How to see the added code in C++ by the compiler?
E.g., we know that when an object of some class goes out of scope, the destructor for that object is called, but how do you see the specific code that does the destructor call? Is that code still written in C++?
Its compiler-dependent and in assembly language. For example, with the Microsoft compiler, compiling with /FAsc will generate a .cod file for each object file containing the assembly code along with the original C++ lines as comments. It will show the calls to constructors/destructors as well.
There's not necessarily any "code" that gets added. C++ is pretty clear on when such things happen, and for the compiler, making a new object clearly means calling its constructor -- no additional "code" anywhere.
You're right, however, things like calls to the constructor or destructor must end up somewhere in the assembly -- but there's absolutely no guarantee that having a look at the assembly reveals much more than what you'd have known without. C++ compilers are pretty mature in these aspects, and inline a lot of things in cases where that makes sense, making the same code look different in different places.
The closest thing you'll get is adding debug symbols to your build and using a debugger to get a call graph -- that will make sure that you notice when what you see as code gets called.
You can add flags to the compile command which will let you see the file in various stages of operations done by the compiler. For e.g., the -S flag will produce a file which would have had the preprocessor done and the initial compilation done, but before the assembler runs. However, this code will not be written in C++.
