llvm-svn: 307083

This is PR28414. 
Previously LLD was unable to link following:
(failed with undefined symbol bar)

Version script:
SOME_VERSION { global: *; };

.global _start
.global bar
.symver _start, bar@@SOME_VERSION
_start:
  jmp bar
Manual has next description:

.symver name, name2@@nodename
In this case, the symbol name must exist and be defined within the file being assembled. It is similar to name2@nodename. 
The difference is name2@@nodename will also be used to resolve references to name2 by the linker
https://sourceware.org/binutils/docs/as/Symver.html

Patch implements that. If we have name@@ver symbol and name is undefined, name@@ver is used to resolve references to name.
If name is defined then multiple definition error is emited, that is consistent with what bfd do.

Differential revision: https://reviews.llvm.org/D33680

llvm-svn: 307077

Two more places.

llvm-svn: 307076

llvm-svn: 307044

Now removeUnusedSyntheticSections operates entirely on the linker
script.

llvm-svn: 307043

* Return type changed to void, because it was unused.
* std::find_if -> llvm::find_if

llvm-svn: 307039

Script commands are processed before unused synthetic sections are
removed. Therefore, if a linker script matches one of these sections
it'll get emitted as an empty output section because the logic for
removing unused synthetic sections ignores script commands which
could have already matched and captured one of these sections. This
patch fixes that by also removing the unused synthetic sections from
the script commands.

Differential Revision: https://reviews.llvm.org/D34800

llvm-svn: 307037

This patch makes changes to allow sections without the SHF_ALLOC bit to be
assigned to segments in a linker script.

The assignment of output sections to segments is performed in
LinkerScript::createPhdrs. Previously, this function would bail as soon as it
encountered an output section which did not have the SHF_ALLOC bit set, thus
preventing any output section without SHF_ALLOC from being assigned to a
segment.

This restriction has now been removed from LinkerScript::createPhdrs and instead
a check for SHF_ALLOC has been added to LinkerScript::adjustSectionsAfterSorting
to not propagate program headers to sections without SHF_ALLOC which matches the
behaviour of bfd linker scripts.

Differential Revision: https://reviews.llvm.org/D34204

llvm-svn: 307013

This reverts commit r306813 because it broke linking of the
FreeBSD base system.

llvm-svn: 306996

This is PR28414. 
Previously LLD was unable to link following:
(failed with undefined symbol bar)

```
Version script:
SOME_VERSION { global: *; };

.global _start
.global bar
.symver _start, bar@@SOME_VERSION
_start:
  jmp bar
```

Manual has next description:
//
.symver name, name2@@nodename
In this case, the symbol name must exist and be defined within the file being assembled. It is similar to name2@nodename. 
**The difference is name2@@nodename will also be used to resolve references to name2 by the linker**
https://sourceware.org/binutils/docs/as/Symver.html
//

Patch implements that. If we have name@@ver symbol and name is undefined, 
name@@ver is used to resolve references to name.

Differential revision: https://reviews.llvm.org/D33680

llvm-svn: 306813

Differential Revision: https://reviews.llvm.org/D34852

llvm-svn: 306772

llvm-svn: 306700

Now that _GLOBAL_OFFSET_TABLE_ is defined, we can just use R_PC for it
if needed.

llvm-svn: 306614

llvm-svn: 306609

We could have add this function either Symbol or SymbolBody. I added it
to Symbol at first. But I noticed that if I've added it to SymbolBody,
we could've removed SymbolBody::setName(). So I'll do that in this patch.

llvm-svn: 306590

This patch adds a utility function to Symbol. This function should
be useful in https://reviews.llvm.org/D33680 too.

llvm-svn: 306587

Add support for the most common SPARC relocations.
Make DT_PLTGOT point to the PLT on SPARC.
Mark the PLT as executable on SPARC.

This adds a basic test that creates a SPARV9 executable
that invokes the exit system call on OpenBSD.

Patch by Mark Kettenis.

Differential Revision: https://reviews.llvm.org/D34618

llvm-svn: 306565

This is PR33596. Previously LLD would crash
because BYTE command synthesized output section,
but it was not assigned to Sec member of OutputSectionCommand.

Behaviour of -script and -r combination is not well defined,
but it seems after this change LLD naturally inherits behavior of
GNU linkers - creates output section requested in script and does not
crash anymore.

Differential revision: https://reviews.llvm.org/D34676

llvm-svn: 306527

This fixes PR33598.

Size field for undefined symbols is not significant.
Setting it to fixed value, like zero, may be useful though.

For example when we have 2 DSO's, like in this PR, if lower level DSO may
change slightly (in part of some symbol's st_size)  and higher-level DSO is
rebuilt, then tools that monitoring checksum of high level DSO file can notice
it and trigger cascade of some other unnecessary actions. 
If we set st_size to zero, that can be avoided.

Differential revision: https://reviews.llvm.org/D34673

llvm-svn: 306526

When -ffunction-sections and ARM C++ exceptions are used each .text.suffix
section will have at least one .ARM.exidx.suffix section and may have an
additional .ARM.extab.suffix section if the unwinding instructions are too
large to inline into the .ARM.exidx table entry. For a large program without
a linker script this can lead to a large number of section header table
entries that can increase the size of the ELF file.

