When the data segment is the last segment, it is correct to leave
it unaligned. However, when the code segment is the last segment,
it should be aligned to the page boundary to avoid loading the
non-segment parts of the ELF file at the end of the file.

Differential Revision: https://reviews.llvm.org/D33630

llvm-svn: 309829

[ELF] - Recommit r309252 "[ELF] - Fix missing relocation when linking executable with --unresolved-symbols=ignore-all"

With fix for undefined weak symbols in executable.

Original commit message:
This is PR32112. Previously when we linked executable with 
--unresolved-symbols=ignore-all and undefined symbols, like:

_start:
callq und@PLT

we did not create relocations, though it looks in that case
we should delegate handling of such symbols to runtime linker,
hence should emit them. Patch fixes that.

Differential revision: https://reviews.llvm.org/D35724

llvm-svn: 309796

Enables multithreaded .gdb_index building.

Differential revision: https://reviews.llvm.org/D36090

llvm-svn: 309688

llvm-svn: 309654

This change makes -gdb-index 40% faster. My test case is self-linking lld.

Differential Revision: https://reviews.llvm.org/D36079

llvm-svn: 309652

We don't write any actual symbols to this stream yet, but for
now we just create the stream and hook it up to the appropriate
places and give it a valid header.

Differential Revision: https://reviews.llvm.org/D35290

llvm-svn: 309608

Before we were doing it with --export-dynamic. That seems incorrect.
The intention of --export-dynamic is to export symbols *defined* in
the executable.

llvm-svn: 309605

They were being placed before sections that were listed.

llvm-svn: 309391

* Removed redundant templating.
* Added missing `static` keyword.

llvm-svn: 309376

Previously we would crash when tried to ALIGN(0).
Patch uses value 1 instead in this case, that
looks to be consistent with GNU linkers
and reasonable and simple behavior itself.

Differential revision: https://reviews.llvm.org/D35942

llvm-svn: 309372

This would have found the error in r309252.

llvm-svn: 309329

llvm-svn: 309326

This is a bit of a hack, but it is *so* convenient.

Now that we create synthetic linker scripts when none is provided, we
always have to handle paired OutputSection and OutputsectionCommand and
keep a mapping from one to the other.

This patch simplifies things by merging them and creating what used to
be OutputSectionCommands really early.

llvm-svn: 309311

Summary:
MSVC link.exe records all external symbol names in the publics stream.
It provides similar functionality to an ELF .symtab.

Reviewers: zturner, ruiu

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D35871

llvm-svn: 309303

Revert r309252 "[ELF] - Fix missing relocation when linking executable with --unresolved-symbols=ignore-all"

It broke bot:
http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/4231

llvm-svn: 309258

llvm-svn: 309254

That is slightly more convinent as allows to store pointer on
program header entry in a more safe way.
 
Change was used in 2 patches currently on review.

Differential revision: https://reviews.llvm.org/D35832

llvm-svn: 309253

This is PR32112. Previously when we linked executable with 
--unresolved-symbols=ignore-all and undefined symbols, like:

_start:
callq und@PLT

we did not create relocations, though it looks in that case
we should delegate handling of such symbols to runtime linker,
hence should emit them. Patch fixes that.

Differential revision: https://reviews.llvm.org/D35724

llvm-svn: 309252

We did the same thing for ELF in r309152, and I want to maintain
COFF and ELF as close as possible.

llvm-svn: 309239

This shows that the logic in --gc-sections is a bit more precise than
what can be easily done in LTO.

llvm-svn: 309234

With this we only ask LTO to keep a C named section if there is a
__start_ or __end symbol.

This is not as strict as lld's --gc-sections, but is as good as we can
get without having a far more detailed ir summary.

llvm-svn: 309232

Matches link.exe
https://reviews.llvm.org/D35872

llvm-svn: 309231

llvm-svn: 309228

It is __stop_<sec>, not __end_<sec>.

llvm-svn: 309225

Rename it because it was too easy to conflict with llvm::object::ObjectFile
which broke buildbots several times.

llvm-svn: 309199

This patch fixes a small issue with respect to how memory region names
are parsed on output section descriptions.  For example, consider:

  .text : { *(.text) } > rom

That can also be written like:

  .text : { *(.text) } >rom

The latter form is accepted by GNU LD and is fairly common.

Differential Revision: https://reviews.llvm.org/D35920

llvm-svn: 309191

llvm-svn: 309188

I believe this compiles fine on all platforms, even on Windows.

llvm-svn: 309182

Also handle overflow correctly in LDR/STR relocations. Even if the
offset range of a 8 byte LDR instruction is 15 bit (even if the immediate
itself is 12 bit) due to a 3 bit shift, only include up to 12 bits of offset
after doing the relocation, by limiting the range of the immediate by the
number of shifted bits.

Differential Revision: https://reviews.llvm.org/D35792

llvm-svn: 309175

llvm-svn: 309162

llvm-svn: 309161

llvm-svn: 309160

llvm-svn: 309153

NFC, just makes it easier to access from non templated code.

llvm-svn: 309152

Was discussed in D35797 thread.

llvm-svn: 309096

Previously we handled this option implicitly, only
for infering unresolved symbols handling policy.

ld man says: "--noinhibit-exec Retain the executable
output file whenever it is still usable",
and we may want to handle other cases too.

Differential revision: https://reviews.llvm.org/D35793

llvm-svn: 309091

This is PR30422,
previously LLD did not render all option aliases in --help.
With this patch it will.

Differential revision: https://reviews.llvm.org/D35477

llvm-svn: 309089

Since the flag is ignored anyway, it doesn't matter whether
it is an alias or not.

llvm-svn: 309055

llvm-svn: 309053

llvm-svn: 309051