[PATCH] D26133: [ELF] Allow relative relocations to absolute symbols in PIC

[Peter Collingbourne via llvm-commits]

This appears to be the relevant part of the fuschia linker script:

https://github.com/fuchsia-mirror/magenta/blob/fad6801bd5c27e9887e912a3c6883dba463ec3d4/third_party/ulib/musl/ldso/base.ld#L6

>From the comment it seems like you are intending to create an
image-relative symbol, no?

Peter

On Fri, Dec 9, 2016 at 2:43 PM, Petr Hosek <phosek at google.com> wrote:

> On Thu, Dec 8, 2016 at 6:32 AM Rafael Avila de Espindola <
> rafael.espindola at gmail.com> wrote:
>
>> It is entirely possible we just have another case where lld gets
>> confused about a symbol being absolute or not. Can you provide the full
>> original code in musl that fails with lld?
>>
>
> I missed your response on the list. The original code that fails with lld
> is pretty much equivalent to the new test case I've added:
>
> # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
> # RUN: echo "PROVIDE_HIDDEN(_BASE = 0);" > %t.script
> # RUN: ld.lld -shared --gc-sections --script %t.script -o %t1 %t
> # RUN: llvm-readobj --elf-output-style=GNU --file-headers --symbols %t1 |
> FileCheck %s
> # CHECK: 0000000000000000     0 NOTYPE  LOCAL  HIDDEN   ABS base
>
> .text
> .globl _start
> _start:
>         lea _BASE(%rip),%rax
>
> Currently, lld fails with the following error:
>
> bin/ld.lld: error: gc-start.o:(.text.internal+0x3): relocation
> R_X86_64_PC32 cannot refer to absolute symbol '_BASE' defined in (internal)
>



-- 
-- 
Peter
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20161209/8fede8b8/attachment.html>