2 
  ?58                  pinNodes.push_back(node);                                                                                                                            ?
   ?59              }                                                                                                                                                        ?
   ?60              nlb::application::Application::instance().interpreter().eval(QString("unset %1").arg(pinIterListVarName));                                               ?
   ?61                                                                                                                                                                       ?
   ?62              if (!pinNodes.empty()) {                                                                                                                                 ?
   ?63                  insert(0, pinNodes.begin(), pinNodes.end());                                                                                                         ?
   ?64              }                                                                                                                                                        ?
   ?65          } catch (const std::exception& e) {                                                                                                                          ?
B+>?66              SA_ASSERT(false, e.what());                                                                                                                              ?
   ?67          }                                                                                                                                                            ?
   ?68      }

这是来自 gdb。我已将断点设置为失败的断言。当我尝试使用p e.what()gdb 打印失败原因时Couldn't find method (null)what

打印 e 给出的是不完整的。

(gdb) p e
$4 = (const struct std::exception &) @0x58f1990: <incomplete type>

我怎样才能打印它？

如果SA_ASSERT的条件为假，则调用此

void printTrace(unsigned int startDepth, QString& buff)
{

    const size_t maxDepth = 200;
    size_t stackDepth;
    void *stackAddrs[maxDepth];
    char **stackStrings;

    stackDepth = backtrace(stackAddrs, maxDepth);
    stackStrings = backtrace_symbols(stackAddrs, stackDepth);

    buff += "Call stack\n";

    unsigned int line = 1;

    for (size_t i = startDepth; i < stackDepth; i++) {
        size_t sz = 500; // just a guess, template names will go much wider
        char *function = reinterpret_cast<char*>(malloc(sz));
        char *begin = 0, *end = 0;
        // find the parentheses and address offset surrounding the mangled name
        for (char *j = stackStrings[i]; *j != 0; ++j) {
            if (*j == '(') {
                begin = j;
            } else if (*j == '+') {
                end = j;
            }
        }
        if (begin && end) {
            begin++;
            *end = 0;
            // found our mangled name, now in [begin, end)
            int status;
            char *ret = abi::__cxa_demangle(begin, function, &sz, &status);
            if (ret) {
                // return value may be a realloc() of the input
                function = ret;
            } else {
                // demangling failed, just pretend it's a C function
                // with no args
                std::strncpy(function, begin, sz);
                std::strncat(function, "()", sz);
                function[sz-1] = ' ';
            }
            buff += QString::number(line++) + QString(")    ") + function + "\n";
        } else {
            // didn't find the mangled name, just print the whole line
            buff += QString::number(line++) + QString(")    ") + stackStrings[i] + "\n";
        }
        free(function);
    }

    free(stackStrings); // malloc()ed by backtrace_symbols

}

gdb 版本

GNU gdb 6.8
Copyright (C) 2008 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu".
4

1 回答 1

2

不完整的类型意味着您缺少一些调试信息。没有它，gdb 将无能为力。例如，它不能打印该类型的对象，因为它不知道该类型的布局。

6.8 版已经很老了。如果可以的话，你应该升级。从那时起，C++ 支持已经有很多很多的错误修复。

"(null)" 看起来像一个 gdb 错误。当您尝试 printf NULL（至少使用 glibc）时会发生这种情况。但是，此错误很可能已在过去 5 年的某个时间得到修复。

于 2013-06-05T17:24:08.423 回答