This patch adds a new field called EmittedDeferredDecls in CodeGenModule
that keeps track of decls that were deferred and have been emitted.
The intention of this patch is to solve issues in the incremental c++,
we'll lose info of decls that are lazily emitted when we undo their
usage.
See example below:
clang-repl> inline int foo() { return 42;}
clang-repl> int bar = foo();
clang-repl> %undo
clang-repl> int baz = foo();
JIT session error: Symbols not found: [ _Z3foov ]
error: Failed to materialize symbols: { (main, { baz, $.incr_module_2.inits.0,
orc_init_func.incr_module_2 }) }
Signed-off-by: Jun Zhang <jun@junz.org>
Differential Revision: https://reviews.llvm.org/D128782
Without this patch, clang will not wrap in an ElaboratedType node types written
without a keyword and nested name qualifier, which goes against the intent that
we should produce an AST which retains enough details to recover how things are
written.
The lack of this sugar is incompatible with the intent of the type printer
default policy, which is to print types as written, but to fall back and print
them fully qualified when they are desugared.
An ElaboratedTypeLoc without keyword / NNS uses no storage by itself, but still
requires pointer alignment due to pre-existing bug in the TypeLoc buffer
handling.
Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>
Differential Revision: https://reviews.llvm.org/D112374
Currently we only implement this for the Itanium ABI since the correct
mangling for the initializers in other ABIs is not yet known.
Intended result:
For a module interface [which includes partition interface and implementation
units] (instead of the generic CXX initializer) we emit a module init that:
- wraps the contained initializations in a control variable to ensure that
the inits only happen once, even if a module is imported many times by
imports of the main unit.
- calls module initializers for imported modules first. Note that the
order of module import is not significant, and therefore neither is the
order of imported module initializers.
- We then call initializers for the Global Module Fragment (if present)
- We then call initializers for the current module.
- We then call initializers for the Private Module Fragment (if present)
For a module implementation unit, or a non-module TU that imports at least one
module we emit a regular CXX init that:
- Calls the initializers for any imported modules first.
- Then proceeds as normal with remaining inits.
For all module unit kinds we include a global constructor entry, this allows
for the (in most cases unusual) possibility that a module object could be
included in a final binary without a specific call to its initializer.
Implementation:
- We provide the module pointer in the AST Context so that CodeGen can act
on it and its sub-modules.
- We need to account for module build lines like this:
` clang -cc1 -std=c++20 Foo.pcm -emit-obj -o Foo.o` or
` clang -cc1 -std=c++20 -xc++-module Foo.cpp -emit-obj -o Foo.o`
- in order to do this, we add to ParseAST to set the module pointer in
the ASTContext, once we establish that this is a module build and we
know the module pointer. To be able to do this, we make the query for
current module public in Sema.
- In CodeGen, we determine if the current build requires a CXX20-style module
init and, if so, we defer any module initializers during the "Eagerly
Emitted" phase.
- We then walk the module initializers at the end of the TU but before
emitting deferred inits (which adds any hidden and static ones, fixing
https://github.com/llvm/llvm-project/issues/51873 ).
- We then proceed to emit the deferred inits and continue to emit the CXX
init function.
Differential Revision: https://reviews.llvm.org/D126189
Information in the function `Prologue Data` is intentionally opaque.
When a function with `Prologue Data` is duplicated. The self (global
value) references inside `Prologue Data` is still pointing to the
original function. This may cause errors like `fatal error: error in backend: Cannot represent a difference across sections`.
This patch detaches the information from function `Prologue Data`
and attaches it to a function metadata node.
This and D116130 fix https://github.com/llvm/llvm-project/issues/49689.
Reviewed By: pcc
Differential Revision: https://reviews.llvm.org/D115844
Add option -fhip-kernel-arg-name to emit kernel argument
name metadata, which is needed for certain HIP applications.
Reviewed by: Artem Belevich, Fangrui Song, Brian Sumner
Differential Revision: https://reviews.llvm.org/D128022
RE-LAND (reverts a revert):
This reverts commit 8e1f47b596.
This patch adds generation of sanitizer metadata attributes (which were
added in D126100) to the clang frontend.
We still currently generate the llvm.asan.globals that's consumed by
the IR pass, but the plan is to eventually migrate off of that onto
purely debuginfo and these IR attributes.
Reviewed By: vitalybuka, kstoimenov
Differential Revision: https://reviews.llvm.org/D126929
This patch adds generation of sanitizer metadata attributes (which were
added in D126100) to the clang frontend.
We still currently generate the `llvm.asan.globals` that's consumed by
the IR pass, but the plan is to eventually migrate off of that onto
purely debuginfo and these IR attributes.
Reviewed By: vitalybuka, kstoimenov
Differential Revision: https://reviews.llvm.org/D126929
The option mdefault-visibility-export-mapping is created to allow
mapping default visibility to an explicit shared library export
(e.g. dllexport). Exactly how and if this is manifested is target
dependent (since it depends on how they map dllexport in the IR).
