[MC][ELF] Support for zero flag section groups

This change introduces support for zero flag ELF section groups to LLVM.
LLVM already supports COMDAT sections, which in ELF are a special type
of ELF

[MC][ELF] Support for zero flag section groups

This change introduces support for zero flag ELF section groups to LLVM.
LLVM already supports COMDAT sections, which in ELF are a special type
of ELF section groups. These are generally useful to enable linker GC
where you want a group of sections to always travel together, that is to
be either retained or discarded as a whole, but without the COMDAT
semantics. Other ELF assemblers already support zero flag ELF section
groups and this change helps us reach feature parity.

Differential Revision: https://reviews.llvm.org/D95851

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[Target] Use Align in TargetLoweringObjectFile::getSectionForConstant.

Differential Revision: https://reviews.llvm.org/D80363

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the ne

Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636

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Move Object format code to lib/BinaryFormat.

This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various type

Move Object format code to lib/BinaryFormat.

This creates a new library called BinaryFormat that has all of
the headers from llvm/Support containing structure and layout
definitions for various types of binary formats like dwarf, coff,
elf, etc as well as the code for identifying a file from its
magic.

Differential Revision: https://reviews.llvm.org/D33843

llvm-svn: 304864

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Target: Change various section classifiers in TargetLoweringObjectFile to take a GlobalObject.

These functions are about classifying a global which will actually be
emitted, so it does not make sens

Target: Change various section classifiers in TargetLoweringObjectFile to take a GlobalObject.

These functions are about classifying a global which will actually be
emitted, so it does not make sense for them to take a GlobalValue which may
for example be an alias.

Change the Mach-O object writer and the Hexagon, Lanai and MIPS backends to
look through aliases before using TargetLoweringObjectFile interfaces. These
are functional changes but all appear to be bug fixes.

Differential Revision: https://reviews.llvm.org/D25917

llvm-svn: 285006

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Move the Mangler from the AsmPrinter down to TLOF and clean up the
TLOF API accordingly.

llvm-svn: 281708

Unbreak non-X86 targets from fallout caused by r261462

llvm-svn: 261463

GlobalValue: use getValueType() instead of getType()->getPointerElementType().

Reviewers: mjacob

Subscribers: jholewinski, arsenm, dsanders, dblaikie

Patch by Eduard Burtescu.

Differential Revisi

GlobalValue: use getValueType() instead of getType()->getPointerElementType().

Reviewers: mjacob

Subscribers: jholewinski, arsenm, dsanders, dblaikie

Patch by Eduard Burtescu.

Differential Revision: http://reviews.llvm.org/D16260

llvm-svn: 257999

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Stop producing .data.rel sections.

If a section is rw, it is irrelevant if the dynamic linker will write to
it or not.

It looks like llvm implemented this because gcc was doing it. It looks
like gc

Stop producing .data.rel sections.

If a section is rw, it is irrelevant if the dynamic linker will write to
it or not.

It looks like llvm implemented this because gcc was doing it. It looks
like gcc implemented this in the hope that it would put all the
relocated items close together and speed up the dynamic linker.

There are two problem with this:
* It doesn't work. Both bfd and gold will map .data.rel to .data and
concatenate the input sections in the order they are seen.
* If we want a feature like that, it can be implemented directly in the
linker since it knowns where the dynamic relocations are.

llvm-svn: 253436

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Move most user of TargetMachine::getDataLayout to the Module one

Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one

Move most user of TargetMachine::getDataLayout to the Module one

Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

This patch is quite boring overall, except for some uglyness in
ASMPrinter which has a getDataLayout function but has some clients
that use it without a Module (llmv-dsymutil, llvm-dwarfdump), so
some methods are taking a DataLayout as parameter.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11090

From: Mehdi Amini <[email protected]>
llvm-svn: 242386

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Remove DataLayout from TargetLoweringObjectFile, redirect to Module

Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the o

Remove DataLayout from TargetLoweringObjectFile, redirect to Module

Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11079

From: Mehdi Amini <[email protected]>
llvm-svn: 242385

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Move alignment from MCSectionData to MCSection.

This starts merging MCSection and MCSectionData.

There are a few issues with the current split between MCSection and
MCSectionData.

* It optimizes t

Move alignment from MCSectionData to MCSection.

This starts merging MCSection and MCSectionData.

There are a few issues with the current split between MCSection and
MCSectionData.

* It optimizes the the not as important case. We want the production
of .o files to be really fast, but the split puts the information used
for .o emission in a separate data structure.

* The ELF/COFF/MachO hierarchy is not represented in MCSectionData,
leading to some ad-hoc ways to represent the various flags.

* It makes it harder to remember where each item is.

The attached patch starts merging the two by moving the alignment from
MCSectionData to MCSection.

Most of the patch is actually just dropping 'const', since
MCSectionData is mutable, but MCSection was not.

llvm-svn: 237936

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Compute the ELF SectionKind from the flags.

Any code creating an MCSectionELF knows ELF and already provides the flags.

SectionKind is an abstraction used by common code that uses a plain
MCSection

Compute the ELF SectionKind from the flags.

Any code creating an MCSectionELF knows ELF and already provides the flags.

SectionKind is an abstraction used by common code that uses a plain
MCSection.

Use the flags to compute the SectionKind. This removes a lot of
guessing and boilerplate from the MCSectionELF construction.

llvm-svn: 227476

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Move DataLayout back to the TargetMachine from TargetSubtargetInfo
derived classes.

Since global data alignment, layout, and mangling is often based on the
DataLayout, move it to the TargetMachine.

