As reported by @kees, GCC treats __builtin_object_size of structures
containing flexible array members (aka arrays with incomplete type) not
just as the sizeof the underlying type, but additionally the size of the
members in a designated initializer list.
Fixes: https://github.com/llvm/llvm-project/issues/62789
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D150892
This reverts commit 0e167fc0a2147c9b673b8afd5fea001b0d127781.
This patch causes its assertion to fire when doing AST-dump, so
reverting so that the author has time to fix this.
During the ISO C++ Committee meeting plenary session the C++23 Standard
has been voted as technical complete.
This updates the reference to c++2b to c++23 and updates the __cplusplus
macro.
Drive-by fixes c++1z -> c++17 and c++2a -> c++20 when seen.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D149553
This amends 2e275e24355cb224981f9beb2b026a3169fc7232. That commit added
a null to pointer cast kind when determining whether the expression can
be a valid constant initializer, but failed to update the constant
expression evaluator to perform the evaluation. This commit updates the
constant expression evaluator to handle that cast kind.
This patch fixes the wrong signal from the constexpr evaluator that
[[gnu::weak]] member pointer comparison is valid, while it is emitting
notes on them.
I found a crashing case fixed by this change and added it as a test
case: https://godbolt.org/z/8391fGjGn
I noticed this while I was working on D146358.
Differential Revision: https://reviews.llvm.org/D148419
This patch improves diagnostic for clang constexpr evaluator by adding
a check for nullptr in function pointer call evaluations.
ex.
```
constexpr int foo(int (*bla)(void)) {
return bla();
}
static_assert(foo(nullptr) == 1);
```
BEFORE this patch, clang generates the following diagnostic for the
code above:
```
<source>:5:15: error: static assertion expression is not an integral constant expression
static_assert(foo(nullptr) == 1);
^~~~~~~~~~~~~~~~~
<source>:2:10: note: subexpression not valid in a constant expression
return bla();
^
<source>:5:15: note: in call to 'foo(nullptr)'
static_assert(foo(nullptr) == 1);
^
1 error generated.
```
AFTER this patch, subexpression not valid in a constant expression note
is replaced with 'bla' evaluates to a null function pointer.
Fixes https://github.com/llvm/llvm-project/issues/59872
Differential Revision: https://reviews.llvm.org/D145793
This patch introduces a new type __externref_t that denotes a WebAssembly opaque
reference type. It also implements builtin __builtin_wasm_ref_null_extern(),
that returns a null value of __externref_t. This lays the ground work
for further builtins and reference types.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D122215
This patch introduces a new type __externref_t that denotes a WebAssembly opaque
reference type. It also implements builtin __builtin_wasm_ref_null_extern(),
that returns a null value of __externref_t. This lays the ground work
for further builtins and reference types.
Differential Revision: https://reviews.llvm.org/D122215
This diff extends D123345 by adding support for std::forward_like.
Test plan: ninja check-clang check-clang-tools check-llvm
Differential revision: https://reviews.llvm.org/D142430
FastEvaluateAsRValue returns `true` without setting a result value for when a
given constant expression is an array or record type.
Clang attributes must be able to support constant expressions that are array or
record types, so proceed with the slower path for evaluation in the case where
`FastEvaluateAsRValue` does not yield an evaluation result.
Differential Revision: https://reviews.llvm.org/D141745
This commit relands the patches for implementing P0960R3 and P1975R0,
which describe initializing aggregates via a parenthesized list.
The relanded commits are:
* 40c52159d3ee - P0960R3 and P1975R0: Allow initializing aggregates from
a parenthesized list of values
* c77a91bb7ba7 - Remove overly restrictive aggregate paren init logic
* 32d7aae04fdb - Fix a clang crash on invalid code in C++20 mode
This patch also fixes a crash in the original implementation.
Previously, if the input tried to call an implicitly deleted copy or
move constructor of a union, we would then try to initialize the union
by initializing it's first element with a reference to a union. This
behavior is incorrect (we should fail to initialize) and if the type of
the first element has a constructor with a single template typename
parameter, then Clang will explode. This patch fixes that issue by
checking that constructor overload resolution did not result in a
deleted function before attempting parenthesized aggregate
initialization.
