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
As reported in https://github.com/llvm/llvm-project/issues/54588
and discussed in https://github.com/itanium-cxx-abi/cxx-abi/issues/139
We are supposed to do a DFS, pre-order, decl-order search for a name for
the union in this case. Prevoiusly we crashed because the IdentiferInfo
pointer was nullptr, so this makes sure we have a name in the cases
described by the ABI.
I added an llvm-unreachable to cover an unexpected case at the end of
the new function with information/reference to the ABI in case we come
up with some way to get back to here.
Differential Revision: https://reviews.llvm.org/D122820
Implement a demangleable strong ownership symbol mangling.
* The original module symbol mangling scheme turned out to be
undemangleable.
* The hoped-for C++17 compatibility of weak ownership turns out to be
fragile
* C++20 now has better ways of controlling C++17 compatibility
The issue is captured on the ABI list at:
https://github.com/itanium-cxx-abi/cxx-abi/issues/134
GCC implements this new mangling.
The old mangling is unceremoniously dropped. No backwards
compatibility, no deprectated old-mangling flag. It was always
labelled experimental. (Old and new manglings cannot be confused.)
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D122256
Also, check that NRVO currently isn't performed in test25. The checks
were accidentally removed when https://reviews.llvm.org/D122425 disabled
inlining.
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
Previously, we would instantiate the UDL by marking the function as
referenced and potentially binding to a temporary; this skipped
transforming the call when the UDL was dependent on a template
parameter.
Now, we defer all the work to instantiating the call expression for the
UDL. This ensures that constant evaluation occurs at compile time
rather than deferring until runtime.
Fixes Issue 54578.
This information isn't preserved in the DWARF description of function
types (though probably should be - it's preserved on the function
declarations/definitions themselves through the DW_AT_noreturn attribute
- but we should move or also include that in the subroutine type itself
too - but for now, with it not being there, the DWARF is lossy and
can't be reconstructed)
Poison trivial class members one-by-one in the reverse order of their
construction, instead of all-at-once at the very end.
For example, in the following code access to `x` from `~B` will
produce an undefined value.
struct A {
struct B b;
int x;
};
Reviewed By: kda
Differential Revision: https://reviews.llvm.org/D119600
-fsanitize-memory-use-after-dtor detects memory access after a
subobject is destroyed but its memory is not yet deallocated.
This is done by poisoning each object memory near the end of its destructor.
Subobjects (members and base classes) do this in their respective
destructors, and the parent class does the same for its members with
trivial destructors.
Inexplicably, base classes with trivial destructors are not handled at
all. This change fixes this oversight by adding the base class poisoning logic
to the parent class destructor.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D119300
This is a preliminary patch ahead of D119792 (I'll rebase that one on top of this).
This shows what Clang's _current_ behaviour is for calculating NRVO in various
common cases. Then, in D119792 (and future patches), I'll be able to demostrate
exactly how LLVM IR for each of these cases changes.
Reviewed By: Quuxplusone
Differential Revision: https://reviews.llvm.org/D119927
Includes verifier changes checking the elementtype, clang codegen
changes to emit the elementtype, and ISel changes using the elementtype.
Basically the same as D120527.
Reviewed By: #opaque-pointers, nikic
Differential Revision: https://reviews.llvm.org/D121847
Includes verifier changes checking the elementtype, clang codegen
changes to emit the elementtype, and ISel changes using the elementtype.
Reviewed By: #opaque-pointers, nikic
Differential Revision: https://reviews.llvm.org/D120527
The existing module symbol mangling scheme turns out to be
undemangleable. It is also desirable to switch to the
strong-ownership model as the hoped-for C++17 compatibility turns out
to be fragile, and we also now have a better way of controlling that.
The issue is captured on the ABI list at:
https://github.com/itanium-cxx-abi/cxx-abi/issues/134
A document describing the issues and new mangling is at:
https://drive.google.com/file/d/1qQjqptzOFT_lfXH8L6-iD9nCRi34wjft/view
This patch is the code-generation part. I have a demangler too, but
that patch is based on some to-be-landed refactoring of the demangler.
The old mangling is unceremoniously dropped. No backwards
compatibility, no deprectated old-mangling flag. It was always
labelled experimental. (Old and new manglings cannot be confused.)
