
         return -1;
     }
     memcpy(token, st, len);
diff --git a/cligen_expand.c b/cligen_expand.c
index 5da9e52..c37af21 100644
--- a/cligen_expand.c
+++ b/cligen_expand.c
@@ -106,12 +106,12 @@ co_expand_sub(cg_obj  *co0,
     co_up_set(con, coparent);
     if (co0->co_command)
         if ((con->co_command = strdup(co0->co_command)) == NULL){
-            fprintf(stderr, "%s: strdup: %s\n", __FUNCTION__, strerror(errno));
+            fprintf(stderr, "%s: strdup: %s\n", __func__, strerror(errno));
             goto done;
         }
     if (co0->co_prefix)
         if ((con->co_prefix = strdup(co0->co_prefix)) == NULL){
-            fprintf(stderr, "%s: strdup: %s\n", __FUNCTION__, strerror(errno));
+            fprintf(stderr, "%s: strdup: %s\n", __func__, strerror(errno));
             goto done;
         }
     if (co0->co_cvec)
@@ -126,7 +126,7 @@ co_expand_sub(cg_obj  *co0,
     if (co0->co_type == CO_VARIABLE){
         if (co0->co_expand_fn_str)
             if ((con->co_expand_fn_str = strdup(co0->co_expand_fn_str)) == NULL){
-                fprintf(stderr, "%s: strdup: %s\n", __FUNCTION__, strerror(errno));
+                fprintf(stderr, "%s: strdup: %s\n", __func__, strerror(errno));
                 goto done;
             }
         if (co0->co_expand_fn_vec)
@@ -134,12 +134,12 @@ co_expand_sub(cg_obj  *co0,
                 goto done;
         if (co0->co_translate_fn_str)
             if ((con->co_translate_fn_str = strdup(co0->co_translate_fn_str)) == NULL){
-                fprintf(stderr, "%s: strdup: %s\n", __FUNCTION__, strerror(errno));
+                fprintf(stderr, "%s: strdup: %s\n", __func__, strerror(errno));
                 goto done;
             }
         if (co0->co_show)
             if ((con->co_show = strdup(co0->co_show)) == NULL){
-                fprintf(stderr, "%s: strdup: %s\n", __FUNCTION__, strerror(errno));
+                fprintf(stderr, "%s: strdup: %s\n", __func__, strerror(errno));
                 goto done;
             }
         if (co0->co_rangecvv_low)
@@ -150,12 +150,12 @@ co_expand_sub(cg_obj  *co0,
                 goto done;
         if (co0->co_choice)
             if ((con->co_choice = strdup(co0->co_choice)) == NULL){
-                fprintf(stderr, "%s: strdup: %s\n", __FUNCTION__, strerror(errno));
+                fprintf(stderr, "%s: strdup: %s\n", __func__, strerror(errno));
                 goto done;
             }
         if (co0->co_regex)
             if ((con->co_regex = cvec_dup(co0->co_regex)) == NULL){
-                fprintf(stderr, "%s: cvec_dup: %s\n", __FUNCTION__, strerror(errno));
+                fprintf(stderr, "%s: cvec_dup: %s\n", __func__, strerror(errno));
                 goto done;
             }
     } /* CO_VARIABLE */
@@ -962,7 +962,7 @@ pt_expand(cligen_handle h,
      */
     cligen_parsetree_sort(ptn, 0);
     if (cligen_logsyntax(h) > 0){
-        fprintf(stderr, "%s:\n", __FUNCTION__);
+        fprintf(stderr, "%s:\n", __func__);
         pt_print1(stderr, ptn, 0);
     }
  ok:
diff --git a/cligen_getline.c b/cligen_getline.c
index 31c1e83..1fb89b8 100644
--- a/cligen_getline.c
+++ b/cligen_getline.c
@@ -55,18 +55,18 @@ static void     gl_init1(void);         /* prepare to edit a line */
 static void     gl_cleanup(void);       /* to undo gl_init1 */
 void            gl_char_init(void);     /* get ready for no echo input */
 void            gl_char_cleanup(void);  /* undo gl_char_init */
-static size_t   (*gl_strlen)(const char *) = (size_t(*)())strlen;
+static size_t   (*gl_strlen)(const char *) = strlen;
                                         /* returns printable prompt width */
 
 static int      gl_addchar(cligen_handle h, int c);     /* install specified char */
 static void     gl_del(cligen_handle h, int loc);       /* del, either left (-1) or cur (0) */
-static inline void gl_fixup(cligen_handle h, char*,int,int);/* fixup state variables and screen */
+static inline void gl_fixup(cligen_handle h, const char*,int,int);/* fixup state variables and screen */
 static int      gl_getc(cligen_handle h);               /* read one char from terminal */
 static void     gl_kill(cligen_handle h, int pos);      /* delete to EOL */
 static void     gl_kill_begin(cligen_handle h, int pos);        /* delete to BEGIN of line */
 static int      gl_kill_word(cligen_handle h, int pos); /* delete word */
 static void     gl_newline(cligen_handle);      /* handle \n or \r */
-static int      gl_puts(char *buf);     /* write a line to terminal */
+static int      gl_puts(const char *buf);     /* write a line to terminal */
 
 static void     gl_transpose(cligen_handle h);  /* transpose two chars */
 static int      gl_yank(cligen_handle h);               /* yank killed text */
@@ -488,7 +488,7 @@ gl_putc(int c)
 /******************** fairly portable part *********************************/
 
 static int
-gl_puts(char *buf)
+gl_puts(const char *buf)
 {
     int len;
 
@@ -586,7 +586,7 @@ gl_getline(cligen_handle h,
     int   c;
     int   loc;
     int   tmp;
-    char *gl_prompt;
+    const char *gl_prompt;
     int   escape = 0;
 #ifdef __unix__
     int   sig;
@@ -1172,7 +1172,7 @@ gl_redraw(cligen_handle h)
  */
 static void
 gl_fixup_noscroll(cligen_handle h,
-                  char         *prompt,
+                  const char   *prompt,
                   int           change,
                   int           cursor)
 {
@@ -1286,7 +1286,7 @@ gl_fixup_noscroll(cligen_handle h,
  */
 static void
 gl_fixup_scroll(cligen_handle h,
-                char         *prompt,
+                const char   *prompt,
                 int           change,
                 int           cursor)
 {
@@ -1396,20 +1396,20 @@ gl_fixup_scroll(cligen_handle h,
 
 static inline void
 gl_fixup(cligen_handle h,
-         char         *prompt,
+         const char         *prompt,
          int           change,
          int           cursor)
 {
     if (gl_scrolling_mode)
-        return gl_fixup_scroll(h, prompt, change, cursor);
+        gl_fixup_scroll(h, prompt, change, cursor);
     else
-        return gl_fixup_noscroll(h, prompt, change, cursor);
+        gl_fixup_noscroll(h, prompt, change, cursor);
 }
 
