[PATCH] D62768: [ELF] Don't create an output section named `/DISCARD/` if it is assigned to the special phdr `NONE`

[Andrew Ng via Phabricator via llvm-commits]

andrewng added a comment.

George's comment reminds me why we didn't take this approach in the first place, as it doesn't work correctly for the following test case:

  # REQUIRES: x86
  # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
  # RUN: echo "PHDRS { \
  # RUN:   exec PT_LOAD FLAGS(0x4 | 0x1); \
  # RUN:   rodata PT_LOAD FLAGS(0x4); \
  # RUN: } \
  # RUN: SECTIONS { \
  # RUN:  .text : { *(.text) } :exec \
  # RUN:  /DISCARD/ : { *(.discard) } :rodata \
  # RUN:  .rodata : { *(.rodata) } \
  # RUN: }" > %t.script
  # RUN: ld.lld -o %t --script %t.script %t.o
  # RUN: llvm-readelf -S -l %t | FileCheck --implicit-check-not=/DISCARD/ %s
  
  ## Check that /DISCARD/ phdr is assigned to subsequent sections.
  
  # CHECK: Section Headers
  # CHECK: .text
  # CHECK-NEXT: .rodata
  
  # CHECK: Segment Sections
  # CHECK-NEXT: .text
  # CHECK-NEXT: .rodata
  
  .section .text,"ax"
   ret
  
  .section .rodata,"a"
   .byte 0
  
  .section .discard,"a"
   .byte 0

However, this use case is a very unusual edge case, although bfd does handle it.


Repository:
  rL LLVM

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https://reviews.llvm.org/D62768