Three values are provided for the option:
* none: the default and behavior without the option, no additional export linkage information is created.
* explicit: add the export for entities with explict default visibility from the source, including RTTI
* all: add the export for all entities with default visibility
This option is useful for targets which do not export symbols as part of
their usual default linkage behaviour (e.g. AIX), such targets
traditionally specified such information in external files (e.g. export
lists), but this mapping allows them to use the visibility information
typically used for this purpose on other (e.g. ELF) platforms.
This relands commit: 8c8a2679a2
with fixes for the compile time and assert problems that were reported
by:
* making shouldMapVisibilityToDLLExport inline and provide an early return
in the case where no mapping is in effect (aka non-AIX platforms)
* don't try to export RTTI types which we will give internal linkage to
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D126340
Originally broken by me in D122608, this is a regression where we
attempt to replace an extern-C thing with 'itself'. The problem is that
we end up deleting it, causing the value to fail when it gets put into
llvm.used.
A variable with `weak` attribute signifies that it can be replaced with
a "strong" symbol link time. Therefore it must not emitted with
"weak_odr" linkage, as that allows the backend to use its value in
optimizations.
The frontend already considers weak const variables as
non-constant (note_constexpr_var_init_weak diagnostic) so this change
makes frontend and backend consistent.
This commit reverses the
f49573d1 weak globals that are const should get weak_odr linkage.
commit from 2009-08-05 which introduced this behavior. Unfortunately
that commit doesn't provide any details on why the change was made.
This was discussed in
https://discourse.llvm.org/t/weak-attribute-semantics-on-const-variables/62311
Differential Revision: https://reviews.llvm.org/D126324
This caused assertions, see comment on the code review:
llvm/clang/lib/AST/Decl.cpp:1510:
clang::LinkageInfo clang::LinkageComputer::getLVForDecl(const clang::NamedDecl *, clang::LVComputationKind):
Assertion `D->getCachedLinkage() == LV.getLinkage()' failed.
> The option mdefault-visibility-export-mapping is created to allow
> mapping default visibility to an explicit shared library export
> (e.g. dllexport). Exactly how and if this is manifested is target
> dependent (since it depends on how they map dllexport in the IR).
>
> Three values are provided for the option:
>
> * none: the default and behavior without the option, no additional export linkage information is created.
> * explicit: add the export for entities with explict default visibility from the source, including RTTI
> * all: add the export for all entities with default visibility
>
> This option is useful for targets which do not export symbols as part of
> their usual default linkage behaviour (e.g. AIX), such targets
> traditionally specified such information in external files (e.g. export
> lists), but this mapping allows them to use the visibility information
> typically used for this purpose on other (e.g. ELF) platforms.
>
> Reviewed By: MaskRay
>
> Differential Revision: https://reviews.llvm.org/D126340
This reverts commit 8c8a2679a2.
The option mdefault-visibility-export-mapping is created to allow
mapping default visibility to an explicit shared library export
(e.g. dllexport). Exactly how and if this is manifested is target
dependent (since it depends on how they map dllexport in the IR).
Three values are provided for the option:
* none: the default and behavior without the option, no additional export linkage information is created.
* explicit: add the export for entities with explict default visibility from the source, including RTTI
* all: add the export for all entities with default visibility
This option is useful for targets which do not export symbols as part of
their usual default linkage behaviour (e.g. AIX), such targets
traditionally specified such information in external files (e.g. export
lists), but this mapping allows them to use the visibility information
typically used for this purpose on other (e.g. ELF) platforms.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D126340
Refactor the code that handles the align clause of 'omp allocate' so
it can be used with globals as well as local variables.
Differential Revision: https://reviews.llvm.org/D126426
CUDA requires that static variables be visible to the host when
offloading. However, The standard semantics of a stiatc variable dictate
that it should not be visible outside of the current file. In order to
access it from the host we need to perform "externalization" on the
static variable on the device. This requires generating a semi-unique
name that can be affixed to the variable as to not cause linker errors.
This is currently done using the CUID functionality, an MD5 hash value
set up by the clang driver. This allows us to achieve is mostly unique
ID that is unique even between multiple compilations of the same file.
However, this is not always availible. Instead, this patch uses the
unique ID from the file to generate a unique symbol name. This will
create a unique name that is consistent between the host and device side
compilations without requiring the CUID to be entered by the driver. The
one downside to this is that we are no longer stable under multiple
compilations of the same file. However, this is a very niche use-case
and is not supported by Nvidia's CUDA compiler so it likely to be good
enough.
Reviewed By: tra
Differential Revision: https://reviews.llvm.org/D125904
An upcoming patch will extend llvm-symbolizer to provide the source line
information for global variables. The goal is to move AddressSanitizer
off of internal debug info for symbolization onto the DWARF standard
(and doing a clean-up in the process). Currently, ASan reports the line
information for constant strings if a memory safety bug happens around
them. We want to keep this behaviour, so we need to emit debuginfo for
these variables as well.
