Commit Graph

871 Commits

Author SHA1 Message Date
Matthias Gehre f64f488670 Reland [LifetimeAnalysis] Support more STL idioms (template forward declaration and DependentNameType)
Reland after https://reviews.llvm.org/D66806 fixed the false-positive diagnostics.

Summary:
This fixes inference of gsl::Pointer on std::set::iterator with libstdc++ (the typedef for iterator
on the template is a DependentNameType - we can only put the gsl::Pointer attribute
on the underlaying record after instantiation)

inference of gsl::Pointer on std::vector::iterator with libc++ (the class was forward-declared,
we added the gsl::Pointer on the canonical decl (the forward decl), and later when the
template was instantiated, there was no attribute on the definition so it was not instantiated).

and a duplicate gsl::Pointer on some class with libstdc++ (we first added an attribute to
a incomplete instantiation, and then another was copied from the template definition
when the instantiation was completed).

We now add the attributes to all redeclarations to fix thos issues and make their usage easier.

Reviewers: gribozavr

Subscribers: Szelethus, xazax.hun, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66179

llvm-svn: 371182
2019-09-06 08:56:30 +00:00
Gabor Horvath 6f98400189 [LifetimeAnalysis] Fix some false positives
Differential Revision: https://reviews.llvm.org/D66806

llvm-svn: 370773
2019-09-03 16:17:24 +00:00
Simon Pilgrim b65370cf05 Fix variable HasArrayDesignator set but not used warning. NFCI.
llvm-svn: 370609
2019-09-01 13:10:08 +00:00
Richard Smith ff9bf925e7 [c++20] Add support for designated direct-list-initialization syntax.
This completes the implementation of P0329R4.

llvm-svn: 370558
2019-08-31 01:00:37 +00:00
Richard Smith 5030928d60 [c++20] Implement semantic restrictions for C++20 designated
initializers.

This has some interesting interactions with our existing extensions to
support C99 designated initializers as an extension in C++. Those are
resolved as follows:

 * We continue to permit the full breadth of C99 designated initializers
   in C++, with the exception that we disallow a partial overwrite of an
   initializer with a non-trivially-destructible type. (Full overwrite
   is OK, because we won't run the first initializer at all.)

 * The C99 extensions are disallowed in SFINAE contexts and during
   overload resolution, where they could change the meaning of valid
   programs.

 * C++20 disallows reordering of initializers. We only check for that for
   the simple cases that the C++20 rules permit (designators of the form
   '.field_name =' and continue to allow reordering in other cases).
   It would be nice to improve this behavior in future.

 * All C99 designated initializer extensions produce a warning by
   default in C++20 mode. People are going to learn the C++ rules based
   on what Clang diagnoses, so it's important we diagnose these properly
   by default.

 * In C++ <= 17, we apply the C++20 rules rather than the C99 rules, and
   so still diagnose C99 extensions as described above. We continue to
   accept designated C++20-compatible initializers in C++ <= 17 silently
   by default (but naturally still reject under -pedantic-errors).

This is not a complete implementation of P0329R4. In particular, that
paper introduces new non-C99-compatible syntax { .field { init } }, and
we do not support that yet.

This is based on a previous patch by Don Hinton, though I've made
substantial changes when addressing the above interactions.

Differential Revision: https://reviews.llvm.org/D59754

llvm-svn: 370544
2019-08-30 22:52:55 +00:00
Richard Smith cd839ccf99 Fix silent wrong-code bugs and crashes with designated initialization.
We failed to correctly handle the 'holes' left behind by designated
initializers in VerifyOnly mode. This would result in us thinking that a
designated initialization would be valid, only to find that it is not
actually valid when we come to build it. In a +Asserts build, that would
assert, and in a -Asserts build, that would silently lose some part of
the initialization or crash.

With this change, when an InitListExpr contains any designators, we now
always build a structured list so that we can track the locations of the
'holes' that we need to go back and fill in.