Additionally, this patch also includes D140159, which contains some
minor fixes made in response to code review comments in the original
implementation that were made after that patch was submitted.
Co-authored-by: Sheng <ox59616e@gmail.com>
Fixes#54040, Fixes#59675
Reviewed By: ilya-biryukov
Differential Revision: https://reviews.llvm.org/D141546
Currently we don't diagnose overflow in a constant expression for the case of
compound assignment with remainder as a operand.
In handleIntIntBinOp the arguments LHS and Result can be the same source but in
the check for remainder in this function we assigned to Result before checking
for overflow. In all the other operations the check is done before Result is
assigned to.
Differential Revision: https://reviews.llvm.org/D140455
Fix an edge case `ExprConstant.cpp`'s `EvaluateWithSubstitution` when called by `CheckEnableIf`
The assertion in `CallStackFrame::getTemporary`
could fail during evaluation of nested calls to a function
using `enable_if` when the second argument was a
value-dependent expression.
This caused a temporary to be created for the second
argument with a given version during the
evaluation of the inner call, but we bailed out
when evaluating the second argument of the
outer call due to the expression being value-dependent.
After bailing out, we tried to clean up the argument's value slot but it
caused an assertion to trigger in `getTemporary` as
a temporary for the second argument existed, but only for the inner call and not the outer call.
See the test case for a more complete description of the issue.
Reviewed By: ahatanak
Differential Revision: https://reviews.llvm.org/D139713
This feature causes clang to crash when compiling Chrome - see
https://crbug.com/1405031 and
https://github.com/llvm/llvm-project/issues/59675
Revert "[clang] Fix a clang crash on invalid code in C++20 mode."
This reverts commit 32d7aae04fdb58e65a952f281ff2f2c3f396d98f.
Revert "[clang] Remove overly restrictive aggregate paren init logic"
This reverts commit c77a91bb7ba793ec3a6a5da3743ed55056291658.
Revert "[clang][C++20] P0960R3 and P1975R0: Allow initializing aggregates from a parenthesized list of values"
This reverts commit 40c52159d3ee337dbed14e4c73b5616ea354c337.
This avoids recomputing string length that is already known at compile time.
It has a slight impact on preprocessing / compile time, see
https://llvm-compile-time-tracker.com/compare.php?from=3f36d2d579d8b0e8824d9dd99bfa79f456858f88&to=e49640c507ddc6615b5e503144301c8e41f8f434&stat=instructions:u
This a recommit of e953ae5bbc313fd0cc980ce021d487e5b5199ea4 and the subsequent fixes caa713559bd38f337d7d35de35686775e8fb5175 and 06b90e2e9c991e211fecc97948e533320a825470.
The above patchset caused some version of GCC to take eons to compile clang/lib/Basic/Targets/AArch64.cpp, as spotted in aa171833ab0017d9732e82b8682c9848ab25ff9e.
The fix is to make BuiltinInfo tables a compilation unit static variable, instead of a private static variable.
Differential Revision: https://reviews.llvm.org/D139881
Revert "Fix lldb option handling since e953ae5bbc313fd0cc980ce021d487e5b5199ea4 (part 2)"
Revert "Fix lldb option handling since e953ae5bbc313fd0cc980ce021d487e5b5199ea4"
GCC build hangs on this bot https://lab.llvm.org/buildbot/#/builders/37/builds/19104
compiling CMakeFiles/obj.clangBasic.dir/Targets/AArch64.cpp.d
The bot uses GNU 11.3.0, but I can reproduce locally with gcc (Debian 12.2.0-3) 12.2.0.
This reverts commit caa713559bd38f337d7d35de35686775e8fb5175.
This reverts commit 06b90e2e9c991e211fecc97948e533320a825470.
This reverts commit e953ae5bbc313fd0cc980ce021d487e5b5199ea4.
