LLDB为本地变量提供“使用未声明的标识符”错误

Question

在以下功能中，我无法在LLDB中看到“ recordMap”。for循环输出键，recordType设置正确，但是'p recordMap'给出错误“使用未声明的标识符”。我在LLDB中可以看到变量'recordType'很好，所以我处于正确的范围内。当我在LLDB中键入'recordMap'时，它会自动完成，就好像它在那里一样。

对于调试和发布，我都将优化设置为“无”。这可能是什么！

void MezNetworkController::showRecord( std::map<string, MezSQLData*> recordMap ) {

    for( auto item : recordMap )
        printf( " KEY: %s\n", item.first.c_str() );

    int recordType = (int) recordMap["messageType"]->intValue();
    printf( recordType );
}

以下是lldb中“ image lookup -va $ pc”的结果：

      Address: Mezmo[0x00015ed0] (Mezmo.__TEXT.__text + 45272)
      Summary: Mezmo`MezNetworkController::showRecord(std::__1::map<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, MezSQLData*, std::__1::less<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::allocator<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, MezSQLData*> > >) + 780 at MezNetworkController.cpp:774
       Module: file = "/Users/paulslocum/Dropbox/_iOS/_414 Messenger_/DerivedData/414 Messenger/Build/Products/Debug-iphoneos/Mezmo.app/Mezmo", arch = "armv7"
  CompileUnit: id = {0x00000000}, file = "/Users/paulslocum/Dropbox/_iOS/_414 Messenger_/414 Messenger/MezNetworkController.cpp", language = "ISO C++:1998"
     Function: id = {0x400015fa2}, name = "showRecord", range = [0x000c2bc4-0x000c42a6)
     FuncType: id = {0x400015fa2}, decl = MezNetworkController.hpp:60, clang_type = "void (void)"
       Blocks: id = {0x400015fa2}, range = [0x000c2bc4-0x000c42a6)
    LineEntry: [0x000c2ed0-0x000c2ee6): /Users/paulslocum/Dropbox/_iOS/_414 Messenger_/414 Messenger/MezNetworkController.cpp:774:38
       Symbol: id = {0x000001f8}, range = [0x000c2bc4-0x000c42a8), name="MezNetworkController::showRecord(std::__1::map<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, MezSQLData*, std::__1::less<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::allocator<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const, MezSQLData*> > >)", mangled="_ZN20MezNetworkController10showRecordENSt3__13mapINS0_12basic_stringIcNS0_11char_traitsIcEENS0_9allocatorIcEEEEP10MezSQLDataNS0_4lessIS7_EENS5_INS0_4pairIKS7_S9_EEEEEE"
     Variable: id = {0x400015fb6}, name = "this", type = "MezNetworkController *", location =  [sp+1068], decl = 
     Variable: id = {0x400015fc5}, name = "recordType", type = "int", location =  [sp+1028], decl = MezNetworkController.cpp:774

Answer 1

变量“recordMap”未在“图像查找”输出中列出；这意味着 LLDB 实际上无法使用您当前的位置

这通常是编译器生成的调试信息存在问题，其中忽略了变量。当调试器没有被告知某个变量或该变量在内存中的位置时，不幸的是它无能为力。

作为解决方法，您可以手动打印键/值绑定（我看到您已经在为键执行此操作），但我会向 clang 编译器提交有关缺少变量的错误报告