Memory leaks 分配具有返回值的可分配多态变量时内存泄漏

我正在努力进行内存管理或正确使用面向对象的Fortran 2008。我的代码在

示例类

模块中存储了具有相同父级的多个派生类型（此处为

Example01

和

Example02

）。我想根据某个变量在子例程

workenv

中加载一个示例（此处

idx\u示例

）。无论选择哪一个，都应该由基类中定义的过程访问，因此我可以执行

调用active\u Example%Info（）

而不管

active\u Example

是什么

使用

ifort

（19.0.1.144）或

gfortran

（7.5.0）编译的以下代码按预期工作。 但是

valgrind

（3.13.0）警告内存泄漏（参见下面的代码）。如何防止内存泄漏并具有相同或类似的功能？（我希望在

Example\u class

模块中拥有控件，并且在

workenv

子例程中不使用多个

if

-条件。）

使用

ifort-free-stand f08示例。f-o示例时

valgrind ./Examples
==1689== Memcheck, a memory error detector
==1689== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==1689== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==1689== Command: ./Examples
==1689== 
==1689== Conditional jump or move depends on uninitialised value(s)
==1689==    at 0x48CFC1: __intel_sse2_strcpy (in /mnt/Data/Examples)
==1689==    by 0x45680E: for__add_to_lf_table (in /mnt/Data/Examples)
==1689==    by 0x43C363: for__open_proc (in /mnt/Data/Examples)
==1689==    by 0x42194D: for__open_default (in /mnt/Data/Examples)
==1689==    by 0x42C092: for_write_seq_lis (in /mnt/Data/Examples)
==1689==    by 0x40304D: example_baseclass_mp_info_ (in /mnt/Data/Examples)
==1689==    by 0x402E17: MAIN__ (in /mnt/Data/Examples)
==1689==    by 0x402A81: main (in /mnt/Data/Examples)
==1689== 
 Example Class 02    
==1689== 
==1689== HEAP SUMMARY:
==1689==     in use at exit: 32 bytes in 1 blocks
==1689==   total heap usage: 11 allocs, 10 frees, 12,775 bytes allocated
==1689== 
==1689== LEAK SUMMARY:
==1689==    definitely lost: 0 bytes in 0 blocks
==1689==    indirectly lost: 0 bytes in 0 blocks
==1689==      possibly lost: 0 bytes in 0 blocks
==1689==    still reachable: 32 bytes in 1 blocks
==1689==         suppressed: 0 bytes in 0 blocks
==1689== Rerun with --leak-check=full to see details of leaked memory
==1689== 
==1689== For counts of detected and suppressed errors, rerun with: -v
==1689== Use --track-origins=yes to see where uninitialised values come from
==1689== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)

使用

gfortran-ffree form-std=f2008示例。f-o示例

：

valgrind ./Examples
==1729== Memcheck, a memory error detector
==1729== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==1729== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==1729== Command: ./Examples
==1729== 
 Example Class 02    
==1729== 
==1729== HEAP SUMMARY:
==1729==     in use at exit: 20 bytes in 1 blocks
==1729==   total heap usage: 23 allocs, 22 frees, 13,536 bytes allocated
==1729== 
==1729== LEAK SUMMARY:
==1729==    definitely lost: 20 bytes in 1 blocks
==1729==    indirectly lost: 0 bytes in 0 blocks
==1729==      possibly lost: 0 bytes in 0 blocks
==1729==    still reachable: 0 bytes in 0 blocks
==1729==         suppressed: 0 bytes in 0 blocks
==1729== Rerun with --leak-check=full to see details of leaked memory
==1729== 
==1729== For counts of detected and suppressed errors, rerun with: -v
==1729== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

---

但是valgrind（3.13.0）警告内存泄漏我认为这可能是valgrind的问题，而不是代码问题，valgrind没有很好地利用Fortran的未来特性。我肯定我在这里看到过Qs和这种效果，但是我能在需要的时候找到它们吗？真见鬼！谢谢你的调查。这绝对是一种可能性，因为乍一看一切似乎都正常。我只是不希望在所有东西都在扩展时出现大量内存问题。同样的20字节丢失也发生在我的机器上（MacOS10.11上的gfortran-9.2）。如果我将函数“Select_Example（）”更改为带有伪类变量“myExample”的子例程，那么泄漏就会消失……我可以用gfortran确认此行为（使用子例程时没有泄漏报告）。有趣的是，当使用ifort编译时，valgrind仍然报告相同的内存泄漏（这次是9个alloc和8个frees）。但是valgrind（3.13.0）警告内存泄漏。我认为这可能是valgrind的问题，而不是代码问题，valgrind不能很好地使用Fortran的未来特性。我肯定我在这里看到过Qs和这种效果，但是我能在需要的时候找到它们吗？真见鬼！谢谢你的调查。这绝对是一种可能性，因为乍一看一切似乎都正常。我只是不希望在所有东西都在扩展时出现大量内存问题。同样的20字节丢失也发生在我的机器上（MacOS10.11上的gfortran-9.2）。如果我将函数“Select_Example（）”更改为带有伪类变量“myExample”的子例程，那么泄漏就会消失……我可以用gfortran确认此行为（使用子例程时没有泄漏报告）。有趣的是，当使用ifort编译时，valgrind仍然报告相同的内存泄漏（这次有9个alloc和8个free）。

valgrind ./Examples
==1729== Memcheck, a memory error detector
==1729== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==1729== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==1729== Command: ./Examples
==1729== 
 Example Class 02    
==1729== 
==1729== HEAP SUMMARY:
==1729==     in use at exit: 20 bytes in 1 blocks
==1729==   total heap usage: 23 allocs, 22 frees, 13,536 bytes allocated
==1729== 
==1729== LEAK SUMMARY:
==1729==    definitely lost: 20 bytes in 1 blocks
==1729==    indirectly lost: 0 bytes in 0 blocks
==1729==      possibly lost: 0 bytes in 0 blocks
==1729==    still reachable: 0 bytes in 0 blocks
==1729==         suppressed: 0 bytes in 0 blocks
==1729== Rerun with --leak-check=full to see details of leaked memory
==1729== 
==1729== For counts of detected and suppressed errors, rerun with: -v
==1729== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)