llvm-project/lld
Dimitry Andric ad5aab8ddb Don't mess up RelIplt symbols during relocatable processing
Summary:
During upgrading of the FreeBSD source tree with lld 7.0.0, I noticed
that it started complaining about `crt1.o` having an "index past the
end of the symbol table".

Such a symbol table looks approximately like this, viewed with `readelf
-s` (note the `Ndx` field being messed up):

```
Symbol table '.symtab' contains 4 entries:
   Num:    Value  Size Type    Bind   Vis      Ndx Name
     0: 00000000     0 NOTYPE  LOCAL  DEFAULT  UND
     1: 00000000     0 SECTION LOCAL  DEFAULT    1
     2: 00000000     0 NOTYPE  WEAK   HIDDEN  RSV[0xffff] __rel_iplt_end
     3: 00000000     0 NOTYPE  WEAK   HIDDEN  RSV[0xffff] __rel_iplt_start
```

At first, it seemed that recent ifunc relocation work had caused this:
<https://reviews.freebsd.org/rS339351>, but it turned out that it was
due to incorrect processing of the object files by lld, when using `-r`
(a.k.a. --relocatable).

Bisecting showed that rL324421 ("Convert a use of Config->Static") was
the commit where this new behavior began.  Simply reverting it solved
the issue, and the `__rel_iplt` symbols had an index of `UND` again.

Looking at Rafael's commit message, I think he simply missed the
possibility of `--relocatable` being in effect, so I have added an
additional check for it.

I also added a simple regression test case.

Reviewers: grimar, ruiu, emaste, espindola

Reviewed By: ruiu

Subscribers: arichardson, krytarowski, llvm-commits

Differential Revision: https://reviews.llvm.org/D53515

llvm-svn: 345002
2018-10-23 05:53:15 +00:00
..
COFF [COFF] Fix error handling on duplicates for import library symbols 2018-10-19 06:39:36 +00:00
Common Allow later -z name=<int> args to override earlier args 2018-09-26 20:50:39 +00:00
ELF Don't mess up RelIplt symbols during relocatable processing 2018-10-23 05:53:15 +00:00
MinGW [MinGW] Pass libpath to the COFF linker 2018-10-10 09:00:03 +00:00
cmake/modules [CMake] Properly conditionalize installation of lld libraries 2018-03-09 13:09:36 +00:00
docs Add an entry to the release notes. 2018-10-09 17:53:33 +00:00
include/lld Use llvm::arrayRefFromStringRef 2018-10-22 08:35:39 +00:00
lib Eliminate dependency to formatv(). NFC. 2018-10-10 20:29:29 +00:00
test Don't mess up RelIplt symbols during relocatable processing 2018-10-23 05:53:15 +00:00
tools/lld Fix typo in error message. NFC. 2018-09-13 15:37:13 +00:00
unittests [Darwin] Use errorHandler from liblldCommon 2018-06-12 02:34:04 +00:00
utils Add a script to run various benchmarks and send the result to lnt. 2017-11-14 16:40:30 +00:00
wasm Use llvm::arrayRefFromStringRef 2018-10-22 08:35:39 +00:00
.arcconfig [lld] Set up .arcconfig to point to new Diffusion LLD repository 2017-12-06 20:56:23 +00:00
.clang-format
.gitignore
CMakeLists.txt [WebAssembly] Initial wasm linker implementation 2017-11-17 18:14:09 +00:00
CODE_OWNERS.TXT [WebAssembly] Initial wasm linker implementation 2017-11-17 18:14:09 +00:00
LICENSE.TXT Update copyright year to 2018. 2018-06-18 12:22:17 +00:00
README.md Note that the test .tar.xz has been updated. 2017-12-22 19:37:32 +00:00

README.md

LLVM Linker (lld)

This directory and its subdirectories contain source code for the LLVM Linker, a modular cross platform linker which is built as part of the LLVM compiler infrastructure project.

lld is open source software. You may freely distribute it under the terms of the license agreement found in LICENSE.txt.

Benchmarking

In order to make sure various developers can evaluate patches over the same tests, we create a collection of self contained programs.

It is hosted at https://s3-us-west-2.amazonaws.com/linker-tests/lld-speed-test.tar.xz

The current sha256 is 10eec685463d5a8bbf08d77f4ca96282161d396c65bd97dc99dbde644a31610f.