Original commit message:
[clang-repl] Implement partial translation units and error recovery.
https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:
Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.
The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.
The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.
Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.
It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.
We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.
We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.
This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:
```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```
Differential revision: https://reviews.llvm.org/D104918
This reverts commit 6775fc6ffa.
It also reverts "[lldb] Fix compilation by adjusting to the new ASTContext signature."
This reverts commit 03a3f86071.
We see some failures on the lldb infrastructure, these changes might play a role
in it. Let's revert it now and see if the bots will become green.
Ref: https://reviews.llvm.org/D104918
https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:
Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.
The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.
The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.
Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.
It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.
We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.
We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.
This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:
```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```
Differential revision: https://reviews.llvm.org/D104918
The Microsoft STL currently has some issues with P2266.
We disable it for now in that mode, but we might come back later with a
more targetted approach.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D105518
The feature was implemented in D99005, but we forgot to add the test
macro.
Reviewed By: Quuxplusone
Differential Revision: https://reviews.llvm.org/D104984
This is mostly a mechanical change, but a testcase that contains
parts of the StringRef class (clang/test/Analysis/llvm-conventions.cpp)
isn't touched.
The default Altivec ABI was implemented but the clang error for specifying
its use still remains. Users could get around this but not specifying the
type of Altivec ABI but we need to remove the error.
Reviewed By: jsji
Differential Revision: https://reviews.llvm.org/D102094
Summary:
The changes introduced in D97680 turns this command line option into a no-op so
it can be removed entirely.
Reviewed By: tianshilei1992
Differential Revision: https://reviews.llvm.org/D102940
When creating a PCH file the use of a temp file will be dictated by the
presence or absence of the -fno-temp-file flag. Creating a module file
will always use a temp file via the new ForceUseTemporary flag.
This fixes bug 50033.
The `PreprocessOnlyAction` doesn't support loading the AST file of a precompiled header. This is problematic for dependency scanning, since the `#include` manufactured for the PCH is treated as textual. This means the PCH contents get scanned with each TU, which is redundant. Moreover, dependencies of the PCH end up being considered dependency of the TU.
To handle AST file of PCH properly, this patch creates new `FrontendAction` that behaves the same way `PreprocessorOnlyAction` does, but treats the manufactured PCH `#include` as a normal compilation would (by not claiming it only uses a preprocessor and creating the default AST consumer).
The AST file is now reported as a file dependency of the TU.
Depends on D103519.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D103524
<string> is currently the highest impact header in a clang+llvm build:
https://commondatastorage.googleapis.com/chromium-browser-clang/llvm-include-analysis.html
One of the most common places this is being included is the APInt.h header, which needs it for an old toString() implementation that returns std::string - an inefficient method compared to the SmallString versions that it actually wraps.
This patch replaces these APInt/APSInt methods with a pair of llvm::toString() helpers inside StringExtras.h, adjusts users accordingly and removes the <string> from APInt.h - I was hoping that more of these users could be converted to use the SmallString methods, but it appears that most end up creating a std::string anyhow. I avoided trying to use the raw_ostream << operators as well as I didn't want to lose having the integer radix explicit in the code.
Differential Revision: https://reviews.llvm.org/D103888
This completes the series implementing p1099, by adding the feature
macro and updating the web page.
Differential Revision: https://reviews.llvm.org/D102242
This renames the expression value categories from rvalue to prvalue,
keeping nomenclature consistent with C++11 onwards.
C++ has the most complicated taxonomy here, and every other language
only uses a subset of it, so it's less confusing to use the C++ names
consistently, and mentally remap to the C names when working on that
context (prvalue -> rvalue, no xvalues, etc).
Renames:
* VK_RValue -> VK_PRValue
* Expr::isRValue -> Expr::isPRValue
* SK_QualificationConversionRValue -> SK_QualificationConversionPRValue
* JSON AST Dumper Expression nodes value category: "rvalue" -> "prvalue"
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Reviewed By: rsmith
Differential Revision: https://reviews.llvm.org/D103720
This patch https://reviews.llvm.org/D102876 caused some lit regressions on z/OS because tmp files were no longer being opened based on binary/text mode. This patch passes OpenFlags when creating tmp files so we can open files in different modes.
Reviewed By: amccarth
Differential Revision: https://reviews.llvm.org/D103806
incorrect std::string use. (Also remove redundant call to
RemoveFileOnSignal.)
Clang writes object files by first writing to a .tmp file and then
renaming to the final .obj name. On Windows, if a compile is killed
partway through the .tmp files don't get deleted.
Currently it seems like RemoveFileOnSignal takes care of deleting the
tmp files on Linux, but on Windows we need to call
setDeleteDisposition on tmp files so that they are deleted when
closed.
