Introduce GA_APPEND()

This macro is used to append an element to a growable array. It replaces this
common idiom:

   ga_grow(&ga, 1);
   ((item_type *)ga.ga_data)[ga.ga_len] = item;
   ++ga.ga_len;

src/nvim/eval.c

@@ -14420,8 +14420,7 @@ error:
     }
   }
 
-  /* add a terminating NUL */
+  // add a terminating NUL
-  ga_grow(&ga, 1);
   ga_append(&ga, NUL);
 
   rettv->vval.v_string = ga.ga_data;
@@ -17640,8 +17639,7 @@ script_autoload (
   else {
     /* Remember the name if it wasn't loaded already. */
     if (i == ga_loaded.ga_len) {
-      ga_grow(&ga_loaded, 1);
+      GA_APPEND(char_u *, &ga_loaded, scriptname);
-      ((char_u **)ga_loaded.ga_data)[ga_loaded.ga_len++] = scriptname;
       tofree = NULL;
     }
 

src/nvim/ex_cmds.c

@@ -5446,11 +5446,9 @@ helptags_one (
   ga_init(&ga, (int)sizeof(char_u *), 100);
   if (add_help_tags || path_full_compare((char_u *)"$VIMRUNTIME/doc",
           dir, FALSE) == kEqualFiles) {
-    ga_grow(&ga, 1);
     s = xmalloc(18 + STRLEN(tagfname));
     sprintf((char *)s, "help-tags\t%s\t1\n", tagfname);
-    ((char_u **)ga.ga_data)[ga.ga_len] = s;
+    GA_APPEND(char_u *, &ga, s);
-    ++ga.ga_len;
   }
 
   /*
@@ -5517,10 +5515,8 @@ helptags_one (
                   || s[1] == '\0')) {
             *p2 = '\0';
             ++p1;
-            ga_grow(&ga, 1);
             s = xmalloc((p2 - p1) + STRLEN(fname) + 2);
-            ((char_u **)ga.ga_data)[ga.ga_len] = s;
+            GA_APPEND(char_u *, &ga, s);
-            ++ga.ga_len;
             sprintf((char *)s, "%s\t%s", p1, fname);
 
             /* find next '*' */

src/nvim/ex_cmds2.c

@@ -1525,8 +1525,7 @@ void get_arglist(garray_T *gap, char_u *str)
 {
   ga_init(gap, (int)sizeof(char_u *), 20);
   while (*str != NUL) {
-    ga_grow(gap, 1);
+    GA_APPEND(char_u *, gap, str);
-    ((char_u **)gap->ga_data)[gap->ga_len++] = str;
 
     /* Isolate one argument, change it in-place, put a NUL after it. */
     str = do_one_arg(str);
@@ -3332,13 +3331,12 @@ static char_u **find_locales(void)
   loc = (char_u *)strtok((char *)locale_a, "\n");
 
   while (loc != NULL) {
-    ga_grow(&locales_ga, 1);
     loc = vim_strsave(loc);
-
+    GA_APPEND(char_u *, &locales_ga, loc);
-    ((char_u **)locales_ga.ga_data)[locales_ga.ga_len++] = loc;
     loc = (char_u *)strtok(NULL, "\n");
   }
   free(locale_a);
+  // Guarantee that .ga_data is NULL terminated
   ga_grow(&locales_ga, 1);
   ((char_u **)locales_ga.ga_data)[locales_ga.ga_len] = NULL;
   return (char_u **)locales_ga.ga_data;

src/nvim/ex_getln.c

@@ -4000,10 +4000,7 @@ static int ExpandUserDefined(expand_T *xp, regmatch_T *regmatch, int *num_file,
       continue;
     }
 
-    ga_grow(&ga, 1);
+    GA_APPEND(char_u *, &ga, vim_strnsave(s, (int)(e - s)));
-
-    ((char_u **)ga.ga_data)[ga.ga_len] = vim_strnsave(s, (int)(e - s));
-    ++ga.ga_len;
 
     *e = keep;
     if (*e != NUL)
@@ -4034,11 +4031,7 @@ static int ExpandUserList(expand_T *xp, int *num_file, char_u ***file)
     if (li->li_tv.v_type != VAR_STRING || li->li_tv.vval.v_string == NULL)
       continue;        /* Skip non-string items and empty strings */
 
-    ga_grow(&ga, 1);
+    GA_APPEND(char_u *, &ga, vim_strsave(li->li_tv.vval.v_string));
-
-    ((char_u **)ga.ga_data)[ga.ga_len] =
-      vim_strsave(li->li_tv.vval.v_string);
-    ++ga.ga_len;
   }
   list_unref(retlist);
 

src/nvim/garray.c

@@ -197,10 +197,7 @@ void ga_concat(garray_T *gap, const char_u *restrict s)
 /// @param c
 void ga_append(garray_T *gap, char c)
 {
-  ga_grow(gap, 1);
+  GA_APPEND(char, gap, c);
-  char *str = gap->ga_data;
-  str[gap->ga_len] = c;
-  gap->ga_len++;
 }
 
 #if defined(UNIX) || defined(WIN3264) || defined(PROTO)

src/nvim/garray.h

@@ -16,6 +16,12 @@ typedef struct growarray {
 
 #define GA_EMPTY(ga_ptr) ((ga_ptr)->ga_len <= 0)
 