 /******************* strlen stuff **************************************/
 
 void
-gl_strwidth(size_t (*func)())
+gl_strwidth(size_t (*func)(const char*))
 {
     if (func != 0) {
         gl_strlen = func;
@@ -1509,7 +1509,7 @@ search_back(cligen_handle h,
             int           new_search)
 {
     int    found = 0;
-    char  *p, *loc;
+    const char  *p, *loc;
     int    last;
 
     search_forw_flg = 0;
@@ -1550,7 +1550,7 @@ search_forw(cligen_handle h,
             int           new_search)
 {
     int    found = 0;
-    char  *p, *loc;
+    const char  *p, *loc;
     int    last;
 
     search_forw_flg = 1;
diff --git a/cligen_getline.h b/cligen_getline.h
index 3580d55..287100d 100644
--- a/cligen_getline.h
+++ b/cligen_getline.h
@@ -23,7 +23,7 @@
 /*
  * Types
  */
-typedef size_t (*gl_strwidth_proc)(char *);
+typedef size_t (*gl_strwidth_proc)(const char *);
 
 /*
  * Prototypes
diff --git a/cligen_handle.c b/cligen_handle.c
index 4835946..f10ba07 100644
--- a/cligen_handle.c
+++ b/cligen_handle.c
@@ -155,7 +155,7 @@ cligen_init(void)
     struct sigaction      sigh;
 
     if ((ch = malloc(sizeof(*ch))) == NULL){
-        fprintf(stderr, "%s: malloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s: malloc: %s\n", __func__, strerror(errno));
         goto done;
     }
     memset(ch, 0, sizeof(*ch));
@@ -303,7 +303,7 @@ cligen_prompt(cligen_handle h)
  */
 int
 cligen_prompt_set(cligen_handle h,
-                  char         *prompt)
+                  const char    *prompt)
 {
     struct cligen_handle *ch = handle(h);
 
@@ -372,7 +372,7 @@ cligen_pt_head_active_set(cligen_handle h,
  * bar @bar;
  * y;
  */
-char*
+const char*
 cligen_treename_keyword(cligen_handle h)
 {
     struct cligen_handle *ch = handle(h);
@@ -1106,12 +1106,12 @@ cligen_buf_init(cligen_handle h)
     struct cligen_handle *ch = handle(h);
 
     if ((ch->ch_buf = malloc(_getline_bufsize)) == NULL){
-        fprintf(stderr, "%s malloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s malloc: %s\n", __func__, strerror(errno));
         return -1;
     }
     memset(ch->ch_buf, 0, _getline_bufsize);
     if ((ch->ch_killbuf = malloc(_getline_killbufsize)) == NULL){
-        fprintf(stderr, "%s malloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s malloc: %s\n", __func__, strerror(errno));
         return -1;
     }
     memset(ch->ch_killbuf, 0, _getline_killbufsize);
@@ -1139,7 +1139,7 @@ cligen_buf_increase(cligen_handle h,
     while (_getline_bufsize < len1 + 1)
       _getline_bufsize *= 2;
     if ((ch->ch_buf = realloc(ch->ch_buf, _getline_bufsize)) == NULL){
-        fprintf(stderr, "%s realloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s realloc: %s\n", __func__, strerror(errno));
         return -1;
     }
     memset(ch->ch_buf+len0, 0, _getline_bufsize-len0);
@@ -1163,7 +1163,7 @@ cligen_killbuf_increase(cligen_handle h,
     while (_getline_killbufsize < len1 + 1)
       _getline_killbufsize *= 2;
     if ((ch->ch_killbuf = realloc(ch->ch_killbuf, _getline_killbufsize)) == NULL){
-        fprintf(stderr, "%s realloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s realloc: %s\n", __func__, strerror(errno));
         return -1;
     }
     memset(ch->ch_killbuf+len0, 0, _getline_killbufsize-len0);
diff --git a/cligen_handle.h b/cligen_handle.h
index b09afd3..bd1acfa 100644
--- a/cligen_handle.h
+++ b/cligen_handle.h
@@ -71,9 +71,9 @@
  * @retval     -1    Error
  * @code
  *  void *wh = NULL;
- *  cligen_eval_wrap_cb(h, &wh, "myfn", __FUNCTION__);
+ *  cligen_eval_wrap_cb(h, &wh, "myfn", __func__);
  *  .. User callback
- *  cligen_eval_wrap_cb(h, &wh, "myfn", __FUNCTION__);
+ *  cligen_eval_wrap_cb(h, &wh, "myfn", __func__);
  * See cligen_eval
  */
 typedef int (cligen_eval_wrap_fn)(void *arg, void **wh, const char *name, const char *fn);
@@ -117,7 +117,7 @@ char cligen_comment(cligen_handle h);
 int cligen_comment_set(cligen_handle h, char c);
 
 char* cligen_prompt(cligen_handle h);
-int cligen_prompt_set(cligen_handle h, char *prompt);
+int cligen_prompt_set(cligen_handle h, const char *prompt);
 
 pt_head *cligen_pt_head_get(cligen_handle h);
 int cligen_pt_head_set(cligen_handle h, pt_head *ph);
@@ -125,7 +125,7 @@ int cligen_pt_head_set(cligen_handle h, pt_head *ph);
 pt_head *cligen_pt_head_active_get(cligen_handle h);
 int cligen_pt_head_active_set(cligen_handle h, pt_head *ph);
 
-char *cligen_treename_keyword(cligen_handle h);
+const char *cligen_treename_keyword(cligen_handle h);
 int cligen_treename_keyword_set(cligen_handle h, char *name);
 
