Commit Graph

5053 Commits

Author SHA1 Message Date
Richard Smith 56bba012d9 [c++20] Fix incorrect assumptions in checks for comparison category types.
In the presence of modules, we can have multiple lookup results for the
same entity, and we need to re-check for completeness each time we
consider a type.
2019-12-09 12:18:33 -08:00
Richard Smith dbd1129724 Stop checking whether std::strong_* has ::equivalent members.
Any attempt to use these would be a bug, so we shouldn't even look for
them.
2019-12-06 11:35:41 -08:00
Richard Smith 759909506c Fix crash if a user-defined conversion is applied in the middle of a
rewrite of an operator in terms of operator<=>.
2019-12-05 18:44:15 -08:00
Richard Smith b220662a45 Properly convert all declaration non-type template arguments when
forming non-type template parameter values.

This reverts commit 93cc9dddd8,
which reverted commit 11d1052785.

We now always form `&x` when forming a pointer to a function rather than
trying to use function-to-pointer decay. This matches the behavior of
the old code in this case, but not the intent as described by the
comments.
2019-12-05 14:32:36 -08:00
David L. Jones 93cc9dddd8 Revert "Properly convert all declaration non-type template arguments when"
This reverts commit 11d1052785.

This change is problematic with function pointer template parameters. For
example, building libcxxabi with futexes (-D_LIBCXXABI_USE_FUTEX) produces this
diagnostic:

    In file included from .../llvm-project/libcxxabi/src/cxa_guard.cpp:15:
    .../llvm-project/libcxxabi/src/cxa_guard_impl.h:416:54: error: address of function 'PlatformThreadID' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
        has_thread_id_support(this->thread_id_address && GetThreadIDArg),
                                                      ~~ ^~~~~~~~~~~~~~
    .../llvm-project/libcxxabi/src/cxa_guard.cpp:38:26: note: in instantiation of member function '__cxxabiv1::(anonymous namespace)::InitByteFutex<&__cxxabiv1::(anonymous namespace)::PlatformFutexWait, &__cxxabiv1::(anonymous namespace)::PlatformFutexWake, &__cxxabiv1::(anonymous namespace)::PlatformThreadID>::InitByteFutex' requested here
      SelectedImplementation imp(raw_guard_object);
                             ^
    .../llvm-project/libcxxabi/src/cxa_guard_impl.h:416:54: note: prefix with the address-of operator to silence this warning
        has_thread_id_support(this->thread_id_address && GetThreadIDArg),
                                                         ^
                                                         &
    1 error generated.

The diagnostic is incorrect: adding the address-of operator also fails ("cannot
take the address of an rvalue of type 'uint32_t (*)()' (aka 'unsigned int
(*)()')").
2019-12-04 22:12:15 -08:00
Richard Smith 11d1052785 Properly convert all declaration non-type template arguments when
forming non-type template parameter values.
2019-12-04 18:55:24 -08:00
James Y Knight 90fce46fa6 Fix crash-on-invalid-code in lambda constant evaluation.
If the lambda used 'this' without without capturing it, an error was
emitted, but the constant evaluator would still attempt to lookup the
capture, and failing to find it, dereference a null pointer.

This only happens in C++17 (as that's when lambdas were made
potentially-constexpr). Therefore, I also updated the
lambda-expressions.cpp test to run in both C++14 and C++17 modes.
2019-12-04 15:12:17 -05:00
Elizabeth Andrews 878a24ee24 Reapply "Fix crash on switch conditions of non-integer types in templates"
This patch reapplies commit 759948467e. Patch was reverted due to a
clang-tidy test fail on Windows. The test has been modified. There
are no additional code changes.

Patch was tested with ninja check-all on Windows and Linux.

Summary of code changes:

Clang currently crashes for switch statements inside a template when the
condition is a non-integer field member because contextual implicit
conversion is skipped when parsing the condition. This conversion is
however later checked in an assert when the case statement is handled.
The conversion is skipped when parsing the condition because
the field member is set as type-dependent based on its containing class.
This patch sets the type dependency based on the field's type instead.