Reviewed By: dblaikie, rnk, aprantl
Differential Revision: https://reviews.llvm.org/D123534
An upcoming patch will extend llvm-symbolizer to provide the source line
information for global variables. The goal is to move AddressSanitizer
off of internal debug info for symbolization onto the DWARF standard
(and doing a clean-up in the process). Currently, ASan reports the line
information for constant strings if a memory safety bug happens around
them. We want to keep this behaviour, so we need to emit debuginfo for
these variables as well.
Reviewed By: dblaikie, rnk, aprantl
Differential Revision: https://reviews.llvm.org/D123534
The DXIL validator version option(/validator-version) decide the validator version when compile hlsl.
The format is major.minor like 1.0.
In normal case, the value of validator version should be got from DXIL validator. Before we got DXIL validator ready for llvm/main, DXIL validator version option is added first to set validator version.
It will affect code generation for DXIL, so it is treated as a code gen option.
A new member std::string DxilValidatorVersion is added to clang::CodeGenOptions.
Then CGHLSLRuntime is added to clang::CodeGenModule.
It is used to translate clang::CodeGenOptions::DxilValidatorVersion into a ModuleFlag under key "dx.valver" at end of clang code generation.
Reviewed By: beanz
Differential Revision: https://reviews.llvm.org/D123884
Different TU's may have this globl var. appending linkage can
only be used with lld recognized special variables.
Change it to internal linkage.
Reviewed by: Artem Belevich
Differential Revision: https://reviews.llvm.org/D124466
This patch is a continuation of https://reviews.llvm.org/D123353.
Not only kernels in anonymous namespace, but also template
kernels with template arguments in anonymous namespace
need to be externalized.
To be more generic, this patch checks the linkage of a kernel
assuming the kernel does not have __global__ attribute. If
the linkage is internal then clang will externalize it.
This patch also fixes the postfix for externalized symbol
since nvptx does not allow '.' in symbol name.
Reviewed by: Artem Belevich
Differential Revision: https://reviews.llvm.org/D124189
Fixes: https://github.com/llvm/llvm-project/issues/54560
In D123649, I got the formula for getFlexibleArrayInitChars slightly
wrong: the flexible array elements can be contained in the tail padding
of the struct. Fix the formula to account for that.
With the fixed formula, we run into another issue: in some cases, we
were emitting extra padding for flexible arrray initializers. Fix
CGExprConstant so it uses a packed struct when necessary, to avoid this
extra padding.
Differential Revision: https://reviews.llvm.org/D123826
Flexible array initialization is a C/C++ extension implemented in many
compilers to allow initializing the flexible array tail of a struct type
that contains a flexible array. In clang, this is currently restricted
to C. But this construct is used in the Microsoft SDK headers, so I'd
like to extend it to C++.
For now, this doesn't handle dynamic initialization; probably not hard
to implement, but it's extra code, and I don't think it's necessary for
the expected uses. And we explicitly fail out of constant evaluation.
I've added some additional code to assert that initializers have the
correct size, with or without flexible array init. This might catch
issues unrelated to flexible array init.
Differential Revision: https://reviews.llvm.org/D123649
For -fgpu-rdc, a host function may call an external kernel
which is defined in an archive of bitcode. Since this external
kernel is only referenced in host function, the device
bitcode does not contain reference to this external
kernel, then the linker will not try to resolve this external
kernel in the archive.
To fix this issue, host-used external kernels and device
variables are tracked. A global array containing pointers
to these external kernels and variables is emitted which
serves as an artificial references to the external kernels
and variables used by host.
Reviewed by: Artem Belevich
Differential Revision: https://reviews.llvm.org/D123441
LTO objects might compiled with different `mbranch-protection` flags which will cause an error in the linker.
Such a setup is allowed in the normal build with this change that is possible.
Reviewed By: pcc
Differential Revision: https://reviews.llvm.org/D123493
Currently, enablement of heap MTE on Android is specified by an ELF note, which
signals to the linker to enable heap MTE. This change allows
-fsanitize=memtag-heap to synthesize these notes, rather than adding them
through the build system. We need to extend this feature to also signal the
linker to do special work for MTE globals (in future) and MTE stack (currently
implemented in the toolchain, but not implemented in the loader).
Current Android uses a non-backwards-compatible ELF note, called
".note.android.memtag". Stack MTE is an ABI break anyway, so we don't mind that
we won't be able to run executables with stack MTE on Android 11/12 devices.
The current expectation is to support the verbiage used by Android, in
that "SYNC" means MTE Synchronous mode, and "ASYNC" effectively means
"fast", using the Kernel auto-upgrade feature that allows
hardware-specific and core-specific configuration as to whether "ASYNC"
would end up being Asynchronous, Asymmetric, or Synchronous on that
particular core, whichever has a reasonable performance delta. Of
course, this is platform and loader-specific.