This patch switches to using TempFile to create the .tmp files we write
when creating object files, since it uses setDeleteDisposition on Windows.
This change applies to both Linux and Windows for consistency.
Differential Revision: https://reviews.llvm.org/D102876
This reverts commit 20797b129f.
Clang writes object files by first writing to a .tmp file and then
renaming to the final .obj name. On Windows, if a compile is killed
partway through the .tmp files don't get deleted.
Currently it seems like RemoveFileOnSignal takes care of deleting the
tmp files on Linux, but on Windows we need to call
setDeleteDisposition on tmp files so that they are deleted when
closed.
This patch switches to using TempFile to create the .tmp files we write
when creating object files, since it uses setDeleteDisposition on Windows.
This change applies to both Linux and Windows for consistency.
Differential Revision: https://reviews.llvm.org/D102876
All fuchsia targets will now use the relative-vtables ABI by default.
Also remove -fexperimental-relative-c++-abi-vtables from test RUNs targeting fuchsia.
Differential Revision: https://reviews.llvm.org/D102374
This patch replaces a `std::pair` by a proper struct in `InitHeaderSearch`. This will be useful in a follow-up: D102923.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D102924
Like other sanitizers, enable __has_feature(coverage_sanitizer) if clang
has enabled at least one SanitizerCoverage instrumentation type.
Because coverage instrumentation selection is not handled via normal
-fsanitize= (and thus not in SanitizeSet), passing this information
through to LangOptions required propagating the already parsed
-fsanitize-coverage= options from CodeGenOptions through to LangOptions
in FixupInvocation().
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D103159
There already exists cl_khr_fp64 extension. So OpenCL C 3.0
and higher should use the feature, earlier versions still
use the extension. OpenCL C 3.0 API spec states that extension
will be not described in the option string if corresponding
optional functionality is not supported (see 4.2. Querying Devices).
Due to that fact the usage of features for OpenCL C 3.0 must
be as follows:
```
$ clang -Xclang -cl-ext=+cl_khr_fp64,+__opencl_c_fp64 ...
$ clang -Xclang -cl-ext=-cl_khr_fp64,-__opencl_c_fp64 ...
```
e.g. the feature and the equivalent extension (if exists)
must be set to the same values
Reviewed By: Anastasia
Differential Revision: https://reviews.llvm.org/D96524
Currently, we have support for SYCL 1.2.1 (also known as SYCL 2017).
This patch introduces the start of support for SYCL 2020 mode, which is
the latest SYCL standard available at (https://www.khronos.org/registry/SYCL/specs/sycl-2020/html/sycl-2020.html).
This sets the default SYCL to be 2020 in the driver, and introduces the
notion of a "default" version (set to 2020) when cc1 is in SYCL mode
but there was no explicit -sycl-std= specified on the command line.
This patch removes duplicates also encountered in the output of clang-scan-deps when one same header file is encountered with different casing and/or different separators ('/' vs '\').
The case of separators can appear when the same file is included externally by
`#include <folder/file.h>`
whereas a file from the same folder does
`#include "file.h"`
Under Windows, clang computes the paths using '/' from the include directive, the `\` from the -I options, and the concatenations use the native `\`, leading to internal paths containing a mix of both separators.
Differential Revision: https://reviews.llvm.org/D102339
This patch enables explicitly building inferred modules.
Effectively a cherry-pick of https://github.com/apple/llvm-project/pull/699 authored by @Bigcheese with libclang and dependency scanner changes omitted.
Contains the following changes:
1. [Clang] Fix the header paths in clang::Module for inferred modules.
* The UmbrellaAsWritten and NameAsWritten fields in clang::Module are a lie for framework modules. For those they actually are the path to the header or umbrella relative to the clang::Module::Directory.
* The exception to this case is for inferred modules. Here it actually is the name as written, because we print out the module and read it back in when implicitly building modules. This causes a problem when explicitly building an inferred module, as we skip the printing out step.
* In order to fix this issue this patch adds a new field for the path we want to use in getInputBufferForModule. It also makes NameAsWritten actually be the name written in the module map file (or that would be, in the case of an inferred module).
2. [Clang] Allow explicitly building an inferred module.
* Building the actual module still fails, but make sure it fails for the right reason.
Split from D100934.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D102491
This patch adds support for GCC's -fstack-usage flag. With this flag, a stack
usage file (i.e., .su file) is generated for each input source file. The format
of the stack usage file is also similar to what is used by GCC. For each
function defined in the source file, a line with the following information is
produced in the .su file.