This patch fixes Bug 40982.
2019-12-03 15:27:19 -08:00
Dávid Bolvanský 549ff601f0 Try to reenable -Wdeprecated-copy under -Wextra 2019-11-27 22:36:51 +01:00
Dávid Bolvanský 4eacc32672 Partially reland "[Diagnostics] Put "deprecated copy" warnings into -Wdeprecated-copy""
But do not enable it under -Wextra until libcxx issue is solved.
2019-11-26 14:41:34 +01:00
Tom Stellard 3c5142597a Revert "[Diagnostic] add a warning which warns about misleading indentation"
This reverts commit 7b86188b50.

This commit introduced bot falures for multi-stage bots with -Werror.
2019-11-25 13:19:57 -08:00
Tom Stellard 0e12815566 Revert "[Diagnostics] Put "deprecated copy" warnings into -Wdeprecated-copy"
This reverts commit 9353c5dd06.

This commit introduced bot falures for multi-stage bots with -Werror.
2019-11-25 13:19:57 -08:00
Tyker 7b86188b50 [Diagnostic] add a warning which warns about misleading indentation
Summary: Add a warning for misleading indentation similar to GCC's -Wmisleading-indentation

Reviewers: aaron.ballman, xbolva00

Reviewed By: aaron.ballman, xbolva00

Subscribers: arphaman, Ka-Ka, thakis

Differential Revision: https://reviews.llvm.org/D70638
2019-11-25 20:46:32 +01:00
Dávid Bolvanský 9e260c12bc [Diagnostics] Make behaviour of Clang's -Wdeprecated-copy same as in GCC
Do not warn for  functions that are explicitly marked delete or default, which follows the behavior of the GCC warning.
2019-11-23 23:57:17 +01:00
Dávid Bolvanský 9353c5dd06 [Diagnostics] Put "deprecated copy" warnings into -Wdeprecated-copy
Summary:
GCC 9 added -Wdeprecated-copy (as part of -Wextra). This diagnostic is already implemented in Clang too, just hidden under -Wdeprecated (not on by default).
This patch adds -Wdeprecated-copy and makes it compatible with GCC 9+.
This diagnostic is heavily tested in deprecated.cpp, so I added simple tests just to check we warn when new flag/-Wextra is enabled.

Reviewers: rsmith, dblaikie

Reviewed By: dblaikie

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70342
2019-11-22 22:37:19 +01:00
Brian Gesiak 0b3d1d1348 [coroutines] Remove assert on CoroutineParameterMoves in Sema::buildCoroutineParameterMoves
Summary:
The assertion of CoroutineParameterMoves happens when build coroutine function with arguments  multiple time while fails to build promise type.

Fix: use return false instead.

Test Plan: check-clang

Reviewers: modocache, GorNishanov, rjmccall

Reviewed By: modocache

Subscribers: rjmccall, EricWF, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69022

Patch by junparser (JunMa)!
2019-11-22 11:39:13 -05:00
Weverything 9740f9f0b6 Add -Wtautological-compare to -Wall
Some warnings in -Wtautological-compare subgroups are DefaultIgnore.
Adding this group to -Wmost, which is part of -Wall, will aid in their
discoverability.

Differential Revision: https://reviews.llvm.org/D69292
2019-11-12 14:36:57 -08:00
Dávid Bolvanský 1da13237a4 [Diagnostics] Try to improve warning message for -Wreturn-type
Summary: I agree with https://easyaspi314.github.io/gcc-vs-clang.html?fbclid=IwAR1VA0qxiWVUusOQUv5z7JESS7ZpeJy-UqAI5mnJscofGLqXcqeErIUB2gU, current warning message is not very good. We should try to improve it..

