46 lines
1.2 KiB
Plaintext
46 lines
1.2 KiB
Plaintext
/* ===== 模块7：高级特性 =====
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* test15_defer — 延迟执行
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* 难度：3/5
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* 验证点：defer 语句、defer 块、多个 defer（逆序执行）、
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* 函数中 defer、块作用域 defer
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*/
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#[extern("vm")] fn vm_printf(fmt: *u8, ...) void;
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fn with_cleanup() void {
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defer vm_printf(" inner defer\n");
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vm_printf(" inside with_cleanup\n");
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}
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fn main() i32 {
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vm_printf("--- defer test ---\n");
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/* defer 语句 */
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defer vm_printf("defer1\n");
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vm_printf("after defer1\n");
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/* defer 块 */
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defer {
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vm_printf("defer block\n");
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}
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vm_printf("after defer block\n");
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/* 函数内 defer */
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with_cleanup();
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vm_printf("after with_cleanup\n");
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/* 多个 defer 应逆序执行出作用域应该立刻执行，包括循环作用域 */
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{
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defer vm_printf("block defer last\n");
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defer vm_printf("block defer middle\n");
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defer vm_printf("block defer first (should print third)\n");
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}
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/* 多个 defer 应逆序执行 */
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defer vm_printf("defer last\n");
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defer vm_printf("defer middle\n");
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defer vm_printf("defer first (should print third)\n");
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vm_printf("--- defer test end ---\n");
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ret 0;
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}
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