We could in principle do better: we only need the structured form if
there is a designator that jumps backwards (and can otherwise check for
the holes as we progress through the initializer list), but dealing with
that turns out to be rather complicated, so it's not done as part of
this patch.

llvm-svn: 370419
2019-08-29 22:49:34 +00:00
Richard Smith 33e9be6c8b Refactor InitListChecker to check only a single (explicit) initializer
list, rather than recursively checking multiple lists in C.

This simplification is in preparation for making InitListChecker
maintain more state that's specific to the explicit initializer list,
particularly when handling designated initialization.

llvm-svn: 370418
2019-08-29 22:49:33 +00:00
Richard Smith 8823dbc552 Refactor InitListChecker to make it a bit clearer that hasError is only
set to true in VerifyOnly mode in cases where it's also set to true when
actually building the initializer list.

Add FIXMEs for the two cases where that's not true. No functionality
change intended.

llvm-svn: 370417
2019-08-29 22:49:32 +00:00
Richard Smith 26a92d5852 Improve behavior in the case of stack exhaustion.
Summary:
Clang performs various recursive operations (such as template instantiation),
and may use non-trivial amounts of stack space in each recursive step (for
instance, due to recursive AST walks). While we try to keep the stack space
used by such steps to a minimum and we have explicit limits on the number of
such steps we perform, it's impractical to guarantee that we won't blow out the
stack on deeply recursive template instantiations on complex ASTs, even with
only a moderately high instantiation depth limit.

The user experience in these cases is generally terrible: we crash with
no hint of what went wrong. Under this patch, we attempt to do better:

 * Detect when the stack is nearly exhausted, and produce a warning with a
   nice template instantiation backtrace, telling the user that we might
   run slowly or crash.

 * For cases where we're forced to trigger recursive template
   instantiation in arbitrarily-deeply-nested contexts, check whether
   we're nearly out of stack space and allocate a new stack (by spawning
   a new thread) after producing the warning.

Reviewers: rnk, aaron.ballman

Subscribers: mgorny, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66361

llvm-svn: 369940
2019-08-26 18:18:07 +00:00
Gabor Horvath 3ba0f3c9b7 [NFC] Add comments to some bool arguments for better readability
llvm-svn: 369928
2019-08-26 17:03:01 +00:00
Gabor Horvath 6379e5c8a4 [LifetimeAnalysis] Make it possible to disable the new warnings
llvm-svn: 369817
2019-08-23 22:21:33 +00:00
Richard Smith 966eea91ad Revert "[LifetimeAnalysis] Support more STL idioms (template forward declaration and DependentNameType)"
This reverts commit r369591, because it causes the formerly-reliable
-Wreturn-stack-address warning to start issuing false positives.
Testcase provided on the commit thread.

llvm-svn: 369677
2019-08-22 17:48:11 +00:00
Matthias Gehre b1c7801290 [LifetimeAnalysis] Support more STL idioms (template forward declaration and DependentNameType)
Summary:
This fixes inference of gsl::Pointer on std::set::iterator with libstdc++ (the typedef for iterator
on the template is a DependentNameType - we can only put the gsl::Pointer attribute
on the underlaying record after instantiation)

inference of gsl::Pointer on std::vector::iterator with libc++ (the class was forward-declared,
we added the gsl::Pointer on the canonical decl (the forward decl), and later when the
template was instantiated, there was no attribute on the definition so it was not instantiated).

and a duplicate gsl::Pointer on some class with libstdc++ (we first added an attribute to
a incomplete instantiation, and then another was copied from the template definition
when the instantiation was completed).

We now add the attributes to all redeclarations to fix thos issues and make their usage easier.

Reviewers: gribozavr

Subscribers: Szelethus, xazax.hun, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66179

llvm-svn: 369591
2019-08-21 22:08:59 +00:00
Gabor Horvath eaee4de503 [LifetimeAnalysis] Add support for free functions
Differential Revision: https://reviews.llvm.org/D66303

llvm-svn: 369408
2019-08-20 16:45:06 +00:00
Jonas Devlieghere 2b3d49b610 [Clang] Migrate llvm::make_unique to std::make_unique
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.