Reviewed By: ChuanqiXu
Differential Revision: https://reviews.llvm.org/D118352
We previously had logic to disable pthreads, set the ThreadModel to Single, and
disable thread-safe statics when the atomics target features is disabled, since
that means that the resulting program will not be used in a threaded context.
Similarly check for the presence of the bulk-memory feature, since that is also
necessary to produce multithreaded programs.
Differential Revision: https://reviews.llvm.org/D121014
This patch adds -Wno-strict-prototypes to all of the test cases that
use functions without prototypes, but not as the primary concern of the
test. e.g., attributes testing whether they can/cannot be applied to a
function without a prototype, etc.
This is done in preparation for enabling -Wstrict-prototypes by
default.
This flag was previously renamed `enable_noundef_analysis` to
`disable-noundef-analysis,` which is not a conventional name. (Driver and
CC1's boolean options are using [no-] prefix)
As discussed at https://reviews.llvm.org/D105169, this patch reverts its
name to `[no-]enable_noundef_analysis` and enables noundef-analysis as
default.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D119998
Currently we are not emitting debug-info for all cases of structured bindings a
C++17 feature which allows us to bind names to subobjects in an initializer.
A structured binding is represented by a DecompositionDecl AST node and the
binding are represented by a BindingDecl. It looks the original implementation
only covered the tuple like case which be represented by a DeclRefExpr which
contains a VarDecl.
If the binding is to a subobject of the struct the binding will contain a
MemberExpr and in the case of arrays it will contain an ArraySubscriptExpr.
This PR adds support emitting debug-info for the MemberExpr and ArraySubscriptExpr
cases as well as llvm and lldb tests for these cases as well as the tuple case.
Differential Revision: https://reviews.llvm.org/D119178
In our downstream, we discovered that the that the .* wildcard
in debug-info-hotpatch.cpp (added https://reviews.llvm.org/D116511)
ended up matching the entire line on our Windows configurations, causing
the -function-padmin check to already be consumed. After digging into it
we weren't able to find any sort of reason why the platform would matter
here, however we suspect there must be some difference in the regex
matcher between systems.
This NFC patch replaces the regex with a more conservative regex that
prevents this from happening by replacing the . match with an 'everything
but double-quote match, [^"].
https://reviews.llvm.org/D120066
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the ninth batch of tests being updated (there are a
significant number of other tests left to be updated).
Due to the way type units work, this would lead to a declaration in a
type unit of a local type in a CU - which is ambiguous. Rather than
trying to resolve that relative to the CU that references the type unit,
let's just not try to simplify these names.
Longer term this should be fixed by not putting the template
instantiation in a type unit to begin with - since it references an
internal linkage type, it can't legitimately be duplicated/in more than
one translation unit, so skip the type unit overhead. (but the right fix
for that is to move type unit management into a DICompositeType flag
(dropping the "identifier" field is not a perfect solution since it
breaks LLVM IR linking decl/def merging during IR linking))
Lambda names aren't entirely canonical (as demonstrated by the
cross-project-test added here) at the moment (we should fix that for a
bunch of reasons) - even if the template referencing them is
non-simplified, other names referencing /that/ template can't be
simplified either because type units might cause a different template to
be picked up that would conflict with the expected name.
(other than for roundtripping precision, it'd be OK to simplify types
that reference types that reference lambdas - but best be consistent
between the roundtrip/verify mode and the actual simplified template
names mode)
When not going through the main Clang->LLVM type cache, we'd
accidentally create multiple different opaque types for a member pointer
type.
This allows us to remove the -verify-type-cache flag now that
check-clang passes with it on. We can do the verification in expensive
builds. Previously microsoft-abi-member-pointers.cpp was failing with
-verify-type-cache.
I suspect that there may be more issues when we have multiple member
pointer types and we clear the cache, but we can leave that for later.
Followup to D118744.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D119215
Take the following as an example
struct z {
z (*p)();
};
z f();
When we attempt to get the LLVM type of f, we recurse into z. z itself
has a function pointer with the same type as f. Given the recursion,
Clang simply treats z::p as a pointer to an empty struct `{}*`. The
LLVM type of f is as expected. So we have two different potential
LLVM types for a given Clang type. If we store one of those into the
cache, when we access the cache with a different context (e.g. we
are/aren't recursing on z) we may get an incorrect result. There is some
attempt to clear the cache in these cases, but it doesn't seem to handle
all cases.
