[llvm] Support indirect symbol replacement with R_ARM_GOT_PREL (#81916)

R_ARM_GOT_PREL is equivalent to GOTPCREL on other architectures, so we
can use it for indirect symbol replacement the same wa

[llvm] Support indirect symbol replacement with R_ARM_GOT_PREL (#81916)

R_ARM_GOT_PREL is equivalent to GOTPCREL on other architectures, so we
can use it for indirect symbol replacement the same way. This is the
equivalent of https://github.com/llvm/llvm-project/pull/67754 for x86_64
and https://github.com/llvm/llvm-project/pull/78003 for AArch64 and
64-bit RISC-V.

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[llvm] Drop unnecessary const from return types (NFC)

Identified with readability-const-return-type.

[DebugInfo][ARM] Fix incorrect debug information for RWPI accessed globals

When compiling for the RWPI relocation model the debug information is wrong:

* the debug location is described as { DW_OP_

[DebugInfo][ARM] Fix incorrect debug information for RWPI accessed globals

When compiling for the RWPI relocation model the debug information is wrong:

* the debug location is described as { DW_OP_addr Var }
instead of { DW_OP_constNu Var DW_OP_bregX 0 DW_OP_plus }
* the relocation type is R_ARM_ABS32 instead of R_ARM_SBREL32

Differential Revision: https://reviews.llvm.org/D111404

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[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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[MC] Add MCSection::NonUniqueID and delete one MCContext::getELFSection overload

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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The initial .text section generated in object files was missing the
SHF_ARM_PURECODE flag when being built with the -mexecute-only flag.
All code sections of an ELF must have the flag set for the fin

The initial .text section generated in object files was missing the
SHF_ARM_PURECODE flag when being built with the -mexecute-only flag.
All code sections of an ELF must have the flag set for the final .text
section to be execute-only, otherwise the flag gets removed.

A HasData flag is added to MCSection to aid in the determination that
the section is empty. A virtual setTargetSectionFlags is added to
MCELFObjectTargetWriter to allow subclasses to set target specific
section flags to be added to sections which we then use in the ARM
backend to set SHF_ARM_PURECODE.

Patch by Ivan Lozano!

Reviewed By: echristo

Differential Revision: https://reviews.llvm.org/D48792

llvm-svn: 341593

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ARM: Remove dead code. NFCI.

llvm-svn: 324565

Rewrite ARM execute only support to avoid the use of a command line flag and unqualified ARMSubtarget lookup.

Paired with a clang commit to use the new behavior.

llvm-svn: 306927

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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Sort the remaining #include lines in include/... and lib/....

I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line

Sort the remaining #include lines in include/... and lib/....

I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787

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[ARM] Remove ThumbTargetMachines. (NFC)

Summary:
Thumb code generation is controlled by ARMSubtarget and the concrete
ThumbLETargetMachine and ThumbBETargetMachine are not needed.

Eric Christopher

[ARM] Remove ThumbTargetMachines. (NFC)

Summary:
Thumb code generation is controlled by ARMSubtarget and the concrete
ThumbLETargetMachine and ThumbBETargetMachine are not needed.

Eric Christopher suggested removing the unneeded target machines in
https://reviews.llvm.org/D33287.

I think it still makes sense to keep separate TargetMachines for big and
little endian as we probably do not want to have different endianess for
difference functions in a single compilation unit. The MIPS backend has
two separate TargetMachines for big and little endian as well.

Reviewers: echristo, rengolin, kristof.beyls, t.p.northover

Reviewed By: echristo

Subscribers: aemerson, javed.absar, arichardson, llvm-commits

Differential Revision: https://reviews.llvm.org/D33318

llvm-svn: 303733

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[ARM] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).

llvm-svn: 293578

[ARM] Implement execute-only support in CodeGen

This implements execute-only support for ARM code generation, which
prevents the compiler from generating data accesses to code sections.
The followin

[ARM] Implement execute-only support in CodeGen

This implements execute-only support for ARM code generation, which
prevents the compiler from generating data accesses to code sections.
The following changes are involved:

* Add the CodeGen option "-arm-execute-only" to the ARM code generator.
* Add the clang flag "-mexecute-only" as well as the GCC-compatible
alias "-mpure-code" to enable this option.
* When enabled, literal pools are replaced with MOVW/MOVT instructions,
with VMOV used in addition for floating-point literals. As the MOVT
instruction is required, execute-only support is only available in
Thumb mode for targets supporting ARMv8-M baseline or Thumb2.
* Jump tables are placed in data sections when in execute-only mode.
* The execute-only text section is assigned section ID 0, and is
marked as unreadable with the SHF_ARM_PURECODE flag with symbol 'y'.
This also overrides selection of ELF sections for globals.

llvm-svn: 289784

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CodeGen: simplify TargetMachine::getSymbol interface. NFC.

No-one actually had a mangler handy when calling this function, and
getSymbol itself went most of the way towards getting its own mangler
(

CodeGen: simplify TargetMachine::getSymbol interface. NFC.

No-one actually had a mangler handy when calling this function, and
getSymbol itself went most of the way towards getting its own mangler
(with a local TLOF variable) so forcing all callers to supply one was
just extra complication.

llvm-svn: 287645

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

llvm-svn: 281708

MC: Clean up MCExpr naming. NFC.

llvm-svn: 238634

Remove calls to bare getSubtarget and clean up the functions
accordingly.

llvm-svn: 227535

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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Allow using normal .eh_frame based unwinding on ARM. Use the same
encodings as x86. Use this exception model for NetBSD.

llvm-svn: 208166

[C++] Use 'nullptr'. Target edition.

llvm-svn: 207197

move getNameWithPrefix and getSymbol to TargetMachine.

TargetLoweringBase is implemented in CodeGen, so before this patch we had
a dependency fom Target to CodeGen. This would show up as a link fail

move getNameWithPrefix and getSymbol to TargetMachine.

TargetLoweringBase is implemented in CodeGen, so before this patch we had
a dependency fom Target to CodeGen. This would show up as a link failure of
llvm-stress when building with -DBUILD_SHARED_LIBS=ON.

This fixes pr18900.

llvm-svn: 201711

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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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