2521 Commits

Author SHA1 Message Date
Akira Hatanaka
6f6156b9fc Revert "[Sema] Diagnose default-initialization, destruction, and copying of"
This reverts commit r365985.

Prior to r365985, clang used to mark C union fields that have
non-trivial ObjC ownership qualifiers as unavailable if the union was
declared in a system header. r365985 stopped doing so, which caused the
swift compiler to crash when it tried to import a non-trivial union.

I have a patch that fixes the crash (https://reviews.llvm.org/D65256),
but I'm temporarily reverting the original patch until we can decide on
whether it's taking the right approach.

llvm-svn: 367076
2019-07-26 00:02:17 +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
Akira Hatanaka
81b03d4a08 [Sema] Diagnose default-initialization, destruction, and copying of
non-trivial C union types

This patch diagnoses uses of non-trivial C unions and structs/unions
containing non-trivial C unions in the following contexts, which require
default-initialization, destruction, or copying of the union objects,
instead of disallowing fields of non-trivial types in C unions, which is
what we currently do:

- function parameters.
- function returns.
- assignments.
- compound literals.
- block captures except capturing of `__block` variables by non-escaping
  blocks.
- local and global variable definitions.
- lvalue-to-rvalue conversions of volatile types.

See the discussion in https://reviews.llvm.org/D62988 for more background.

rdar://problem/50679094

Differential Revision: https://reviews.llvm.org/D63753

llvm-svn: 365985
2019-07-13 01:47:15 +00:00
Saar Raz
d7aae33a95 [Concepts] Concept definitions (D40381)
First in a series of patches to land C++2a Concepts support.
This patch adds AST and parsing support for concept-declarations.

llvm-svn: 365699
2019-07-10 21:25:49 +00:00
Francis Visoiu Mistrih
e0308279cb [Bitcode] Move Bitstream to a separate library
This moves Bitcode/Bitstream*, Bitcode/BitCodes.h to Bitstream/.

This is needed to avoid a circular dependency when using the bitstream
code for parsing optimization remarks.

Since Bitcode uses Core for the IR part:

libLLVMRemarks -> Bitcode -> Core

and Core uses libLLVMRemarks to generate remarks (see
IR/RemarkStreamer.cpp):

Core -> libLLVMRemarks

we need to separate the Bitstream and Bitcode part.

For clang-doc, it seems that it doesn't need the whole bitcode layer, so
I updated the CMake to only use the bitstream part.

Differential Revision: https://reviews.llvm.org/D63899

llvm-svn: 365091
2019-07-03 22:40:07 +00:00
Fangrui Song
7264a474b7 Change std::{lower,upper}_bound to llvm::{lower,upper}_bound or llvm::partition_point. NFC
llvm-svn: 365006
2019-07-03 08:13:17 +00:00
Erik Pilkington
eee944e7f9 [C++2a] Add __builtin_bit_cast, used to implement std::bit_cast
This commit adds a new builtin, __builtin_bit_cast(T, v), which performs a
bit_cast from a value v to a type T. This expression can be evaluated at
compile time under specific circumstances.

The compile time evaluation currently doesn't support bit-fields, but I'm
planning on fixing this in a follow up (some of the logic for figuring this out
is in CodeGen). I'm also planning follow-ups for supporting some more esoteric
types that the constexpr evaluator supports, as well as extending
__builtin_memcpy constexpr evaluation to use the same infrastructure.

rdar://44987528

Differential revision: https://reviews.llvm.org/D62825

llvm-svn: 364954
2019-07-02 18:28:13 +00:00
JF Bastien
0e82895826 BitStream reader: propagate errors
The bitstream reader handles errors poorly. This has two effects:

 * Bugs in file handling (especially modules) manifest as an "unexpected end of
   file" crash
 * Users of clang as a library end up aborting because the code unconditionally
   calls `report_fatal_error`

The bitstream reader should be more resilient and return Expected / Error as
soon as an error is encountered, not way late like it does now. This patch
starts doing so and adopting the error handling where I think it makes sense.
There's plenty more to do: this patch propagates errors to be minimally useful,
and follow-ups will propagate them further and improve diagnostics.

