Summary:
I've found that most often the proper way to fix this warning is to add
`static`, because if the code otherwise compiles and links, the function
or variable is apparently not needed outside of the TU.
We can't provide a fix-it hint for variable declarations, because
multiple VarDecls can share the same type, and if we put static in front
of that, we affect all declared variables, some of which might have
previous declarations.
We also provide no fix-it hint for the rare case of an `extern` function
definition, because that would require removing `extern` and I have no
idea how to get the source location of the storage class specifier from
a FunctionDecl. I believe this information is only available earlier in
the AST construction from DeclSpec::getStorageClassSpecLoc(), but we
don't have that here.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D59402
llvm-svn: 363749
Summary:
Since the addition of __builtin_is_constant_evaluated the result of an expression can change based on whether it is evaluated in constant context. a lot of semantic checking performs evaluations with out specifying context. which can lead to wrong diagnostics.
for example:
```
constexpr int i0 = (long long)__builtin_is_constant_evaluated() * (1ll << 33); //#1
constexpr int i1 = (long long)!__builtin_is_constant_evaluated() * (1ll << 33); //#2
```
before the patch, #2 was diagnosed incorrectly and #1 wasn't diagnosed.
after the patch #1 is diagnosed as it should and #2 isn't.
Changes:
- add a flag to Sema to passe in constant context mode.
- in SemaChecking.cpp calls to Expr::Evaluate* are now done in constant context when they should.
- in SemaChecking.cpp diagnostics for UB are not checked for in constant context because an error will be emitted by the constant evaluator.
- in SemaChecking.cpp diagnostics for construct that cannot appear in constant context are not checked for in constant context.
- in SemaChecking.cpp diagnostics on constant expression are always emitted because constant expression are always evaluated.
- semantic checking for initialization of constexpr variables is now done in constant context.
- adapt test that were depending on warning changes.
- add test.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D62009
llvm-svn: 363488
Summary:
this revision adds Lexing, Parsing and Basic Semantic for the consteval specifier as specified by http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1073r3.html
with this patch, the consteval specifier is treated as constexpr but can only be applied to function declaration.
Changes:
- add the consteval keyword.
- add parsing of consteval specifier for normal declarations and lambdas expressions.
- add the whether a declaration is constexpr is now represented by and enum everywhere except for variable because they can't be consteval.
- adapt diagnostic about constexpr to print constexpr or consteval depending on the case.
- add tests for basic semantic.
Reviewers: rsmith, martong, shafik
Reviewed By: rsmith
Subscribers: eraman, efriedma, rnkovacs, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D61790
llvm-svn: 363362
Summary:
[[ https://bugs.llvm.org/show_bug.cgi?id=41549 | bug report ]]
Before this patch, implicit deduction guides were generated from the first declaration found by lookup.
With this patch implicit deduction guides are generated from the definition of the class template.
Also added test that was previously failing.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits, Quuxplusone
Tags: #clang
Differential Revision: https://reviews.llvm.org/D63072
llvm-svn: 363361
Summary:
this is a bugfixe for [[ https://bugs.llvm.org/show_bug.cgi?id=41400 | PR41400 ]]
added nullptr check at the relevent place and test
Reviewers: rsmith, riccibruno
Reviewed By: rsmith
Subscribers: jkooker, jkorous, riccibruno, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D60523
llvm-svn: 363360
packs.
Two changes:
* Track odr-use via FunctionParmPackExprs to properly handle dependent
odr-uses of packs in generic lambdas.
* Do not instantiate implicit captures; instead, regenerate them by
instantiating the body of the lambda. This is necessary to
distinguish between cases where only one element of a pack is
captured and cases where the entire pack is captured.
This reinstates r362358 (reverted in r362375) with a fix for an
uninitialized variable use in UpdateMarkingForLValueToRValue.
llvm-svn: 362531
prettyprint
__declspec(nothrow) should work on function pointers as well as function
references, so this changes it to FunctionLike. Additionally,
FunctionLike needed to be modified to permit function references.
Finally, the TypePrinter didn't properly print the NoThrow exception
specifier, so make sure we get that right as well.
llvm-svn: 362435
As reported here: https://bugs.llvm.org/show_bug.cgi?id=42100
This fairly common pattern ends up being an error in MinGW, so relax it
in all cases to a warning.
llvm-svn: 362434
Two changes:
* Track odr-use via FunctionParmPackExprs to properly handle dependent
odr-uses of packs in generic lambdas.
