When reserving copy relocation space for a shared symbol, scan the DSO's
program headers to see if the symbol is in a read-only segment. If so,
reserve space for that symbol in a new synthetic section named .bss.rel.ro
which will be covered by the relro program header.

This fixes the security issue disclosed on the binutils mailing list at:
https://sourceware.org/ml/libc-alpha/2016-12/msg00914.html

Differential Revision: https://reviews.llvm.org/D28272

llvm-svn: 291524

This is in preparation for my next change, which will introduce a relro
nobits section. That requires that relro sections appear at the end of the
progbits part of the r/w segment so that the relro nobits section can appear
contiguously.

Because of the amount of churn required in the test suite, I'm making this
change separately.

llvm-svn: 291523

Use the new --cmakedir option to obtain LLVM_CMAKE_PATH straight from
llvm-config instead of reconstructing it locally.

llvm-svn: 291502

Rafael suggested in review to wrap the `.` in an
`ABSOLUTE` op to force the section to be in the
*ABS* "section":

  * http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20170109/417865.html

llvm-svn: 291501

This patch enables something like "-o /dev/null".
Previouly, it failed because such files cannot be renamed.

Differential Revision: https://reviews.llvm.org/D28010

llvm-svn: 291496

The linkonce feature is a sort of proto-comdat. As far as I am aware no
compiler produces linkonce sections anymore, but some glibc i386 object
files contain definitions of symbol "__x86.get_pc_thunk.bx" in linkonce
sections. Drop those sections to avoid duplicate symbol errors.

This is glibc PR20543, we should remove this hack once that has been
fixed for a while.

Fixes PR31215.

Differential Revision: https://reviews.llvm.org/D28430

llvm-svn: 291474

This patch allows for linker scripts to assign a new value
to a symbol that is already defined (either in an object file
or the linker script itself).

llvm-svn: 291459

Summary:
Lld's build had a couple of issues which prevented a successfull
LLVM_LINK_LLVM_DYLIB compilation.

- add_llvm_library vs llvm_add_library: One adds a library to libLLVM.so, other
  one doesn't. Lld was using the wrong one, causing symbols to be mupltiply
  defined in things linking to libLLVM.
- confusion when to use LINK_LIBS vs LINK_COMPONENTS in llvm_add_library
- not using LLVM_LINK_COMPONENTS for add_lld_tool

With these fixes lld compiles and it's test suite passes both in
LLVM_LINK_LLVM_DYLIB mode and without it.

Reviewers: ruiu, beanz

Subscribers: llvm-commits, mgorny

Differential Revision: https://reviews.llvm.org/D28397

llvm-svn: 291432

This patch moves convertToUnixPathSeparator from LLD to LLVM.

Differential Revision: https://reviews.llvm.org/D28444

llvm-svn: 291414

Previously, files added using INCLUDE directive weren't added
to reproduce archives. In this patch, I defined a function to
open a file and use that from Driver and LinkerScript.

llvm-svn: 291413

llvm-svn: 291348

In order to keep symbol lookup a simple name lookup this patch adds
versioned symbols with an explicit @ to the symbol table.

llvm-svn: 291293

Should bring back the windows bots.

llvm-svn: 291263

llvm-svn: 291261

llvm-svn: 291257

llvm-svn: 291224

llvm-svn: 291223

The two overloaded functions hid each other. This patch merges them.

llvm-svn: 291222

Now TarWriter takes care of path separator conversion, so we don't
need to handle that in LLD.

llvm-svn: 291221

Previously, when we printed out a path obtained from DWARF debug info,
we replaced \ with / on Windows. But that doesn't make sense. We should
respect the system's path separator.

llvm-svn: 291219

llvm-svn: 291212

This is how we use TarWriter in LLD. Now LLD does not append
a file extension, so you need to pass `--reproduce foo.tar`
instead of `--reproduce foo`.

Differential Revision: https://reviews.llvm.org/D28103

llvm-svn: 291210

llvm-svn: 291113

llvm-svn: 291110

After Mark's patch I was wondering what was the rationale for the ELF
spec requiring us to merge only sections with matching flags and
types. I tried emailing
https://groups.google.com/forum/#!forum/generic-abi, but looks like my
emails are not being posted (the list is probably moderated). I
emailed Cary Coutant instead.

Cary pointed out that the section was a late addition and didn't got
the scrutiny it deserved. Given that and the problems found by
implementing the letter of the standard, I propose changing lld to
merge all sections with the same name and issue errors if the types or
some critical flags are different.

This should allow an unmodified firefox linked with lld to run.

This also merges some code with the linkerscript path.

llvm-svn: 291107

We no longer tail merge section names.

llvm-svn: 290988

The glibc dynamic loader rounds the size down, so without this the loader
will fail to change the memory protection for the last page.

Differential Revision: https://reviews.llvm.org/D28267

llvm-svn: 290986

The GUID should match between the RSDS and the PDB.  This should repair
the build bots, though we should be ensuring that the GUIDs match.
Unfortunately, different build bots seem to be getting different GUIDs.

llvm-svn: 290981

The PDB GUID, Age, and version are tied together by the RSDS record in
the binary.  Pass along the BuildId information into the createPDB to
allow us to tie the binary and the PDB together.

llvm-svn: 290975

    
In a shared library an undefined symbol is implicitly imported. If the
symbol is called as a function a PLT entry is generated for it. When the
caller is a Thumb b.w a thunk to the PLT entry is needed as all PLT
entries are in ARM state.
    
This change allows undefined symbols to have thunks in the same way that
shared symbols may have thunks.

llvm-svn: 290951

llvm-svn: 290932

Assert that the size of the MD5 result is the same size as the signature
field being populated.  Use the sizeof operator to determine the size of
the field being written rather than hardcoding it to the magic number
16.  NFC.

llvm-svn: 290764

llvm-svn: 290510

This fixes issue revealed by r289961.

Differential revision: https://reviews.llvm.org/D28045

llvm-svn: 290419

We managed new MemoryBuffers in different ways in LinkerScript.cpp and
Driver.cpp. With this patch, they are managed in the same way.

llvm-svn: 290411

This is necessary for the distribution targets which assume that
each component has an install target. This also moves the CMake
macros into a separate file akin to other LLVM projects.

Differential Revision: https://reviews.llvm.org/D27876

llvm-svn: 290391

Differential revision: https://reviews.llvm.org/D27194

llvm-svn: 290339

This is last known noticable fatal() in target.cpp.
We also have other ones for unknown relocations or
creating unknown targets, but that one can be just error I think.

Used yaml2obj to generate test.

Differential revision: https://reviews.llvm.org/D28049

llvm-svn: 290335

Vectors returned form that function contained nullptrs or Undefined symbols.
This patch filter them out. This makes use of the function a bit easier.

llvm-svn: 290334

Previously, that was an alias to -color-diagnostics=auto. However,
Clang's -fcolor-diagnostics is an alias to -fcolor-diagnostics=always,
so that was confusing. This patch fixes that issue.

llvm-svn: 290332