Replace uses of variable-length arrays with try_malloc()/free().

diff --git a/TODO b/TODO
index 3b6088702927f9015c2dc43dceb4b0aa6f83c4e9..a5a87c34fd62b8bbd2130eb55e35226ee91d0843 100644 (file)
--- a/TODO
+++ b/TODO
@@ -4,8 +4,6 @@ IN GENERAL:
 
 - check for return values of *printf()
 
-- be more strict and humble when allocating memory from the stack
-
 - expand use of hardcoded_strings module(s)
 
 BOTH SERVER/CLIENT:

diff --git a/src/client/control.c b/src/client/control.c
index 43041eaef820b02ad60f938211cb45ffd2d9f853..f97f5bdcffe0b8a8e0a4ef2f70e5792af4dd5d93 100644 (file)
--- a/src/client/control.c
+++ b/src/client/control.c
@@ -2,22 +2,24 @@
 
 #include "control.h"
 #include <stdint.h> /* uint8_t, uint16_t, uint32_t, UINT32_MAX */
+#include <stdlib.h> /* free() */
 #include <stdio.h> /* sprintf() */
 #include <string.h> /* strlen() */
 #include "../common/rexit.h" /* exit_err() */
+#include "../common/try_malloc.h" /* try_malloc() */
 #include "interface_conf.h" /* reload_interface_conf(), save_interface_conf() */
 #include "io.h" /* send() */
 #include "keybindings.h" /* get_command_to_keycode(), get_keycode_to_command(),
                           * mod_selected_keyb(), move_keyb_selection()
                           */
-#include "map.h" /* for map_scroll(), map_center(), toggle_autofocus() */
+#include "map.h" /* map_scroll(), map_center(), toggle_autofocus() */
 #include "wincontrol.h" /* shift_active_win(), resize_active_win(),
                          * toggle_win_size_type(), toggle_window(),
                          * cycle_active_win(), scroll_v_screen(),
                          * toggle_linebreak_type(), toggle_winconfig()
                          */
 #include "windows.h" /* get_win_by_id() */
-#include "world.h" /* for global world */
+#include "world.h" /* world */
 
 
 
@@ -156,6 +158,7 @@ static uint8_t try_client_commands(struct Command * command)
 
 static uint8_t try_server_commands(struct Command * command)
 {
+    char * f_name = "try_server_commands()";
     if (command->server_msg)
     {
         uint8_t arg = (uint8_t) command->arg;
@@ -165,9 +168,10 @@ static uint8_t try_server_commands(struct Command * command)
         }
         uint8_t command_size = strlen(command->server_msg);
         uint8_t arg_size = 3;
-        char msg[command_size + 1 + arg_size + 1];
+        char * msg = try_malloc(command_size + 1 + arg_size + 1, f_name);
         sprintf(msg, "%s %d", command->server_msg, arg);
         send(msg);
+        free(msg);
         return 1;
     }
     return 0;

diff --git a/src/client/draw_wins.c b/src/client/draw_wins.c
index 69278e8393631a351326ae725e682a304a267ab7..b6a9c3e4506f94b69767363198534b7df5fac83f 100644 (file)
--- a/src/client/draw_wins.c
+++ b/src/client/draw_wins.c
@@ -178,12 +178,13 @@ static void add_line_long(struct Win * win, char * line, attr_t attri)
 static void add_line_compact(struct Win * win, char * line, attr_t attri,
                              uint16_t * offset, uint8_t last)
 {
+    char * f_name = "add_line_compact()";
     uint16_t y_start = win->winmap_size.y - (win->winmap_size.y > 0);
     try_resize_winmap(win, y_start + 1, win->frame_size.x);
     uint16_t len_line = strlen(line);
     char * separator = last ? "" : " / ";
     uint32_t len_line_new = len_line + strlen(separator);
-    char line_new[len_line_new];
+    char * line_new = try_malloc(len_line_new, f_name);
     sprintf(line_new, "%s%s", line, separator);
     uint16_t x = 0;
     uint16_t y;
@@ -204,6 +205,7 @@ static void add_line_compact(struct Win * win, char * line, attr_t attri,
             try_resize_winmap(win, y + 1 + 1, win->winmap_size.x);
         }
     }
+    free(line_new);
     *offset = x;
 }
 