Differential Revision: https://reviews.llvm.org/D118948
clang to emit DWARF information for global alias variable as
DW_TAG_imported_declaration. This change also handles nested
(recursive) imported declarations.
Reviewed by: dblaikie, aprantl
Differential Revision: https://reviews.llvm.org/D120989
This change merges code for emit of target and target_clones multiversion
resolver functions and, in doing so, corrects handling of target_clones
functions that are declared but not defined. Previously, a use of such
a target_clones function would result in an attempted emit of an ifunc
that referenced an undefined resolver function. Ifunc references to
undefined resolver functions are not allowed and, when the LLVM verifier
is not disabled (via '-disable-llvm-verifier'), resulted in the verifier
issuing a "IFunc resolver must be a definition" error and aborting the
compilation. With this change, ifuncs and resolver function definitions
are always emitted for used target_clones functions regardless of whether
the target_clones function is defined (if the function is defined, then
the ifunc and resolver are emitted regardless of whether the function is
used).
This change has the side effect of causing target_clones variants and
resolver functions to be emitted in a different order than they were
previously. This is harmless and is reflected in the updated tests.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D122958
This change modifies CodeGenModule::emitMultiVersionFunctions() in preparation
for a change that will merge support for emitting target_clones resolvers into
this function. This change mostly serves to isolate indentation changes from
later behavior modifying changes.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D122957
Previously, GetOrCreateMultiVersionResolver() required the caller to provide
a GlobalDecl along with an llvm::type and FunctionDecl. The latter two can be
cheaply obtained from the first, and the llvm::type parameter is not always
used, so requiring the caller to provide them was unnecessary and created the
possibility that callers would pass an inconsistent set. This change simplifies
the interface to only require the GlobalDecl value.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D122956
We expect that `extern "C"` static functions to be usable in things like
inline assembly, as well as ifuncs:
See the bug report here: https://github.com/llvm/llvm-project/issues/54549
However, we were diagnosing this as 'not defined', because the
ifunc's attempt to look up its resolver would generate a declared IR
function.
Additionally, as background, the way we allow these static extern "C"
functions to work in inline assembly is by making an alias with the C
mangling in MOST situations to the version we emit with
internal-linkage/mangling.
The problem here was multi-fold: First- We generated the alias after the
ifunc was checked, so the function by that name didn't exist yet.
Second, the ifunc's generation caused a symbol to exist under the name
of the alias already (the declared function above), which suppressed the
alias generation.
This patch fixes all of this by moving the checking of ifuncs/CFE aliases
until AFTER we have generated the extern-C alias. Then, it does a
'fixup' around the GlobalIFunc to make sure we correct the reference.
Differential Revision: https://reviews.llvm.org/D122608
This builtin returns the address of a global instance of the
`std::source_location::__impl` type, which must be defined (with an
appropriate shape) before calling the builtin.
It will be used to implement std::source_location in libc++ in a
future change. The builtin is compatible with GCC's implementation,
and libstdc++'s usage. An intentional divergence is that GCC declares
the builtin's return type to be `const void*` (for
ease-of-implementation reasons), while Clang uses the actual type,
`const std::source_location::__impl*`.
In order to support this new functionality, I've also added a new
'UnnamedGlobalConstantDecl'. This artificial Decl is modeled after
MSGuidDecl, and is used to represent a generic concept of an lvalue
constant with global scope, deduplicated by its value. It's possible
that MSGuidDecl itself, or some of the other similar sorts of things
in Clang might be able to be refactored onto this more-generic
concept, but there's enough special-case weirdness in MSGuidDecl that
I gave up attempting to share code there, at least for now.
Finally, for compatibility with libstdc++'s <source_location> header,
I've added a second exception to the "cannot cast from void* to T* in
constant evaluation" rule. This seems a bit distasteful, but feels
like the best available option.
Reviewers: aaron.ballman, erichkeane
Differential Revision: https://reviews.llvm.org/D120159
Currently we use the `-fembed-offload-object` option to embed a binary
file into the host as a named section. This is currently only used as a
codegen action, meaning we only handle this option correctly when the
input is a bitcode file. This patch adds the same handling to embed an
offloading object after we complete code generation. This allows us to
embed the object correctly if the input file is source or bitcode.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D120270
Due to various implementation constraints, despite the programmer
choosing a 'processor' cpu_dispatch/cpu_specific needs to use the
'feature' list of a processor to identify it. This results in the
identified processor in source-code not being propogated to the
optimizer, and thus, not able to be tuned for.
This patch changes to use the actual cpu as written for tune-cpu so that
opt can make decisions based on the cpu-as-spelled, which should better
match the behavior expected by the programmer.
Note that the 'valid' list of processors for x86 is in
llvm/include/llvm/Support/X86TargetParser.def. At the moment, this list
contains only Intel processors, but other vendors may wish to add their
own entries as 'alias'es (or with different feature lists!).