 /* After an evaluation (callback), which node in the parse-tree? */
diff --git a/cligen_hello.c b/cligen_hello.c
index 32795b1..a4f38e9 100644
--- a/cligen_hello.c
+++ b/cligen_hello.c
@@ -66,7 +66,7 @@ str2fn(char  *name,
 }
 
 /*! The command syntax specification */
-static char *hello_syntax = "prompt=\"hello> \";\n"
+static const char *hello_syntax = "prompt=\"hello> \";\n"
     "hello(\"Greet the world\") world, cb(\"Hello World!\");"
     ;
 
diff --git a/cligen_history.c b/cligen_history.c
index 2adfe1a..4e1e60e 100644
--- a/cligen_history.c
+++ b/cligen_history.c
@@ -75,6 +75,13 @@
 #include "cligen_history_internal.h"
 #include "cligen_history.h"
 
+/*
+ * A well-defined empty string, used whenever one is needed as a placeholder,
+ * avoiding a malloc. By having it explicit, one can (more) easily spot a
+ * free(a) where a == CH_EMPTY_STR error.
+ */
+static char CH_EMPTY_STR[] = "";
+
 /*! Makes a copy of the string
  *
  * @param[in] p     String input
@@ -82,7 +89,7 @@
  * @retval    NULL  Error
  */
 static char *
-hist_save(char *p)
+hist_save(const char *p)
 {
     char *s = NULL;
     int   len = strlen(p)+1;
@@ -111,11 +118,11 @@ hist_save(char *p)
  */
 int
 hist_add(cligen_handle h,
-         char         *buf)
+         const char   *buf)
 {
     struct cligen_handle *ch = handle(h);
     int                   retval = -1;
-    char                 *p = buf;
+    const char                 *p = buf;
     int                   len;
 
     if (strlen(buf) >= cligen_buf_size(h))
@@ -136,7 +143,7 @@ hist_add(cligen_handle h,
             if (ch->ch_hist_buf[ch->ch_hist_last] && *ch->ch_hist_buf[ch->ch_hist_last]) {
                 free(ch->ch_hist_buf[ch->ch_hist_last]);
             }
-            ch->ch_hist_buf[ch->ch_hist_last] = ""; /* NB not-malloced, check in hist_free */
+            ch->ch_hist_buf[ch->ch_hist_last] = CH_EMPTY_STR;
         }
     }
     ch->ch_hist_cur = ch->ch_hist_last;
@@ -170,11 +177,11 @@ hist_exit(cligen_handle h)
  *
  * @param[in] h     CLIgen handle
  */
-char *
+const char *
 hist_prev(cligen_handle h)
 {
     struct cligen_handle *ch = handle(h);
-    char *p = 0;
+    const char *p = 0;
     int   next = (ch->ch_hist_cur - 1 + ch->ch_hist_size) % ch->ch_hist_size;
 
     if (ch->ch_hist_buf[ch->ch_hist_cur] != 0 && next != ch->ch_hist_last) {
@@ -192,11 +199,11 @@ hist_prev(cligen_handle h)
  *
  * @param[in] h     CLIgen handle
  */
-char *
+const char *
 hist_next(cligen_handle h)
 {
     struct cligen_handle *ch = handle(h);
-    char *p = 0;
+    const char *p = 0;
 
     if (ch->ch_hist_cur != ch->ch_hist_last) {
         ch->ch_hist_cur = (ch->ch_hist_cur+1) % ch->ch_hist_size;
@@ -263,7 +270,7 @@ hist_copy(cligen_handle h,
 int
 hist_copy_prev(cligen_handle h)
 {
-    char *ptr = hist_prev(h);
+    const char *ptr = hist_prev(h);
 
     strncpy(cligen_buf(h), ptr, cligen_buf_size(h));
     return 0;
@@ -289,7 +296,7 @@ hist_copy_pos(cligen_handle h)
 int
 hist_copy_next(cligen_handle h)
 {
-    char *ptr = hist_next(h);
+    const char *ptr = hist_next(h);
 
     strncpy(cligen_buf(h), ptr, cligen_buf_size(h));
     return 0;
@@ -322,7 +329,7 @@ cligen_hist_init(cligen_handle h,
     ch->ch_hist_size = lines+1; /* circular buffer needs an extra element */
     for (i=0; i < old_size; i++)
         if (ch->ch_hist_buf[i]){
-            if (strlen(ch->ch_hist_buf[i]))
+            if (CH_EMPTY_STR != ch->ch_hist_buf[i])
                 free(ch->ch_hist_buf[i]);
             ch->ch_hist_buf[i] = NULL;
         }
@@ -331,7 +338,7 @@ cligen_hist_init(cligen_handle h,
     ch->ch_hist_cur = 0;
     ch->ch_hist_last = 0;
     ch->ch_hist_pre = 0;
-    ch->ch_hist_buf[0] = ""; /* NB not-malloced, check in hist_free */
+    ch->ch_hist_buf[0] = CH_EMPTY_STR;
     for (i=1; i < ch->ch_hist_size; i++) /* reset all entries */
         ch->ch_hist_buf[i] = (char *)0;
     retval = 0;
diff --git a/cligen_history_internal.h b/cligen_history_internal.h
index bfda04c..b869b47 100644
--- a/cligen_history_internal.h
+++ b/cligen_history_internal.h
@@ -55,10 +55,10 @@
 /*
  * Prototypes
  */
-int   hist_add(cligen_handle h, char *);
+int   hist_add(cligen_handle h, const char *);
 int   hist_exit(cligen_handle h);
-char *hist_next(cligen_handle h);
-char *hist_prev(cligen_handle h);
+const char *hist_next(cligen_handle h);
+const char *hist_prev(cligen_handle h);
 int   hist_pos_set(cligen_handle h, int pos);
 int   hist_pos(cligen_handle h);
 int   hist_last_get(cligen_handle h);
diff --git a/cligen_match.c b/cligen_match.c
index a4c21dd..d31fa47 100644
--- a/cligen_match.c
+++ b/cligen_match.c
@@ -761,7 +761,7 @@ callbacks_merge(cg_obj       *coref,
             strcmp(coref->co_callbacks->cc_fn_str, "prepend_me") == 0){
             /* Assume only single coref parameter */
             if ((cv = cvec_i(coref->co_callbacks->cc_cvec, 0)) == NULL){
-                fprintf(stderr, "%s no first element in coref cvec\n", __FUNCTION__);
+                fprintf(stderr, "%s no first element in coref cvec\n", __func__);
                 goto done;
             }
             cvv = cvec_from_var(cv);
@@ -838,7 +838,7 @@ match_pattern_sets(cligen_handle  h,
 
