Why is my memory layout different?

Question

The following code snippet:

void (*foo)();
char X[1];
char Y[10];

could intuitively give me one possible alignment:

|  Y[10]  |
|---------|
|  X[1]   |
|---------|
|  foo    |
|---------|

I studied this by creating an ASM file using:

gcc -S -o stack stack.c

Then I realized that the order in which these variables are pressed is different. So, if I accidentally did X[1], I expected to refer to Y[0], but in the actual layout, writing something in X[1]overwrites the first byte of the memory cell allocated for foo. Is reorganization a compiler optimization step or can someone tell me why this is happening?

Answer 1

Why do you say "need"?

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Answer 2

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-, . :

push A
push B

A , B, B ( A). C:

int stk[BIG];
int stk_top = BIG;

 void stk_push(int x) {
     stk_top--;
     stk[stk_top] = x;
 }

, stk_top , .

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Answer 3

: char , .

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Answer 4

|   var   | address |
|---------|---------|
|  Y[10]  |  x      |
|---------|---------|
|  X[1]   |  x + 10 |
|---------|---------|
|  foo    |  x + 11 |
|---------|---------|

, , ( ), , , . , X[1] = *(x + 10 + 1) = foo

Answer 5

, .

Answer 6

, ? 4- . ?

char x[11];
char *y = &x[1];