https://bugs.llvm.org/show_bug.cgi?id=42311
<rdar://problem/33159405>

Differential Revision: https://reviews.llvm.org/D63518

llvm-svn: 364464
2019-06-26 19:50:12 +00:00
Gauthier Harnisch
83c7b61052 [clang] Add storage for APValue in ConstantExpr
Summary:
When using ConstantExpr we often need the result of the expression to be kept in the AST. Currently this is done on a by the node that needs the result and has been done multiple times for enumerator, for constexpr variables... . This patch adds to ConstantExpr the ability to store the result of evaluating the expression. no functional changes expected.

Changes:
 - Add trailling object to ConstantExpr that can hold an APValue or an uint64_t. the uint64_t is here because most ConstantExpr yield integral values so there is an optimized layout for integral values.
 - Add basic* serialization support for the trailing result.
 - Move conversion functions from an enum to a fltSemantics from clang::FloatingLiteral to llvm::APFloatBase. this change is to make it usable for serializing APValues.
 - Add basic* Import support for the trailing result.
 - ConstantExpr created in CheckConvertedConstantExpression now stores the result in the ConstantExpr Node.
 - Adapt AST dump to print the result when present.

basic* : None, Indeterminate, Int, Float, FixedPoint, ComplexInt, ComplexFloat,
the result is not yet used anywhere but for -ast-dump.

Reviewers: rsmith, martong, shafik

Reviewed By: rsmith

Subscribers: rnkovacs, hiraditya, dexonsmith, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D62399

llvm-svn: 363493
2019-06-15 10:24:47 +00:00
Gauthier Harnisch
796ed03b84 [C++20] add Basic consteval specifier
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
2019-06-14 08:56:20 +00:00
Richard Smith
1bbad59379 For DR712: store on a MemberExpr whether it constitutes an odr-use.
llvm-svn: 363087
2019-06-11 17:50:36 +00:00
Richard Smith
715f7a1bd0 For DR712: store on a DeclRefExpr whether it constitutes an odr-use.
Begin restructuring to support the forms of non-odr-use reference
permitted by DR712.

llvm-svn: 363086
2019-06-11 17:50:32 +00:00
Richard Smith
dcf17ded66 Convert MemberExpr creation and serialization to work the same way as
most / all other Expr subclasses.

This reinstates r362551, reverted in r362597, with a fix to a bug that
caused MemberExprs to sometimes have a null FoundDecl after a round-trip
through an AST file.

llvm-svn: 362756
2019-06-06 23:24:15 +00:00
Benjamin Kramer
9b2b8ad8b1 Revert "Factor out duplicated code building a MemberExpr and marking it" and "Convert MemberExpr creation and serialization to work the same way as"
This reverts commits r362551 and r362563. Crashes during modules selfhost.

llvm-svn: 362597
2019-06-05 11:46:57 +00:00
Richard Smith
c32ef4bc0b Convert MemberExpr creation and serialization to work the same way as
most / all other Expr subclasses.

llvm-svn: 362551
2019-06-04 21:29:28 +00:00
Jennifer Yu
b8fee677bf Re-check in clang support gun asm goto after fixing tests.
llvm-svn: 362410
2019-06-03 15:57:25 +00:00
Erich Keane
d0f34fd198 Revert "clang support gnu asm goto."
This reverts commit 954ec09aed4f2be04bb5f4e10dbb4ea8bd19ef9a.

Reverting due to test failures as requested by Jennifer Yu.