Reviewers: rsmith, aaron.ballman, easyaspi314

Reviewed By: aaron.ballman

Subscribers: arphaman, Quuxplusone, mehdi_amini, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D69762
2019-11-09 17:54:58 +01:00
Melanie Blower d0b3e73175 Revert "Reapply "Fix crash on switch conditions of non-integer types in templates""
This reverts commit 759948467e.
There were build bot failures in clang-tidy
2019-11-08 14:18:15 -08:00
Melanie Blower 759948467e Reapply "Fix crash on switch conditions of non-integer types in templates"
This patch reapplies commit 76945821b9. The first version broke
buildbots due to clang-tidy test fails. The fails are because some
errors in templates are now diagnosed earlier (does not wait till
instantiation). I have modified the tests to add checks for these
diagnostics/prevent these diagnostics. There are no additional code
changes.

Summary of code changes:

Clang currently crashes for switch statements inside a template when the
condition is a non-integer field member because contextual implicit
conversion is skipped when parsing the condition. This conversion is
however later checked in an assert when the case statement is handled.
The conversion is skipped when parsing the condition because
the field member is set as type-dependent based on its containing class.
This patch sets the type dependency based on the field's type instead.

This patch fixes Bug 40982.

Reviewers: rnk, gribozavr2

Patch by: Elizabeth Andrews (eandrews)

Differential revision: https://reviews.llvm.org/D69950
2019-11-08 10:17:06 -08:00
Reid Kleckner 7177ce978e [SEH] Defer checking filter expression types until instantiaton
While here, wordsmith the error a bit. Now clang says:
  error: filter expression has non-integral type 'Foo'

Fixes PR43779

Reviewers: amccarth

Differential Revision: https://reviews.llvm.org/D69969
2019-11-07 14:52:04 -08:00
Edward Jones 90ecfa2f5f Revert "[Sema] Suppress -Wchar-subscripts if the index is a literal char"
This reverts commit 7adab7719e.
2019-11-07 18:45:40 +00:00
Edward Jones 7adab7719e [Sema] Suppress -Wchar-subscripts if the index is a literal char
Assume that the user knows what they're doing if they provide a char
literal as an array index. This more closely matches the behavior of
GCC.

Differential Revision: https://reviews.llvm.org/D58896
2019-11-07 15:45:44 +00:00
Dávid Bolvanský 55507110b9 [Diagnostics] Improve some error messages related to bad use of dynamic_cast 2019-11-04 16:26:43 +01:00
Dávid Bolvanský b06305e449 [Diagnostics] Warn for std::is_constant_evaluated in constexpr mode
Summary:
constexpr int fn1() {
  if constexpr (std::is_constant_evaluated()) // condition is always true!
    return 0;
  else
    return 1;
}

constexpr int fn2() {
  if (std::is_constant_evaluated())
    return 0;
  else
    return 1;
}

Solves PR42977

Reviewers: rsmith, aaron.ballman

Reviewed By: rsmith

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69518
2019-10-31 10:03:11 +01:00
Richard Smith bb06149131 Fix __attribute__((enable_if)) to treat arguments with side-effects as
non-constant.

We previously failed the entire condition evaluation if an unmodeled
side-effect was encountered in an argument, even if that argument was
unused in the attribute's condition.
2019-10-30 13:39:29 -07:00
Aaron Puchert ae3159e497 Thread safety analysis: Peel away NoOp implicit casts in initializers
Summary:
This happens when someone initializes a variable with guaranteed copy
elision and an added const qualifier. Fixes PR43826.