If this is not done, there is two potential performance issues with the
patch, but I believe them to be worth it in light of the improvements to
behavior and performance.
1- In the event that the user spelled "ProcessorB", but we only have the
features available to test for "ProcessorA" (where A is B minus
features),
AND there is an optimization opportunity for "B" that negatively affects
"A", the optimizer will likely choose to do so.
2- In the event that the user spelled VendorI's processor, and the
feature
list allows it to run on VendorA's processor of similar features, AND
there
is an optimization opportunity for VendorIs that negatively affects
"A"s,
the optimizer will likely choose to do so. This can be fixed by adding
an
alias to X86TargetParser.def.
Differential Revision: https://reviews.llvm.org/D121410
The purpose of this change is to fix the following codegen bug:
```
// main.c
__attribute__((cpu_specific(generic)))
int *foo(void) { static int z; return &z;}
int main() { return *foo() = 5; }
// other.c
__attribute__((cpu_dispatch(generic))) int *foo(void);
// run:
clang main.c other.c -o main; ./main
```
This will segfault prior to the change, and return the correct
exit code 5 after the change.
The underlying cause is that when a translation unit contains
a cpu_specific function without the corresponding cpu_dispatch
the generated code binds the reference to foo() against a
GlobalIFunc whose resolver is undefined. This is invalid: the
resolver must be defined in the same translation unit as the
ifunc, but historically the LLVM bitcode verifier did not check
that. The generated code then binds against the resolver rather
than the ifunc, so it ends up calling the resolver rather than
the resolvee. In the example above it treats its return value as
an int *, therefore trying to write to program text.
The root issue at the representation level is that GlobalIFunc,
like GlobalAlias, does not support a "declaration" state. The
object which provides the correct semantics in these cases
is a Function declaration, but unlike Functions, changing a
declaration to a definition in the GlobalIFunc case constitutes
a change of the object type, as opposed to simply emitting code
into a Function.
I think this limitation is unlikely to change, so I implemented
the fix by returning a function declaration rather than an ifunc
when encountering cpu_specific, and upgrading it to an ifunc
when emitting cpu_dispatch.
This uses `takeName` + `replaceAllUsesWith` in similar vein to
other places where the correct IR object type cannot be known
locally/up-front, like in `CodeGenModule::EmitAliasDefinition`.
Previous discussion in: https://reviews.llvm.org/D112349
Signed-off-by: Itay Bookstein <ibookstein@gmail.com>
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D120266
To make uses of the deprecated constructor easier to spot, and to
ensure that no new uses are introduced, rename it to
Address::deprecated().
While doing the rename, I've filled in element types in cases
where it was relatively obvious, but we're still left with 135
calls to the deprecated constructor.
We have the `clang -cc1` command-line option `-funwind-tables=1|2` and
the codegen option `VALUE_CODEGENOPT(UnwindTables, 2, 0) ///< Unwind
tables (1) or asynchronous unwind tables (2)`. However, this is
encoded in LLVM IR by the presence or the absence of the `uwtable`
attribute, i.e. we lose the information whether to generate want just
some unwind tables or asynchronous unwind tables.
Asynchronous unwind tables take more space in the runtime image, I'd
estimate something like 80-90% more, as the difference is adding
roughly the same number of CFI directives as for prologues, only a bit
simpler (e.g. `.cfi_offset reg, off` vs. `.cfi_restore reg`). Or even
more, if you consider tail duplication of epilogue blocks.
Asynchronous unwind tables could also restrict code generation to
having only a finite number of frame pointer adjustments (an example
of *not* having a finite number of `SP` adjustments is on AArch64 when
untagging the stack (MTE) in some cases the compiler can modify `SP`
in a loop).
Having the CFI precise up to an instruction generally also means one
cannot bundle together CFI instructions once the prologue is done,
they need to be interspersed with ordinary instructions, which means
extra `DW_CFA_advance_loc` commands, further increasing the unwind
tables size.
That is to say, async unwind tables impose a non-negligible overhead,
yet for the most common use cases (like C++ exceptions), they are not
even needed.
This patch extends the `uwtable` attribute with an optional
value:
- `uwtable` (default to `async`)
- `uwtable(sync)`, synchronous unwind tables
- `uwtable(async)`, asynchronous (instruction precise) unwind tables
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D114543
The module flag to indicate use of hostcall is insufficient to catch
all cases where hostcall might be in use by a kernel. This is now
replaced by a function attribute that gets propagated to top-level
kernel functions via their respective call-graph.
If the attribute "amdgpu-no-hostcall-ptr" is absent on a kernel, the
default behaviour is to emit kernel metadata indicating that the
kernel uses the hostcall buffer pointer passed as an implicit
argument.