Differential revision: https://reviews.llvm.org/D66259

llvm-svn: 368942
2019-08-14 23:04:18 +00:00
Matthias Gehre 1bebc22bd9 [LifetimeAnalysis] Support std::stack::top() and std::optional::value()
Summary: Diagnose dangling pointers that come from std::stack::top() and std::optional::value().

Reviewers: gribozavr

Subscribers: cfe-commits, xazax.hun

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66164

llvm-svn: 368929
2019-08-14 21:55:57 +00:00
Gabor Horvath bfe0c37601 [LifetimeAnalysis] Fix false negatives of statement local lifetime analysis for some STL implementation
Differential Revision: https://reviews.llvm.org/D66152

llvm-svn: 368871
2019-08-14 16:34:56 +00:00
Gabor Horvath c6802b231f Fix multiple lifetime warning messages for range based for loop
llvm-svn: 368588
2019-08-12 16:19:39 +00:00
Sven van Haastregt 06385d013d [OpenCL] Ignore parentheses for sampler initialization
The sampler handling logic in SemaInit.cpp would inadvertently treat
parentheses around sampler arguments as an implicit cast, leading to
an unreachable "can't implicitly cast lvalue to rvalue with
this cast kind".  Fix by ignoring parentheses once we are in the
sampler initializer case.

Differential Revision: https://reviews.llvm.org/D66080

llvm-svn: 368561
2019-08-12 12:44:26 +00:00
Gabor Horvath e812bf5530 Properly detect temporary gsl::Owners through reference initialization chains.
llvm-svn: 368534
2019-08-11 14:39:42 +00:00
Gabor Horvath 3560ed0523 Properly handle reference initialization when detecting gsl::Pointer initialization chains
llvm-svn: 368528
2019-08-11 08:05:28 +00:00
Gabor Horvath eb563af70b Fix a false positive warning when initializing members with gsl::Owners.
llvm-svn: 368501
2019-08-10 00:32:29 +00:00
Gabor Horvath 795c3667d9 Attempt to reapply "Even more warnings utilizing gsl::Owner/gsl::Pointer annotations"
llvm-svn: 368499
2019-08-09 23:03:50 +00:00
Gabor Horvath 67a7530b47 Revert Even more warnings utilizing gsl::Owner/gsl::Pointer annotations
This reverts r368454 (git commit 7c3c8ba8da)

llvm-svn: 368463
2019-08-09 19:01:23 +00:00
Gabor Horvath fd85c894eb Revert Fix a build bot failure and multiple warnings instances for range base for loops
This reverts r368459 (git commit 2bf522aea6)

llvm-svn: 368462
2019-08-09 18:58:09 +00:00
Gabor Horvath 2bf522aea6 Fix a build bot failure and multiple warnings instances for range base for loops
llvm-svn: 368459
2019-08-09 17:42:41 +00:00
Gabor Horvath 7c3c8ba8da Even more warnings utilizing gsl::Owner/gsl::Pointer annotations
Differential Revision: https://reviews.llvm.org/D65127

llvm-svn: 368454
2019-08-09 17:11:32 +00:00
Gabor Horvath c1dafd7b53 More warnings regarding gsl::Pointer and gsl::Owner attributes
Differential Revision: https://reviews.llvm.org/D65120

llvm-svn: 368446
2019-08-09 15:16:35 +00:00
Richard Trieu 155b8d02c3 Update fix-it hints for std::move warnings.
Fix -Wpessimizing-move and -Wredundant-move when warning on initializer lists.
The new fix-it hints for removing the std::move call will now also suggest
removing the braces for the initializer list so that the resulting code will
still be compilable.

This fixes PR42832

llvm-svn: 368237
2019-08-08 00:12:51 +00:00
Gabor Horvath e5e10b526f Teach some warnings to respect gsl::Pointer and gsl::Owner attributes
This patch extends some existing warnings to utilize the knowledge about the gsl::Pointer and gsl::Owner attributes.