Conflicts:
	clang/test/CodeGen/asm-goto.c

llvm-svn: 362106
2019-05-30 15:38:02 +00:00
Jennifer Yu
954ec09aed clang support gnu asm goto.
Syntax:
  asm [volatile] goto ( AssemblerTemplate
                      :
                      : InputOperands
                      : Clobbers
                      : GotoLabels)

https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html

New llvm IR is "callbr" for inline asm goto instead "call" for inline asm
For:
asm goto("testl %0, %0; jne %l1;" :: "r"(cond)::label_true, loop);
IR:
callbr void asm sideeffect "testl $0, $0; jne ${1:l};", "r,X,X,~{dirflag},~{fpsr},~{flags}"(i32 %0, i8* blockaddress(@foo, %label_true), i8* blockaddress(@foo, %loop)) #1
          to label %asm.fallthrough [label %label_true, label %loop], !srcloc !3

asm.fallthrough:                                

Compiler need to generate:
1> a dummy constarint 'X' for each label.
2> an unique fallthrough label for each asm goto stmt " asm.fallthrough%number".


Diagnostic 
1>	duplicate asm operand name are used in output, input and label.
2>	goto out of scope.

llvm-svn: 362045
2019-05-30 01:05:46 +00:00
Richard Smith
0353e5a6cd Permit static local structured bindings to be named from arbitrary scopes inside their declaring scope.
llvm-svn: 361686
2019-05-25 01:04:17 +00:00
Richard Smith
fd42079255 Fix crash deserializing a CUDAKernelCallExpr with a +Asserts binary.
The assertion in setConfig read from the (uninitialized) CONFIG
expression.

llvm-svn: 361680
2019-05-24 23:26:07 +00:00
Richard Smith
b2997f579a [c++20] P0780R2: Support pack-expansion of init-captures.
This permits an init-capture to introduce a new pack:

  template<typename ...T> auto x = [...a = T()] { /* a is a pack */ };

To support this, the mechanism for allowing ParmVarDecls to be packs has
been extended to support arbitrary local VarDecls.

llvm-svn: 361300
2019-05-21 20:10:50 +00:00
Eric Fiselier
708afb56c1 Implement __builtin_LINE() et. al. to support source location capture.
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
2019-05-16 21:04:15 +00:00
Richard Smith
c7214f6510 PR41845: Detect and reject mismatched inner/outer pack expansion sizes
in fold expressions rather than crashing.

llvm-svn: 360563
2019-05-13 08:31:14 +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
Richard Smith
b23c5e8c3d [c++20] Implement P0846R0: allow (ADL-only) calls to template-ids whose
template name is not visible to unqualified lookup.

In order to support this without a severe degradation in our ability to
diagnose typos in template names, this change significantly restructures
the way we handle template-id-shaped syntax for which lookup of the
template name finds nothing.

Instead of eagerly diagnosing an undeclared template name, we now form a
placeholder template-name representing a name that is known to not find
any templates. When the parser sees such a name, it attempts to
disambiguate whether we have a less-than comparison or a template-id.
Any diagnostics or typo-correction for the name are delayed until its
point of use.

The upshot should be a small improvement of our diagostic quality
overall: we now take more syntactic context into account when trying to
resolve an undeclared identifier on the left hand side of a '<'. In
fact, this works well enough that the backwards-compatible portion (for
an undeclared identifier rather than a lookup that finds functions but
no function templates) is enabled in all language modes.

llvm-svn: 360308
2019-05-09 03:31:27 +00:00
Leonard Chan
c72aaf62d3 Recommit r359859 "[Attribute/Diagnostics] Print macro if definition is an attribute declaration"
Updated with fix for read of uninitialized memory.

llvm-svn: 360109
2019-05-07 03:20:17 +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
Leonard Chan
ef2dc25a96 Revert "[Attribute/Diagnostics] Print macro if definition is an attribute declaration"
This reverts commit fc40cbd9d8c63e65eed3590ba925321afe782e1d.

llvm-svn: 359859
2019-05-03 03:28:06 +00:00
Leonard Chan
fc40cbd9d8 [Attribute/Diagnostics] Print macro if definition is an attribute declaration
If an address_space attribute is defined in a macro, print the macro instead
when diagnosing a warning or error for incompatible pointers with different
address_spaces.

We allow this for all attributes (not just address_space), and for multiple
attributes declared in the same macro.

Differential Revision: https://reviews.llvm.org/D51329

llvm-svn: 359826
2019-05-02 20:38:14 +00:00
Richard Smith
f19a8b0517 Replace ad-hoc tracking of pattern for an instantiated class-scope
explicit function specialization with the MemberSpecializationInfo used
everywhere else.