The attribute may be placed explicitly by the user, or inferred by the
AMDGPU attributor by examining the call-graph. The attribute is
inferred only if the function is not being sanitized, and the
implictarg_ptr does not result in a load of any byte in the hostcall
pointer argument.
Reviewed By: jdoerfert, arsenm, kpyzhov
Differential Revision: https://reviews.llvm.org/D119216
code object version determines ABI, therefore should not be mixed.
This patch emits amdgpu_code_object_version module flag in LLVM IR
based on code object version (default 4).
The amdgpu_code_object_version value is code object version times 100.
LLVM IR with different amdgpu_code_object_version module flag cannot
be linked.
The -cc1 option -mcode-object-version=none is for ROCm device library use
only, which supports multiple ABI.
Reviewed by: Artem Belevich
Differential Revision: https://reviews.llvm.org/D119026
This issue is an oversight in D108621.
Literals in HIP are emitted as global constant variables with default
address space which maps to Generic address space for HIPSPV. In
SPIR-V such variables translate to OpVariable instructions with
Generic storage class which are not legal. Fix by mapping literals
to CrossWorkGroup address space.
The literals are not mapped to UniformConstant because the “flat”
pointers in HIP may reference them and “flat” pointers are modeled
as Generic pointers in SPIR-V. In SPIR-V/OpenCL UniformConstant
pointers may not be casted to Generic.
Patch by: Henry Linjamäki
Reviewed by: Yaxun Liu
Differential Revision: https://reviews.llvm.org/D118876
Even if the reference itself is dllexport, the temporary should not be.
In fact, we're already giving it internal linkage, so dllexporting it
is not just wasteful, but will fail to link, as in the example below:
$ cat /tmp/a.cc
void _DllMainCRTStartup() {}
const int __declspec(dllexport) &foo = 42;
$ clang-cl -fuse-ld=lld /tmp/a.cc /Zl /link /dll /out:a.dll
lld-link: error: <root>: undefined symbol: int const &foo::$RT1
Differential revision: https://reviews.llvm.org/D118980
Branch protection in M-class is supported by
- Armv8.1-M.Main
- Armv8-M.Main
- Armv7-M
Attempting to enable this for other architectures, either by
command-line (e.g -mbranch-protection=bti) or by target attribute
in source code (e.g. __attribute__((target("branch-protection=..."))) )
will generate a warning.
In both cases function attributes related to branch protection will not
be emitted. Regardless of the warning, module level attributes related to
branch protection will be emitted when it is enabled via the command-line.
The following people also contributed to this patch:
- Victor Campos
Reviewed By: chill
Differential Revision: https://reviews.llvm.org/D115501
Intel's CET/IBT requires every indirect branch target to be an ENDBR instruction. Because of that, the compiler needs to correctly emit these instruction on function's prologues. Because this is a security feature, it is desirable that only actual indirect-branch-targeted functions are emitted with ENDBRs. While it is possible to identify address-taken functions through LTO, minimizing these ENDBR instructions remains a hard task for user-space binaries because exported functions may end being reachable through PLT entries, that will use an indirect branch for such. Because this cannot be determined during compilation-time, the compiler currently emits ENDBRs to every non-local-linkage function.
Despite the challenge presented for user-space, the kernel landscape is different as no PLTs are used. With the intent of providing the most fit ENDBR emission for the kernel, kernel developers proposed an optimization named "ibt-seal" which replaces the ENDBRs for NOPs directly in the binary. The discussion of this feature can be seen in [1].
This diff brings the enablement of the flag -mibt-seal, which in combination with LTO enforces a different policy for ENDBR placement in when the code-model is set to "kernel". In this scenario, the compiler will only emit ENDBRs to address taken functions, ignoring non-address taken functions that are don't have local linkage.
A comparison between an LTO-compiled kernel binaries without and with the -mibt-seal feature enabled shows that when -mibt-seal was used, the number of ENDBRs in the vmlinux.o binary patched by objtool decreased from 44383 to 33192, and that the number of superfluous ENDBR instructions nopped-out decreased from 11730 to 540.
The 540 missed superfluous ENDBRs need to be investigated further, but hypotheses are: assembly code not being taken care of by the compiler, kernel exported symbols mechanisms creating bogus address taken situations or even these being removed due to other binary optimizations like kernel's static_calls. For now, I assume that the large drop in the number of ENDBR instructions already justifies the feature being merged.
[1] - https://lkml.org/lkml/2021/11/22/591
Reviewed By: xiangzhangllvm
Differential Revision: https://reviews.llvm.org/D116070
HIP program with printf call fails to compile with -fsanitize=address
option, because of appending module flag - amdgpu_hostcall twice, one
for printf and one for sanitize option. This patch fixes that issue.
Patch by: Praveen Velliengiri
Reviewed by: Yaxun Liu, Roman Lebedev
Differential Revision: https://reviews.llvm.org/D116216
Use the AttributeSet constructor instead. There's no good reason
why AttrBuilder itself should exact the AttributeSet from the
AttributeList. Moving this out of the AttrBuilder generally results
in cleaner code.
