[PATCH] D107133: [AVR] emit `MCSA_Global` references to `__do_global_ctors` and `__do_global_dtors`

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added inline comments.


================
Comment at: llvm/test/CodeGen/AVR/ctors.ll:11
+
+; CHECK: .globl __do_global_ctors
+ at llvm.global_ctors = appending global [1 x { i32, void () addrspace(1)*, i8* }] [{ i32, void () addrspace(1)*, i8* } { i32 65535, void () addrspace(1)* @do_nothing, i8* null }]
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mhjacobson wrote:
> MaskRay wrote:
> > This is insufficient. It should additionally check whether the label is defined.
> The label isn't expected to be defined.  The symbol comes from libgcc.a.
> 
> This directive simply tells the assembler to emit an undefined-symbol reference to `__do_global_ctors`.  The actual implementation comes at link time, from libgcc.
> 
> For comparison, see `llvm/test/CodeGen/AVR/clear-bss.ll`, which does the same thing.
> 
> (Apologies if I'm misunderstanding your request here.)
OK. This is resolved. Thanks for the reply.

Please add `;; Emit .globl __do_global_ctors to leave an undefined symbol. This matches GNU as and is needed to pull the definition from libgcc.a` or something similar.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D107133/new/

https://reviews.llvm.org/D107133