This change makes it so we only use the cache when we are not in any
sort of function context, i.e. `noRecordsBeingLaidOut() &&
FunctionsBeingProcessed.empty()`, which are the cases where we may
decide to choose a different LLVM type for a given Clang type. LLVM
types for builtin types are never recursive so they're always ok.
This allows us to clear the type cache less often (as seen with the
removal of one of the calls to `TypeCache.clear()`). We
still need to clear it when we use a placeholder type then replace it
later with the final type and other dependent types need to be
recalculated.
I've added a check that the cached type matches what we compute. It
triggered in this test case without the fix. It's currently not
check-clang clean so it's not on by default for something like expensive
checks builds.
This change uncovered another issue where the LLVM types for an argument
and its local temporary don't match. For example in type-cache-3, when
expanding z::dc's argument into a temporary alloca, we ConvertType() the
type of z::p which is `void ({}*)*`, which doesn't match the alloca GEP
type of `{}*`.
No noticeable compile time changes:
https://llvm-compile-time-tracker.com/compare.php?from=3918dd6b8acf8c5886b9921138312d1c638b2937&to=50bdec9836ed40e38ece0657f3058e730adffc4c&stat=instructionsFixes#53465.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D118744
After fa87fa97fb, this was no longer guaranteed to be the cleanup
just added by this code, if IsEHCleanup got disabled. Instead, use
stable_begin(), which _is_ guaranteed to be the cleanup just added.
This caused a crash when a object that is callee destroyed (e.g. with the MS ABI) was passed in a call from a noexcept function.
Added a test to verify.
Fixes: fa87fa97fb
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
EHTerminateScope is used to implement C++ noexcept semantics. Per C++
[except.terminate], it is implemented-defined whether no, some, or all
cleanups are run prior to terminatation.
Therefore, the code to run cleanups on the way towards termination is
unnecessary, and may be omitted.
After this change, we will still run some cleanups: any cleanups in a
function called from the noexcept function will continue to run, while
those in the noexcept function itself will not.
(Commit attempt 2: check InnermostEHScope != stable_end() before accessing it.)
Differential Revision: https://reviews.llvm.org/D113620
When we don't enable atomics we completely disabled threading in
which case there is no point in generating thread safe code for
static initialization.
This should always be safe because, in WebAssembly, it is not
possible to link object compiled without the atomics feature into a
mutli-threaded program.
See https://github.com/emscripten-core/emscripten/pull/16152
Differential Revision: https://reviews.llvm.org/D118571
ConstStructBuilder::Finalize in CGExprConstant.ccp assumes that the
passed in QualType is a RecordType. In some instances, the type is a
reference to a RecordType and the reference needs to be removed first.
Differential Revision: https://reviews.llvm.org/D117376
Part of the _BitInt feature in C2x
(http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2763.pdf) is a new
macro in limits.h named BITINT_MAXWIDTH that can be used to determine
the maximum width of a bit-precise integer type. This macro must expand
to a value that is at least as large as ULLONG_WIDTH.
This adds an implementation-defined macro named __BITINT_MAXWIDTH__ to
specify that value, which is used by limits.h for the standard macro.
This also limits the maximum bit width to 128 bits because backends do
not currently support all mathematical operations (such as division) on
wider types yet. This maximum is expected to be increased in the future.
Problem: Migration to new PM broke flatten attribute.
This is one use case why LLVM should support inlining call-site with alwaysinline. The flatten attribute is nowdays broken, so we should either land patch like this one or remove everything related to flatten attribute from Clang.
Second use case is something like "per call site inlining intrinsics" to control inlining even more; mentioned in
https://lists.llvm.org/pipermail/cfe-dev/2018-September/059232.html
Fixes https://github.com/llvm/llvm-project/issues/53360
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D117965
This patch adds support for the MSVC /HOTPATCH flag: https://docs.microsoft.com/sv-se/cpp/build/reference/hotpatch-create-hotpatchable-image?view=msvc-170&viewFallbackFrom=vs-2019
The flag is translated to a new -fms-hotpatch flag, which in turn adds a 'patchable-function' attribute for each function in the TU. This is then picked up by the PatchableFunction pass which would generate a TargetOpcode::PATCHABLE_OP of minsize = 2 (which means the target instruction must resolve to at least two bytes). TargetOpcode::PATCHABLE_OP is only implemented for x86/x64. When targetting ARM/ARM64, /HOTPATCH isn't required (instructions are always 2/4 bytes and suitable for hotpatching).