     token = cvec_i_str(cvt, level+1); /* for debugging */
 #ifdef _DEBUG_SETS
-    fprintf(stderr, "%s %*s level: %d token:%s\npt:\n", __FUNCTION__, level*3,"",
+    fprintf(stderr, "%s %*s level: %d token:%s\npt:\n", __func__, level*3,"",
                 level, strlen(token)?token:"\"\"");
     pt_print(stderr, pt);
 #endif
@@ -846,7 +846,7 @@ match_pattern_sets(cligen_handle  h,
     if (match_pattern_sets_local(h, cvt, cvr, pt, level, best, cvv, &mr0) < 0)
         goto done;
 #ifdef _DEBUG_SETS
-    fprintf(stderr, "%s %*s matchnr:%d\n", __FUNCTION__, level*3,"", mr_pt_len_get(mr0));
+    fprintf(stderr, "%s %*s matchnr:%d\n", __func__, level*3,"", mr_pt_len_get(mr0));
 #endif
     if (mr_pt_len_get(mr0) != 1){ /* If not unique match exit here */
         *mrp = mr0;
@@ -882,7 +882,7 @@ match_pattern_sets(cligen_handle  h,
             goto done;
     }
 #ifdef _DEBUG_SETS
-    fprintf(stderr, "%s %*s match co:%s\n", __FUNCTION__, level*3,"", co_match->co_command);
+    fprintf(stderr, "%s %*s match co:%s\n", __func__, level*3,"", co_match->co_command);
 #endif
     if (mr_last_get(mr0) && (strcmp(token, "") != 0)){
         mr_flags_set_co_match(mr0, co_match);
@@ -931,7 +931,7 @@ match_pattern_sets(cligen_handle  h,
     }
     if (pt_sets_get(ptn)){ /* For sets, iterate */
 #ifdef _DEBUG_SETS
-        fprintf(stderr, "%s %*s sets:\n", __FUNCTION__, level*3,"");
+        fprintf(stderr, "%s %*s sets:\n", __func__, level*3,"");
 #endif
         while (!last_level(cvt, level)){
             if (mrc != NULL)
@@ -946,12 +946,12 @@ match_pattern_sets(cligen_handle  h,
                                    &mrc) < 0)
                 goto done;
 #ifdef _DEBUG_SETS
-            fprintf(stderr, "%s %*s sets matchnr: %d\n", __FUNCTION__, level*3,"", mr_pt_len_get(mrc));
+            fprintf(stderr, "%s %*s sets matchnr: %d\n", __func__, level*3,"", mr_pt_len_get(mrc));
 #endif
             if (mr_pt_len_get(mrc) != 1)
                 break;
 #ifdef _DEBUG_SETS
-            fprintf(stderr, "%s %*s sets match co: %s\n", __FUNCTION__, level*3,"",
+            fprintf(stderr, "%s %*s sets match co: %s\n", __func__, level*3,"",
                     mr_pt_i_get(mrc, 0)->co_command);
 #endif
             if (mrcprev != NULL)
diff --git a/cligen_object.c b/cligen_object.c
index 804dac5..7db51dc 100644
--- a/cligen_object.c
+++ b/cligen_object.c
@@ -1228,7 +1228,7 @@ co_value_set(cg_obj *co,
     }
     if (str != NULL)
         if ((co->co_value = strdup(str)) == NULL){
-            fprintf(stderr, "%s: strdup: %s\n", __FUNCTION__, strerror(errno));
+            fprintf(stderr, "%s: strdup: %s\n", __func__, strerror(errno));
             return -1;
         }
     return 0;
diff --git a/cligen_object.h b/cligen_object.h
index 4cdca4e..3179afe 100644
--- a/cligen_object.h
+++ b/cligen_object.h
@@ -181,7 +181,7 @@ struct cg_obj{
     struct cg_obj_common co_common;   /* Inline of common fields accessed by macros below */
     /*--- Up to here common with cg_obj_cmd */
     union {                           /* depends on co_type: */
-        struct {        } cou_cmd;    /* CO_COMMAND */
+        // struct {        } cou_cmd;    /* CO_COMMAND */
         struct cg_varspec cou_var;    /* CO_VARIABLE */
         //                            /* CO_REFERENCE */
     } u;
diff --git a/cligen_parse.h b/cligen_parse.h
index c01c683..67f9969 100644
--- a/cligen_parse.h
+++ b/cligen_parse.h
@@ -63,10 +63,10 @@ struct cgy_list{
 /*! CLIgen yacc parse structure, with all accumulated state of a parse session */
 struct cligen_parse_yacc{
     cligen_handle         cy_handle;       /* cligen_handle */
-    char                 *cy_name;         /* Name of syntax (for error string) */
+    const char           *cy_name;         /* Name of syntax (for error string) */
     char                 *cy_treename;     /* Name of syntax (for error string) */
     int                   cy_linenum;      /* Number of \n in parsed buffer */
-    char                 *cy_parse_string; /* original (copy of) parse string */
+    const char           *cy_parse_string; /* original (copy of) parse string */
     void                 *cy_lexbuf;       /* internal parse buffer from lex */
     cvec                 *cy_globals;      /* global variables after parsing */
     cvec                 *cy_cvec;         /* local variables (per-command) */
@@ -99,7 +99,7 @@ int cgy_exit(cligen_yacc *cy);
 
 int cligen_parselex(void *_ya);
 int cligen_parseparse(void *);
-void cligen_parseerror(void *_ya, char*);
+void cligen_parseerror(void *_ya, const char*);
 int cligen_parse_debug(int d);
 