* Do not instantiate implicit captures; instead, regenerate them by
instantiating the body of the lambda. This is necessary to
distinguish between cases where only one element of a pack is
captured and cases where the entire pack is captured.
........
Fixes http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win buildbot failures
llvm-svn: 362375
packs.
Two changes:
* Track odr-use via FunctionParmPackExprs to properly handle dependent
odr-uses of packs in generic lambdas.
* Do not instantiate implicit captures; instead, regenerate them by
instantiating the body of the lambda. This is necessary to
distinguish between cases where only one element of a pack is
captured and cases where the entire pack is captured.
llvm-svn: 362358
Summary:
https://bugs.llvm.org/show_bug.cgi?id=41909 describes an issue in which
a generic lambda that takes a dependent argument `auto set` causes the
template instantiation machinery for coroutine body statements to crash
with an ICE. The issue is two-fold:
1. The paths taken by the template instantiator contain several asserts
that the coroutine promise must not have a dependent type.
2. The template instantiator unconditionally builds corotuine statements
that depend on the promise type, which cannot be dependent.
To work around the issue, prevent the template instantiator from building
dependent coroutine statements if the coroutine promise type is dependent.
Since we only expect this to occur in the case of a generic lambda, limit
the workaround behavior to just that case.
Reviewers: GorNishanov, EricWF, lewissbaker, tks2103
Reviewed By: GorNishanov
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D62550
llvm-svn: 362348
The previously added warning ended up causing false positives when
nothrow was used on member functions, where the exception specification
wasn't yet parsed. So, throw() and noexcept(true) both were incorrectly
warning. There doesn't seem to be a good way to force these to be parsed
to identify which they are (and likely should not be), so suppress the warning.
For now, unevaluated/uninstantiated are left as warnings as I am not
creative enough to find a reproducer that causes a false positive for
either.
llvm-svn: 362236
The implementation of the NoThrow ExceptionSpecificationType missed a
switch statement for forming the diagnostic when an out-of-line member
redeclaration misses the exception specification. This patch adds the
correct case statement.
llvm-svn: 362225
We need to know whether the destructor is trivial in order to tell
whether other parts of the class are valid (in particular, this affects
whether the type is a literal type, which affects whether defaulted
special members can be declared constexpr or are implicitly constexpr).
llvm-svn: 362184
and returned to the context in which 'this' should be captured.
This means we now always mark 'this' referenced from the context in
which it's actually referenced, rather than potentially from some
context nested within that.
llvm-svn: 362182
As reported here https://bugs.llvm.org/show_bug.cgi?id=42000, it was
possible to get the constexpr version of __builtin_*_overflow to give
the wrong answer.
This was because when extending the operands to fit the largest type (so
that the math could be done), the decision on whether to sign/zero
extend the operands was based on the result signedness, not on the
operands signedness.
In the reported case, (unsigned char)255 - (int)100 needed
to have each extended to the int in order to do the math. However, when
extending the first operand to 'int', we incorrectly sign extended it
instead of zero extending. Thus, the result didnt fit back into the
unsigned char.
The fix for this was simply to choose zero/sign extension based on the
sign of the operand itself.
Differential Revision: https://reviews.llvm.org/D62665
llvm-svn: 362157
In response to https://bugs.llvm.org/show_bug.cgi?id=33235, it became
clear that the current mechanism of hacking through checks for the
exception specification of a function gets confused really quickly when
there are alternate exception specifiers.
This patch introcues EST_NoThrow, which is the equivilent of
EST_noexcept when caused by EST_noThrow. The existing implementation is
left in place to cover functions with no FunctionProtoType.
Differential Revision: https://reviews.llvm.org/D62435
llvm-svn: 362119
We need to eagerly instantiate constexpr functions used in them even if
the default argument is never actually used, because we might evaluate
portions of it when performing semantic checks.
llvm-svn: 361670
HandleUnionActiveMemberChange forgot to walk over a nop implicit
conversion node and got stuck in the process.