Reviewers: aaron.ballman, rsmith

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D69533
2019-10-30 00:37:32 +01:00
Richard Smith eb535d2341 Accept __is_same_as as a GCC-compatibility synonym for the proper trait name __is_same. 2019-10-29 14:44:38 -07:00
Richard Smith 52590319a2 Fix argument numbering confusion when diagnosing a non-viable operator().
This could lead to crashes if operator() is a variadic template, as we
could end up asking for an out-of-bounds argument.
2019-10-29 13:08:39 -07:00
Richard Smith 39eef2cbb6 PR43775: don't produce a bogus 'auto' -Wc++98-compat warning for CTAD 2019-10-27 21:42:58 -07:00
Richard Smith faee39baa8 PR43762: when implicitly changing the active union member for an
assignment during constant evaluation, only start the lifetime of
trivially-default-constructible union members.
2019-10-27 12:31:16 -07:00
Richard Smith 70f59b5bbc When diagnosing an ambiguity, only note the candidates that contribute
to the ambiguity, rather than noting all viable candidates.
2019-10-24 14:58:29 -07:00
Richard Smith d052a578de [c++2a] Allow comparison functions to be explicitly defaulted.
This adds some initial syntactic checking that only the appropriate
function signatures can be defaulted. No implicit definitions are
generated yet.
2019-10-22 18:16:17 -07:00
Richard Trieu 8b0d14a8f0 New tautological warning for bitwise-or with non-zero constant always true.
Taking a value and the bitwise-or it with a non-zero constant will always
result in a non-zero value. In a boolean context, this is always true.

if (x | 0x4) {}  // always true, intended '&'

This patch creates a new warning group -Wtautological-bitwise-compare for this
warning. It also moves in the existing tautological bitwise comparisons into
this group. A few other changes were needed to the CFGBuilder so that all bool
contexts would be checked. The warnings in -Wtautological-bitwise-compare will
be off by default due to using the CFG.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=42666
Differential Revision: https://reviews.llvm.org/D66046

llvm-svn: 375318
2019-10-19 00:57:23 +00:00
Richard Smith 974c8b7e2f [c++20] Add rewriting from comparison operators to <=> / ==.
This adds support for rewriting <, >, <=, and >= to a normal or reversed
call to operator<=>, for rewriting != to a normal or reversed call to
operator==, and for rewriting <=> and == to reversed forms of those same
operators.

Note that this is a breaking change for various C++17 code patterns,
including some in use in LLVM. The most common patterns (where an
operator== becomes ambiguous with a reversed form of itself) are still
accepted under this patch, as an extension (with a warning). I'm hopeful
that we can get the language rules fixed before C++20 ships, and the
extension warning is aimed primarily at providing data to inform that
decision.

llvm-svn: 375306
2019-10-19 00:04:43 +00:00
Richard Smith 61dadfc894 PR43674: fix incorrect constant evaluation of 'switch' where no case
label corresponds to the condition.

llvm-svn: 374954
2019-10-15 22:23:11 +00:00
Richard Smith 7e8fe67f0e PR43080: Do not build context-sensitive expressions during name classification.
Summary:
We don't know what context to use until the classification result is
consumed by the parser, which could happen in a different semantic
context. So don't build the expression that results from name
classification until we get to that point and can handle it properly.

This covers everything except C++ implicit class member access, which
is a little awkward to handle properly in the face of the protected
member access check. But it at least fixes all the currently-filed
instances of PR43080.

Reviewers: efriedma

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68896

llvm-svn: 374826
2019-10-14 21:53:03 +00:00
Richard Smith 1e3a8d12a1 Suppress false-positive -Wdeprecated-volatile warning from __is_*_assignable(volatile T&, U).
llvm-svn: 374580
2019-10-11 17:59:09 +00:00
Richard Smith e381f33651 PR43629: Fix crash evaluating constexpr placement new on a subobject of
an out-of-lifetime object.

llvm-svn: 374465
2019-10-10 22:31:17 +00:00
Gauthier Harnisch 59c6df9b2c [clang] prevent crash for nonnull attribut in constant context (Bug 43601)
Summary:

bug : https://bugs.llvm.org/show_bug.cgi?id=43601

Reviewers: rnk

Reviewed By: rnk

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68716

llvm-svn: 374285
2019-10-10 07:13:20 +00:00
Richard Smith 4a6861a7e5 [c++20] P1152R4: warn on any simple-assignment to a volatile lvalue
whose value is not ignored.