 #endif  /* _CLIGEN_PARSE_H_ */
diff --git a/cligen_parse.l b/cligen_parse.l
index 36e7fee..a6bf6b1 100644
--- a/cligen_parse.l
+++ b/cligen_parse.l
@@ -77,7 +77,7 @@ stripdup(char *s0)
   char *s;
 
   if ((s1 = strdup(s0)) == NULL){
-    fprintf(stderr, "%s: strdup: %s\n", __FUNCTION__, strerror(errno));
+    fprintf(stderr, "%s: strdup: %s\n", __func__, strerror(errno));
     return NULL;
   }
   while ((s = index(s1, '\\')) != NULL)
@@ -231,8 +231,9 @@ cgl_init(cligen_yacc *cy)
   BEGIN(INITIAL);
   cy->cy_lexbuf = yy_scan_string (cy->cy_parse_string);
 #if 1 /* XXX: just to use unput to avoid warning  */
+  char bogus[] = "";
   if (0)
-    yyunput(0, "");
+    yyunput(0, bogus);
 #endif
 
   return 0;
diff --git a/cligen_parse.y b/cligen_parse.y
index 2137670..2d235f2 100644
--- a/cligen_parse.y
+++ b/cligen_parse.y
@@ -126,7 +126,7 @@ cligen_parse_debug(int d)
  * @param[in]  cy  CLIgen yacc parse struct
  */
 void cligen_parseerror(void *_cy,
-                       char *s)
+                       const char *s)
 {
     cligen_yacc *cy = (cligen_yacc *)_cy;
 
@@ -147,7 +147,7 @@ void cligen_parseerror(void *_cy,
  */
 static cg_var *
 create_cv(cligen_yacc *cy,
-          char        *type,
+          const char  *type,
           char        *str)
 {
     cg_var   *cv = NULL;
@@ -184,16 +184,16 @@ cgy_flag(cligen_yacc *cy,
     int                  retval = -1;
 
     if (debug)
-        fprintf(stderr, "%s: %s 1\n", __FUNCTION__, var);
+        fprintf(stderr, "%s: %s 1\n", __func__, var);
     if (cs){ /* XXX: why cs? */
         if (cy->cy_cvec == NULL){
             if ((cy->cy_cvec = cvec_new(0)) == NULL){
-                fprintf(stderr, "%s: cvec_new:%s\n", __FUNCTION__, strerror(errno));
+                fprintf(stderr, "%s: cvec_new:%s\n", __func__, strerror(errno));
                 goto done;
             }
         }
         if ((cv = cvec_add(cy->cy_cvec, CGV_INT32)) == NULL){
-            fprintf(stderr, "%s: realloc:%s\n", __FUNCTION__, strerror(errno));
+            fprintf(stderr, "%s: realloc:%s\n", __func__, strerror(errno));
             goto done;
         }
         cv_name_set(cv, var);
@@ -260,7 +260,7 @@ cgy_treename(cligen_yacc *cy,
     if (cy->cy_treename)
         free(cy->cy_treename);
     if ((cy->cy_treename = strdup(name)) == NULL){
-        fprintf(stderr, "%s: strdup: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s: strdup: %s\n", __func__, strerror(errno));
         goto done;
     }
     retval = 0;
@@ -281,7 +281,7 @@ cgy_assignment(cligen_yacc *cy,
     struct cgy_stack *cs = cy->cy_stack;
     int              retval = -1;
     cg_var          *cv;
-    char            *treename_keyword;
+    const char      *treename_keyword;
     cligen_handle    h = cy->cy_handle;
 
     if (cs == NULL){
@@ -289,16 +289,16 @@ cgy_assignment(cligen_yacc *cy,
         goto done;
     }
     if (debug)
-        fprintf(stderr, "%s: %s=%s\n", __FUNCTION__, var, val);
+        fprintf(stderr, "%s: %s=%s\n", __func__, var, val);
 
     if (cs->cs_next != NULL){ /* local */
         if (cy->cy_cvec == NULL)
             if ((cy->cy_cvec = cvec_new(0)) == NULL){
-                fprintf(stderr, "%s: cvec_new:%s\n", __FUNCTION__, strerror(errno));
+                fprintf(stderr, "%s: cvec_new:%s\n", __func__, strerror(errno));
                 goto done;
             }
         if ((cv = cvec_add(cy->cy_cvec, CGV_STRING)) == NULL){
-            fprintf(stderr, "%s: realloc:%s\n", __FUNCTION__, strerror(errno));
+            fprintf(stderr, "%s: realloc:%s\n", __func__, strerror(errno));
             goto done;
         }
         cv_name_set(cv, var);
@@ -314,7 +314,7 @@ cgy_assignment(cligen_yacc *cy,
         else {
             if ((cv = cvec_find(cy->cy_globals, var)) == NULL){
                 if ((cv = cvec_add(cy->cy_globals, CGV_STRING)) == NULL){
-                    fprintf(stderr, "%s: realloc:%s\n", __FUNCTION__, strerror(errno));
+                    fprintf(stderr, "%s: realloc:%s\n", __func__, strerror(errno));
                     goto done;
                 }
                 cv_name_set(cv, var);
@@ -339,14 +339,14 @@ cgy_callback(cligen_yacc *cy,
     cg_callback      *cc, **ccp;
 
     if (debug)
-        fprintf(stderr, "%s: %s\n", __FUNCTION__, cb_str);
+        fprintf(stderr, "%s: %s\n", __func__, cb_str);
     if (cs == NULL)
         return 0;
     ccp = &cy->cy_callbacks;
     while (*ccp != NULL)
         ccp = &((*ccp)->cc_next);
     if ((cc = malloc(sizeof(*cc))) == NULL){
-        fprintf(stderr, "%s: malloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s: malloc: %s\n", __func__, strerror(errno));
         cligen_parseerror1(cy, "Allocating cligen callback");
         return -1;
     }
@@ -458,9 +458,9 @@ cgy_list_push(cg_obj           *co,
     struct cgy_list *cl;
 
     if (debug)
-        fprintf(stderr, "%s\n", __FUNCTION__);
+        fprintf(stderr, "%s\n", __func__);
     if ((cl = malloc(sizeof(*cl))) == NULL) {
-        fprintf(stderr, "%s: malloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s: malloc: %s\n", __func__, strerror(errno));
         return -1;
     }
     cl->cl_next = *cl0;
@@ -502,7 +502,7 @@ cgy_var_create(cligen_yacc *cy)
 
     /* Create unassigned variable object */
     if ((co = cov_new(CGV_ERR, NULL)) == NULL){
-        fprintf(stderr, "%s: malloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s: malloc: %s\n", __func__, strerror(errno));
         cligen_parseerror1(cy, "Allocating cligen object");
         return NULL;
     }
@@ -510,7 +510,7 @@ cgy_var_create(cligen_yacc *cy)
         co_flags_set(co, CO_FLAGS_OPTION);
     }
     if (debug)
-        fprintf(stderr, "%s: pre\n", __FUNCTION__);
+        fprintf(stderr, "%s: pre\n", __func__);
     return co;
 }
 