This change introduces a default rule for .ARM.extab.* to be placed in
a single output section called .ARM.extab . This follows the behavior of
ld.gold and ld.bfd.

fixes pr33407

Differential Revision: https://reviews.llvm.org/D34678

llvm-svn: 306522

This patch fills holes in executable sections with 0xd4 (ARM) or
0xef (MIPS). These trap instructions were suggested by Theo de Raadt.

llvm-svn: 306322

llvm-svn: 306308

`addInputSec` returns void. Even though it is syntactically correct,
the use of `return` here is just confusing.

llvm-svn: 306307

Most "reserved" symbols are in ElfSym and it looks like there's no
reason to not do the same thing for _GLOBAL_OFFSET_TABLE_. This should
help https://reviews.llvm.org/D34618 too.

llvm-svn: 306292

On many architectures gcc and clang will recognize _GLOBAL_OFFSET_TABLE_ - .
and produce a relocation that can be processed without needing to know the
value of _GLOBAL_OFFSET_TABLE_. This is not always the case; for example ARM
gcc produces R_ARM_BASE_PREL but clang produces the more general
R_ARM_REL32 to _GLOBAL_OFFSET_TABLE_. To evaluate this relocation
correctly _GLOBAL_OFFSET_TABLE_ must be defined to be the either the base of
the GOT or end of the GOT dependent on architecture..

If/when llvm-mc is changed to recognize _GLOBAL_OFFSET_TABLE_ - . this
change will not be necessary for new objects. However there may still be
old objects and versions of clang.

Differential Revision: https://reviews.llvm.org/D34355

llvm-svn: 306282

Previously, when symbol A is renamed B, both A and B end up having
the same name. This is because name is a symbol's attribute, and
we memcpy symbols for symbol renaming.

This pathc saves the original symbol name and restore it after memcpy
to keep the original name.

This patch shouldn't change program's meaning, but names in symbol
tables make more sense than before.

llvm-svn: 306036

Differential Revision: https://reviews.llvm.org/D34442

llvm-svn: 305983

This is unnecessary because --gc-sections runs before ICF.

Differential Revision: https://reviews.llvm.org/D34465

llvm-svn: 305954

The --exclude-libs option is not a popular option, but at least some
programs in Android depend on it, so it's worth to support it.

Differential Revision: https://reviews.llvm.org/D34422

llvm-svn: 305920

llvm-svn: 305877

The option numbers in the macro were off by one which
leads to some confusion.  There are actually 12 arguments
to this macro.

Differential Revision: https://reviews.llvm.org/D34413

llvm-svn: 305823

This is patch for GSoC project, bash-completion for clang.

To use this on bash, please run `source clang/utils/bash-autocomplete.sh`.
bash-autocomplete.sh is code for bash-completion.

In this patch, Options.td was mainly changed in order to add value class
in Options.inc.

llvm-svn: 305805

I found this while trying to build u-boot. It uses -Ttext in
combination with linker scripts.

My first reaction was to change the linker scripts to have the correct
value, but I found that it is actually quite convenient to have -Ttext
take precedence.

By having just

.text : { *(.text) }

In the script, they can define the text address in a single Makefile
and pass it to ld with -Ttext and for the C code with
-DFoo=value. Doing the same with linker scripts would require them to
be generated during the build.

llvm-svn: 305766

Differential Revision: https://reviews.llvm.org/D34358

llvm-svn: 305742

This patch adds support for segment NONE in linker scripts which enables the
specification that a section should not be assigned to any segment.

Note that GNU ld does not disallow the definition of a segment named NONE, which
if defined, effectively overrides the behaviour described above. This feature
has been copied.

Differential Revision: https://reviews.llvm.org/D34203

llvm-svn: 305700

In r305364, Rui changed the mechanism that parses -z option values slightly.
This caused a bug, as demonstrated by this test, which now fails:

---
# REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
# RUN: ld.lld %t.o -o %t -z max-page-size

.global _start
_start:
  nop
---

Before, the link succeeded and set the max-page-size to the target default.

After we get the following two error messages:
"invalid max-page-size: "
"max-page-size: value isn't a power of 2"

The latter error is because an uninitialised variable ends up being passed back
to getMaxPageSize).

This change ensures we only get the first error.

Reviewers: ruiu

Differential Revision: https://reviews.llvm.org/D34234

llvm-svn: 305679

    
The get{ARM,AArch64}UndefinedRelativeWeakVA() functions should only be
called for PC-relative relocations. Complete the supported pc-relative
relocations in the switch statement and make the default case unreachable.

The R_ARM_TARGET relocation can be evaluated as R_ARM_REL32 but it is only
used in the context of exception tables, and is never output with respect
to a weak reference so it does not appear in the switch statement.
    
Differential Revision: https://reviews.llvm.org/D34138

llvm-svn: 305673

We would crash before.

llvm-svn: 305615

We would crash instead before.

llvm-svn: 305614

We would crash instead before.

llvm-svn: 305613