Not NFC: the ad-hoc pattern tracking was not being serialized /
deserialized properly. That's fixed here.

llvm-svn: 359747
2019-05-02 00:49:14 +00:00
Bruno Ricci
2751b69dd3 [Serialization] Stable serialization order for OpenCLTypeExtMap and OpenCLDeclExtMap
Sort the elements of Sema::OpenCLTypeExtMap and Sema::OpenCLDeclExtMap
by TypeIDs and DeclIDs to guarantee a stable serialization order.

Differential Revision: https://reviews.llvm.org/D60835

Reviewed By: Anastasia

Reviewers: Anastasia, lebedev.ri
llvm-svn: 358674
2019-04-18 15:13:27 +00:00
Fangrui Song
75e74e077c Range-style std::find{,_if} -> llvm::find{,_if}. NFC
llvm-svn: 357359
2019-03-31 08:48:19 +00:00
Anton Afanasyev
d880de2d19 Adds -ftime-trace option to clang that produces Chrome chrome://tracing compatible JSON profiling output dumps.
This change adds hierarchical "time trace" profiling blocks that can be visualized in Chrome, in a "flame chart" style. Each profiling block can have a "detail" string that for example indicates the file being processed, template name being instantiated, function being optimized etc.

This is taken from GitHub PR: https://github.com/aras-p/llvm-project-20170507/pull/2

Patch by Aras Pranckevičius.

Differential Revision: https://reviews.llvm.org/D58675

llvm-svn: 357340
2019-03-30 08:42:48 +00:00
Alexey Bataev
e04483ee35 [OPENMP]Initial support for 'allocate' clause.
Added parsing/sema analysis of the allocate clause.

llvm-svn: 357068
2019-03-27 14:14:31 +00:00
Alexey Bataev
27ef9518de [OPENMP]Improve detection of omp_allocator_handle_t type and predefined
allocators.

It is better to deduce omp_allocator_handle_t type from the predefined
allocators, because omp.h header might not define it explicitly. Plus,
it allows to identify the predefined allocators correctly when trying to
build the allcoator for the global variables.

llvm-svn: 356607
2019-03-20 20:14:22 +00:00
Roman Lebedev
b570060fd8 [clang][OpeMP] Model OpenMP structured-block in AST (PR40563)
Summary:
https://www.openmp.org/wp-content/uploads/OpenMP-API-Specification-5.0.pdf, page 3:
```
structured block

For C/C++, an executable statement, possibly compound, with a single entry at the
top and a single exit at the bottom, or an OpenMP construct.

COMMENT: See Section 2.1 on page 38 for restrictions on structured
blocks.
```
```
2.1 Directive Format

Some executable directives include a structured block. A structured block:
• may contain infinite loops where the point of exit is never reached;
• may halt due to an IEEE exception;
• may contain calls to exit(), _Exit(), quick_exit(), abort() or functions with a
_Noreturn specifier (in C) or a noreturn attribute (in C/C++);
• may be an expression statement, iteration statement, selection statement, or try block, provided
that the corresponding compound statement obtained by enclosing it in { and } would be a
structured block; and

Restrictions
Restrictions to structured blocks are as follows:
• Entry to a structured block must not be the result of a branch.
• The point of exit cannot be a branch out of the structured block.
C / C++
• The point of entry to a structured block must not be a call to setjmp().
• longjmp() and throw() must not violate the entry/exit criteria.
```

Of particular note here is the fact that OpenMP structured blocks are as-if `noexcept`,
in the same sense as with the normal `noexcept` functions in C++.
I.e. if throw happens, and it attempts to travel out of the `noexcept` function
(here: out of the current structured-block), then the program terminates.

Now, one of course can say that since it is explicitly prohibited by the Specification,
then any and all programs that violate this Specification contain undefined behavior,
and are unspecified, and thus no one should care about them. Just don't write broken code /s

But i'm not sure this is a reasonable approach.
I have personally had oss-fuzz issues of this origin - exception thrown inside
of an OpenMP structured-block that is not caught, thus causing program termination.
This issue isn't all that hard to catch, it's not any particularly different from
diagnosing the same situation with the normal `noexcept` function.