Differential Revision: https://reviews.llvm.org/D64256

llvm-svn: 368072
2019-08-06 19:13:29 +00:00
Anastasia Stulova 8d99a5c0e6 [OpenCL] Allow OpenCL C style vector initialization in C++
Allow creating vector literals from other vectors.

 float4 a = (float4)(1.0f, 2.0f, 3.0f, 4.0f);
 float4 v = (float4)(a.s23, a.s01);

Differential revision: https://reviews.llvm.org/D65286

llvm-svn: 367675
2019-08-02 11:19:35 +00:00
Neil Hickey 8ece3b6719 [OpenCL] Fixing sampler initialisations for C++ mode.
Allow conversions between integer and sampler type.

Differential Revision: https://reviews.llvm.org/D64791

llvm-svn: 366212
2019-07-16 14:57:32 +00:00
Rui Ueyama 49a3ad21d6 Fix parameter name comments using clang-tidy. NFC.
This patch applies clang-tidy's bugprone-argument-comment tool
to LLVM, clang and lld source trees. Here is how I created this
patch:

$ git clone https://github.com/llvm/llvm-project.git
$ cd llvm-project
$ mkdir build
$ cd build
$ cmake -GNinja -DCMAKE_BUILD_TYPE=Debug \
    -DLLVM_ENABLE_PROJECTS='clang;lld;clang-tools-extra' \
    -DCMAKE_EXPORT_COMPILE_COMMANDS=On -DLLVM_ENABLE_LLD=On \
    -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ../llvm
$ ninja
$ parallel clang-tidy -checks='-*,bugprone-argument-comment' \
    -config='{CheckOptions: [{key: StrictMode, value: 1}]}' -fix \
    ::: ../llvm/lib/**/*.{cpp,h} ../clang/lib/**/*.{cpp,h} ../lld/**/*.{cpp,h}

llvm-svn: 366177
2019-07-16 04:46:31 +00:00
Anastasia Stulova 3562edb9c4 [Sema] Fix diagnostic for addr spaces in reference binding
Extend reference binding behavior to account for address spaces.

Differential Revision: https://reviews.llvm.org/D62914

llvm-svn: 364032
2019-06-21 11:36:15 +00:00
Anastasia Stulova 1da9e4c910 [Sema] Improved diagnostic for qualifiers in reference binding
Improved wording and also simplified by using printing
method from qualifiers.

Differential Revision: https://reviews.llvm.org/D62914

llvm-svn: 364023
2019-06-21 10:50:02 +00:00
Anastasia Stulova c25ea86d43 [Sema] Diagnose addr space mismatch while constructing objects
If we construct an object in some arbitrary non-default addr space
it should fail unless either:
- There is an implicit conversion from the address space to default
/generic address space.
- There is a matching ctor qualified with an address space that is
either exactly matching or convertible to the address space of an
object.

Differential Revision: https://reviews.llvm.org/D62156

llvm-svn: 363944
2019-06-20 16:23:28 +00:00
Richard Smith 14059d2a13 Remove unused SK_LValueToRValue initialization step.
In addition to being unused and duplicating code, this was also wrong
(it didn't properly mark the operand as being potentially not odr-used).

This reinstates r363340, reverted in r363352.

llvm-svn: 363430
2019-06-14 17:46:39 +00:00
Richard Smith 27252a1f95 PR23833, DR2140: an lvalue-to-rvalue conversion on a glvalue of type
nullptr_t does not access memory.

We now reuse CK_NullToPointer to represent a conversion from a glvalue
of type nullptr_t to a prvalue of nullptr_t where necessary.