<source_file>:<line_number>:<function_name> <size_in_byte> <static/dynamic>
"Static" means that the function's frame size is static and the size info is an
accurate reflection of the frame size. While "dynamic" means the function's
frame size can only be determined at run-time because the function manipulates
the stack dynamically (e.g., due to variable size objects). The size info only
reflects the size of the fixed size frame objects in this case and therefore is
not a reliable measure of the total frame size.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D100509
DisableGeneratingGlobalModuleIndex was being set by
CompilerInstance::findOrCompileModuleAndReadAST most of (but not all of)
the times it returned `nullptr` as a "normal" failure. Pull that up to
the caller, CompilerInstance::loadModule, to simplify the code. This
resolves a number of FIXMEs added during the refactoring in
5cca622310.
The extra cases where this is set are all some version of a fatal error,
and the only client of the field, shouldBuildGlobalModuleIndex, seems
to be unreachable in that case. Even if there is some corner case where
this has an effect, it seems like the right/consistent behaviour.
Differential Revision: https://reviews.llvm.org/D101672
Rename CompilerInstance's ModuleBuildFailed field to
DisableGeneratingGlobalModuleIndex, which more precisely describes its
role. Otherwise, it's hard to suss out how it's different from
ModuleLoader::HadFatalFailure, and what sort of code simplifications are
safe.
Differential Revision: https://reviews.llvm.org/D101670
5cca622310 refactored
CompilerInstance::loadModule, splitting out
findOrCompileModuleAndReadAST, but was careful to avoid making any
functional changes. It added ModuleLoader::OtherUncachedFailure to
facilitate this and left behind FIXMEs asking why certain failures
weren't cached.
After a closer look, I think we can just remove this and simplify the
code. This changes the behaviour of the following (simplified) code from
CompilerInstance::loadModule, causing a failure to be cached more often:
```
if (auto MaybeModule = MM.getCachedModuleLoad(*Path[0].first))
return *MaybeModule;
if (ModuleName == getLangOpts().CurrentModule)
return MM.cacheModuleLoad(PP.lookupModule(...));
ModuleLoadResult Result = findOrCompileModuleAndReadAST(...);
if (Result.isNormal()) // This will be 'true' more often.
return MM.cacheModuleLoad(..., Module);
return Result;
```
`MM` here is a ModuleMap owned by the Preprocessor. Here are the cases
where `findOrCompileModuleAndReadAST` starts returning a "normal" failed
result:
- Emitted `diag::err_module_not_found`, where there's no module map
found.
- Emitted `diag::err_module_build_disabled`, where implicitly building
modules is disabled.
- Emitted `diag::err_module_cycle`, which detects module cycles in the
implicit modules build system.
- Emitted `diag::err_module_not_built`, which avoids building a module
in this CompilerInstance if another one tried and failed already.
- `compileModuleAndReadAST()` was called and failed to build.
The four errors are all fatal, and last item also reports a fatal error,
so it this extra caching has no functionality change... but even if it
did, it seems fine to cache these failed results within a ModuleMap
instance (note that each CompilerInstance has its own Preprocessor and
ModuleMap).
Differential Revision: https://reviews.llvm.org/D101667
Original commit message:
In http://lists.llvm.org/pipermail/llvm-dev/2020-July/143257.html we have
mentioned our plans to make some of the incremental compilation facilities
available in llvm mainline.
This patch proposes a minimal version of a repl, clang-repl, which enables
interpreter-like interaction for C++. For instance:
./bin/clang-repl
clang-repl> int i = 42;
clang-repl> extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=42
clang-repl> quit
The patch allows very limited functionality, for example, it crashes on invalid
C++. The design of the proposed patch follows closely the design of cling. The
idea is to gather feedback and gradually evolve both clang-repl and cling to
what the community agrees upon.
The IncrementalParser class is responsible for driving the clang parser and
codegen and allows the compiler infrastructure to process more than one input.
Every input adds to the “ever-growing” translation unit. That model is enabled
by an IncrementalAction which prevents teardown when HandleTranslationUnit.
The IncrementalExecutor class hides some of the underlying implementation
details of the concrete JIT infrastructure. It exposes the minimal set of
functionality required by our incremental compiler/interpreter.
The Transaction class keeps track of the AST and the LLVM IR for each
incremental input. That tracking information will be later used to implement
error recovery.
The Interpreter class orchestrates the IncrementalParser and the
IncrementalExecutor to model interpreter-like behavior. It provides the public
API which can be used (in future) when using the interpreter library.
Differential revision: https://reviews.llvm.org/D96033
This reverts commit 44a4000181.
We are seeing build failures due to missing dependency to libSupport and
CMake Error at tools/clang/tools/clang-repl/cmake_install.cmake
file INSTALL cannot find
In http://lists.llvm.org/pipermail/llvm-dev/2020-July/143257.html we have
mentioned our plans to make some of the incremental compilation facilities
available in llvm mainline.