Now, clang static analyzer does not presently model exceptions.
But clang-tidy has a simplisic [[ https://clang.llvm.org/extra/clang-tidy/checks/bugprone-exception-escape.html | bugprone-exception-escape ]] check,
and it is even refactored as a `ExceptionAnalyzer` class for reuse.
So it would be trivial to use that analyzer to check for
exceptions escaping out of OpenMP structured blocks. (D59466)

All that sounds too great to be true. Indeed, there is a caveat.
Presently, it's practically impossible to do. To check a OpenMP structured block
you need to somehow 'get' the OpenMP structured block, and you can't because
it's simply not modelled in AST. `CapturedStmt`/`CapturedDecl` is not it's representation.

Now, it is of course possible to write e.g. some AST matcher that would e.g.
match every OpenMP executable directive, and then return the whatever `Stmt` is
the structured block of said executable directive, if any.
But i said //practically//. This isn't practical for the following reasons:
1. This **will** bitrot. That matcher will need to be kept up-to-date,
   and refreshed with every new OpenMP spec version.
2. Every single piece of code that would want that knowledge would need to
   have such matcher. Well, okay, if it is an AST matcher, it could be shared.
   But then you still have `RecursiveASTVisitor` and friends.
   `2 > 1`, so now you have code duplication.

So it would be reasonable (and is fully within clang AST spirit) to not
force every single consumer to do that work, but instead store that knowledge
in the correct, and appropriate place - AST, class structure.

Now, there is another hoop we need to get through.
It isn't fully obvious //how// to model this.
The best solution would of course be to simply add a `OMPStructuredBlock` transparent
node. It would be optimal, it would give us two properties:
* Given this `OMPExecutableDirective`, what's it OpenMP structured block?
* It is trivial to  check whether the `Stmt*` is a OpenMP structured block (`isa<OMPStructuredBlock>(ptr)`)

But OpenMP structured block isn't **necessarily** the first, direct child of `OMP*Directive`.
(even ignoring the clang's `CapturedStmt`/`CapturedDecl` that were inserted inbetween).
So i'm not sure whether or not we could re-create AST statements after they were already created?
There would be other costs to a new AST node: https://bugs.llvm.org/show_bug.cgi?id=40563#c12
```
1. You will need to break the representation of loops. The body should be replaced by the "structured block" entity.
2. You will need to support serialization/deserialization.
3. You will need to support template instantiation.
4. You will need to support codegen and take this new construct to account in each OpenMP directive.
```

Instead, there **is** an functionally-equivalent, alternative solution, consisting of two parts.

Part 1:
* Add a member function `isStandaloneDirective()` to the `OMPExecutableDirective` class,
  that will tell whether this directive is stand-alone or not, as per the spec.
  We need it because we can't just check for the existance of associated statements,
  see code comment.
* Add a member function `getStructuredBlock()` to the OMPExecutableDirective` class itself,
  that assert that this is not a stand-alone directive, and either return the correct loop body
  if this is a loop-like directive, or the captured statement.
This way, given an `OMPExecutableDirective`, we can get it's structured block.
Also, since the knowledge is ingrained into the clang OpenMP implementation,
it will not cause any duplication, and //hopefully// won't bitrot.

Great we achieved 1 of 2 properties of `OMPStructuredBlock` approach.