@@ -355,13 +357,15 @@ extern void draw_win_map(struct Win * win)
 
 extern void draw_win_info(struct Win * win)
 {
+    char * f_name = "draw_win_info()";
     char * dsc_turn      = "Turn: ";
     char * dsc_hitpoints = "\nHitpoints: ";
     uint16_t maxl = strlen(dsc_turn) + 5 + strlen(dsc_hitpoints) + 3;
-    char text[maxl + 1];
+    char * text = try_malloc(maxl + 1, f_name);
     sprintf(text, "%s%d%s%d",
             dsc_turn, world.turn, dsc_hitpoints, world.player_lifepoints);
     add_text_with_linebreaks(win, text);
+    free(text);
 }
 
 
@@ -455,6 +459,7 @@ extern void draw_winconf_keybindings(struct Win * win)
 
 extern void draw_winconf_geometry(struct Win * win)
 {
+    char * f_name = "draw_winconf_geometry()";
     char * title = "Window's geometry:\n\n";
     char * h_title = "Height to save: ";
     char h_value[6 + 1];                       /* 6: int16_t value max strlen */
@@ -475,8 +480,9 @@ extern void draw_winconf_geometry(struct Win * win)
                          + strlen(h_title) + strlen(h_value) + strlen(h_type)
                          + strlen(w_title) + strlen(w_value) + strlen(w_type)
                          + strlen(breaks_title) + strlen(breaks_type);
-    char text[text_size + 1];
+    char * text = try_malloc(text_size + 1, f_name);
     sprintf(text, "%s%s%s%s%s%s%s%s%s", title, h_title, h_value, h_type,
             w_title, w_value, w_type, breaks_title, breaks_type);
     add_text_with_linebreaks(win, text);
+    free(text);
 }

diff --git a/src/client/wincontrol.c b/src/client/wincontrol.c
index 09cff03caaa756b9e095a5ce10b45dc829636da0..e1a4fbd485a9dd0df65326f6d6d03b2966ee0934 100644 (file)
--- a/src/client/wincontrol.c
+++ b/src/client/wincontrol.c
@@ -328,10 +328,11 @@ extern void resize_active_win(char change)
 
 extern void shift_active_win(char dir)
 {
+    char * f_name = "shift_active_win()";
     uint8_t len_order = strlen(world.winDB.order);
     if (1 < len_order)
     {
-        char tmp[len_order + 1];
+        char * tmp = try_malloc(len_order + 1, f_name);
         tmp[len_order] = '\0';
         uint8_t pos = get_win_pos_in_order(world.winDB.active);
         if ('f' == dir)
@@ -362,6 +363,7 @@ extern void shift_active_win(char dir)
                 world.winDB.order[pos - 1] = world.winDB.active;
             }
         }
+        free(tmp);
         update_wins(get_win_by_id(world.winDB.order[0]));
     }
 }

diff --git a/src/client/windows.c b/src/client/windows.c
index faf1f8a642484a37235ae5b29eb3fe9698e75686..7327fc246f5ff8d939a425fee458bd120c60aee9 100644 (file)
--- a/src/client/windows.c
+++ b/src/client/windows.c
@@ -13,6 +13,7 @@
 #include <stdlib.h> /* free() */
 #include <string.h> /* memcpy(), strlen(), strnlen(), memset() */
 #include "../common/rexit.h" /* exit_trouble(), exit_err() */
+#include "../common/try_malloc.h" /* try_malloc() */
 #include "draw_wins.h" /* draw_winconf_geometry(), draw_winconf_keybindings(),
                         * draw_win_inventory(), draw_win_info(), draw_win_log(),
                         * draw_win_available_keybindings(), draw_win_map(),
@@ -153,7 +154,8 @@ static void scroll_hint(struct yx_uint16 fsize, char dir, uint16_t dist,
     {
         dsc_space = fsize.y;
     }                                  /* vv-- 10 = max strlen for uint16_t */
-    char scrolldsc[1 + strlen(more) + 1 + 10 + 1 + strlen(unit) + 1 + 1];
+    uint16_t size = 1 + strlen(more) + 1 + 10 + 1 + strlen(unit) + 1 + 1;
+    char * scrolldsc = try_malloc(size, "scroll_hint()");
     sprintf(scrolldsc, " %d %s %s ", dist, more, unit);
 
     /* Decide on offset of the description text inside the scroll hint line. */
@@ -188,6 +190,7 @@ static void scroll_hint(struct yx_uint16 fsize, char dir, uint16_t dist,
         }
         mvwaddch(world.winDB.v_screen, start.y + draw_offset, start.x + q, c);
     }
+    free(scrolldsc);
 }
 