Additionally, when using /Z7, we generate a 'hot patchable' flag in the CodeView debug stream, in the S_COMPILE3 record. This flag is then picked up by LLD (or link.exe) and is used in conjunction with the linker /FUNCTIONPADMIN flag to generate extra space before each function, to accommodate for live patching long jumps. Please see: d703b92296/lld/COFF/Writer.cpp (L1298)
The outcome is that we can finally use Live++ or Recode along with clang-cl.
NOTE: It seems that MSVC cl.exe always enables /HOTPATCH on x64 by default, although if we did the same I thought we might generate sub-optimal code (if this flag was active by default). Additionally, MSVC always generates a .debug$S section and a S_COMPILE3 record, which Clang doesn't do without /Z7. Therefore, the following MSVC command-line "cl /c file.cpp" would have to be written with Clang such as "clang-cl /c file.cpp /HOTPATCH /Z7" in order to obtain the same result.
Depends on D43002, D80833 and D81301 for the full feature.
Differential Revision: https://reviews.llvm.org/D116511
When adding new attributes, existing attributes are dropped. While
this appears to be a longstanding issue, this was highlighted by D105169
which dropped a lot of attributes due to adding the new noundef
attribute.
Ahmed Bougacha (@ab) tracked down the issue and provided the fix in
CGCall.cpp. I bundled it up and updated the tests.
Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.
Test updates are made as a separate patch: D108453
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D105169
EHTerminateScope is used to implement C++ noexcept semantics. Per C++
[except.terminate], it is implemented-defined whether no, some, or all
cleanups are run prior to terminatation.
Therefore, the code to run cleanups on the way towards termination is
unnecessary, and may be omitted.
After this change, we will still run some cleanups: any cleanups in a
function called from the noexcept function will continue to run, while
those in the noexcept function itself will not.
Differential Revision: https://reviews.llvm.org/D113620
TLS initializers, for example constructors of thread-local variables, don't necessarily get called. If a thread was created before a module is loaded, the module's TLS initializers are not executed for this particular thread.
This is why Microsoft added support for dynamic TLS initialization. Before every use of thread-local variables, a check is added that runs the module's TLS initializers on-demand.
To do this, the method `__dyn_tls_on_demand_init` gets called. Internally, it simply calls `__dyn_tls_init`.
No additional TLS initializer that sets the guard needs to be emitted, as the guard always gets set by `__dyn_tls_init`.
The guard is also checked again within `__dyn_tls_init`. This makes our check redundant, however, as Microsoft's compiler also emits this check, the behaviour is adopted here.
Reviewed By: majnemer
Differential Revision: https://reviews.llvm.org/D115456
When `-ftrivial-auto-var-init=` is enabled, allocas unconditionally
receive auto-initialization since [1].
In certain cases, it turns out, this is causing problems. For example,
when using alloca to add a random stack offset, as the Linux kernel does
on syscall entry [2]. In this case, none of the alloca'd stack memory is
ever used, and initializing it should be controllable; furthermore, it
is not always possible to safely call memset (see [2]).
Introduce `__builtin_alloca_uninitialized()` (and
`__builtin_alloca_with_align_uninitialized`), which never performs
initialization when `-ftrivial-auto-var-init=` is enabled.
[1] https://reviews.llvm.org/D60548
[2] https://lkml.kernel.org/r/YbHTKUjEejZCLyhX@elver.google.com
Reviewed By: glider
Differential Revision: https://reviews.llvm.org/D115440
When calling emitArrayDestroy(), the pointer will usually have
ConvertTypeForMem(EltType) as the element type, as one would expect.
However, globals with initializers sometimes don't use the same
types as values normally would, e.g. here the global uses
{ double, i32 } rather than %struct.T as element type.
Add an early cast to the global destruction path to avoid this
special case. The cast would happen lateron anyway, it only gets
moved to an earlier point.
Differential Revision: https://reviews.llvm.org/D116219
This implements the clang side of D116531. The elementtype
attribute is added for all indirect constraints (*) and tests are
updated accordingly.