@@ -527,7 +527,7 @@ cgy_var_name_type(cligen_yacc *cy,
     cy->cy_var->co_command = name;
     if ((cy->cy_var->co_vtype = cv_str2type(type)) == CGV_ERR){
         cligen_parseerror1(cy, "Invalid type");
-        fprintf(stderr, "%s: Invalid type: %s\n", __FUNCTION__, type);
+        fprintf(stderr, "%s: Invalid type: %s\n", __func__, type);
         return -1;
     }
     return 0;
@@ -555,7 +555,7 @@ cgy_var_post(cligen_yacc *cy)
         coy->co_vtype = cv_str2type(coy->co_command);
 #endif
     if (debug)
-        fprintf(stderr, "%s: cmd:%s vtype:%d\n", __FUNCTION__,
+        fprintf(stderr, "%s: cmd:%s vtype:%d\n", __func__,
                 coy->co_command,
                 coy->co_vtype );
     if (coy->co_vtype == CGV_ERR){
@@ -611,7 +611,7 @@ cgy_cmd(cligen_yacc *cy,
         cop = cl->cl_obj;
         if (debug)
             fprintf(stderr, "%s: %s parent:%s\n",
-                    __FUNCTION__, cmd, cop->co_command);
+                    __func__, cmd, cop->co_command);
         if ((conew = co_new(cmd, cop)) == NULL) {
             cligen_parseerror1(cy, "Allocating cligen object");
             return -1;
@@ -739,7 +739,7 @@ cgy_var_choice_append(cligen_yacc *cy,
 
     len = strlen(str)+strlen(app) + 2;
     if ((s = realloc(str, len)) == NULL) {
-        fprintf(stderr, "%s: realloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s: realloc: %s\n", __func__, strerror(errno));
         return NULL;
     }
     strncat(s, "|", len-1);
@@ -789,7 +789,7 @@ cgy_terminal(cligen_yacc *cy)
             if (co->co_cvec)
                 cvec_free(co->co_cvec);
             if ((co->co_cvec = cvec_dup(cy->cy_cvec)) == NULL){ /* this leaks */
-                fprintf(stderr, "%s: cvec_dup: %s\n", __FUNCTION__, strerror(errno));
+                fprintf(stderr, "%s: cvec_dup: %s\n", __func__, strerror(errno));
                 goto done;
             }
         }
@@ -843,10 +843,10 @@ ctx_push(cligen_yacc *cy,
     cg_obj           *co;
 
     if (debug)
-        fprintf(stderr, "%s\n", __FUNCTION__);
+        fprintf(stderr, "%s\n", __func__);
     /* Create new stack element */
     if ((cs = malloc(sizeof(*cs))) == NULL) {
-        fprintf(stderr, "%s: malloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s: malloc: %s\n", __func__, strerror(errno));
         return -1;
     }
     memset(cs, 0, sizeof(*cs));
@@ -879,7 +879,7 @@ ctx_peek_swap(cligen_yacc *cy)
     cg_obj           *co;
 
     if (debug)
-        fprintf(stderr, "%s\n", __FUNCTION__);
+        fprintf(stderr, "%s\n", __func__);
     if ((cs = cy->cy_stack) == NULL){
 #if 1
         cligen_parseerror1(cy, "No surrounding () or []");
@@ -918,7 +918,7 @@ ctx_peek_swap2(cligen_yacc *cy)
     cg_obj           *co;
 
     if (debug)
-        fprintf(stderr, "%s\n", __FUNCTION__);
+        fprintf(stderr, "%s\n", __func__);
     if ((cs = cy->cy_stack) == NULL){
 #if 1
         cligen_parseerror1(cy, "No surrounding () or []");
@@ -962,9 +962,9 @@ ctx_pop_add(cligen_yacc *cy)
     cg_obj           *co;
 
     if (debug)
-        fprintf(stderr, "%s\n", __FUNCTION__);
+        fprintf(stderr, "%s\n", __func__);
     if ((cs = cy->cy_stack) == NULL){
-        fprintf(stderr, "%s: cgy_stack empty\n", __FUNCTION__);
+        fprintf(stderr, "%s: cgy_stack empty\n", __func__);
         return -1; /* shouldnt happen */
     }
     cy->cy_stack = cs->cs_next;
@@ -997,9 +997,9 @@ ctx_pop(cligen_yacc *cy)
     cg_obj           *co;
 
     if (debug)
-        fprintf(stderr, "%s\n", __FUNCTION__);
+        fprintf(stderr, "%s\n", __func__);
     if ((cs = cy->cy_stack) == NULL){
-        fprintf(stderr, "%s: cgy_stack empty\n", __FUNCTION__);
+        fprintf(stderr, "%s: cgy_stack empty\n", __func__);
         return -1; /* shouldnt happen */
     }
     cy->cy_stack = cs->cs_next;
@@ -1094,7 +1094,7 @@ cg_range_create(cligen_yacc *cy,
         if ((yv->co_rangecvv_low = cvec_from_var(cv1)) == NULL)
             goto done;
     }
-    else if (cvec_append_var(yv->co_rangecvv_low, cv1) < 0)
+    else if (cvec_append_var(yv->co_rangecvv_low, cv1) == NULL)
         goto done;
     /* Then create upper bound cv */
     if ((cv2 = cv_new(cvtype)) == NULL){
@@ -1122,7 +1122,7 @@ cg_range_create(cligen_yacc *cy,
         if ((yv->co_rangecvv_upp = cvec_from_var(cv2)) == NULL)
             goto done;
     }
-    else if (cvec_append_var(yv->co_rangecvv_upp, cv2) < 0)
+    else if (cvec_append_var(yv->co_rangecvv_upp, cv2) == NULL)
         goto done;
     /* Then increment range vector length */
     yv->co_rangelen++;
@@ -1212,7 +1212,7 @@ cgy_init(cligen_yacc *cy,
          cg_obj      *co_top)
 {
     if (debug)
-        fprintf(stderr, "%s\n", __FUNCTION__);
+        fprintf(stderr, "%s\n", __func__);
     /* Add top-level object */
     if (cgy_list_push(co_top, &cy->cy_list) < 0)
         return -1;
@@ -1230,7 +1230,7 @@ cgy_exit(cligen_yacc *cy)
     struct cgy_stack *cs;
 
