This fixes pr34301.

As the bug points out, we want to keep some relocations with undefined
weak symbols. This means that we cannot always claim that these
symbols are not preemptible as we do now.

Unfortunately, we cannot also just always claim that they are
preemptible. Doing so would, for example, cause us to try to create a
plt entry when we don't even have a dynamic symbol table.

What almost works is to say that weak undefined symbols are
preemptible if and only if we have a dynamic symbol table. Almost
because we don't want to fail the build trying to create a copy
relocation to a weak undefined.

llvm-svn: 313372

Patch removes one of OutputSectionFactory::addInputSec methods.
That allows to simplify reporting of discarded sections and
should help to D37561.

Differential revision: https://reviews.llvm.org/D37735

llvm-svn: 313361

_gp points to a position in the file, so it is not really absolute. It
is also simpler to not force it to be absolute, so if there is no
strong ABI requirement we should not do it.

llvm-svn: 313333

The isShared case was handled by the isInCurrentDSO check.

llvm-svn: 313190

llvm-svn: 313188

llvm-svn: 313184

This reduces the size of SharedSymbol which in turn reduces the size
of Symbol from 88 to 80 bytes.

llvm-svn: 313154

There is no need to scan over all input sections for relocatable output.
As we do not process or scan relocations anyways.
Patch moves check for Config->Relocatable out to avoid that and also removes
excessive check for isa<EhInputSection> from first for loop. 
It is excessive because we handle all of them in a second for loop below.
That all allowed to simplify code.

Differential revision: https://reviews.llvm.org/D37746

llvm-svn: 313127

This should fix the lto bootstrap.

It is somewhat hard to remember about lazy symbols deep down in the
link. It might be worth it replacing them with undefined symbols once
we are done adding files.

llvm-svn: 313103

llvm-svn: 313095

https://reviews.llvm.org/rL312796 meant that references to garbage collected common symbols would cause a segfault.

This change fixes the behaviour for references to stripped common symbols.

Differential Revision: https://reviews.llvm.org/D37718

llvm-svn: 313086

It is not needed since it is always 0.

llvm-svn: 313076

llvm-svn: 313051

Given our representation of symbols as section + offset, we can
finalize symbols like _end as soon as the section is known.

llvm-svn: 313048

The patch implements initial support of microMIPS code linking:
  - Handle microMIPS specific relocations.
  - Emit both R1-R5 and R6 microMIPS PLT records.

For now linking mixed set of regular and microMIPS object files is not
supported. Also the patch does not handle (setup and clear) the
least-significant bit of an address which is utilized as the ISA mode
bit and allows to make jump between regular and microMIPS code without
any thunks.

Differential revision: https://reviews.llvm.org/D37335

llvm-svn: 313028

Replace OutputSection *Cmd to OutputSection *OS. The Commands vector was
moved to OutputSection but the names of the variables were not. This patch
changes the names to match.

Differential Revision: https://reviews.llvm.org/D37627

llvm-svn: 313015

This fixes two more cases where we were aligning the offset in a
section, instead of the final address.

llvm-svn: 312983

When given

foobar = ALIGN(., 0x100);

my expectation from what the manual says is that the final address of
foobar will be aligned. It seems that bfd aligns the offset in the
section, which causes some odd results if the section is not 0x100
aligned. Gold aligns the address.

This changes lld to align the final address.

llvm-svn: 312979

When building COFF programs many targets such as mingw prefer
to have a gnu ld frontend. Rather then having a fully fledged
standalone driver we wrap a shim around the LINK driver.

Extra tests were provided by mstorsjo

Reviewers: mstorsjo, ruiu

Differential Revision: https://reviews.llvm.org/D33880

llvm-svn: 312926

llvm-svn: 312823

llvm-svn: 312820

llvm-svn: 312812

We handled all undefined symbols before this.

llvm-svn: 312808

llvm-svn: 312807

This allows combining --dynamic-list and version scripts too. The
version script controls which symbols are visible, and
--dynamic-list controls which of those are preemptible.

Unlike previous versions, undefined symbols are still considered
preemptible, which was the issue breaking the cfi tests.

This fixes pr34053.

llvm-svn: 312806

to separate commons based on file name patterns. The following linker script
construct does not work because commons are allocated before section placement
is done and the only synthesized BssSection that holds all commons has no file
associated with it:
SECTIONS { .common_0 : { *file0.o(COMMON) }}

This patch changes the allocation of commons to create a section per common
symbol and let the section logic do the layout.

Differential revision: https://reviews.llvm.org/D37489

llvm-svn: 312796

llvm-svn: 312789

llvm-svn: 312787

REGION_ALIAS(alias, region)

Alias names can be added to existing memory regions created with
the MEMORY command. Each name corresponds to at most one
memory region.

Differential revision: https://reviews.llvm.org/D37477

llvm-svn: 312777

This reverts commit r312757.

Evgenii Stepanov reports that it broke some tests.

llvm-svn: 312771

If --dynamic-list is given, only those symbols are preemptible.

This allows combining --dynamic-list and version scripts too. The
version script controls which symbols are visible, and --dynamic-list
controls which of those are preemptible.

This fixes pr34053.

llvm-svn: 312757

llvm-svn: 312753

To support errata patching on AArch64 we need to be able to overwrite
an arbitrary instruction with a branch. For AArch64 it is sufficient to
always write all the bits of the branch instruction and not just the
immediate field. This is safe as the non-immediate bits of the branch
instruction are always the same.

Differential Revision: https://reviews.llvm.org/D36745

llvm-svn: 312727

As was suggested in D34956 thread.

llvm-svn: 312712

It is a bit more convinent and helps to simplify logic 
of program headers allocation a little.

Differential revision: https://reviews.llvm.org/D34956

llvm-svn: 312711

The default padding for an executable segment is the target trap
instruction which for x86_64 is 0xCC. However, the .eh_frame section
requires the padding to be zero. The code that writes the .eh_frame
section assumes that its segment is zero initialized and does not
explicitly write the zero padding. This does not work when the .eh_frame
section is in the executable segment (for example when using
-no-rosegment).

This patch changes the .eh_frame writing code to explicitly write the
zero padding.

Differential Revision: https://reviews.llvm.org/D37462

llvm-svn: 312706

If using --format=binary with an input file name that has one or more non-ascii
characters in, LLD has undefined behaviour (it crashes on my Windows Debug build)
when calling isalnum with these non-ascii characters. Instead, of calling
std::isalnum, this patch uses an internal version that ignores the locale and
checks a specific subset of characters.

Reviewers: ruiu

Differential Revision: https://reviews.llvm.org/D37331

llvm-svn: 312705

llvm-svn: 312675

llvm-svn: 312669

Differential Revision: https://reviews.llvm.org/D37524

llvm-svn: 312656