 
@@ -207,6 +210,8 @@ static void winscroll_hint(struct Win * w, char dir, uint16_t dist)
 
 static void draw_win_borderlines(struct Win * w)
 {
+    char * f_name = "draw_win_borderlines()";
+
     /* Draw vertical and horizontal border lines. */
     uint16_t y, x;
     for (y = w->start.y; y <= w->start.y + w->frame_size.y; y++)
@@ -230,7 +235,7 @@ static void draw_win_borderlines(struct Win * w)
             offset = (w->frame_size.x - (strlen(w->title) + 2)) / 2;
         }                                    /* +2 is for padding/decoration */
         uint16_t length_visible = strnlen(w->title, w->frame_size.x - 2);
-        char title[length_visible + 3];
+        char * title = try_malloc(length_visible + 3, f_name);
         char decoration = ' ';
         if (w->id == world.winDB.active)
         {
@@ -240,6 +245,7 @@ static void draw_win_borderlines(struct Win * w)
         title[0] = title[length_visible + 1] = decoration;
         title[length_visible + 2] = '\0';
         mvwaddstr(world.winDB.v_screen, w->start.y-1, w->start.x+offset, title);
+        free(title);
     }
 }
 
@@ -431,9 +437,10 @@ extern void winch_called()
 
 extern void reset_windows_on_winch()
 {
+    char * f_name = "reset_windows_on_winch()";
     endwin();  /* "[S]tandard way" to recalibrate ncurses post SIGWINCH, says */
     refresh(); /* <http://invisible-island.net/ncurses/ncurses-intro.html>.   */
-    char tmp_order[strlen(world.winDB.order) + 1];
+    char * tmp_order = try_malloc(strlen(world.winDB.order) + 1, f_name);
     sprintf(tmp_order, "%s", world.winDB.order);
     uint8_t i;
     char tmp_active = world.winDB.active;
@@ -441,6 +448,7 @@ extern void reset_windows_on_winch()
     delwin(world.winDB.v_screen);
     make_v_screen_and_init_win_sizes();
     for (i = 0; i < strlen(tmp_order); toggle_window(tmp_order[i]), i++);
+    free(tmp_order);
     world.winDB.active = tmp_active;
 }
 

diff --git a/src/common/readwrite.c b/src/common/readwrite.c
index 045bc4fbbc89f80ff2044bc971e98251488d1681..abc8ca82b36ab8928c60804412934664a272c1c7 100644 (file)
--- a/src/common/readwrite.c
+++ b/src/common/readwrite.c
@@ -6,24 +6,28 @@
 #include <stdio.h> /* FILE, fseek(), sprintf(), fgets(), fgetc(), ferror(),
                     * fputc(), fwrite(), fclose(), fopen(), clearerr()
                     */
+#include <stdlib.h> /* free() */
 #include <string.h> /* strlen() */
-#include <unistd.h> /* for access(), unlink() */
+#include <unistd.h> /* access(), unlink() */
 #include "rexit.h" /* exit_err(), exit_trouble() */
+#include "try_malloc.h" /* try_malloc() */
 
 
 
 extern FILE * try_fopen(char * path, char * mode, char * f)
 {
+    char * f_name = "try_fopen()";
     char * msg1 = "Trouble in ";
     char * msg2 = " with fopen() (mode '";
     char * msg3 = "') on path '";
     char * msg4 = "'.";
     uint16_t size = strlen(msg1) + strlen(msg2) + strlen(msg3) + strlen(msg4)
                     + strlen(f) + strlen(path) + strlen(mode) + 1;
-    char msg[size];
+    char * msg = try_malloc(size, f_name);
     sprintf(msg, "%s%s%s%s%s%s%s", msg1, f, msg2, mode, msg3, path, msg4);
     FILE * file_p = fopen(path, mode);
     exit_err(NULL == file_p, msg);
+    free(msg);
     return file_p;
 }
 
