With sufficiently tortured code, it's possible to cause a stack
overflow when parsing declarators. Thus, we now check for resource
exhaustion when recursively parsing declarators so that we can at least
warn the user we're about to crash before we actually crash.
Fixes#51642
Differential Revision: https://reviews.llvm.org/D124915
This adds an extension warning when using the preprocessor conditionals
in a language mode they're not officially supported in, and an opt-in
warning for compatibility with previous standards.
Fixes#55306
Differential Revision: https://reviews.llvm.org/D125178
D87451 added -mignore-xcoff-visibility for AIX targets and made it the default (which mimicked the behaviour of the XL 16.1 compiler on AIX).
However, ignoring hidden visibility has unwanted side effects and some libraries depend on visibility to hide non-ABI facing entities from user headers and
reserve the right to change these implementation details based on this (https://libcxx.llvm.org/DesignDocs/VisibilityMacros.html). This forces us to use
internal linkage fallbacks for these cases on AIX and creates an unwanted divergence in implementations on the plaform.
For these reasons, it's preferable to not add -mignore-xcoff-visibility by default, which is what this patch does.
Reviewed By: DiggerLin
Differential Revision: https://reviews.llvm.org/D125141
This adds the -Wgnu-line-marker diagnostic flag, grouped under -Wgnu,
to warn about use of the GNU linemarker preprocessor extension.
Fixes#55067
Differential Revision: https://reviews.llvm.org/D124534
CUDA/HIP programs use __noinline__ like a keyword e.g.
__noinline__ void foo() {} since __noinline__ is defined
as a macro __attribute__((noinline)) in CUDA/HIP runtime
header files.
However, gcc and clang supports __attribute__((__noinline__))
the same as __attribute__((noinline)). Some C++ libraries
use __attribute__((__noinline__)) in their header files.
When CUDA/HIP programs include such header files,
clang will emit error about invalid attributes.
This patch fixes this issue by supporting __noinline__ as
a keyword, so that CUDA/HIP runtime could remove
the macro definition.
Reviewed by: Aaron Ballman, Artem Belevich
Differential Revision: https://reviews.llvm.org/D124866
The controlling expression of a _Generic selection expression undergoes
lvalue conversion, array conversion, and function conversion before
picking the association. This means that array types, function types,
and qualified types are all unreachable code if they're used as an
association. I've been caught by this twice in the past few months and
I figure that if a WG14 member can't seem to remember this rule, users
are also likely to struggle with it. So this adds an on-by-default
unreachable code diagnostic for generic selection expression
associations.
Note, we don't have to worry about function types as those are already
a constraint violation which generates an error.
Differential Revision: https://reviews.llvm.org/D125259
Ensures an -Wenum-conversion warning happens when one of the enums is
signed and the other is unsigned. Also adds a test file to verify these
warnings.
This warning would not happen since the -Wsign-conversion would make a
diagnostic then return, never allowing the -Wenum-conversion checks.
For example:
C
enum PE { P = -1 };
enum NE { N };
enum NE conv(enum PE E) { return E; }
Before this would only create a diagnostic with -Wsign-conversion and
never on -Wenum-conversion. Now it will create a diagnostic for both
-Wsign-conversion and -Wenum-conversion.
I could change it to just warn on -Wenum-conversion as that was what I
initially did. Seeing PR35200 (or GitHub Issue 316268), I let both
diagnostics check so that the sign conversion could generate a warning.
Like regular assignment, compound assignment operators can be assumed to
write to their left-hand side operand. So we strengthen the requirements
there. (Previously only the default read access had been required.)
Just like operator->, operator->* can also be assumed to dereference the
left-hand side argument, so we require read access to the pointee. This
will generate new warnings if the left-hand side has a pt_guarded_by
attribute. This overload is rarely used, but it was trivial to add, so
why not. (Supporting the builtin operator requires changes to the TIL.)
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D124966
This includes a fix for the libc++ issue I ran across with friend
declarations not properly being identified as overloads.
This reverts commit 45c07db31c.