This patch proposes a minimal version of a repl, clang-repl, which enables
interpreter-like interaction for C++. For instance:
./bin/clang-repl
clang-repl> int i = 42;
clang-repl> extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=42
clang-repl> quit
The patch allows very limited functionality, for example, it crashes on invalid
C++. The design of the proposed patch follows closely the design of cling. The
idea is to gather feedback and gradually evolve both clang-repl and cling to
what the community agrees upon.
The IncrementalParser class is responsible for driving the clang parser and
codegen and allows the compiler infrastructure to process more than one input.
Every input adds to the “ever-growing” translation unit. That model is enabled
by an IncrementalAction which prevents teardown when HandleTranslationUnit.
The IncrementalExecutor class hides some of the underlying implementation
details of the concrete JIT infrastructure. It exposes the minimal set of
functionality required by our incremental compiler/interpreter.
The Transaction class keeps track of the AST and the LLVM IR for each
incremental input. That tracking information will be later used to implement
error recovery.
The Interpreter class orchestrates the IncrementalParser and the
IncrementalExecutor to model interpreter-like behavior. It provides the public
API which can be used (in future) when using the interpreter library.
Differential revision: https://reviews.llvm.org/D96033
Add front end diagnostics to report error for unimplemented TLS models set by
- compiler option `-ftls-model`
- attributes like `__thread int __attribute__((tls_model("local-exec"))) var_name;`
Reviewed by: aaron.ballman, nemanjai, PowerPC
Differential Revision: https://reviews.llvm.org/D102070
This implements the flag proposed in RFC
http://lists.llvm.org/pipermail/cfe-dev/2020-August/066437.html.
The goal is to add a way to override the default target C++ ABI through a
compiler flag. This makes it easier to test and transition between different
C++ ABIs through compile flags rather than build flags.
In this patch:
- Store -fc++-abi= in a LangOpt. This isn't stored in a CodeGenOpt because
there are instances outside of codegen where Clang needs to know what the
ABI is (particularly through ASTContext::createCXXABI), and we should be
able to override the target default if the flag is provided at that point.
- Expose the existing ABIs in TargetCXXABI as values that can be passed
through this flag.
- Create a .def file for these ABIs to make it easier to check flag values.
- Add an error for diagnosing bad ABI flag values.
Differential Revision: https://reviews.llvm.org/D85802
Remove an early return from an `else` block that's immediately followed
by an equivalent early return after the `else` block.
Differential Revision: https://reviews.llvm.org/D101671
AMDGPU backend need to know whether floating point opcodes that support exception
flag gathering quiet and propagate signaling NaN inputs per IEEE754-2008, which is
conveyed by a function attribute "amdgpu-ieee". "amdgpu-ieee"="false" turns this off.
Without this function attribute backend assumes it is on for compute functions.
-mamdgpu-ieee and -mno-amdgpu-ieee are added to Clang to control this function attribute.
By default it is on. -mno-amdgpu-ieee requires -fno-honor-nans or equivalent.
Reviewed by: Matt Arsenault
Differential Revision: https://reviews.llvm.org/D77013
Reduces numbers of files built for clang-format from 575 to 449.
Requires two small changes:
1. Don't use llvm::ExceptionHandling in LangOptions. This isn't
even quite the right type since we don't use all of its values.
Tweaks the changes made in:
- https://reviews.llvm.org/D93215
- https://reviews.llvm.org/D93216
2. Move section name validation code added (long ago) in commit 30ba67439 out
of libBasic into Sema and base the check on the triple. This is a bit less
OOP-y, but completely in line with what we do in many other places in Sema.
No behavior change.
Differential Revision: https://reviews.llvm.org/D101463
Language options are not available when a target is being created,
thus, a new method is introduced. Also, some refactoring is done,
such as removing OpenCL feature macros setting from TargetInfo.
Reviewed By: Anastasia
Differential Revision: https://reviews.llvm.org/D101087
Reverts parts of https://reviews.llvm.org/D17183, but keeps the
resetDataLayout() API and adds an assert that checks that datalayout string and
user label prefix are in sync.
Approach 1 in https://reviews.llvm.org/D17183#2653279
Reduces number of TUs build for 'clang-format' from 689 to 575.
I also implemented approach 2 in D100764. If someone feels motivated
to make us use DataLayout more, it's easy to revert this change here
and go with D100764 instead. I don't plan on doing more work in this
area though, so I prefer going with the smaller, more self-consistent change.
Differential Revision: https://reviews.llvm.org/D100776
NFC, this simplifies the main parsing/generating functions by moving logic around conditional `LangOptions` where it belongs.
Reviewed By: Bigcheese
Differential Revision: https://reviews.llvm.org/D100653
Vassil Vassilev