[llvm-dev] Is BlockAddress always correct ?

[PenYiWang via llvm-dev]

Hi

I use BlockAddress to get the address of BasicBlock ,

and I use GlobalVariable 's getInitializer()

to pass the address of BasicBlock to the global variable of my own program

and then I print it out.

But , I found that  BlockAddress is not always correct.

For example, some function's rsp (stack pointer) or other register is
maintained by caller,

so  it would be like:
https://i.imgur.com/Rwuy5ju.png
  0x42c37a: e8 c1 7a 00 00     call   433e40 <retrieve_url>
  0x42c37f: 48 83 c4 20           add    rsp,0x20
  0x42c383: eb 00                    jmp    42c385 <main+0x16b5>

What I want is the basic block which is "excatly" after the function call ,
0x42c37f

I want BlockAddress give me  0x42c37f.

But actually, the output my program print  out is   0x42c383.

I guess "add    rsp,0x20" is seen as within the basic block  of the
function call.

Maybe reset the rsp (stack pointer) is part of the function call.

Can I say there is bug in BlockAddress ?

Or there is some bug in LLVM's backend?

How to solve this problem?

Force clang/llvm not to use caller-saved convention or something like that ?

Thanks
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