This reverts commit f6dff93641.
This diagnostic is also in the -Wcomment group, which is in the -Wall
group, so the diagnostic is enabled in a wider context than GCC does.
That turns out to be disruptive for the Linux kernel builds still using
-std=gnu89 because the kernel requires C source files to start with //
comments: https://kernel.org/doc/html/v5.18-rc5/process/license-rules.html#license-identifier-syntax
Compared to the old implementation:
* In C++, we only recurse into aggregate classes.
* Unnamed bit-fields are not printed.
* Constant evaluation is supported.
* Proper conversion is done when passing arguments through `...`.
* Additional arguments are supported and are injected prior to the
format string; this directly supports use with `fprintf`, for example.
* An arbitrary callable can be passed rather than only a function
pointer. In particular, in C++, a function template or overload set is
acceptable.
* All text generated by Clang is printed via `%s` rather than directly;
this avoids issues where Clang's pretty-printing output might itself
contain a `%` character.
* Fields of types that we don't know how to print are printed with a
`"*%p"` format and passed by address to the print function.
* No return value is produced.
Reviewed By: aaron.ballman, erichkeane, yihanaa
Differential Revision: https://reviews.llvm.org/D124221
GCC warns with a pedantic warning when -std=gnu89, but Clang would only
diagnose in -std=c89 mode. Clang now matches the GCC behavior in both
modes.
Fixes#18427
We had a think-o that would allow a user to declare a scoped
enumeration in C language modes "as a C++11 extension". This is a
think-o because there's no way for the user to spell the name of the
enumerators; C does not have '::' for a fully-qualified name. See
commit d0d87b5972 for details on why this
is unintentional for C.
Fixes#42372
If the operand to `sizeof` is an expression of VLA type, the operand is
still evaluated, so we should not issue a diagnostic about ignoring the
side effects in this case, as they're not actually ignored.
Fixes#48010
The flag was added when the C++20 draft did not allow for concept
caching. The final C++20 standard permits the caching, so flag is
redundant. See http://wg21.link/p2104r0.
Reviewed By: sammccall
Differential Revision: https://reviews.llvm.org/D125014
We'd nondeterministically assert (and later crash) when calculating the size or
alignment of a __bf16 type when the type isn't supported on a target because of
reading uninitialized values. Now we check whether the type is supported first.
Fixes#50171
When constant evaluating the initializer for an object of vector type,
we would call APInt::trunc() but truncate to the same bit-width the
object already had, which would cause an assertion. Instead, use
APInt::truncOrSelf() so that we no longer assert in this situation.
Fix#50216
We were failing to check if the controlling expression is dependent or
not when testing whether it has side effects. This would trigger an
assertion. Instead, if the controlling expression is dependent, we
suppress the check and diagnostic.
This fixes Issue 50227.
C89 allowed a type specifier to be elided with the resulting type being
int, aka implicit int behavior. This feature was subsequently removed
in C99 without a deprecation period, so implementations continued to
support the feature. Now, as with implicit function declarations, is a
good time to reevaluate the need for this support.
This patch allows -Wimplicit-int to issue warnings in C89 mode (off by
default), defaults the warning to an error in C99 through C17, and
disables support for the feature entirely in C2x. It also removes a
warning about missing declaration specifiers that really was just an
implicit int warning in disguise and other minor related cleanups.
This reverts commit a97899108e.
The patch caused some problems with the libc++ `__range_adaptor_closure`
that I haven't been able to figure out the cause of, so I am reverting
while I figure out whether this is a solvable problem/issue with the
CFE, or libc++ depending on an older 'incorrect' behavior.
The Itanium C++ ABI says prefixes are substitutable. For most prefixes
we already handle this: the manglePrefix(const DeclContext *, bool) and
manglePrefix(QualType) overloads explicitly handles substitutions or
defer to functions that handle substitutions on their behalf. The
manglePrefix(NestedNameSpecifier *) overload, however, is different and
handles some cases implicitly, but not all. The Identifier case was not
handled; this change adds handling for it, as well as a test case.