Differential Revision: https://reviews.llvm.org/D116666
This reverts commit 640beb38e7.
That commit caused performance degradtion in Quicksilver test QS:sGPU and a functional test failure in (rocPRIM rocprim.device_segmented_radix_sort).
Reverting until we have a better solution to s_cselect_b64 codegen cleanup
Change-Id: Ibf8e397df94001f248fba609f072088a46abae08
Reviewed By: kzhuravl
Differential Revision: https://reviews.llvm.org/D115960
Change-Id: Id169459ce4dfffa857d5645a0af50b0063ce1105
This builds on the code from D114963, and extends it to handle calls both direct and indirect. With the revised code structure (from series of previously landed NFCs), this is pretty straight forward.
One thing to note is that we can not infer writeonly for arguments which might be captured. If the pointer can be read back by the caller, and then read through, we have no way to track that. This is the same restriction we have for readonly, except that we get no mileage out of the "callee can be readonly" exception since a writeonly param on a readonly function is either a) readnone or b) UB. This means we can't actually infer much unless nocapture has already been inferred.
Differential Revision: https://reviews.llvm.org/D115003
The fold for merging a GEP of GEP into a single GEP currently bails
if doing so would result in notional overindexing. The justification
given in the comment above this check is dangerously incorrect: GEPs
with notional overindexing are perfectly fine, and if some code
treats them incorrectly, then that code is broken, not the GEP.
Such a GEP might legally appear in source IR, so only preventing
its creation cannot be sufficient. (The constant folder also ends
up canonicalizing the GEP to remove the notional overindexing, but
that's neither here nor there.)
This check dates back to
bd4fef4a89,
and as far as I can tell the original issue this was trying to
patch around has since been resolved.
Differential Revision: https://reviews.llvm.org/D116587
Reland integrates build fixes & further review suggestions.
Thanks to @zturner for the initial S_OBJNAME patch!
Differential Revision: https://reviews.llvm.org/D43002
Also revert all subsequent fixes:
- abd1cbf5e5 [Clang] Disable debug-info-objname.cpp test on Unix until I sort out the issue.
- 00ec441253 [Clang] debug-info-objname.cpp test: explictly encode a x86 target when using %clang_cl to avoid falling back to a native CPU triple.
- cd407f6e52 [Clang] Fix build by restricting debug-info-objname.cpp test to x86.
Summary: This patch records the access flag for
class/struct/union types in the clang part.
The summary of binary size change and debug info size change due to the DW_AT_accessibility attribute are as the following table. They are built with flags of `clang -O0 -g` (no -gz).
| section | before | after | change | % |
| .debug_loc | 929821 | 929821 |0|0|
|.debug_abbrev | 5885289 | 5971547 |+86258|+1.466%|
|.debug_info | 497613455 | 498122074 |+508619|+0.102%|
|.debug_ranges | 45731664 | 45731664 |0|0|
|.debug_str | 233842595 | 233839388 |-3207| -0.001%|
|.debug_line | 149773166 | 149764583 |-8583|-0.006%|
|total (debug) |933775990 |934359077|+583087 |+0.062%|
|total (binary) |1394617288 | 1395200024| +582736|+0.042%|
Reviewed By: dblaikie, shchenz
Differential Revision: https://reviews.llvm.org/D115503
This implements p2085, allowing out-of-class defaulting of comparison
operators, primarily so they need not be inline, IIUC intent. this was
mostly straigh forward, but required reimplementing
Sema::CheckExplicitlyDefaultedComparison, as now there's a case where
we have no a priori clue as to what class a defaulted comparison may
be for. We have to inspect the parameter types to find out. Eg:
class X { ... };
bool operator==(X, X) = default;
Thus reimplemented the parameter type checking, and added 'is this a
friend' functionality for the above case.
Reviewed By: mizvekov
Differential Revision: https://reviews.llvm.org/D104478
There are instances where clang codegen creates stores to
address space 4 in ctors, which causes a crash in llc.
This store was being optimized out at opt levels > 0.
For example:
pragma omp declare target
static const double log_smallx = log2(smallx);
pragma omp end declare target
This patch ensures that any global const that does not
have constant initialization stays in address space 1.
