From 8dee74c3d0d69c60fbb5bef6274c1760ed78ce56 Mon Sep 17 00:00:00 2001
From: dm1sh <me@dmitriy.icu>
Date: Fri, 16 Apr 2021 21:09:48 +0500
Subject: [PATCH] Improved error handling

---
 run.c   | 74 +++++++++++++++++++++++++++++++++++++++++----------------
 stack.c | 41 +++++++++++++++++++++++++-------
 stack.h |  8 +++----
 3 files changed, 89 insertions(+), 34 deletions(-)

diff --git a/run.c b/run.c
index de3a9e6..8aab562 100644
--- a/run.c
+++ b/run.c
@@ -17,56 +17,88 @@ int run(command_t **buff, stack_t *stack)
 
 int exec(command_t cmd, stack_t *stack)
 {
+  int *res;
+
   switch (cmd.code)
   {
+  case NONE:
+    break;
   case PUSH:
-    stack_push(stack, cmd.args[0]);
-    break;
+  {
+    stack_push(stack, cmd.args[0], res);
+
+    if (res != NULL)
+      return *res;
+  }
+  break;
   case POP:
-    stack_pop(stack);
-    break;
+  {
+    stack_pop(stack, res);
+
+    if (res != NULL)
+      return *res;
+  }
+  break;
   case ADD:
   {
-    int b = stack_pop(stack);
-    int a = stack_pop(stack);
+    int b = stack_pop(stack, res);
+    int a = stack_pop(stack, res);
+    if (res != NULL)
+      return *res;
 
-    stack_push(stack, a + b);
+    stack_push(stack, a + b, res);
+    if (res != NULL)
+      return *res;
   }
   break;
   case SUB:
   {
-    int b = stack_pop(stack);
-    int a = stack_pop(stack);
+    int b = stack_pop(stack, res);
+    int a = stack_pop(stack, res);
+    if (res != NULL)
+      return *res;
 
-    stack_push(stack, a - b);
+    stack_push(stack, a - b, res);
+    if (res != NULL)
+      return *res;
   }
   break;
   case MUL:
   {
-    int b = stack_pop(stack);
-    int a = stack_pop(stack);
+    int b = stack_pop(stack, res);
+    int a = stack_pop(stack, res);
+    if (res != NULL)
+      return *res;
 
-    stack_push(stack, a * b);
+    stack_push(stack, a * b, res);
+    if (res != NULL)
+      return *res;
   }
   break;
   case DIV:
   {
-    int b = stack_pop(stack);
-    int a = stack_pop(stack);
+    int b = stack_pop(stack, res);
+    int a = stack_pop(stack, res);
+    if (res != NULL)
+      return *res;
 
-    stack_push(stack, a / b);
+    stack_push(stack, a / b, res);
+    if (res != NULL)
+      return *res;
   }
   break;
   case MOD:
   {
-    int b = stack_pop(stack);
-    int a = stack_pop(stack);
+    int b = stack_pop(stack, res);
+    int a = stack_pop(stack, res);
+    if (res != NULL)
+      return *res;
 
-    stack_push(stack, a % b);
+    stack_push(stack, a % b, res);
+    if (res != NULL)
+      return *res;
   }
   break;
-  case NONE:
-    break;
   default:
     return -1;
   }
diff --git a/stack.c b/stack.c
index 1fb05fa..f67d285 100644
--- a/stack.c
+++ b/stack.c
@@ -1,14 +1,22 @@
 #include "./stack.h"
 
-stack_t *stack_new(int size)
+stack_t *stack_new(int size, int *result)
 {
+  result = NULL;
+
   stack_t *stack = (stack_t *)malloc(sizeof(stack_t));
   if (stack == NULL)
-    return -1;
+  {
+    *result = -1;
+    return *result;
+  }
 
   stack->mem = (int *)malloc(sizeof(int) * size);
   if (stack->mem == NULL)
-    return -1;
+  {
+    *result = -1;
+    return *result;
+  }
 
   stack->size = size;
   stack->cursor = -1;
@@ -16,10 +24,15 @@ stack_t *stack_new(int size)
   return stack;
 }
 
-int stack_push(stack_t *stack, int value)
+int stack_push(stack_t *stack, int value, int *result)
 {
+  result = NULL;
+
   if (stack->cursor > stack->size - 1)
-    return 1;
+  {
+    *result = 1;
+    return *result;
+  }
 
   stack->mem[stack->cursor + 1] = value;
   stack->cursor += 1;
@@ -27,10 +40,15 @@ int stack_push(stack_t *stack, int value)
   return 0;
 }
 
-int stack_pop(stack_t *stack)
+int stack_pop(stack_t *stack, int *result)
 {
+  result = NULL;
+
   if (stack->cursor == -1)
-    return 1;
+  {
+    *result = 1;
+    return *result;
+  }
 
   int value = stack->mem[stack->cursor];
   stack->cursor -= 1;
@@ -38,10 +56,15 @@ int stack_pop(stack_t *stack)
   return value;
 }
 
-int stack_get(stack_t *stack, int pos)
+int stack_get(stack_t *stack, int pos, int *result)
 {
+  result = NULL;
+
   if (pos < 0 || pos >= stack->size)
-    return 1;
+  {
+    *result = 1;
+    return *result;
+  }
 
   return stack->mem[pos];
 }
\ No newline at end of file
diff --git a/stack.h b/stack.h
index 408c658..e964460 100644
--- a/stack.h
+++ b/stack.h
@@ -10,9 +10,9 @@ typedef struct stack
   int cursor;
 } stack_t;
 
-stack_t *stack_new(int size);
-int stack_push(stack_t *stack, int value);
-int stack_pop(stack_t *stack);
-int stack_get(stack_t *stack, int pos);
+stack_t *stack_new(int size, int *result);
+int stack_push(stack_t *stack, int value, int *result);
+int stack_pop(stack_t *stack, int *result);
+int stack_get(stack_t *stack, int pos, int *result);
 
 #endif
\ No newline at end of file