Move DataLayout back to the TargetMachine from TargetSubtargetInfo
derived classes.

Since global data alignment, layout, and mangling is often based on the
DataLayout, move it to the TargetMachine. This ensures that global
data is going to be layed out and mangled consistently if the subtarget
changes on a per function basis. Prior to this all targets(*) have
had subtarget dependent code moved out and onto the TargetMachine.

*One target hasn't been migrated as part of this change: R600. The
R600 port has, as a subtarget feature, the size of pointers and
this affects global data layout. I've currently hacked in a FIXME
to enable progress, but the port needs to be updated to either pass
the 64-bitness to the TargetMachine, or fix the DataLayout to
avoid subtarget dependent features.

llvm-svn: 227113

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Remove the TargetMachine forwards for TargetSubtargetInfo based
information and update all callers. No functional change.

llvm-svn: 214781

CodeGen: Stick constant pool entries in COMDAT sections for WinCOFF

COFF lacks a feature that other object file formats support: mergeable
sections.

To work around this, MSVC sticks constant pool e

CodeGen: Stick constant pool entries in COMDAT sections for WinCOFF

COFF lacks a feature that other object file formats support: mergeable
sections.

To work around this, MSVC sticks constant pool entries in special COMDAT
sections so that each constant is in it's own section. This permits
unused constants to be dropped and it also allows duplicate constants in
different translation units to get merged together.

This fixes PR20262.

Differential Revision: http://reviews.llvm.org/D4482

llvm-svn: 213006

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Add back r201608, r201622, r201624 and r201625

r201608 made llvm corretly handle private globals with MachO. r201622 fixed
a bug in it and r201624 and r201625 were changes for using private linkage,

Add back r201608, r201622, r201624 and r201625

r201608 made llvm corretly handle private globals with MachO. r201622 fixed
a bug in it and r201624 and r201625 were changes for using private linkage,
assuming that llvm would do the right thing.

They all got reverted because r201608 introduced a crash in LTO. This patch
includes a fix for that. The issue was that TargetLoweringObjectFile now has
to be initialized before we can mangle names of private globals. This is
trivially true during the normal codegen pipeline (the asm printer does it),
but LTO has to do it manually.

llvm-svn: 201700

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Revert r201622 and r201608.

This causes the LLVMgold plugin to segfault. More information on the
replies to r201608.

llvm-svn: 201669

Fix PR18743.

The IR
@foo = private constant i32 42

is valid, but before this patch we would produce an invalid MachO from it. It
was invalid because it would use an L label in a section where the l

Fix PR18743.

The IR
@foo = private constant i32 42

is valid, but before this patch we would produce an invalid MachO from it. It
was invalid because it would use an L label in a section where the liker needs
the labels in order to atomize it.

One way of fixing it would be to just reject this IR in the backend, but that
would not be very front end friendly.

What this patch does is use an 'l' prefix in sections that we know the linker
requires symbols for atomizing them. This allows frontends to just use
private and not worry about which sections they go to or how the linker handles
them.

One small issue with this strategy is that now a symbol name depends on the
section, which is not available before codegen. This is not a problem in
practice. The reason is that it only happens with private linkage, which will
be ignored by the non codegen users (llvm-nm and llvm-ar).

llvm-svn: 201608

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XCore target: Handle common linkage

llvm-svn: 201563

XCore target: fix const section handling

Xcore target ABI requires const data that is externally visible
to be handled differently if it has C-language linkage rather than
C++ language linkage.

Cla

XCore target: fix const section handling

Xcore target ABI requires const data that is externally visible
to be handled differently if it has C-language linkage rather than
C++ language linkage.

Clang now emits ".cp.rodata" section information.

All other externally visible constant data will be placed in the DP section.

llvm-svn: 201144

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Pass the Mangler by reference.

It is never null and it is not used in casts, so there is no reason to use a
pointer. This matches how we pass TM.

llvm-svn: 201025

Revert r199871 and replace it with a simple check in the debug info
code to see if we're emitting a function into a non-default
text section. This is still a less-than-ideal solution, but more
contai

Revert r199871 and replace it with a simple check in the debug info
code to see if we're emitting a function into a non-default
text section. This is still a less-than-ideal solution, but more
contained than r199871 to determine whether or not we're emitting
code into an array of comdat sections.

llvm-svn: 200269

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Add a variable to track whether or not we've used a unique section,
e.g. linkonce, to TargetMachine and set it when we've done so
for ELF targets currently. This involved making TargetMachine
non-con

Add a variable to track whether or not we've used a unique section,
e.g. linkonce, to TargetMachine and set it when we've done so
for ELF targets currently. This involved making TargetMachine
non-const in a TLOF use and propagating that change around - I'm
open to other ideas.

This will be used in a future commit to handle emitting debug
information with ranges.

llvm-svn: 199871

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XCore target: Add large code model

When using large code model:
Global objects larger than 'CodeModelLargeSize' bytes are placed in sections named with a trailing ".large"
The folded global address

XCore target: Add large code model

When using large code model:
Global objects larger than 'CodeModelLargeSize' bytes are placed in sections named with a trailing ".large"
The folded global address of such objects are lowered into the const pool.

During inspection it was noted that LowerConstantPool() was using a default offset of zero.
A fix was made, but due to only offsets of zero being generated, testing only verifies the change is not detrimental.

Correct the flags emitted for explicitly specified sections.

We assume the size of the object queried by getSectionForConstant() is never greater than CodeModelLargeSize.
To handle greater than CodeModelLargeSize, changes to AsmPrinter would be required.

llvm-svn: 196087

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