Thus, there is a second part needed:
* How can we check whether a given `Stmt*` is `OMPStructuredBlock`?
Well, we can't really, in general. I can see this workaround:
```
class FunctionASTVisitor : public RecursiveASTVisitor<FunctionASTVisitor> {
  using Base = RecursiveASTVisitor<FunctionASTVisitor>;
public:
  bool VisitOMPExecDir(OMPExecDir *D) {
    OmpStructuredStmts.emplace_back(D.getStructuredStmt());
  }
  bool VisitSOMETHINGELSE(???) {
    if(InOmpStructuredStmt)
      HI!
  }
  bool TraverseStmt(Stmt *Node) {
    if (!Node)
      return Base::TraverseStmt(Node);
    if (OmpStructuredStmts.back() == Node)
      ++InOmpStructuredStmt;
    Base::TraverseStmt(Node);
    if (OmpStructuredStmts.back() == Node) {
      OmpStructuredStmts.pop_back();
      --InOmpStructuredStmt;
    }
    return true;
  }
  std::vector<Stmt*> OmpStructuredStmts;
  int InOmpStructuredStmt = 0;
};
```
But i really don't see using it in practice.
It's just too intrusive; and again, requires knowledge duplication.

.. but no. The solution lies right on the ground.
Why don't we simply store this `i'm a openmp structured block` in the bitfield of the `Stmt` itself?
This does not appear to have any impact on the memory footprint of the clang AST,
since it's just a single extra bit in the bitfield. At least the static assertions don't fail.
Thus, indeed, we can achieve both of the properties without a new AST node.

We can cheaply set that bit right in sema, at the end of `Sema::ActOnOpenMPExecutableDirective()`,
by just calling the `getStructuredBlock()` that we just added.
Test coverage that demonstrates all this has been added.

This isn't as great with serialization though. Most of it does not use abbrevs,
so we do end up paying the full price (4 bytes?) instead of a single bit.
That price, of course, can be reclaimed by using abbrevs.
In fact, i suspect that //might// not just reclaim these bytes, but pack these PCH significantly.

I'm not seeing a third solution. If there is one, it would be interesting to hear about it.
("just don't write code that would require `isa<OMPStructuredBlock>(ptr)`" is not a solution.)

Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=40563 | PR40563 ]].

Reviewers: ABataev, rjmccall, hfinkel, rsmith, riccibruno, gribozavr

Reviewed By: ABataev, gribozavr

Subscribers: mgorny, aaron.ballman, steveire, guansong, jfb, jdoerfert, cfe-commits

Tags: #clang, #openmp

Differential Revision: https://reviews.llvm.org/D59214

llvm-svn: 356570
2019-03-20 16:32:36 +00:00
Roman Lebedev
773c391d4a [NFC][clang][PCH][ObjC] Add some missing VisitStmt(S);
Summary:
These ObjC AST classes inherit from Stmt, but don't call `VisitStmt(S);`.
Some were founded with help of existing tests (with `NumStmtFields` bumped to `1`),
but some of them don't even have PCH test coverage. :/

Reviewers: arphaman, sammccall, smeenai, aprantl, rsmith, jordan_rose

Reviewed By: jordan_rose

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D59197

llvm-svn: 355987
2019-03-12 21:31:00 +00:00
Alexey Bataev
9cc10fc926 [OPENMP 5.0]Initial support for 'allocator' clause.
Added parsing/sema analysis/serialization/deserialization for the
'allocator' clause of the 'allocate' directive.

llvm-svn: 355952
2019-03-12 18:52:33 +00:00
Duncan P. N. Exon Smith
70d759b4eb Modules: Add LangOptions::CacheGeneratedPCH
Add an option to cache the generated PCH in the ModuleCache when
emitting it.  This protects clients that build PCHs and read them in the
same process, allowing them to avoid race conditions between parallel
jobs the same way that Clang's implicit module build system does.

rdar://problem/48740787

llvm-svn: 355950
2019-03-12 18:38:04 +00:00
Duncan P. N. Exon Smith
0a2be46cfd Modules: Invalidate out-of-date PCMs as they're discovered
Leverage the InMemoryModuleCache to invalidate a module the first time
it fails to import (and to lock a module as soon as it's built or
imported successfully).  For implicit module builds, this optimizes
importing deep graphs where the leaf module is out-of-date; see example
near the end of the commit message.

Previously the cache finalized ("locked in") all modules imported so far
when starting a new module build.  This was sufficient to prevent
loading two versions of the same module, but was somewhat arbitrary and
hard to reason about.