Cases where there is a mangling of a cpu-dispatch/cpu-specific function
before the function becomes 'multiversion' (such as a member function)
causes the wrong name to be emitted for one of the variants/resolver,
since the name is cached. Make sure we invalidate the cache in
cpu-dispatch/cpu-specific modes, like we previously did for just target
multiversioning.
to repro error.
As mentioned yesterday, I've got a problem that I can only reproduce on
Godbolt (none of the build configs on my local machine!), so this is at
least somewhat usable until I figure out a cause.
I'm attempting to debug an issue that I can only get to happen on
godbolt, where the cpu-dispatch resolver for an out of line member
function is generated with the wrong name, causing a link failure.
This class is solely used as a lightweight and clean way to build a set of
attributes to be removed from an AttrBuilder. Previously AttrBuilder was used
both for building and removing, which introduced odd situation like creation of
Attribute with dummy value because the only relevant part was the attribute
kind.
Differential Revision: https://reviews.llvm.org/D116110
Control-Flow Integrity (CFI) replaces references to address-taken
functions with pointers to the CFI jump table. This is a problem
for low-level code, such as operating system kernels, which may
need the address of an actual function body without the jump table
indirection.
This change adds the __builtin_function_start() builtin, which
accepts an argument that can be constant-evaluated to a function,
and returns the address of the function body.
Link: https://github.com/ClangBuiltLinux/linux/issues/1353
Depends on D108478
Reviewed By: pcc, rjmccall
Differential Revision: https://reviews.llvm.org/D108479
Change all uses of the deprecated constructor to pass the
element type explicitly and drop it.
For cases where the correct element type was not immediately
obvious to me or would require a slightly larger change I'm
falling back to explicitly calling getPointerElementType() for now.
With C++17 the exception specification has been made part of the
function type, and therefore part of mangled type names.
However, it's valid to convert function pointers with an exception
specification to function pointers with the same argument and return
types but without an exception specification, which means that e.g. a
function of type "void () noexcept" can be called through a pointer
of type "void ()". We must therefore consider the two types to be
compatible for CFI purposes.
We can do this by stripping the exception specification before mangling
the type name, which is what this patch does.
Differential Revision: https://reviews.llvm.org/D115015
Handle branch protection option on the commandline as well as a function
attribute. One patch for both mechanisms, as they use the same underlying
parsing mechanism.
These are recorded in a set of LLVM IR module-level attributes like we do for
AArch64 PAC/BTI (see https://reviews.llvm.org/D85649):
- command-line options are "translated" to module-level LLVM IR
attributes (metadata).
- functions have PAC/BTI specific attributes iff the
__attribute__((target("branch-protection=...))) was used in the function
declaration.
- command-line option -mbranch-protection to armclang targeting Arm,
following this grammar:
branch-protection ::= "-mbranch-protection=" <protection>
protection ::= "none" | "standard" | "bti" [ "+" <pac-ret-clause> ]
| <pac-ret-clause> [ "+" "bti"]
pac-ret-clause ::= "pac-ret" [ "+" <pac-ret-option> ]
pac-ret-option ::= "leaf" ["+" "b-key"] | "b-key" ["+" "leaf"]
b-key is simply a placeholder to make it consistent with AArch64's
version. In Arm, however, it triggers a warning informing that b-key is
unsupported and a-key will be selected instead.
- Handle _attribute_((target(("branch-protection=..."))) for AArch32 with the
same grammer as the commandline options.
This patch is part of a series that adds support for the PACBTI-M extension of
the Armv8.1-M architecture, as detailed here:
https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/armv8-1-m-pointer-authentication-and-branch-target-identification-extension
The PACBTI-M specification can be found in the Armv8-M Architecture Reference
Manual:
https://developer.arm.com/documentation/ddi0553/latest
The following people contributed to this patch:
- Momchil Velikov
- Victor Campos
- Ties Stuij
Reviewed By: vhscampos
Differential Revision: https://reviews.llvm.org/D112421
See discussion in D51650, this change was a little aggressive in an
error while doing a 'while we were here', so this removes that error
condition, as it is apparently useful.
This reverts commit bb4934601d.
AMD64 ABI mandates caller to specify the number of used SSE registers
when passing variable arguments.
GCC also provides option -mskip-rax-setup to skip the setup of rax when
SSE is disabled. This helps to reduce the code size, see pr23258.
Reviewed By: nickdesaulniers
Differential Revision: https://reviews.llvm.org/D112413
As discussed here: https://lwn.net/Articles/691932/
GCC6.0 adds target_clones multiversioning. This functionality is
an odd cross between the cpu_dispatch and 'target' MV, but is compatible
with neither.
This attribute allows you to list all options, then emits a separately
optimized version of each function per-option (similar to the
cpu_specific attribute). It automatically generates a resolver, just
like the other two.
