Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D115907
Beautify dump format, add indent for nested struct and struct members, also fix test cases in dump-struct-builtin.c
for example:
struct:
```
struct A {
int a;
struct B {
int b;
struct C {
struct D {
int d;
union E {
int x;
int y;
} e;
} d;
int c;
} c;
} b;
};
```
Before:
```
struct A {
int a = 0
struct B {
int b = 0
struct C {
struct D {
int d = 0
union E {
int x = 0
int y = 0
}
}
int c = 0
}
}
}
```
After:
```
struct A {
int a = 0
struct B {
int b = 0
struct C {
struct D {
int d = 0
union E {
int x = 0
int y = 0
}
}
int c = 0
}
}
}
```
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D122704
Remove anonymous tag locations, powered by 'PrintingPolicy',
@aaron.ballman once suggested removing this extra information in
https://reviews.llvm.org/D122248
struct:
struct S {
int a;
struct /* Anonymous*/ {
int x;
} b;
int c;
};
Before:
struct S {
int a = 0
struct S::(unnamed at ./builtin_dump_struct.c:20:3) {
int x = 0
}
int c = 0
}
After:
struct S {
int a = 0
struct S::(unnamed) {
int x = 0
}
int c = 0
}
Differntial Revision: https://reviews.llvm.org/D122670
Member access for an atomic structure or union is unconditional
undefined behavior (C11 6.5.2.3p5). However, we would issue a confusing
error message about the base expression not being a structure or union
type.
GCC issues a warning for this case. Clang now warns as well, but the
warning is defaulted to an error because the actual access is still
unsafe.
This fixes Issue 54563.
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Reviewed By: tejohnson
Differential Revision: https://reviews.llvm.org/D115907
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.
In C, assignment expressions result in an rvalue whose type is the type
of the lhs of the assignment after it undergoes lvalue to rvalue
conversion. lvalue to rvalue conversion in C strips all qualifiers
including _Atomic.
We used getUnqualifiedType() which does not strip the _Atomic qualifier
when we should have used getAtomicUnqualifiedType(). This corrects the
usage and adds some comments to getUnqualifiedType() to make it more
clear that it does not strip _Atomic and that's on purpose (see C11
6.2.5p27).
This addresses Issue 48742.
Update `WeakUndeclaredIdentifiers` to hold a collection of weak
aliases per identifier instead of only one.
This also allows the "used" state to be removed from `WeakInfo`
because it is really only there as an alternative to removing
processed map entries, and we can represent that using an empty set
now. The serialization code is updated for the removal of the field.
Additionally, a PCH test is added for the new functionality.
The records are grouped by the "target" identifier, which was already
being used as a key for lookup purposes. We also store only one record
per alias name; combined, this means that diagnostics are grouped by
the "target" and limited to one per alias (which should be acceptable).
Fixes PR28611.
Fixesllvm/llvm-project#28985.
Reviewed By: aaron.ballman, cebowleratibm
Differential Revision: https://reviews.llvm.org/D121927
Co-authored-by: Rachel Craik <rcraik@ca.ibm.com>
Co-authored-by: Jamie Schmeiser <schmeise@ca.ibm.com>
Fix clang crash and add bitfield support in __builtin_dump_struct.
In clang13.0.x, a struct with three or more members and a bitfield at
the same time will cause a crash. In clang15.x, as long as the struct
has one bitfield, it will cause a crash in clang.
Open issue: https://github.com/llvm/llvm-project/issues/54462
Differential Revision: https://reviews.llvm.org/D122248
Currently, Clang handles some qualifiers correctly for __auto_type, but
it does not handle the restrict or _Atomic qualifiers in the same way
that GCC does. This patch handles those qualifiers so that they attach
to the deduced type the same as const and volatile already do.
This fixes https://github.com/llvm/llvm-project/issues/53652
This reverts commit edb7ba714acba1d18a20d9f4986d2e38aee1d109.
This changes BLR_BTI to take variable_ops meaning that we can accept
a register or a label. The pattern still expects one argument so we'll
never get more than one. Then later we can check the type of the operand
to choose BL or BLR to emit.
(this is what BLR_RVMARKER does but I missed this detail of it first time around)
Also require NoSLSBLRMitigation which I missed in the first version.
Some implementations of setjmp will end with a br instead of a ret.
This means that the next instruction after a call to setjmp must be
a "bti j" (j for jump) to make this work when branch target identification
is enabled.
The BTI extension was added in armv8.5-a but the bti instruction is in the
hint space. This means we can emit it for any architecture version as long
as branch target enforcement flags are passed.
The starting point for the hint number is 32 then call adds 2, jump adds 4.
Hence "hint #36" for a "bti j" (and "hint #34" for the "bti c" you see
at the start of functions).
The existing Arm command line option -mno-bti-at-return-twice has been
applied to AArch64 as well.
Support is added to SelectionDAG Isel and GlobalIsel. FastIsel will
defer to SelectionDAG.
Based on the change done for M profile Arm in https://reviews.llvm.org/D112427Fixes#48888
Reviewed By: danielkiss
Differential Revision: https://reviews.llvm.org/D121707
Allow goto, labelled statements as well as `static`, `thread_local`, and
non-literal variables in `constexpr` functions.
As specified. for all of the above (except labelled statements) constant
evaluation of the construct still fails.
For `constexpr` bodies, the proposal is implemented with diagnostics as
a language extension in older language modes. For determination of
whether a lambda body satisfies the requirements for a constexpr
function, the proposal is implemented only in C++2b mode to retain the
semantics of older modes for programs conforming to them.
