结构体存储位置咨询：栈与堆区分及代码变量存储位置解析

Let's break down the storage locations of your variables clearly, using your code as a reference:

1. The c1 variable #

Your line:

color c1;

Assuming this is defined inside a function (as a local variable) (the most common scenario), c1 lives in the stack memory. It's an automatic variable—when the function finishes executing, this stack memory is automatically cleaned up by the system.

If c1 were defined at the global scope (outside all functions) or marked with the static keyword, it would instead reside in the global/static memory segment, not the stack.

2. The c2 pointer and its allocated memory #

Your line:

color* c2 = malloc(sizeof(color));

This has two distinct components to unpack:

• The pointer variable c2 itself: Just like c1 (if it's a local variable), c2 is stored in the stack. It's a small variable (usually 4 or 8 bytes, depending on your system's architecture) that holds a memory address.
• The memory c2 points to: The block of memory returned by malloc(sizeof(color)) is allocated in the heap. This is where the actual color struct data (the red, green, blue values) lives. Unlike stack memory, heap memory isn't automatically released—you must call free(c2) later to avoid memory leaks.

Quick Summary #

• c1: Stack (if local) / global/static segment (if global or static)
• c2 (the pointer variable): Stack (if local) / global/static segment (if global or static)
• *c2 (the struct data c2 points to): Heap

内容的提问来源于stack exchange，提问作者Michael Berend