The mangling however, is... ODD to say the least. The mangling format
is:
<normal_mangling>.<option string>.<option ordinal>.
Differential Revision:https://reviews.llvm.org/D51650
this patch - https://reviews.llvm.org/D110337 changes the way how hostcall
hidden argument is emitted for printf, but the sanitized kernels also use
hostcall buffer to report a error for invalid memory access, which is not
handled by the above patch and it leads to vdi runtime error:
Device::callbackQueue aborting with error : HSA_STATUS_ERROR_MEMORY_FAULT:
Agent attempted to access an inaccessible address. code: 0x2b
Patch by: Praveen Velliengiri
Reviewed by: Yaxun Liu, Matt Arsenault
Differential Revision: https://reviews.llvm.org/D112820
Two identical instantiations of a template function can be emitted by two TU's
with linkonce_odr linkage without causing duplicate symbols in linker. MSVC
also requires these symbols be in comdat sections. Linux does not require
the symbols in comdat sections to be merged by linker but by default
clang puts them in comdat sections.
If a template kernel is instantiated identically in two TU's. MSVC requires
that them to be in comdat sections, otherwise MSVC linker will diagnose them as
duplicate symbols. However, currently clang does not put instantiated template
kernels in comdat sections, which causes link error for MSVC.
This patch allows putting instantiated template kernels into comdat sections.
Reviewed by: Artem Belevich, Reid Kleckner
Differential Revision: https://reviews.llvm.org/D112492
Previously, the Backend_Emit{Nothing,BC,LL} modes did
not run the LLVM verifier since it is usually added via
the TargetMachine::addPassesToEmitFile method according
to the DisableVerify parameter. This is called from
EmitAssemblyHelper::AddEmitPasses, which is only relevant
for BackendAction-s that require CodeGen.
Note:
* In these particular situations the verifier is added
to the optimization pipeline rather than the codegen
pipeline so that it runs prior to the BC/LL emission
pass.
* This change applies to both the old and the new PMs.
* Because the clang tests use -emit-llvm ubiquitously,
this change will enable the verifier for them.
* A small bug is fixed in emitIFuncDefinition so that
the clang/test/CodeGen/ifunc.c test would pass:
the emitIFuncDefinition incorrectly passed the
GlobalDecl of the IFunc itself to the call to
GetOrCreateLLVMFunction for creating the resolver.
Signed-off-by: Itay Bookstein <ibookstein@gmail.com>
Reviewed By: rjmccall
Differential Revision: https://reviews.llvm.org/D113352
The existing CGOpenMPRuntimeAMDGCN and CGOpenMPRuntimeNVPTX classes are
just code bloat. By removing them, the codebase gets a bit cleaner.
Reviewed By: jdoerfert, JonChesterfield, tianshilei1992
Differential Revision: https://reviews.llvm.org/D113421
The existing CGOpenMPRuntimeAMDGCN and CGOpenMPRuntimeNVPTX classes are
just code bloat. By removing them, the codebase gets a bit cleaner.
Reviewed By: jdoerfert, JonChesterfield, tianshilei1992
Differential Revision: https://reviews.llvm.org/D113421
Verify that the resolver exists, that it is a defined
Function, and that its return type matches the ifunc's
type. Add corresponding check to BitcodeReader, change
clang to emit the correct type, and fix tests to comply.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D112349
This reverts commit 121b2252de.
The following code causes a crash in some circumstances:
struct k {
~k() __attribute__((annotate(""))) {}
};
void m() { k(); }
As discussed in:
* https://reviews.llvm.org/D94166
* https://lists.llvm.org/pipermail/llvm-dev/2020-September/145031.html
The GlobalIndirectSymbol class lost most of its meaning in
https://reviews.llvm.org/D109792, which disambiguated getBaseObject
(now getAliaseeObject) between GlobalIFunc and everything else.
In addition, as long as GlobalIFunc is not a GlobalObject and
getAliaseeObject returns GlobalObjects, a GlobalAlias whose aliasee
is a GlobalIFunc cannot currently be modeled properly. Creating
aliases for GlobalIFuncs does happen in the wild (e.g. glibc). In addition,
calling getAliaseeObject on a GlobalIFunc will currently return nullptr,
which is undesirable because it should return the object itself for
non-aliases.
This patch refactors the GlobalIFunc class to inherit directly from
GlobalObject, and removes GlobalIndirectSymbol (while inlining the
relevant parts into GlobalAlias and GlobalIFunc). This allows for
calling getAliaseeObject() on a GlobalIFunc to return the GlobalIFunc
itself, making getAliaseeObject() more consistent and enabling
alias-to-ifunc to be properly modeled in the IR.
I exercised some judgement in the API clients of GlobalIndirectSymbol:
some were 'monomorphized' for GlobalAlias and GlobalIFunc, and
some remained shared (with the type adapted to become GlobalValue).
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D108872
Jun Zhang