使用调试选项时，dwarfdump为空(dwarfdump is empty when using debug options)

使用调试选项时，dwarfdump为空(dwarfdump is empty when using debug options)

我试图使用dwarfdump从C ++文件中获取DWARF信息。 C ++文件非常简单 -

int foo();

我通过g++ -g -c test.cpp编译它。 然后我做了dwarfdump test.o ，但出于某种原因，我得到了

---------------------------------------------------------------------- File: test.o (x86_64) ---------------------------------------------------------------------- .debug_info contents: < EMPTY >

为什么是这样？ 我怎样才能得到我的调试矮人信息？

Im trying to get DWARF info from a C++ file using dwarfdump. The C++ file is very simple -

int foo();

I compile it by doing g++ -g -c test.cpp. I then do dwarfdump test.o, but for some reason I get

---------------------------------------------------------------------- File: test.o (x86_64) ---------------------------------------------------------------------- .debug_info contents: < EMPTY >

Why is this? And how can I get my debug dwarf info?

最满意答案

我弄清楚出了什么问题。 没有生成调试信息。 这是因为优化器实现了int foo（）; 永远不会被调用，也没有声明，因此不需要调试信息。 将功能更改为

int foo(){ int x=5; }

足以生成调试信息。

I figured out what was wrong. No debug information was generated. This is because the optimizer realizes that int foo(); is never called and has no declaration, and as such does not need debug info. Changing the function to

int foo(){ int x=5; }

is enough to generate debug info.