gsoap/valgrind; 没有泄漏但存在内存错误。

Question

我正在使用 gSoap 编写 Web 服务客户端，并使用 Valgrind 检查内存问题。

Valgrind 报告没有泄漏，但显示了这些奇怪（至少对我来说）的内存错误消息：

==3529== Conditional jump or move depends on uninitialised value(s)
==3529==    at 0x405D6DC: soap_reference (stdsoap2.c:6926)
==3529==    by 0x405305D: soap_serialize_string (sepomexC.c:4982)
==3529==    by 0x404AF5E: soap_serialize_ns1__asentamientosPorCodigoPostalRqType (sepomexC.c:2629)
==3529==    by 0x40500F3: soap_serialize_PointerTons1__asentamientosPorCodigoPostalRqType (sepomexC.c:4103)
==3529==    by 0x4046666: soap_serialize___sep__consultarAsentamientosPorCodigoPostal (sepomexC.c:1233)
==3529==    by 0x4053A7D: soap_call___sep__consultarAsentamientosPorCodigoPostal (sepomexClient.c:186)
==3529==    by 0x40417CA: consultarAsentamientosPorCodigoPostal (main.c:73)
==3529==    by 0x804870C: main (sepomexmain.c:31)
==3529== 
==3529== Conditional jump or move depends on uninitialised value(s)
==3529==    at 0x4061AA5: soap_element_id (stdsoap2.c:9583)
==3529==    by 0x4068B0C: soap_outstring (stdsoap2.c:12681)
==3529==    by 0x4052DAE: soap_out_xsd__integer (sepomexC.c:4918)
==3529==    by 0x404B062: soap_out_ns1__asentamientosPorCodigoPostalRqType (sepomexC.c:2643)
==3529==    by 0x4050179: soap_out_PointerTons1__asentamientosPorCodigoPostalRqType (sepomexC.c:4111)
==3529==    by 0x4046698: soap_out___sep__consultarAsentamientosPorCodigoPostal (sepomexC.c:1238)
==3529==    by 0x4046818: soap_put___sep__consultarAsentamientosPorCodigoPostal (sepomexC.c:1274)
==3529==    by 0x4053AF6: soap_call___sep__consultarAsentamientosPorCodigoPostal (sepomexClient.c:193)
==3529==    by 0x40417CA: consultarAsentamientosPorCodigoPostal (main.c:73)
==3529==    by 0x804870C: main (sepomexmain.c:31)

==3529== 
==3529== HEAP SUMMARY:
==3529==     in use at exit: 0 bytes in 0 blocks
==3529==   total heap usage: 160 allocs, 160 frees, 16,161 bytes allocated
==3529== 
==3529== All heap blocks were freed -- no leaks are possible
==3529== 
==3529== For counts of detected and suppressed errors, rerun with: -v
==3529== Use --track-origins=yes to see where uninitialised values come from
==3529== ERROR SUMMARY: 3 errors from 2 contexts (suppressed: 21 from 8)

没有泄漏是好消息，但是这些错误重要吗？据我了解，它们是在stdsoap2.c（一个gSoap文件）中生成的。

谢谢。

编辑：感谢您的答案。正如你们中的一些人告诉我，我有未初始化的东西，那就是我的请求结构变量。我这样修复了它：

struct ns1__myRequestType request;
memset(&request, 0, sizeof(struct ns1__myRequestType));

现在Valgrind的输出“干净”了:)非常感谢。

- user1274605

---

你能发一下你的 main() 函数的代码吗？ - hmjd

是的，它们通常非常重要，这可能是因为您的代码将未初始化的内容传递到了gSoap库中。 - nos

Answer 1

它基本上指的是基于未初始化变量进行了某些分支。这些变量可能只是在库函数中本地作用域的自动变量，在使用if、while、switch或其他形式的分支表达式之前没有被赋值而在堆栈上分配。一般来说，这不是一个好的做法，因为它可能导致未定义的行为，但如果错误是内部库错误，则编写者可能正在执行某种类型的假定内存覆盖操作等，使得这些变量在标准C语法中非正式“初始化”而不是显式初始化。另一个可能性是你可能还将指向未初始化变量的指针传递给库函数之一，这是糟糕的编程方式，可能会产生不可预测的结果或安全风险。

- Jason