Note - a second patch is in the works where all global
constants are placed in address space 1 during
codegen and then the opt pass InferAdressSpaces
will promote to address space 4 where necessary.
Reviewed By: JonChesterfield
Differential Revision: https://reviews.llvm.org/D115661
According to [module.unit]p7.2.3, a declaration within a linkage-specification
should be attached to the global module.
This let user to forward declare types across modules.
Reviewed by: rsmith, aaron.ballman
Differential Revision: https://reviews.llvm.org/D110215
WG14 adopted the _ExtInt feature from Clang for C23, but renamed the
type to be _BitInt. This patch does the vast majority of the work to
rename _ExtInt to _BitInt, which accounts for most of its size. The new
type is exposed in older C modes and all C++ modes as a conforming
extension. However, there are functional changes worth calling out:
* Deprecates _ExtInt with a fix-it to help users migrate to _BitInt.
* Updates the mangling for the type.
* Updates the documentation and adds a release note to warn users what
is going on.
* Adds new diagnostics for use of _BitInt to call out when it's used as
a Clang extension or as a pre-C23 compatibility concern.
* Adds new tests for the new diagnostic behaviors.
I want to call out the ABI break specifically. We do not believe that
this break will cause a significant imposition for early adopters of
the feature, and so this is being done as a full break. If it turns out
there are critical uses where recompilation is not an option for some
reason, we can consider using ABI tags to ease the transition.
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
Allow toggling of -fnew-infallible so last instance takes precedence
Testing:
ninja check-all
Reviewed By: bruno
Differential Revision: https://reviews.llvm.org/D113523
We've found that when profiling, counts are only generated for the real definition of constructor aliases (C2 in mangled name). However, when compiling the C1 version is present at the callsite and leads to a lack of counts due to this aliasing. This causes us to miss out on inlining an otherwise hot constructor.
-mconstructor-aliases is AFAICT an optimization, so having a disabling flag if wanted seems valuable.
Testing:
ninja check-all
Reviewed By: wenlei
Differential Revision: https://reviews.llvm.org/D114130
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.
c17d9b4b12 added REQUIRES lines to a lot of Arm and AArch64
test, but added them to the very beginning, before the existing
update_cc_test_checks lines. This just moves them later so as to not
mess up the existing ordering when the checks are regenerated.
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
at the start of the entry block, which in turn would aid better code transformation/optimization.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D110257
This splits out the generated headers and conditonalises them upon the
target being enabled.
The motivation here is that the RISCV header alone added 10MB to the
resource directory, which was previously at 10MB, increasing the build
size and time. This header is contributing ~50% of the size of the
resource headers (~10MB).
The ARM generated headers are contributing about ~10% or 1MB.
This could be extended further adding only the static resource headers
for the targets that the LLVM build supports.
The changes to the tests for ARM mirror what the RISCV target already
did and rnk identified as a possible issue.
Testing:
cmake -G Ninja -D LLVM_TARGETS_TO_BUILD=X86 -D LLVM_ENABLE_PROJECTS="clang;lld" ../clang
ninja check-clang
Differential Revision: https://reviews.llvm.org/D112890
Reviewed By: craig.topper
Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.
Test updates are made as a separate patch: D108453
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D105169
[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default (2)
This patch updates test files after D105169.
Autogenerated test codes are changed by `utils/update_cc_test_checks.py,` and non-autogenerated test codes are changed as follows:
(1) I wrote a python script that (partially) updates the tests using regex: {F18594904} The script is not perfect, but I believe it gives hints about which patterns are updated to have `noundef` attached.
(2) The remaining tests are updated manually.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D108453
Resolve lit failures in clang after 8ca4b3e's land
Fix lit test failures in clang-ppc* and clang-x64-windows-msvc
Fix missing failures in clang-ppc64be* and retry fixing clang-x64-windows-msvc
Fix internal_clone(aarch64) inline assembly
The structured bindings decomposition of a non-dependent array in a dependent context (a template) were, upon instantiation, creating nested OpaqueValueExprs that would trigger assertions in CodeGen. Additionally the OpaqueValuesExpr's contained SourceExpr is being emitted in CodeGen, but there was no code for its transform in template instantiation. This would trigger other assertions such as when emitting a DeclRefExpr that refers to a VarDecl that is not marked as ODR-used.
