X-Git-Url: https://git.danieliu.xyz/?a=blobdiff_plain;f=src%2Fcstack.c;h=4763b5b5c9b4e2e48860810499d07bc0061d310a;hb=6d627bac82f84e39beda51981ddf3a6ddabbbe78;hp=a5ecc0695fd770bfc3d246dccf8320d0fdf6499d;hpb=fc7c1dab34261fe195f2f4186c39a5686ca6ab53;p=smdp.git

diff --git a/src/cstack.c b/src/cstack.c
index a5ecc06..4763b5b 100644
--- a/src/cstack.c
+++ b/src/cstack.c
@@ -19,27 +19,36 @@
  *
  */
 
+#include <stdio.h> // fprintf
 #include <stdlib.h> // malloc, realloc
 
 #include "cstack.h"
 
 cstack_t *cstack_init() {
-    cstack_t *stack = malloc(sizeof(cstack_t));
-    stack->content = NULL;
-    stack->alloc = stack->size = 0;
-    stack->head = -1;
-    stack->push = cstack_push;
-    stack->pop = cstack_pop;
-    stack->top = cstack_top;
-    stack->empty = cstack_empty;
-    stack->delete = cstack_delete;
+    cstack_t *stack = NULL;
+    if((stack = malloc(sizeof(cstack_t))) != NULL) {
+        stack->content = NULL;
+        stack->alloc = stack->size = 0;
+        stack->head = -1;
+        stack->push = cstack_push;
+        stack->pop = cstack_pop;
+        stack->top = cstack_top;
+        stack->empty = cstack_empty;
+        stack->delete = cstack_delete;
+    } else {
+        fprintf(stderr, "%s\n", "cstack_init() failed to allocate memory.");
+        exit(EXIT_FAILURE);
+    }
     return stack;
 }
 
 void cstack_push(cstack_t *self, char c) {
     if(self->size + sizeof(c) > self->alloc) {
         self->alloc += (sizeof(char));
-        self->content = realloc(self->content, self->alloc);
+        if((self->content = realloc(self->content, self->alloc)) == NULL) {
+            fprintf(stderr, "%s\n", "cstack_push() failed to reallocate memory.");
+            exit(EXIT_FAILURE);
+        }
     }
     self->content[++self->head] = c;
     self->size += (sizeof(char));
@@ -50,13 +59,11 @@ char cstack_pop(cstack_t *self) {
     return self->content[self->head--];
 }
 
-int cstack_top(cstack_t *self, char c) {
-    if(self->head >= 0 && self->content[self->head] == c)
-        return 1;
-    return 0;
+bool cstack_top(cstack_t *self, char c) {
+    return self->head >= 0 && self->content[self->head] == c;
 }
 
-int cstack_empty(cstack_t *self) {
+bool cstack_empty(cstack_t *self) {
     return self->head == -1;
 }