@@ -73,6 +77,7 @@ extern char * try_fgets(char * line, int linemax, FILE * file, char * f)
 extern void try_fclose_unlink_rename(FILE * file, char * p1, char * p2,
                                      char * f)
 {
+    char * f_name = "try_fclose_unlink_rename()";
     try_fclose(file, f);
     char * msg1 = "Trouble in ";
     char * msg4 = "'.";
@@ -81,17 +86,19 @@ extern void try_fclose_unlink_rename(FILE * file, char * p1, char * p2,
         char * msg2 = " with unlink() on path '";
         uint16_t size = strlen(msg1) + strlen(msg2) + strlen(msg4)
                         + strlen(f) + strlen(p2) + 1;
-        char msg[size];
+        char * msg = try_malloc(size, f_name);
         sprintf(msg, "%s%s%s%s%s", msg1, f, msg2, p2, msg4);
         exit_err(unlink(p2), msg);
+        free(msg);
     }
     char * msg2 = " with rename() from '";
     char * msg3 = "' to '";
     uint16_t size = strlen(msg1) + strlen(f) + strlen(msg2) + strlen(p1)
                     + strlen(msg3) + strlen(p2) + strlen(msg4) + 1;
-    char msg[size];
+    char * msg = try_malloc(size, f_name);
     sprintf(msg, "%s%s%s%s%s%s%s", msg1, f, msg2, p1, msg3, p2, msg4);
     exit_err(rename(p1, p2), msg);
+    free(msg);
 }
 
 

diff --git a/src/common/rexit.c b/src/common/rexit.c
index facf63fffc71a53a9ffd9c0581383f9954bde4f1..d8598cd04888b519694b51250d3b349539387fa7 100644 (file)
--- a/src/common/rexit.c
+++ b/src/common/rexit.c
@@ -4,8 +4,9 @@
 #include <errno.h> /* global errno */
 #include <stdint.h> /* uint16_t */
 #include <stdio.h> /* printf(), perror(), sprintf() */
-#include <stdlib.h> /* exit(), EXIT_FAILURE */
+#include <stdlib.h> /* exit(), free(), EXIT_FAILURE */
 #include <string.h> /* strlen() */
+#include "try_malloc.h" /* try_malloc() */
 
 
 
@@ -43,12 +44,14 @@ extern void exit_err(int err, char * msg)
 
 extern void exit_trouble(int err, char * parent, char * child)
 {
+    char * f_name = "exit_trouble()";
     char * p1 = "Trouble in ";
     char * p2 = " with ";
     char * p3 = ".";
     uint16_t size = strlen(p1) + strlen(parent) + strlen(p2) + strlen(child)
                     + strlen(p3) + 1;
-    char msg[size];
+    char * msg = try_malloc(size, f_name);
     sprintf(msg, "%s%s%s%s%s", p1, parent, p2, child, p3);
     exit_err(err, msg);
+    free(msg);
 }

diff --git a/src/common/try_malloc.c b/src/common/try_malloc.c
index 2a219274bb84060fc8704781b790058e147f2c6b..70392be27618c8c3a0dba5c4cc40dd4118702721 100644 (file)
--- a/src/common/try_malloc.c
+++ b/src/common/try_malloc.c
@@ -2,14 +2,23 @@
 
 #include "try_malloc.h"
 #include <stdlib.h> /* for malloc */
+#include <stdio.h> /* sprintf() */
+#include <string.h> /* strlen() */
 #include <sys/types.h> /* for size_t */
-#include "rexit.h" /* for exit_trouble() */
+#include "rexit.h" /* for exit_err() */
 
 
 
 extern void * try_malloc(size_t size, char * f)
 {
+    char * prefix = "Trouble with malloc() in ";
+    char * msg = malloc(strlen(prefix) + strlen(f) + 1 + 1);
+    exit_err(NULL == msg,
+             "Trouble in try_malloc() with malloc() for error message string.");
+    int test = sprintf(msg, "%s%s.", prefix, f);
+    exit_err(test < 0, "Trouble in try_malloc() with sprintf().");
     void * p = malloc(size);
-    exit_trouble(NULL == p, f, "malloc()");
+    exit_err(NULL == p, msg); /* Bypass exit_trouble() calling try_malloc(). */
+    free(msg);
     return p;
 }

diff --git a/src/server/init.c b/src/server/init.c
index 624d800f6db17a0492922fc1aba7fe867fb66f57..a91bd2aaac3c5a4d7898d1f2f4b8d25699e255db 100644 (file)
--- a/src/server/init.c
+++ b/src/server/init.c
@@ -43,7 +43,7 @@ static void replay_game()
     exit_err(access(s[PATH_RECORD], F_OK), "No record found to replay.");
     FILE * file = try_fopen(s[PATH_RECORD], "r", f_name);
     uint32_t linemax = textfile_width(file);
-    char line[linemax + 1];
+    char * line = try_malloc(linemax + 1, f_name);
     while (   world.turn < world.replay
            && NULL != try_fgets(line, linemax + 1, file, f_name))
     {
@@ -61,6 +61,7 @@ static void replay_game()
             }
         }
     }
+    free(line);
     try_fclose(file, f_name);
 }
 