     if (debug)
-        fprintf(stderr, "%s\n", __FUNCTION__);
+        fprintf(stderr, "%s\n", __func__);
 
     cy->cy_var = NULL;
     cgy_list_delete(&cy->cy_list);
diff --git a/cligen_parsetree.c b/cligen_parsetree.c
index f614586..7d8abbd 100644
--- a/cligen_parsetree.c
+++ b/cligen_parsetree.c
@@ -363,7 +363,7 @@ pt_copy(parse_tree *pt,
     }
     if (pt_len_get(ptn) &&
         (ptn->pt_vec = (cg_obj **)malloc(pt_len_get(ptn)*sizeof(cg_obj *))) == NULL){
-        fprintf(stderr, "%s: malloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s: malloc: %s\n", __func__, strerror(errno));
         goto done;
     }
     j=0;
diff --git a/cligen_print.c b/cligen_print.c
index 79d1b1e..4487493 100644
--- a/cligen_print.c
+++ b/cligen_print.c
@@ -361,7 +361,7 @@ pt_dump1(FILE       *f,
     int     i;
     cg_obj *co;
 
-    cligen_output(f, "%*s %p pt", indent*3, "", pt);
+    cligen_output(f, "%*s %p pt", indent*3, "", (void*)pt);
     cligen_output(f, " [%d]", pt_len_get(pt));
     cligen_output(f, "\n");
     for (i=0; i<pt_len_get(pt); i++){
@@ -400,24 +400,24 @@ co_dump1(FILE    *f,
 
     switch (co->co_type){
     case CO_COMMAND:
-        cligen_output(f, "%*s %p co %s", indent*3, "", co, co->co_command);
+        cligen_output(f, "%*s %p co %s", indent*3, "", (void*)co, co->co_command);
         if (co_sets_get(co))
             cligen_output(f, " SETS");
         if (co->co_ref)
-            cligen_output(f, " ref:%p", co->co_ref);
+            cligen_output(f, " ref:%p", (void*)co->co_ref);
         break;
     case CO_REFERENCE:
-        cligen_output(f, "%*s %p co @%s", indent*3, "", co, co->co_command);
+        cligen_output(f, "%*s %p co @%s", indent*3, "", (void*)co, co->co_command);
         break;
     case CO_VARIABLE:
-        cligen_output(f, "%*s %p co <%s> ", indent*3, "", co, co->co_command);
+        cligen_output(f, "%*s %p co <%s> ", indent*3, "", (void*)co, co->co_command);
         if (co->co_ref)
-            cligen_output(f, " ref:%p", co->co_ref);
+            cligen_output(f, " ref:%p", (void*)co->co_ref);
         if (co->co_treeref_orig)
-            cligen_output(f, " treeref:%p", co->co_treeref_orig);
+            cligen_output(f, " treeref:%p", (void*)co->co_treeref_orig);
         break;
     case CO_EMPTY:
-        cligen_output(f, "%*s %p empty", indent*3, "", co);
+        cligen_output(f, "%*s %p empty", indent*3, "", (void*)co);
         break;
     }
     if (co->co_flags & CO_FLAGS_TOPOFTREE)
diff --git a/cligen_read.c b/cligen_read.c
index f19a138..1c3888f 100644
--- a/cligen_read.c
+++ b/cligen_read.c
@@ -321,7 +321,7 @@ show_help_columns(cligen_handle h,
     if (mr_pt_len_get(mr) > 0){ /* min, max only defined if matchlen > 0 */
         /* Go through match vector and collect commands and helps */
         if ((chvec = calloc(mr_pt_len_get(mr), sizeof(struct cligen_help))) ==NULL){
-            fprintf(stderr, "%s calloc: %s\n", __FUNCTION__, strerror(errno));
+            fprintf(stderr, "%s calloc: %s\n", __func__, strerror(errno));
             goto done;
         }
         nrcmd = 0;
@@ -348,7 +348,7 @@ show_help_columns(cligen_handle h,
                 continue;
             ch = &chvec[nrcmd];
             if ((ch->ch_cmd = strdup(cmd)) == NULL){
-                fprintf(stderr, "%s strdup: %s\n", __FUNCTION__, strerror(errno));
+                fprintf(stderr, "%s strdup: %s\n", __func__, strerror(errno));
                 goto done;
             }
             if (co->co_helpstring && cligen_txt2cvv(co->co_helpstring, &ch->ch_helpvec) < 0)
@@ -529,12 +529,12 @@ cli_complete(cligen_handle h,
 
     string = cligen_buf(h);
     if (string == NULL){
-        fprintf(stderr, "%s Input string NULL\n", __FUNCTION__);
+        fprintf(stderr, "%s Input string NULL\n", __func__);
         goto done;
     }
     slen = cligen_buf_size(h);
     if ((s = malloc(slen)) == NULL){ /* s is a temporary copy */
-        fprintf(stderr, "%s malloc: %s\n", __FUNCTION__, strerror(errno));
+        fprintf(stderr, "%s malloc: %s\n", __func__, strerror(errno));
         goto done;
     }
     strncpy(s, string, slen);
@@ -661,7 +661,7 @@ cliread_parse(cligen_handle  h,
         goto done;
     }
     if (cligen_logsyntax(h) > 0){
-        fprintf(stderr, "%s:\n", __FUNCTION__);
+        fprintf(stderr, "%s:\n", __func__);
         pt_print1(stderr, pt, 0);
     }
     cli_trim(&string, cligen_comment(h));
@@ -888,7 +888,7 @@ cligen_eval_pipe_pre(cligen_handle h,
         signal_unblock(SIGINT);
 