This reinstates r363337, reverted in r363352.

llvm-svn: 363429
2019-06-14 17:46:38 +00:00
Nico Weber 3d02b895ed Revert 363295, it caused PR42276. Also revert follow-ups 363337, 363340.
Revert 363340 "Remove unused SK_LValueToRValue initialization step."
Revert 363337 "PR23833, DR2140: an lvalue-to-rvalue conversion on a glvalue of type"
Revert 363295 "C++ DR712 and others: handle non-odr-use resulting from an lvalue-to-rvalue conversion applied to a member access or similar not-quite-trivial lvalue expression."

llvm-svn: 363352
2019-06-14 04:05:17 +00:00
Richard Smith aca017e802 Remove unused SK_LValueToRValue initialization step.
In addition to being unused and duplicating code, this was also wrong
(it didn't properly mark the operand as being potentially not odr-used).

llvm-svn: 363340
2019-06-13 23:47:42 +00:00
Richard Smith 0476d069e3 PR23833, DR2140: an lvalue-to-rvalue conversion on a glvalue of type
nullptr_t does not access memory.

We now reuse CK_NullToPointer to represent a conversion from a glvalue
of type nullptr_t to a prvalue of nullptr_t where necessary.

This reinstates r345562, reverted in r346065, now that CodeGen's
handling of non-odr-used variables has been fixed.

llvm-svn: 363337
2019-06-13 23:31:04 +00:00
Richard Smith c69cc84253 PR42220: take into account the possibility of aggregates with base
classes when checking an InitListExpr for lifetime extension.

llvm-svn: 363188
2019-06-12 18:32:22 +00:00
Anastasia Stulova 5145b1e442 [Sema] Prevent binding incompatible addr space ref to temporaries
References to arbitrary address spaces can't always be bound to
temporaries. This change extends the reference binding logic to
check that the address space of a temporary can be implicitly
converted to the address space in a reference when temporary
materialization is performed.

Differential Revision: https://reviews.llvm.org/D61318

llvm-svn: 362604
2019-06-05 14:03:34 +00:00
Erik Pilkington f8ccf05293 [Sema] Mark array element destructors referenced during initialization
This fixes a crash where we would neglect to mark a destructor referenced for an
__attribute__((no_destory)) array. The destructor is needed though, since if an
exception is thrown we need to cleanup the elements.

rdar://48462498

Differential revision: https://reviews.llvm.org/D61165

llvm-svn: 360446
2019-05-10 17:52:26 +00:00
Richard Smith 76b9027f35 [c++20] Add support for explicit(bool), as described in P0892R2.
Patch by Tyker!

Differential Revision: https://reviews.llvm.org/D60934

llvm-svn: 360311
2019-05-09 03:59:21 +00:00
Hans Wennborg d2b9fc88c8 Revert r359949 "[clang] adding explicit(bool) from c++2a"
This caused Clang to start erroring on the following:

  struct S {
    template <typename = int> explicit S();
  };

  struct T : S {};

  struct U : T {
    U();
  };
  U::U() {}

  $ clang -c /tmp/x.cc
  /tmp/x.cc:10:4: error: call to implicitly-deleted default constructor of 'T'
  U::U() {}
     ^
  /tmp/x.cc:5:12: note: default constructor of 'T' is implicitly deleted
    because base class 'S' has no default constructor
  struct T : S {};
             ^
  1 error generated.

See discussion on the cfe-commits email thread.

This also reverts the follow-ups r359966 and r359968.

> this patch adds support for the explicit bool specifier.
>
> Changes:
> - The parsing for the explicit(bool) specifier was added in ParseDecl.cpp.
> - The storage of the explicit specifier was changed. the explicit specifier was stored as a boolean value in the FunctionDeclBitfields and in the DeclSpec class. now it is stored as a PointerIntPair<Expr*, 2> with a flag and a potential expression in CXXConstructorDecl, CXXDeductionGuideDecl, CXXConversionDecl and in the DeclSpec class.
> - Following the AST change, Serialization, ASTMatchers, ASTComparator and ASTPrinter were adapted.
> - Template instantiation was adapted to instantiate the potential expressions of the explicit(bool) specifier When instantiating their associated declaration.
> - The Add*Candidate functions were adapted, they now take a Boolean indicating if the context allowing explicit constructor or conversion function and this boolean is used to remove invalid overloads that required template instantiation to be detected.
> - Test for Semantic and Serialization were added.
>
> This patch is not yet complete. I still need to check that interaction with CTAD and deduction guides is correct. and add more tests for AST operations. But I wanted first feedback.
> Perhaps this patch should be spited in smaller patches, but making each patch testable as a standalone may be tricky.
>
> Patch by Tyker
>
> Differential Revision: https://reviews.llvm.org/D60934

llvm-svn: 360024
2019-05-06 09:51:10 +00:00
Nicolas Lesser 5fe2ddbdf4 [clang] adding explicit(bool) from c++2a
this patch adds support for the explicit bool specifier.