This patch implements P0960R3, which allows initialization of aggregates
via parentheses.
As an example:
```
struct S { int i, j; };
S s1(1, 1);
int arr1[2](1, 2);
```
This patch also implements P1975R0, which fixes the wording of P0960R3
for single-argument parenthesized lists so that statements like the
following are allowed:
```
S s2(1);
S s3 = static_cast<S>(1);
S s4 = (S)1;
int (&&arr2)[] = static_cast<int[]>(1);
int (&&arr3)[2] = static_cast<int[2]>(1);
```
This patch was originally authored by @0x59616e and completed by
@ayzhao.
Fixes#54040, Fixes#54041
Co-authored-by: Sheng <ox59616e@gmail.com>
Full write up : https://discourse.llvm.org/t/c-20-rfc-suggestion-desired-regarding-the-implementation-of-p0960r3/63744
Reviewed By: ilya-biryukov
Differential Revision: https://reviews.llvm.org/D129531
to member naming a weak member to nullptr.
This fixes a miscompile where constant evaluation would incorrectly
determine that a weak member function pointer is never null.
In passing, also improve the diagnostics for constant evaluation of some
nearby cases.
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
This implement the C++23 paper P2647R1 (adopted in Kona)
Reviewed By: #clang-language-wg, erichkeane
Differential Revision: https://reviews.llvm.org/D138851
This patch replaces those occurrences of NoneType that would trigger
an error if the definition of NoneType were missing in None.h.
To keep this patch focused, I am deliberately not replacing None with
std::nullopt in this patch or updating comments. They will be
addressed in subsequent patches.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
Differential Revision: https://reviews.llvm.org/D138539
Use FastEvaluateAsRValue() in EvaluateAsConstantExpr() as well, to
short-circuit evaluation of simple integrals.
Differential Revision: https://reviews.llvm.org/D138115
Integer-to-float conversion was handled in constant evaluator with
default rounding mode. This change fixes the behavior and the conversion
is made using rounding mode stored in ImplicitCastExpr node.
Differential Revision: https://reviews.llvm.org/D137719
The -fstrict-flex-arrays=3 is the most restrictive type of flex arrays.
No number, including 0, is allowed in the FAM. In the cases where a "0"
is used, the resulting size is the same as if a zero-sized object were
substituted.
This is needed for proper _FORTIFY_SOURCE coverage in the Linux kernel,
among other reasons. So while the only reason for specifying a
zero-length array at the end of a structure is for specify a FAM,
treating it as such will cause _FORTIFY_SOURCE not to work correctly;
__builtin_object_size will report -1 instead of 0 for a destination
buffer size to keep any kernel internals from using the deprecated
members as fake FAMs.
For example:
struct broken {
int foo;
int fake_fam[0];
struct something oops;
};
There have been bugs where the above struct was created because "oops"
was added after "fake_fam" by someone not realizing. Under
__FORTIFY_SOURCE, doing:
memcpy(p->fake_fam, src, len);
raises no warnings when __builtin_object_size(p->fake_fam, 1) returns -1
and may stomp on "oops."
Omitting a warning when using the (invalid) zero-length array is how GCC
treats -fstrict-flex-arrays=3. A warning in that situation is likely an
irritant, because requesting this option level is explicitly requesting
this behavior.
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836
Differential Revision: https://reviews.llvm.org/D134902
The time profiler in `Expr::isIntegerConstantExpr` used to
call `Loc->printToString`, it was inconsistent with other time
profiles in the file and caused segfaults if `Loc` was `nullptr`.
Fixes https://github.com/llvm/llvm-project/issues/58551
Reviewed By: dyung, jloser
Differential Revision: https://reviews.llvm.org/D136549
Add time profiler for various constexpr evaluation events
so that slow event could be visible on the visualized flame chart.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D136022
The `__has_constexpr_builtin` macro can be used to check
whether the builtin in constant-evaluated by Clang frontend.
Reviewed By: aaron.ballman, shafik
Differential Revision: https://reviews.llvm.org/D136036