@@ -170,7 +171,7 @@ extern void run_game()
     {
         FILE * file = try_fopen(path_savefile, "r", f_name);
         uint32_t linemax = textfile_width(file);
-        char line[linemax + 1];
+        char * line = try_malloc(linemax + 1, f_name);
         while (NULL != try_fgets(line, linemax + 1, file, f_name))
         {
             if (strlen(line) && strcmp("\n", line))
@@ -178,14 +179,16 @@ extern void run_game()
                 obey_msg(line, 0);
             }
         }
+        free(line);
         try_fclose(file, f_name);
     }
     else
     {
         char * command = s[CMD_MAKE_WORLD];
-        char msg[strlen(command) + 1 + 11 + 1];
+        char * msg = try_malloc(strlen(command) + 1 + 11 + 1, f_name);
         sprintf(msg, "%s %d", command, (int) time(NULL));
         obey_msg(msg, 1);
+        free(msg);
     }
     io_loop();
 }

diff --git a/src/server/io.c b/src/server/io.c
index 4d1b609c07457da46b3b0f94f9a65a0202d2b867..bc9d8773feab3b68cb9c4705aa20a80afb9bbac9 100644 (file)
--- a/src/server/io.c
+++ b/src/server/io.c
@@ -180,7 +180,8 @@ static void read_file_into_queue()
 static void update_worldstate_file()
 {
     char * f_name = "update_worldstate_file()";
-    char path_tmp[strlen(s[PATH_WORLDSTATE]) + strlen(s[PATH_SUFFIX_TMP]) + 1];
+    uint16_t size = strlen(s[PATH_WORLDSTATE]) + strlen(s[PATH_SUFFIX_TMP]) + 1;
+    char * path_tmp = try_malloc(size, f_name);
     sprintf(path_tmp, "%s%s", s[PATH_WORLDSTATE], s[PATH_SUFFIX_TMP]);
     FILE * file = try_fopen(path_tmp, "w", f_name);
     struct Thing * player = get_player();
@@ -196,6 +197,7 @@ static void update_worldstate_file()
         try_fwrite(world.log, strlen(world.log), 1, file, f_name);
     }
     try_fclose_unlink_rename(file, path_tmp, s[PATH_WORLDSTATE], f_name);
+    free(path_tmp);
     set_cleanup_flag(CLEANUP_WORLDSTATE);
     char * dot = ".\n";;
     try_fwrite(dot, strlen(dot), 1, world.file_out, f_name);

diff --git a/src/server/run.c b/src/server/run.c
index 78b158bd10d5dbc3cd0079ae218e8af0c97f475a..9ab9f30b08f0c9dd71eb245b7a600f7f61f51fc1 100644 (file)
--- a/src/server/run.c
+++ b/src/server/run.c
@@ -16,6 +16,7 @@
                                   * textfile_width(), try_fputc()
                                   */
 #include "../common/rexit.h" /* exit_trouble(), exit_err() */
+#include "../common/try_malloc.h" /* try_malloc() */
 #include "ai.h" /* ai() */
 #include "cleanup.h" /* set_cleanup_flag(), unset_cleanup_flag() */
 #include "field_of_view.h" /* build_fov_map() */
@@ -198,7 +199,6 @@ static uint8_t parse_thing_manipulation(char * tok0, char * tok1)
               || parse_thing_command(tok0, tok1, t)
               || parse_val(tok0, tok1, s[CMD_ARGUMENT], '8', (char *)&t->arg)
               || parse_val(tok0, tok1, s[CMD_PROGRESS],'8',(char *)&t->progress)
-
               || parse_val(tok0, tok1, s[CMD_LIFEPOINTS],'8',
                                                         (char *) &t->lifepoints)
               || parse_position(tok0, tok1, t)
@@ -309,23 +309,26 @@ static void turn_over()
 static void record_msg(char * msg)
 {
     char * f_name = "record_msg()";
-    char path_tmp[strlen(s[PATH_RECORD]) + strlen(s[PATH_SUFFIX_TMP]) + 1];
+    uint16_t size = strlen(s[PATH_RECORD]) + strlen(s[PATH_SUFFIX_TMP]) + 1;
+    char * path_tmp = try_malloc(size, f_name);
     sprintf(path_tmp, "%s%s", s[PATH_RECORD], s[PATH_SUFFIX_TMP]);
     FILE * file_tmp  = try_fopen(path_tmp, "w", f_name);
     if (!access(s[PATH_RECORD], F_OK))
     {
         FILE * file_read = try_fopen(s[PATH_RECORD], "r", f_name);
         uint32_t linemax = textfile_width(file_read);
-        char line[linemax + 1];
+        char * line = try_malloc(linemax + 1, f_name);
         while (try_fgets(line, linemax + 1, file_read, f_name))
         {
             try_fwrite(line, strlen(line), 1, file_tmp, f_name);
         }
+        free(line);
         try_fclose(file_read, f_name);
     }
     try_fwrite(msg, strlen(msg), 1, file_tmp, f_name);
     try_fputc('\n', file_tmp, f_name);
     try_fclose_unlink_rename(file_tmp, path_tmp, s[PATH_RECORD], f_name);
+    free(path_tmp);
 }
 