Now the cache explicitly tracks module state, where each module must be
one of:

- Unknown: module not in the cache (yet).
- Tentative: module in the cache, but not yet fully imported.
- ToBuild: module found on disk could not be imported; need to build.
- Final: module in the cache has been successfully built or imported.

Preventing repeated failed imports avoids variation in builds based on
shifting filesystem state.  Now it's guaranteed that a module is loaded
from disk exactly once.  It now seems safe to remove
FileManager::invalidateCache, but I'm leaving that for a later commit.

The new, precise logic uncovered a pre-existing problem in the cache:
the map key is the module filename, and different contexts use different
filenames for the same PCM file.  (In particular, the test
Modules/relative-import-path.c does not build without this commit.
r223577 started using a relative path to describe a module's base
directory when importing it within another module.  As a result, the
module cache sees an absolute path when (a) building the module or
importing it at the top-level, and a relative path when (b) importing
the module underneath another one.)

The "obvious" fix is to resolve paths using FileManager::getVirtualFile
and change the map key for the cache to a FileEntry, but some contexts
(particularly related to ASTUnit) have a shorter lifetime for their
FileManager than the InMemoryModuleCache.  This is worth pursuing
further in a later commit; perhaps by tying together the FileManager and
InMemoryModuleCache lifetime, or moving the in-memory PCM storage into a
VFS layer.

For now, use the PCM's base directory as-written for constructing the
filename to check the ModuleCache.

Example
=======

To understand the build optimization, first consider the build of a
module graph TU -> A -> B -> C -> D with an empty cache:

    TU builds A'
       A' builds B'
          B' builds C'
             C' builds D'
                imports D'
          B' imports C'
             imports D'
       A' imports B'
          imports C'
          imports D'
    TU imports A'
       imports B'
       imports C'
       imports D'

If we build TU again, where A, B, C, and D are in the cache and D is
out-of-date, we would previously get this build:

    TU imports A
       imports B
       imports C
       imports D (out-of-date)
    TU builds A'
       A' imports B
          imports C
          imports D (out-of-date)
          builds B'
          B' imports C
             imports D (out-of-date)
             builds C'
             C' imports D (out-of-date)
                builds D'
                imports D'
          B' imports C'
             imports D'
       A' imports B'
          imports C'
          imports D'
     TU imports A'
        imports B'
        imports C'
        imports D'

After this commit, we'll immediateley invalidate A, B, C, and D when we
first observe that D is out-of-date, giving this build:

    TU imports A
       imports B
       imports C
       imports D (out-of-date)
    TU builds A' // The same graph as an empty cache.
       A' builds B'
          B' builds C'
             C' builds D'
                imports D'
          B' imports C'
             imports D'
       A' imports B'
          imports C'
          imports D'
    TU imports A'
       imports B'
       imports C'
       imports D'

The new build matches what we'd naively expect, pretty closely matching
the original build with the empty cache.

rdar://problem/48545366

llvm-svn: 355778
2019-03-09 17:44:01 +00:00
Duncan P. N. Exon Smith
8bef5cd49a Modules: Rename MemoryBufferCache to InMemoryModuleCache
Change MemoryBufferCache to InMemoryModuleCache, moving it from Basic to
Serialization.  Another patch will start using it to manage module build
more explicitly, but this is split out because it's mostly mechanical.

Because of the move to Serialization we can no longer abuse the
Preprocessor to forward it to the ASTReader.  Besides the rename and
file move, that means Preprocessor::Preprocessor has one fewer parameter
and ASTReader::ASTReader has one more.

llvm-svn: 355777
2019-03-09 17:33:56 +00:00
Alexey Bataev
25ed0c07c1 [OPENMP 5.0]Add initial support for 'allocate' directive.
Added parsing/sema analysis/serialization/deserialization support for
'allocate' directive.

llvm-svn: 355614
2019-03-07 17:54:44 +00:00
Duncan P. N. Exon Smith
9dda8f540c Modules: Add -Rmodule-import
Add a remark for importing modules.  Depending on whether this is a
direct import (into the TU being built by this compiler instance) or
transitive import (into an already-imported module), the diagnostic has
two forms:

    importing module 'Foo' from 'path/to/Foo.pcm'
    importing module 'Foo' into 'Bar' from 'path/to/Foo.pcm'