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D122663
This reverts commit 0c31da4838.
I've solved the issue with the PointerUnion by making the
`FunctionTemplateDecl` pointer be a NamedDecl, that could be a
`FunctionDecl` or `FunctionTemplateDecl` depending. This is enforced
with an assert.
This reverts commit 4b6c2cd647.
The patch caused numerous ARM 32 bit build failures, since we added a
5th item to the PointerUnion, and went over the 2-bits available in the
32 bit pointers.
As reported here: https://github.com/llvm/llvm-project/issues/44178
Concepts are not supposed to be instantiated until they are checked, so
this patch implements that and goes through significant amounts of work
to make sure we properly re-instantiate the concepts correctly.
Differential Revision: https://reviews.llvm.org/D119544
By default -fsanitize=address already compiles with this check, why not use it.
For compatibly it can be disabled with env ASAN_OPTIONS=detect_stack_use_after_return=0.
Reviewed By: eugenis, kda, #sanitizers, hans
Differential Revision: https://reviews.llvm.org/D124057
Temporarily revert the option to fix
https://bugs.chromium.org/p/chromium/issues/detail?id=1319387
This reverts option default and documentation of the commit. Test
changes are not being reverted as they are improvement and break
reliance on option defaults.
Additional memory usage is a problem on mobile devices with low memory.
Even heavy thread desktop programs may need some FakeStack tunning.
This reverts commit 4b4437c084.
When doing overload resolution, we have to check that candidates' parameter types are equal before trying to find a better candidate through checking which candidate is more constrained.
This revision adds this missing check and makes us diagnose those cases as ambiguous calls when the types are not equal.
Fixes GitHub issue https://github.com/llvm/llvm-project/issues/53640
Reviewed By: erichkeane
Differential Revision: https://reviews.llvm.org/D123182
By default -fsanitize=address already compiles with this check,
why not use it.
For compatibly it can be disabled with env ASAN_OPTIONS=detect_stack_use_after_return=0.
Reviewed By: eugenis, kda, #sanitizers, hans
Differential Revision: https://reviews.llvm.org/D124057
This is extended to all `std::` functions that take a reference to a
value and return a reference (or pointer) to that same value: `move`,
`forward`, `move_if_noexcept`, `as_const`, `addressof`, and the
libstdc++-specific function `__addressof`.
We still require these functions to be declared before they can be used,
but don't instantiate their definitions unless their addresses are
taken. Instead, code generation, constant evaluation, and static
analysis are given direct knowledge of their effect.
This change aims to reduce various costs associated with these functions
-- per-instantiation memory costs, compile time and memory costs due to
creating out-of-line copies and inlining them, code size at -O0, and so
on -- so that they are not substantially more expensive than a cast.
Most of these improvements are very small, but I measured a 3% decrease
in -O0 object file size for a simple C++ source file using the standard
library after this change.
We now automatically infer the `const` and `nothrow` attributes on these
now-builtin functions, in particular meaning that we get a warning for
an unused call to one of these functions.
In C++20 onwards, we disallow taking the addresses of these functions,
per the C++20 "addressable function" rule. In earlier language modes, a
compatibility warning is produced but the address can still be taken.
The same infrastructure is extended to the existing MSVC builtin
`__GetExceptionInfo`, which is now only recognized in namespace `std`
like it always should have been.
This is a re-commit of
fc30901096,
a571f82a50,
64c045e25b, and
de6ddaeef3,
and reverts aa643f455a.
This change also includes a workaround for users using libc++ 3.1 and
earlier (!!), as apparently happens on AIX, where std::move sometimes
returns by value.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D123345
Revert "Fixup D123950 to address revert of D123345"
This reverts commit aa643f455a.
This reverts commit 69dd89fdcb.
This reverts commit 04000c2f92.
The current states breaks libstdc++ usage (https://reviews.llvm.org/D119136#3455423).
The fixup has been reverted as it caused other valid code to be disallowed.
I think we should start from the clean state by reverting all relevant commits.
Aaron Ballman