 

diff --git a/src/server/thing_actions.c b/src/server/thing_actions.c
index 2531ae9532152a8e13a27d283088dfee19181ccf..bb8f585ef0d1cf60649da7c8476486ab0f276d1b 100644 (file)
--- a/src/server/thing_actions.c
+++ b/src/server/thing_actions.c
@@ -113,6 +113,7 @@ static void update_log(char * text)
 
 static void actor_hits_actor(struct Thing * hitter, struct Thing * hitted)
 {
+    char * f_name = "actor_hits_actor()";
     struct ThingType * tt_hitter = get_thing_type(hitter->type);
     struct ThingType * tt_hitted = get_thing_type(hitted->type);
     struct Thing * player = get_player();
@@ -129,9 +130,10 @@ static void actor_hits_actor(struct Thing * hitter, struct Thing * hitted)
         msg3 = tt_hitted->name;
     }
     uint8_t len = 1 + strlen(msg1) + 1 + strlen(msg2) + 1 + strlen(msg3) + 2;
-    char msg[len];
+    char * msg = try_malloc(len, f_name);
     sprintf(msg, "\n%s %s %s.", msg1, msg2, msg3);
     update_log(msg);
+    free(msg);
     hitted->lifepoints--;
     if (0 == hitted->lifepoints)
     {
@@ -168,6 +170,7 @@ static uint8_t match_dir(char d, char ** dsc_d, char match, char * dsc_match)
 
 static void playerbonus_move(char d, uint8_t passable)
 {
+    char * f_name = "playerbonus_move()";
     char * dsc_dir = "north-east";
     if (   match_dir(d, &dsc_dir, 'd', "east")
         || match_dir(d, &dsc_dir, 'c', "south-east")
@@ -182,9 +185,10 @@ static void playerbonus_move(char d, uint8_t passable)
     {
         dsc_move = "You fail to move ";
     }
-    char msg[strlen(dsc_move) + strlen (dsc_dir) + 3];
+    char * msg = try_malloc(strlen(dsc_move) + strlen (dsc_dir) + 3, f_name);
     sprintf(msg, "\n%s%s.", dsc_move, dsc_dir);
     update_log(msg);
+    free(msg);
 }
 
 

diff --git a/src/server/things.c b/src/server/things.c
index e0aa674851fcb2527fe74e70df448c9eca52167c..81d59318cf8e36b19a7cebe0d8ebc68571cc5493 100644 (file)
--- a/src/server/things.c
+++ b/src/server/things.c
@@ -186,12 +186,15 @@ extern struct Thing * get_player()
 
 extern struct ThingType * get_thing_type(uint8_t id)
 {
+    char * f_name = "get_thing_type()";
     struct ThingType * tt = world.thing_types;
     for (; NULL != tt && id != tt->id; tt = tt->next);
     char * err_intro = "Requested thing type of unused ID ";
-    char err[strlen(err_intro) + 3 + 1 + 1];
+    uint16_t size = strlen(err_intro) + 3 + 1 + 1;
+    char * err = try_malloc(size, f_name);
     sprintf(err, "%s%d.", err_intro, id);
     exit_err(NULL == tt, err);
+    free(err);
     return tt;
 }