         if ((retval = (*fn)(cligen_userhandle(h)?cligen_userhandle(h):h, cvv, cc->cc_cvec)) != 0)
-            fprintf(stderr, "%s child retval:%d\n", __FUNCTION__, retval);
+            fprintf(stderr, "%s child retval:%d\n", __func__, retval);
         exit(retval);
     }
     /* parent */
@@ -1048,7 +1048,7 @@ cligen_eval(cligen_handle h,
             cligen_fn_str_set(h, cc->cc_fn_str);
             /* Eval wrapper function so upper layers can make checks before and after callback */
             if (wrapfn)
-                (*wrapfn)(wraparg, &wh, cc->cc_fn_str, __FUNCTION__);
+                (*wrapfn)(wraparg, &wh, cc->cc_fn_str, __func__);
             if ((*fn)(cligen_userhandle(h)?cligen_userhandle(h):h,
                                 cvv1,
                                 argv) < 0){
@@ -1058,7 +1058,7 @@ cligen_eval(cligen_handle h,
                 goto done;
             }
             if (wrapfn && wh != NULL)
-                (*wrapfn)(wraparg, &wh, cc->cc_fn_str, __FUNCTION__);
+                (*wrapfn)(wraparg, &wh, cc->cc_fn_str, __func__);
             if (argv != NULL)
                 cvec_free(argv);
             cligen_fn_str_set(h, NULL);
diff --git a/cligen_syntax.c b/cligen_syntax.c
index 4ced2c9..7b0e441 100644
--- a/cligen_syntax.c
+++ b/cligen_syntax.c
@@ -71,8 +71,8 @@
  */
 int
 clispec_parse_str(cligen_handle h,
-                  char         *str,
-                  char         *name,
+                  const char   *str,
+                  const char   *name,
                   char         *treename,
                   parse_tree   *ptp,
                   cvec         *cvv)
@@ -111,7 +111,7 @@ clispec_parse_str(cligen_handle h,
         cy.cy_globals  = cvv;
     else
         if ((cy.cy_globals = cvec_new(0)) == NULL){
-            fprintf(stderr, "%s: malloc: %s\n", __FUNCTION__, strerror(errno));
+            fprintf(stderr, "%s: malloc: %s\n", __func__, strerror(errno));
             goto done;
         }
     if (strlen(str)){ /* Not empty */
@@ -176,7 +176,7 @@ clispec_parse_str(cligen_handle h,
 int
 clispec_parse_file(cligen_handle h,
                    FILE         *f,
-                   char         *name,
+                   const char   *name,
                    char         *treename,
                    parse_tree   *pt,
                    cvec         *cvv)
@@ -200,7 +200,7 @@ clispec_parse_file(cligen_handle h,
             break;
         if (i == len-1){
             if ((buf = realloc(buf, 2*len)) == NULL){
-                fprintf(stderr, "%s: realloc: %s\n", __FUNCTION__, strerror(errno));
+                fprintf(stderr, "%s: realloc: %s\n", __func__, strerror(errno));
                 goto done;
             }
             memset(buf+len, 0, len);
@@ -263,7 +263,7 @@ cligen_callbackv_str2fn(parse_tree   *pt,
                     co_callback_fn_set(cc, str2fn(cc->cc_fn_str, arg, &callback_err));
                     if (callback_err != NULL){
                         fprintf(stderr, "%s: error: No such function: %s (%s)\n",
-                                __FUNCTION__, cc->cc_fn_str, callback_err);
+                                __func__, cc->cc_fn_str, callback_err);
                         goto done;
                     }
                 }
@@ -317,7 +317,7 @@ cligen_expandv_str2fn(parse_tree       *pt,
                 co->co_expandv_fn = str2fn(co->co_expand_fn_str, arg, &callback_err);
                 if (callback_err != NULL){
                     fprintf(stderr, "%s: error: No such function: %s\n",
-                            __FUNCTION__, co->co_expand_fn_str);
+                            __func__, co->co_expand_fn_str);
                     goto done;
                 }
             }
@@ -356,7 +356,7 @@ cligen_translate_str2fn(parse_tree         *pt,
                 co->co_translate_fn = str2fn(co->co_translate_fn_str, arg, &callback_err);
                 if (callback_err != NULL){
                     fprintf(stderr, "%s: error: No such function: %s\n",
-                            __FUNCTION__, co->co_translate_fn_str);
+                            __func__, co->co_translate_fn_str);
                     goto done;
                 }
             }
diff --git a/cligen_syntax.h b/cligen_syntax.h
index 9f8a261..b14f928 100644
--- a/cligen_syntax.h
+++ b/cligen_syntax.h
@@ -60,15 +60,15 @@ typedef translate_cb_t *(translate_str2fn_t)(char *str, void *arg, char **err);
  */
 int
 clispec_parse_str(cligen_handle  h,
-                  char          *str,
-                  char          *name,
+                  const char    *str,
+                  const char    *name,
                   char          *treename,
                   parse_tree    *pt,
                   cvec          *globals);
 int
 clispec_parse_file(cligen_handle h,
                    FILE         *f,
-                   char         *name,
+                   const char   *name,
                    char         *treename,
                    parse_tree   *obsolete,
                    cvec         *globals);
diff --git a/configure b/configure
index 73cf9c2..230418b 100755
--- a/configure
+++ b/configure
@@ -2490,10 +2490,10 @@ fi
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: debug is $ac_enable_debug" >&5
 printf "%s\n" "debug is $ac_enable_debug" >&6; }
 if test "$ac_enable_debug" = "yes"; then
-   : ${CFLAGS="-g -Wall"}
+   : ${CFLAGS="-g -Wall -Wwrite-strings -Wpedantic"}
    INSTALLFLAGS=""
 else
-   : ${CFLAGS="-O2 -Wall"}
+   : ${CFLAGS="-O2 -Wall -Wwrite-strings -Wpedantic"}
 fi
 
 ac_config_headers="$ac_config_headers cligen_config.h"
diff --git a/configure.ac b/configure.ac
index ce89fc5..27bb6f5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -56,10 +56,10 @@ AC_ARG_ENABLE(debug, AS_HELP_STRING([--enable-debug],[Build with debug symbols,
 
 AC_MSG_RESULT(debug is $ac_enable_debug)        
 if test "$ac_enable_debug" = "yes"; then
-   : ${CFLAGS="-g -Wall"}
+   : ${CFLAGS="-g -Wall -Wwrite-strings -Wpedantic"}
    INSTALLFLAGS=""      
 else
-   : ${CFLAGS="-O2 -Wall"}
+   : ${CFLAGS="-O2 -Wall -Wwrite-strings -Wpedantic"}
 fi
 
 AC_CONFIG_HEADERS([cligen_config.h])