crash with --gc-sections

[llvmbot]

Bugzilla Link	28575
Resolution	FIXED
Resolved on	Jan 24, 2017 10:14
Version	unspecified
OS	Linux
Reporter	LLVM Bugzilla Contributor
CC	@compnerd,@emaste

Extended Description

lld crashes trying to link the following test when --gc-sections is used

.globl	_start

_start:
.cfi_startproc
.cfi_personality 3, foobar
.cfi_endproc
.section .foobar,"ax"
foobar:

The problem is that we fail to mark .foobar live. When looking at .eh_frame section we don't want to mark live the section whose address range is being described, but we do have to mark like sections that are used for the exception handling personality of any cie we keep.

[llvmbot]

My current idea on how to fix it:

• In EhInputSection::split, record the first relocation of each piece.
• In markLive, check if a piece is a cie and process the corresponding relocations.
• Use the already computed relocations in OutputSections.cpp (remove getReloc).

[llvmbot]

Fixed in r276329.