Return error messages as 'const char *', not 'char *'.

They're never dynamically allocated, and are almost always string
literals, so const is more appropriate.

4 files changed, 15 insertions, 14 deletions

diff --git a/unfinished/group.c b/unfinished/group.c
index a9ae704..b812b04 100644
--- a/unfinished/group.c
+++ b/unfinished/group.c
@@ -240,7 +240,7 @@ static game_params *custom_params(const config_item *cfg)
     return ret;
 }
 
-static char *validate_params(const game_params *params, int full)
+static const char *validate_params(const game_params *params, int full)
 {
     if (params->w < 3 || params->w > 26)
         return "Grid size must be between 3 and 26";
@@ -777,7 +777,7 @@ done
  * Gameplay.
  */
 
-static char *validate_grid_desc(const char **pdesc, int range, int area)
+static const char *validate_grid_desc(const char **pdesc, int range, int area)
 {
     const char *desc = *pdesc;
     int squares = 0;
@@ -807,7 +807,7 @@ static char *validate_grid_desc(const char **pdesc, int range, int area)
     return NULL;
 }
 
-static char *validate_desc(const game_params *params, const char *desc)
+static const char *validate_desc(const game_params *params, const char *desc)
 {
     int w = params->w, a = w*w;
     const char *p = desc;
@@ -907,7 +907,7 @@ static void free_game(game_state *state)
 }
 
 static char *solve_game(const game_state *state, const game_state *currstate,
-                        const char *aux, char **error)
+                        const char *aux, const char **error)
 {
     int w = state->par.w, a = w*w;
     int i, ret;
@@ -2106,7 +2106,8 @@ int main(int argc, char **argv)
 {
     game_params *p;
     game_state *s;
-    char *id = NULL, *desc, *err;
+    char *id = NULL, *desc;
+    const char *err;
     digit *grid;
     int grade = FALSE;
     int ret, diff, really_show_working = FALSE;
diff --git a/unfinished/separate.c b/unfinished/separate.c
index a7b4fc9..7fd8da8 100644
--- a/unfinished/separate.c
+++ b/unfinished/separate.c
@@ -170,7 +170,7 @@ static game_params *custom_params(const config_item *cfg)
     return NULL;
 }
 
-static char *validate_params(const game_params *params, int full)
+static const char *validate_params(const game_params *params, int full)
 {
     return NULL;
 }
@@ -646,7 +646,7 @@ static char *new_game_desc(const game_params *params, random_state *rs,
     return desc;
 }
 
-static char *validate_desc(const game_params *params, const char *desc)
+static const char *validate_desc(const game_params *params, const char *desc)
 {
     return NULL;
 }
@@ -676,7 +676,7 @@ static void free_game(game_state *state)
 }
 
 static char *solve_game(const game_state *state, const game_state *currstate,
-                        const char *aux, char **error)
+                        const char *aux, const char **error)
 {
     return NULL;
 }
diff --git a/unfinished/slide.c b/unfinished/slide.c
index 05a3f8b..9770013 100644
--- a/unfinished/slide.c
+++ b/unfinished/slide.c
@@ -273,7 +273,7 @@ static game_params *custom_params(const config_item *cfg)
     return ret;
 }
 
-static char *validate_params(const game_params *params, int full)
+static const char *validate_params(const game_params *params, int full)
 {
     if (params->w > MAXWID)
 	return "Width must be at most " STR(MAXWID);
@@ -886,7 +886,7 @@ static char *new_game_desc(const game_params *params, random_state *rs,
     return ret;
 }
 
-static char *validate_desc(const game_params *params, const char *desc)
+static const char *validate_desc(const game_params *params, const char *desc)
 {
     int w = params->w, h = params->h, wh = w*h;
     int *active, *link;
@@ -1121,7 +1121,7 @@ static void free_game(game_state *state)
 }
 
 static char *solve_game(const game_state *state, const game_state *currstate,
-                        const char *aux, char **error)
+                        const char *aux, const char **error)
 {
     int *moves;
     int nmoves;
diff --git a/unfinished/sokoban.c b/unfinished/sokoban.c
index edd0f28..1264690 100644
--- a/unfinished/sokoban.c
+++ b/unfinished/sokoban.c
@@ -233,7 +233,7 @@ static game_params *custom_params(const config_item *cfg)
     return ret;
 }
 
-static char *validate_params(const game_params *params, int full)
+static const char *validate_params(const game_params *params, int full)
 {
     if (params->w < 4 || params->h < 4)
 	return "Width and height must both be at least 4";
@@ -802,7 +802,7 @@ static char *new_game_desc(const game_params *params, random_state *rs,
     return desc;
 }
 
-static char *validate_desc(const game_params *params, const char *desc)
+static const char *validate_desc(const game_params *params, const char *desc)
 {
     int w = params->w, h = params->h;
     int area = 0;
@@ -899,7 +899,7 @@ static void free_game(game_state *state)
 }
 
 static char *solve_game(const game_state *state, const game_state *currstate,
-                        const char *aux, char **error)
+                        const char *aux, const char **error)
 {
     return NULL;
 }