Reviewed By: aaron.ballman, hubert.reinterpretcast, erichkeane
Differential Revision: https://reviews.llvm.org/D111400
These diagnostics were added to a diagnostic group, but that diagnostic
group was not under -Wgnu. I've now split them into their own
diagnostic group that is added both to the original group (so user's
currently opting in or out of these should not see a change) and under
the -Wgnu group so that -Wno-gnu can be used to disable all GNU
extension diagnostics. This fixes Issue 54444.
This adds support for multiple attributes in `#pragma clang attribute push`, for example:
```
```
or
```
```
Related attributes can now be applied with a single pragma, which makes it harder for developers to make an accidental error later when editing the code.
rdar://78269653
Differential Revision: https://reviews.llvm.org/D121283
Reimplements MisExpect diagnostics from D66324 to reconstruct its
original checking methodology only using MD_prof branch_weights
metadata.
New checks rely on 2 invariants:
1) For frontend instrumentation, MD_prof branch_weights will always be
populated before llvm.expect intrinsics are lowered.
2) for IR and sample profiling, llvm.expect intrinsics will always be
lowered before branch_weights are populated from the IR profiles.
These invariants allow the checking to assume how the existing branch
weights are populated depending on the profiling method used, and emit
the correct diagnostics. If these invariants are ever invalidated, the
MisExpect related checks would need to be updated, potentially by
re-introducing MD_misexpect metadata, and ensuring it always will be
transformed the same way as branch_weights in other optimization passes.
Frontend based profiling is now enabled without using LLVM Args, by
introducing a new CodeGen option, and checking if the -Wmisexpect flag
has been passed on the command line.
Differential Revision: https://reviews.llvm.org/D115907
If we are equality comparing an FP literal with a value cast from a type
where the literal can't be represented, that's known true or false and
probably a programmer error.
Fixes issue #54222.
https://github.com/llvm/llvm-project/issues/54222
Note - I added the optimizer change with:
9397bdc67eb2
...and as discussed in the post-commit comments, that transform might be
too dangerous without this warning in place, so it was reverted to allow
this change first.
Differential Revision: https://reviews.llvm.org/D121306
GCC supports:
- `namespace <gnu attributes> identifier`
- `namespace identifier <gnu attributes>`
But clang supports only `namespace identifier <gnu attributes>` and diagnostics for `namespace <gnu attributes> identifier` case looks unclear:
Code:
```
namespace __attribute__((visibility("hidden"))) A
{
}
```
Diags:
```
test.cpp:1:49: error: expected identifier or '{'
namespace __attribute__((visibility("hidden"))) A
^
test.cpp:1:49: error: C++ requires a type specifier for all declarations
test.cpp:3:2: error: expected ';' after top level declarator
}
```
This patch adds support for `namespace <gnu attributes> identifier` and also forbids gnu attributes for nested namespaces (this already done for C++ attributes).
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D121245
WG14 adopted N2775 (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2775.pdf)
at our Feb 2022 meeting. This paper adds a literal suffix for
bit-precise types that automatically sizes the bit-precise type to be
the smallest possible legal _BitInt type that can represent the literal
value. The suffix chosen is wb (for a signed bit-precise type) which
can be combined with the u suffix (for an unsigned bit-precise type).
The preprocessor continues to operate as-if all integer types were
intmax_t/uintmax_t, including bit-precise integer types. It is a
constraint violation if the bit-precise literal is too large to fit
within that type in the context of the preprocessor (when still using
a pp-number preprocessing token), but it is not a constraint violation
in other circumstances. This allows you to make bit-precise integer
literals that are wider than what the preprocessor currently supports
in order to initialize variables, etc.
We were not creating an evaluation context for the TU scope, so we
never popped an evaluation context for it. Popping the evaluation
context triggers a number of diagnostics, including warnings about
immediate invocations that we were previously missing.
Note: I think we have an additional issue that we should solve, but not
as part of this patch. I don't think Clang is properly modeling static
initialization as happening before constant expression evaluation. I
think structure members members are zero initialized per
http://eel.is/c++draft/basic.start.static#1,
https://eel.is/c++draft/basic.start.static#2.sentence-2, and
http://eel.is/c++draft/dcl.init#general-6.2 and the new test case
actually should be accepted. However, it's also worth noting that other
compilers behave the way this patch makes Clang behave:
https://godbolt.org/z/T7noqhdPr
See post-commit discussion on https://reviews.llvm.org/D120305.
This change breaks the clang-ppc64le-rhel buildbot, though
there is suspicion that it's an issue with the bot. The change
also had a larger than expected impact on compile-time and
code-size.
This reverts commit 3c4ed02698afec021c6bca80740d1e58e3ee019e
and some followup changes.
Default the option introduced in D113372 to ON to match all(?) major Linux
distros. This matches GCC and improves consistency with Android and linux-musl
which always default to PIE.
Note: CLANG_DEFAULT_PIE_ON_LINUX will be removed in the future.
Reviewed By: thesamesam
Differential Revision: https://reviews.llvm.org/D120305
Otherwise callers of these functions have to check both the return value
for and the contents of the returned llvm::Optional.
Fixes#53742
Differential Revision: https://reviews.llvm.org/D119525
Adds a new option InsertBraces to insert the optional braces after
if, else, for, while, and do in C++.
Differential Revision: https://reviews.llvm.org/D120217