As a cleanup I changed the declaration of `E` so it can't
be accidentally accessed after the loop.
llvm-svn: 361571
Summary:
This adds a new error for missing parentheses around lambdas in delete operators.
```
int main() {
delete []() { return new int(); }();
}
```
This will result in:
```
test.cpp:2:3: error: '[]' after delete interpreted as 'delete[]'
delete []() { return new int(); }();
^~~~~~~~~
test.cpp:2:9: note: add parentheses around the lambda
delete []() { return new int(); }();
^
( )
```
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: riccibruno, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D36357
llvm-svn: 361119
class type in constant evaluation.
This reinstates r360977, reverted in r360987, now that its rerequisite
patch is reinstated and fixed.
llvm-svn: 361067
object rather than tracking the originating expression.
This is groundwork for supporting polymorphic typeid expressions. (Note
that this somewhat regresses our support for DR1968, but it turns out
that that never actually worked anyway, at least in non-trivial cases.)
This reinstates r360974, reverted in r360988, with a fix for a
static_assert failure on 32-bit builds: force Type base class to have
8-byte alignment like the rest of Clang's AST nodes.
llvm-svn: 360995
object rather than tracking the originating expression.
This is groundwork for supporting polymorphic typeid expressions. (Note
that this somewhat regresses our support for DR1968, but it turns out
that that never actually worked anyway, at least in non-trivial cases.)
llvm-svn: 360974
Summary:
This patch implements the source location builtins `__builtin_LINE(), `__builtin_FUNCTION()`, `__builtin_FILE()` and `__builtin_COLUMN()`. These builtins are needed to implement [`std::experimental::source_location`](https://rawgit.com/cplusplus/fundamentals-ts/v2/main.html#reflection.src_loc.creation).
With the exception of `__builtin_COLUMN`, GCC also implements these builtins, and Clangs behavior is intended to match as closely as possible.
Reviewers: rsmith, joerg, aaron.ballman, bogner, majnemer, shafik, martong
Reviewed By: rsmith
Subscribers: rnkovacs, loskutov, riccibruno, mgorny, kunitoki, alexr, majnemer, hfinkel, cfe-commits
Differential Revision: https://reviews.llvm.org/D37035
llvm-svn: 360937
evaluation.
This reinstates r360559, reverted in r360580, with a fix to avoid
crashing if evaluation-for-overflow mode encounters a virtual call on an
object of a class with a virtual base class, and to generally not try to
resolve virtual function calls to objects whose (notional) vptrs are not
readable. (The standard rules are unclear here, but this seems like a
reasonable approach.)
llvm-svn: 360635
their lifetime in constant expressions.
This is undefined behavior per [class.cdtor]p2.
We continue to allow this for objects whose values are not visible
within the constant evaluation, because there's no way we can tell
whether the access is defined or not, existing code relies on the
ability to make such calls, and every other compiler allows such
calls.
This reinstates r360499, reverted in r360531.
llvm-svn: 360538
evaluation.
It's not enough to just track the LValueBase that we're evaluating, we
need to also track the path to the objects whose constructors are
running.
This reinstates r360464 (reverted in r360531) with a workaround for an
MSVC bug that previously caused the Windows bots to fail.
llvm-svn: 360537
Reject attempts to call non-static member functions on objects outside
their lifetime in constant expressions.
This is undefined behavior per [class.cdtor]p2.
We continue to allow this for objects whose values are not visible
within the constant evaluation, because there's no way we can tell
whether the access is defined or not, existing code relies on the
ability to make such calls, and every other compiler allows such
calls.
........
Fix handling of objects under construction during constant expression
evaluation.
It's not enough to just track the LValueBase that we're evaluating, we
need to also track the path to the objects whose constructors are
running.
........
Fixes windows buildbots
llvm-svn: 360531
their lifetime in constant expressions.
This is undefined behavior per [class.cdtor]p2.
We continue to allow this for objects whose values are not visible
within the constant evaluation, because there's no way we can tell
whether the access is defined or not, existing code relies on the
ability to make such calls, and every other compiler allows such
calls.
llvm-svn: 360499
evaluation.
It's not enough to just track the LValueBase that we're evaluating, we
need to also track the path to the objects whose constructors are
running.
llvm-svn: 360464
Vivek Pandya