Changes:
- The parsing for the explicit(bool) specifier was added in ParseDecl.cpp.
- The storage of the explicit specifier was changed. the explicit specifier was stored as a boolean value in the FunctionDeclBitfields and in the DeclSpec class. now it is stored as a PointerIntPair<Expr*, 2> with a flag and a potential expression in CXXConstructorDecl, CXXDeductionGuideDecl, CXXConversionDecl and in the DeclSpec class.
- Following the AST change, Serialization, ASTMatchers, ASTComparator and ASTPrinter were adapted.
- Template instantiation was adapted to instantiate the potential expressions of the explicit(bool) specifier When instantiating their associated declaration.
- The Add*Candidate functions were adapted, they now take a Boolean indicating if the context allowing explicit constructor or conversion function and this boolean is used to remove invalid overloads that required template instantiation to be detected.
- Test for Semantic and Serialization were added.

This patch is not yet complete. I still need to check that interaction with CTAD and deduction guides is correct. and add more tests for AST operations. But I wanted first feedback.
Perhaps this patch should be spited in smaller patches, but making each patch testable as a standalone may be tricky.

Patch by Tyker

Differential Revision: https://reviews.llvm.org/D60934

llvm-svn: 359949
2019-05-04 00:09:00 +00:00
David Blaikie 5e32805050 SemaOverload: Complete candidates before emitting the error, to ensure diagnostics emitted (or suppressed) during completion don't interfere with the overload notes
Because diagnostics and their notes are not connected at the API level,
if the error message for an overload is emitted, then the overload
candidates are completed - if a diagnostic is emitted during that work,
the notes related to overload candidates would be attached to the latter
diagnostic, not the original error. Sort of worse, if the latter
diagnostic was disabled, the notes are disabled.

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D61357

llvm-svn: 359854
2019-05-03 00:44:50 +00:00
Anastasia Stulova 094c72660a [PR41276] Fixed incorrect generation of addr space cast for 'this' in C++.
Improved classification of address space cast when qualification
conversion is performed - prevent adding addr space cast for
non-pointer and non-reference types. Take address space correctly
from the pointee.

Also pass correct address space from 'this' object using
AggValueSlot when generating addrspacecast in the constructor
call.

Differential Revision: https://reviews.llvm.org/D59988

llvm-svn: 357682
2019-04-04 10:48:36 +00:00
Bruno Ricci 70ad396bc4 [Sema][NFCI] Don't allocate storage for the various CorrectionCandidateCallback unless we are going to do some typo correction
The various CorrectionCandidateCallbacks are currently heap-allocated
unconditionally. This was needed because of delayed typo correction.
However these allocations represent currently 15.4% of all allocations
(number of allocations) when parsing all of Boost (!), mostly because
of ParseCastExpression, ParseStatementOrDeclarationAfterAttrtibutes
and isCXXDeclarationSpecifier. Note that all of these callback objects
are small. Let's not do this.

Instead initially allocate the callback on the stack, and only do a
heap allocation if we are going to do some typo correction. Do this by:

1. Adding a clone function to each callback, which will do a polymorphic
   clone of the callback. This clone function is required to be implemented
   by every callback (of which there is a fair amount). Make sure this is
   the case by making it pure virtual.

2. Use this clone function when we are going to try to correct a typo.

This additionally cut the time of -fsyntax-only on all of Boost by 0.5%
(not that much, but still something). No functional changes intended.

Differential Revision: https://reviews.llvm.org/D58827

Reviewed By: rnk

llvm-svn: 356925
2019-03-25 17:08:51 +00:00