We don't warn on all the cases that are deprecated: specifically, we
choose to not warn for now if there are parentheses around the
assignment but its value is not actually used. This seems like a more
defensible rule, particularly for cases like sizeof(v = a), where the
parens are part of the operand rather than the sizeof syntax.

llvm-svn: 374135
2019-10-09 02:04:54 +00:00
Richard Smith 84ef9c6493 [c++20] Implement most of P1152R4.
Diagnose some now-deprecated uses of volatile types:
 * as function parameter types and return types
 * as the type of a structured binding declaration
 * as the type of the lvalue operand of an increment / decrement /
   compound assignment operator

This does not implement a check for the deprecation of simple
assignments whose results are used; that check requires somewhat
more complexity and will be addressed separately.

llvm-svn: 374133
2019-10-09 00:49:40 +00:00
Richard Smith df3761f6dc [c++20] Check for a class-specific operator delete when deleting an
object of class type with a virtual destructor.

llvm-svn: 373875
2019-10-07 03:14:28 +00:00
Richard Smith 74ce7112c3 Fix behavior of __builtin_bit_cast when the From and To types are the
same.

We were missing the lvalue-to-rvalue conversion entirely in this case,
and in fact still need the full CK_LValueToRValueBitCast conversion to
perform a load with no TBAA.

llvm-svn: 373874
2019-10-07 02:45:12 +00:00
Richard Smith 1e9c0cecab [Sema] Avoids an assertion failure when an invalid conversion declaration is used
Summary:
When using a user-defined conversion function template with a deduced return type the compiler gives a set of warnings:
```
bug.cc:252:44: error: cannot specify any part of a return type in the declaration of a conversion function; use an alias template to declare a conversion to 'auto (Ts &&...) const'
  template <typename... Ts> operator auto()(Ts &&... xs) const;
                                           ^~~~~~~~~~~~~~~~~~~
bug.cc:252:29: error: conversion function cannot convert to a function type
  template <typename... Ts> operator auto()(Ts &&... xs) const;
                            ^
error: pointer to function type cannot have 'const' qualifier
```
after which it triggers an assertion failure. It seems the last error is incorrect and doesn't have any location information. This patch stops the compilation after the second warning.

Fixes bug 31422.

Patch by Mark de Wever!

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: bbannier, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64820

llvm-svn: 373862
2019-10-06 18:40:59 +00:00
David Bolvansky 3acc649b86 [NFCI] Slightly improve warning message
llvm-svn: 373818
2019-10-05 08:09:06 +00:00
Richard Smith 5258202a81 PR43519: don't inject a diagnostic when constant-evaulation of a
pointer-to-member call can't determine a callee.

We will have produced a diagnostic already if the callee is known to be
unevaluatable, and diagnosing here rejects valid code during potential
constant expression checking.

llvm-svn: 373553
2019-10-03 01:20:27 +00:00
Richard Smith b542602c5f For P0784R7: support placement new-expressions in constant evaluation.
For now, we restrict this support to use from within the standard
library implementation, since we're required to make parts of the
standard library that use placement new work, but not permitted to
make uses of placement new from user code work.

llvm-svn: 373547
2019-10-03 00:39:35 +00:00
Richard Smith 19ad523971 For P0784R7: allow direct calls to operator new / operator delete from
std::allocator::{allocate,deallocate} in constant evaluation.

llvm-svn: 373546
2019-10-03 00:39:33 +00:00
Richard Trieu e388725316 Revert r368237 - Update fix-it hints for std::move warnings.
r368237 attempted to improve fix-its for move warnings, but introduced some
regressions to -Wpessimizing-move.  Revert that change and add the missing
test cases to the pessimizing move test to prevent future regressions.

llvm-svn: 373421
2019-10-02 02:32:15 +00:00