This is all based on cursory deduction, but with the way the code flows from SemaTemplateInstantiate back to SemaInit, it is apparent that the nesting of OpaqueValueExpr is unintentional.
This commit fixes https://bugs.llvm.org/show_bug.cgi?id=45964 and possible other issues involving OpaqueValueExprs in template instantiations might be resolved.
Reviewed By: aaron.ballman, rjmccall
Differential Revision: https://reviews.llvm.org/D108482
Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.
Test updates are made as a separate patch: D108453
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D105169
Now in libcxx and clang, all the coroutine components are defined in
std::experimental namespace.
And now the coroutine TS is merged into C++20. So in the working draft
like N4892, we could find the coroutine components is defined in std
namespace instead of std::experimental namespace.
And the coroutine support in clang seems to be relatively stable. So I
think it may be suitable to move the coroutine component into the
experiment namespace now.
This patch would make clang lookup coroutine_traits in std namespace
first. For the compatibility consideration, clang would lookup in
std::experimental namespace if it can't find definitions in std
namespace. So the existing codes wouldn't be break after update
compiler.
And in case the compiler found std::coroutine_traits and
std::experimental::coroutine_traits at the same time, it would emit an
error for it.
The support for looking up std::experimental::coroutine_traits would be
removed in Clang16.
Reviewed By: lxfind, Quuxplusone
Differential Revision: https://reviews.llvm.org/D108696
This patch reverts incorrect IR introduced in commit d11ec6f67e
[Clang] Enable IC/IF mode for __ibm128, for complex types declared
using __attribute__((mode(TC))). TC corresponds to an unspecified
128-bit format, which on some targets is a double-double format
(like __ibm128_t) and on others is float128_t. The bug in d11ec6f67e
is that long double is only safe to use when it's known to be one of
these formats.
Differential Revision: https://reviews.llvm.org/D112975
There's a nuanced check about when to use suffixes on these integer
non-type-template-parameters, but when rebuilding names for
-gsimple-template-names there isn't enough data in the DWARF to
determine when to use suffixes or not. So turn on suffixes always to
make it easy to match up names in llvm-dwarfdump --verify.
I /think/ if we correctly modelled auto non-type-template parameters
maybe we could put suffixes only on those. But there's also some logic
in Clang that puts the suffixes on overloaded functions - at least
that's what the parameter says (see D77598 and printTemplateArguments
"TemplOverloaded" parameter) - but I think maybe it's for anything that
/can/ be overloaded, not necessarily only the things that are overloaded
(the argument value is hardcoded at the various callsites, doesn't seem
to depend on overload resolution/searching for overloaded functions). So
maybe with "auto" modeled more accurately, and differentiating between
function templates (always using type suffixes there) and class/variable
templates (only using the suffix for "auto" types) we could correctly
use integer type suffixes only in the minimal set of cases.
But that seems all too much fuss, so let's just put integer type
suffixes everywhere always in the debug info of integer non-type
template parameters in template names.
(more context:
* https://reviews.llvm.org/D77598#inline-1057607
* https://groups.google.com/g/llvm-dev/c/ekLMllbLIZg/m/-dhJ0hO1AAAJ )
Differential Revision: https://reviews.llvm.org/D111477
Upon further investigation and discussion,
this is actually the opposite direction from what we should be taking,
and this direction wouldn't solve the motivational problem anyway.
Additionally, some more (polly) tests have escaped being updated.
So, let's just take a step back here.
This reverts commit f3190dedee.
This reverts commit 749581d21f.
This reverts commit f3df87d57e.
This reverts commit ab1dbcecd6.
There's precedent for that in `CreateOr()`/`CreateAnd()`.
The motivation here is to avoid bloating the run-time check's IR
in `SCEVExpander::generateOverflowCheck()`.
Refs. https://reviews.llvm.org/D109368#3089809
While we could emit such a tautological `select`,
it will stick around until the next instsimplify invocation,
which may happen after we count the cost of this redundant `select`.
Which is precisely what happens with loop vectorization legality checks,
and that artificially increases the cost of said checks,
which is bad.
There is prior art for this in `IRBuilderBase::CreateAnd()`/`IRBuilderBase::CreateOr()`.
Refs. https://reviews.llvm.org/D109368#3089809
Erich Keane