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

StringRefZ is a class to represent a null-terminated string. String
length is computed lazily, so it's more efficient than StringRef to
represent strings in string table.

The motivation of defining this new class is to merge functions
that only differ in string types; we have many constructors that takes
`const char *` or `StringRef`. With StringRefZ, we can merge them.

Differential Revision: https://reviews.llvm.org/D27037

llvm-svn: 288172

llvm-svn: 287967

Now that lld switched to lib/LTO, which always calls setDataLayout(),
we don't need this check anymore.
Thanks to Peter for pointing out!

llvm-svn: 287699

This would trigger an assertion at runtime otherwise.

Differential Revision: https://reviews.llvm.org/D26482

llvm-svn: 286562

Previously, we do this piece of code to iterate over all input sections.

  for (elf::ObjectFile<ELFT> *F : Symtab.getObjectFiles())
    for (InputSectionBase<ELFT> *S : F->getSections())

It turned out that this mechanisms doesn't work well with synthetic
input sections because synthetic input sections don't belong to any
input file.

This patch defines a vector that contains all input sections including
synthetic ones.

llvm-svn: 286051

Differential revision: https://reviews.llvm.org/D26320

llvm-svn: 286030

Previously, we have a lot of BumpPtrAllocators, but all these
allocators virtually have the same lifetime because they are
not freed until the linker finishes its job. This patch aggregates
them into a single allocator.

Differential revision: https://reviews.llvm.org/D26042

llvm-svn: 285452

We used to have one allocator per file, which reduces the advantage of
using an allocator in the first place.

This is a small speed up is most cases. The largest speedup was in
1.014X in chromium no-gc. The largest slowdown was scylla at 1.003X.

llvm-svn: 285205

llvm-svn: 284705

Differential Revision:   https://reviews.llvm.org/D25452

llvm-svn: 283817

Before the default was whatever number hardware_concurrency() returned.
Users can specify the number of threads via --lto-jobs=X option.

llvm-svn: 283787

Because LTO::run doesn't change HasError, it doesn't make
sense to check that value.

llvm-svn: 282801

llvm-svn: 282795

We have a few "check" functions in Error.h. All of them are to
check for an error and strip an error object if there was no error,
except "void check(Error E)", which doesn't return anything.
This patch renames it and moves it to the .cpp file where it is used.

llvm-svn: 282764

It's better because it's a verb.

llvm-svn: 282763

llvm-svn: 282668

llvm-svn: 282662

Differential Revision:  https://reviews.llvm.org/D24492

llvm-svn: 282656

I found out this wasn't tested when looking at Vedant's coverage bot
numbers, so, thanks to him. While I'm here, switch the error message
to be lld-compliant (first letter lowercase).

llvm-svn: 282335

Previously, all input files were owned by the symbol table.
Files were created at various places, such as the Driver, the lazy
symbols, or the bitcode compiler, and the ownership of new files
was transferred to the symbol table using std::unique_ptr.
All input files were then free'd when the symbol table is freed
which is on program exit.

I think we don't have to transfer ownership just to free all
instance at once on exit.

In this patch, all instances are automatically collected to a
vector and freed on exit. In this way, we no longer have to
use std::unique_ptr.

Differential Revision: https://reviews.llvm.org/D24493

llvm-svn: 281425

Before this lld was always creating common symbols itself. It worked,
but prevented them from being internalized when possible.

Now it preserves common symbols is the bitcode and they are internalized.

Fixes pr30184.

llvm-svn: 280242

Given that we almost always want to handle it as DefinedRegular, just
use DefinedRegular.

llvm-svn: 280226

llvm-svn: 280224

Differential Revision:  https://reviews.llvm.org/D24037

llvm-svn: 280144

Previously, each subclass of SymbolBody had a pointer to a source
file from which it was created. So, there was no single way to get
a source file for a symbol. We had getSourceFile<ELFT>(), but the
function was a bit inconvenient as it's a template.

This patch makes SymbolBody have a pointer to a source file.
If a symbol is not created from a file, the pointer has a nullptr.

llvm-svn: 275701

llvm-svn: 275694

Differential Revision: https://reviews.llvm.org/D22396

llvm-svn: 275526

llvm-svn: 275524

llvm-svn: 275523

This patch corresponds to r275511 for COFF.

llvm-svn: 275521

llvm-svn: 275477

llvm-svn: 273462

This fixes PR28218. Thanks to Rafael for spotting a failure in
the SHARED_LIBS build!

Differential Revision:  http://reviews.llvm.org/D21577

llvm-svn: 273451

This reverts commit r273247.

lld should always use the new relocations.

llvm-svn: 273266

llvm-svn: 272475

Differential Revision:  http://reviews.llvm.org/D20888

llvm-svn: 271605

When we undefine, we also preserve type of symbol so that we get
it right in the combined LTO object.

Differential Revision:  http://reviews.llvm.org/D20851

llvm-svn: 271403

Differential Revision: http://reviews.llvm.org/D20704

llvm-svn: 270968

llvm-svn: 269607