Also drop a redundant FileCheck invocation in Rmodule-build.m that was
using -Reverything, since the notes from -Rmodule-import were confusing
it.

https://reviews.llvm.org/D58891

llvm-svn: 355477
2019-03-06 02:50:46 +00:00
Duncan P. N. Exon Smith
fae03d8add Modules: Document that ReadASTCore exits its final loop via return, NFC
The final loop never breaks.  Document that by following it with
llvm_unreachable.

llvm-svn: 355294
2019-03-03 20:17:53 +00:00
Akira Hatanaka
c5792aa90f Avoid needlessly copying a block to the heap when a block literal
initializes a local auto variable or is assigned to a local auto
variable that is declared in the scope that introduced the block
literal.

rdar://problem/13289333

https://reviews.llvm.org/D58514

llvm-svn: 355012
2019-02-27 18:17:16 +00:00
Michael Kruse
0336c75c36 [OpenMP 5.0] Parsing/sema support for from clause with mapper modifier.
This patch implements the parsing and sema support for the OpenMP
'from'-clause with potential user-defined mappers attached.
User-defined mappers are a new feature in OpenMP 5.0. A 'from'-clause
can have an explicit or implicit associated mapper, which instructs the
compiler to generate and use customized mapping functions. An example is
shown below:

    struct S { int len; int *d; };
    #pragma omp declare mapper(id: struct S s) map(s, s.d[0:s.len])
    struct S ss;
    #pragma omp target update from(mapper(id): ss) // use the mapper with name 'id' to map ss from device

Contributed-by: Lingda Li <lildmh@gmail.com>

Differential Revision: https://reviews.llvm.org/D58638

llvm-svn: 354817
2019-02-25 20:34:15 +00:00
Michael Kruse
01f670df8f [OpenMP 5.0] Parsing/sema support for to clause with mapper modifier.
This patch implements the parsing and sema support for OpenMP to clause
with potential user-defined mappers attached. User defined mapper is a
new feature in OpenMP 5.0. A to/from clause can have an explicit or
implicit associated mapper, which instructs the compiler to generate and
use customized mapping functions. An example is shown below:

    struct S { int len; int *d; };
    #pragma omp declare mapper(id: struct S s) map(s, s.d[0:s.len])
    struct S ss;
    #pragma omp target update to(mapper(id): ss) // use the mapper with name 'id' to map ss to device

Contributed-by: <lildmh@gmail.com>

Differential Revision: https://reviews.llvm.org/D58523

llvm-svn: 354698
2019-02-22 22:29:42 +00:00
Michael Kruse
4304e9d143 [OpenMP 5.0] Parsing/sema support for map clause with mapper modifier.
This patch implements the parsing and sema support for OpenMP map
clauses with potential user-defined mapper attached. User defined mapper
is a new feature in OpenMP 5.0. A map clause can have an explicit or
implicit associated mapper, which instructs the compiler to generate
extra data mapping. An example is shown below:

    struct S { int len; int *d; };
    #pragma omp declare mapper(id: struct S s) map(s, s.d[0:s.len])
    struct S ss;
    #pragma omp target map(mapper(id) tofrom: ss) // use the mapper with name 'id' to map ss

Contributed-by: Lingda Li <lildmh@gmail.com>

Differential Revision: https://reviews.llvm.org/D58074

llvm-svn: 354347
2019-02-19 16:38:20 +00:00
Richard Smith
520a37f52f [modules] Fix handling of initializers for templated global variables.
For global variables with unordered initialization that are instantiated
within a module, we previously did not emit the global (or its
initializer) at all unless it was used in the importing translation unit
(and sometimes not even then!), leading to misbehavior and link errors.

We now emit the initializer for an instantiated global variable with
unordered initialization with side-effects in a module into every
translation unit that imports the module. This is unfortunate, but
mostly matches the behavior of a non-modular compilation and seems to be
the best that we can reasonably do.

llvm-svn: 353240
2019-02-05 23:37:13 +00:00