+#define GA_APPEND(item_type, gap, item)                                    \
+  do {                                                                     \
+    ga_grow(gap, 1);                                                       \
+    ((item_type *)(gap)->ga_data)[(gap)->ga_len++] = (item);               \
+  } while (0)
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "garray.h.generated.h"
 #endif

src/nvim/os/users.c

@@ -21,16 +21,13 @@ int os_get_usernames(garray_T *users)
   ga_init(users, sizeof(char *), 20);
 
 # if defined(HAVE_GETPWENT) && defined(HAVE_PWD_H)
-  char *user;
   struct passwd *pw;
 
   setpwent();
   while ((pw = getpwent()) != NULL) {
     // pw->pw_name shouldn't be NULL but just in case...
     if (pw->pw_name != NULL) {
-      ga_grow(users, 1);
+      GA_APPEND(char *, users, xstrdup(pw->pw_name));
-      user = xstrdup(pw->pw_name);
-      ((char **)(users->ga_data))[users->ga_len++] = user;
     }
   }
   endpwent();

src/nvim/path.c

@@ -625,7 +625,6 @@ static void expand_path_option(char_u *curdir, garray_T *gap)
   char_u      *path_option = *curbuf->b_p_path == NUL
                              ? p_path : curbuf->b_p_path;
   char_u      *buf;
-  char_u      *p;
   int len;
 
   buf = xmalloc(MAXPATHL);
@@ -639,7 +638,7 @@ static void expand_path_option(char_u *curdir, garray_T *gap)
        * "/path/file"  + "./subdir" -> "/path/subdir" */
       if (curbuf->b_ffname == NULL)
         continue;
-      p = path_tail(curbuf->b_ffname);
+      char_u *p = path_tail(curbuf->b_ffname);
       len = (int)(p - curbuf->b_ffname);
       if (len + (int)STRLEN(buf) >= MAXPATHL)
         continue;
@@ -666,10 +665,7 @@ static void expand_path_option(char_u *curdir, garray_T *gap)
       simplify_filename(buf);
     }
 
-    ga_grow(gap, 1);
+    GA_APPEND(char_u *, gap, vim_strsave(buf));
-
-    p = vim_strsave(buf);
-    ((char_u **)gap->ga_data)[gap->ga_len++] = p;
   }
 
   free(buf);
@@ -1194,7 +1190,6 @@ addfile (
     int flags
 )
 {
-  char_u      *p;
   bool isdir;
 
   /* if the file/dir doesn't exist, may not add it */
@@ -1215,10 +1210,7 @@ addfile (
   if (!isdir && (flags & EW_EXEC) && !os_can_exe(f))
     return;
 
-  /* Make room for another item in the file list. */
+  char_u *p = xmalloc(STRLEN(f) + 1 + isdir);
-  ga_grow(gap, 1);
-
-  p = xmalloc(STRLEN(f) + 1 + isdir);
 
   STRCPY(p, f);
 #ifdef BACKSLASH_IN_FILENAME
@@ -1231,7 +1223,7 @@ addfile (
   if (isdir && (flags & EW_ADDSLASH))
     add_pathsep(p);
 #endif
-  ((char_u **)gap->ga_data)[gap->ga_len++] = p;
+  GA_APPEND(char_u *, gap, p);
 }
 #endif /* !NO_EXPANDPATH */
 

src/nvim/spell.c

@@ -9138,8 +9138,7 @@ someerror:
           if (c < 0) {
             goto someerror;
           }
-          ga_grow(&ga, 1);
+          GA_APPEND(char_u, &ga, c);
-          ((char_u *)ga.ga_data)[ga.ga_len++] = c;
           if (c == NUL)
             break;
         }

src/nvim/syntax.c

@@ -1963,9 +1963,7 @@ syn_current_attr (
             /* Add the index to a list, so that we can check
              * later that we don't match it again (and cause an
              * endless loop). */
-            ga_grow(&zero_width_next_ga, 1);
+            GA_APPEND(int, &zero_width_next_ga, next_match_idx);
-            ((int *)(zero_width_next_ga.ga_data))
-            [zero_width_next_ga.ga_len++] = next_match_idx;
             next_match_idx = -1;
           } else
             cur_si = push_next_match(cur_si);

src/nvim/tag.c

@@ -1995,8 +1995,7 @@ static garray_T tag_fnames = GA_EMPTY_INIT_VALUE;
  */
 static void found_tagfile_cb(char_u *fname, void *cookie)
 {
-  ga_grow(&tag_fnames, 1);
+  GA_APPEND(char_u *, &tag_fnames, vim_strsave(fname));
-  ((char_u **)(tag_fnames.ga_data))[tag_fnames.ga_len++] = vim_strsave(fname);
 }
 
 #if defined(EXITFREE) || defined(PROTO)

src/nvim/undo.c

@@ -2249,7 +2249,6 @@ void ex_undolist(exarg_T *eap)
   while (uhp != NULL) {
     if (uhp->uh_prev.ptr == NULL && uhp->uh_walk != nomark
         && uhp->uh_walk != mark) {
-      ga_grow(&ga, 1);
       vim_snprintf((char *)IObuff, IOSIZE, "%6ld %7ld  ",
           uhp->uh_seq, changes);
       u_add_time(IObuff + STRLEN(IObuff), IOSIZE - STRLEN(IObuff),
@@ -2260,7 +2259,7 @@ void ex_undolist(exarg_T *eap)
         vim_snprintf_add((char *)IObuff, IOSIZE,
             "  %3ld", uhp->uh_save_nr);
       }
-      ((char_u **)(ga.ga_data))[ga.ga_len++] = vim_strsave(IObuff);
+      GA_APPEND(char_u *, &ga, vim_strsave(IObuff));
     }
 
     uhp->uh_walk = mark;