; REQUIRES: x86
; RUN: llvm-as %s -o %t.o
; RUN: ld.lld -m elf_x86_64 %t.o -o %t -save-temps
; RUN: llvm-dis %t.0.4.opt.bc -o - | FileCheck %s

target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

module asm ".weak patatino"
module asm ".equ patatino, foo"

declare void @patatino()

define void @foo() {
  ret void
}

define void @_start() {
  call void @patatino()
  ret void
}

; CHECK: @llvm.compiler.used = appending global [1 x i8*] [i8* bitcast (void ()* @foo to i8*)], section "llvm.metadata"
; CHECK: define internal void @foo


; REQUIRES: x86
; RUN: llvm-as %s -o %t.o
; RUN: ld.lld -m elf_x86_64 %t.o -o %t -save-temps
; RUN: llvm-dis %t.0.4.opt.bc -o - | FileCheck %s

target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

module asm ".weak patatino"
module asm ".equ patatino, foo"

declare void @patatino()

define void @foo() {
  ret void
}

define void @_start() {
  call void @patatino()
  ret void
}

; CHECK: define void @foo


Mark undefined module asm symbols as used.
LTO: Mark undefined module asm symbols as used.

Marking them as used causes them to be considered visible outside of LTO. This
prevents the symbols from being internalized or discarded, either by GlobalDCE
or by summary-based dead stripping in ThinLTO.

This change makes it unnecessary to add these symbols to llvm.compiler.used
in the backend, as the symbols are kept alive by virtue of being external,
so remove the backend code that handles that.

Fixes PR32798.

Differential Revision: https://reviews.llvm.org/D32544

git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@301438 91177308-0d34-0410-b5e6-96231b3b80d8
