Commit Graph

2894 Commits

Author SHA1 Message Date
Alexey Bataev 80256605f8 [OpenMP] support depend clause for taskwait directive, by Deepak
Eachempati.

This patch adds clang (parsing, sema, serialization, codegen) support for the 'depend' clause on the 'taskwait' directive.

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D113540
2021-11-19 06:30:17 -08:00
Ilya Kuteev 8a4fcfc242 Remove non-affecting module maps from PCM files.
Problem:
PCM file includes references to all module maps used in compilation which created PCM. This problem leads to PCM-rebuilds in distributed compilations as some module maps could be missing in isolated compilation. (For example in our distributed build system we create a temp folder for every compilation with only modules and headers that are needed for that particular command).

Solution:
Add only affecting module map files to a PCM-file.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D106876
2021-11-18 11:18:26 +01:00
Kazu Hirata 74115602e8 [clang] Use range-based for loops with llvm::reverse (NFC) 2021-11-17 19:40:48 -08:00
Nathan Ridge 7a8c7946fc [clang] Allocate 2 bits to store the constexpr specifier kind when serializing
Now that consteval and constinit are possible values, 1 bit
is no longer enough.

Fixes https://github.com/clangd/clangd/issues/887

Differential Revision: https://reviews.llvm.org/D111971
2021-11-17 16:56:46 -05:00
David Pagan b0de656bdf Initial parsing/sema for 'align' clause
Added basic parsing/sema/serialization support for 'align' clause for use with
'allocate' directive.
2021-11-09 07:34:18 -05:00
Volodymyr Sapsai 7ad693a322 [modules] Update visibility for merged ObjCProtocolDecl definitions.
Merge definition visibility the same way we do for other decls. Without
the fix the added test emits `-Wobjc-method-access` as it cannot find a
visible protocol. Make this warning `-Werror` so the test would fail
when protocol visibility regresses.

rdar://83600696

Differential Revision: https://reviews.llvm.org/D111860
2021-11-08 13:54:00 -08:00
Mike Rice 4eac7bcf1a [OpenMP] Add parsing/sema/serialization for 'bind' clause.
Differential Revision: https://reviews.llvm.org/D113154
2021-11-04 14:40:30 -07:00
Volodymyr Sapsai 0a35cc40b8 [clang][objc] Speed up populating the global method pool from modules.
For each selector encountered in the source code, we need to load
selectors from the imported modules and check that we are calling a
selector with compatible types.

At the moment, for each module we are storing methods declared in the
headers belonging to this module and methods from the transitive closure
of imported modules. When a module is imported by a few other modules,
methods from the shared module are duplicated in each importer. As the
result, we can end up with lots of identical methods that we try to add
to the global method pool. Doing this duplicate work is useless and
relatively expensive.

Avoid processing duplicate methods by storing in each module only its
own methods and not storing methods from dependencies. Collect methods
from dependencies by walking the graph of module dependencies.

The issue was discovered and reported by Richard Howell. He has done the
hard work for this fix as he has investigated and provided a detailed
explanation of the performance problem.

Differential Revision: https://reviews.llvm.org/D110123
2021-11-03 17:11:14 -07:00
Mike Rice 6f9c25167d [OpenMP] Initial parsing/sema for the 'omp loop' construct
Adds basic parsing/sema/serialization support for the #pragma omp loop
directive.

Differential Revision: https://reviews.llvm.org/D112499
2021-10-28 08:26:43 -07:00
Nico Weber c7aaa2efef [clang] Add range accessor for ObjCAtTryStmt catch_stmts and use it
No behavior change.

Differential Revision: https://reviews.llvm.org/D112543
2021-10-27 08:57:05 -04:00
Kazu Hirata 16ceb44e62 [clang] Use llvm::{count,count_if,find_if,all_of,none_of} (NFC) 2021-10-25 09:14:45 -07:00
Volodymyr Sapsai 048d2c76ef [modules] Update visibility for merged ObjCInterfaceDecl definitions.
We keep using the first encountered definition and need to take into
account visibility from subsequent definitions. For example, if the
first definition is hidden and the second is visible, we need to make
the first one visible too.

rdar://82263843

Differential Revision: https://reviews.llvm.org/D110453
2021-10-21 15:06:39 -07:00
Volodymyr Sapsai c5931267db [modules] While merging ObjCInterfaceDecl definitions, merge them as decl contexts too.
While working on https://reviews.llvm.org/D110280 I've tried to merge
decl contexts as it seems to be correct and matching our handling of
decl contexts from different modules. It's not required for the fix in
https://reviews.llvm.org/D110280 but it revealed a missing diagnostic,
so separating this change into a separate commit.

Renamed some variables to distinguish diagnostic like "declaration of
'x' does not match" for different cases.

Differential Revision: https://reviews.llvm.org/D110287
2021-10-20 18:48:29 -07:00
Kazu Hirata d245f2e859 [clang] Use llvm::erase_if (NFC) 2021-10-17 13:50:29 -07:00
Kazu Hirata e567f37dab [clang] Use llvm::is_contained (NFC) 2021-10-13 20:41:55 -07:00
Jan Svoboda 28fa77feeb [clang][modules] Avoid using uninitialized SourceLocation
At this point, `F.ImportLoc` has not been initialized by the `ASTReader` yet and using it leads to an assertion failure.

Introduced in 638c673a8c and 4445135109.
2021-10-13 11:24:01 +02:00
Jan Svoboda 6a1f50b84a [clang][deps] Prune unused header search paths
To reduce the number of explicit builds of a single module, we can try to squash multiple occurrences of the module with different command-lines (and context hashes) by removing benign command-line options. The greatest contributors to benign differences between command-lines are the header search paths.

In this patch, the lookup cache in `HeaderSearch` is used to identify paths that were actually used when implicitly building the module during scanning. This information is serialized into the unhashed control block of the implicitly-built PCM. The dependency scanner then loads this and may use it to prune the header search paths before computing the context hash of the module and generating the command-line.

We could also prune the header search paths when serializing `HeaderSearchOptions` into the PCM. That way, we could do it only once instead of every load of the PCM file by dependency scanner. However, that would result in a PCM file whose contents don't produce the same context hash as the original build, which is probably highly surprising.

There is an alternative approach to storing extra information into the PCM: wire up preprocessor callbacks to capture the used header search paths on-the-fly during preprocessing of modularized headers (similar to what we currently do for the main source file and textual headers). Right now, that's not compatible with the fact that we do an actual implicit build producing PCM files during dependency scanning. The second run of dependency scanner loads the PCM from the first run, skipping the preprocessing altogether, which would result in different results between runs. We can revisit this approach when we stop building implicitly during dependency scanning.

Depends on D102923.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D102488
2021-10-12 12:39:23 +02:00
Jan Svoboda 638c673a8c [clang][modules] NFC: Propagate import `SourceLocation` into `HeaderSearch::lookupModule`
This patch propagates the import `SourceLocation` into `HeaderSearch::lookupModule`. This enables remarks on search path usage (implemented in D102923) to point to the source code that initiated header search.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D111557
2021-10-12 09:31:51 +02:00
Volodymyr Sapsai 9fad9de5c0 [modules] Fix IRGen assertion on accessing ObjC ivar inside a method.
When have ObjCInterfaceDecl with the same name in 2 different modules,
hitting the assertion

> Assertion failed: (Index < RL->getFieldCount() && "Ivar is not inside record layout!"),
> function lookupFieldBitOffset, file llvm-project/clang/lib/AST/RecordLayoutBuilder.cpp, line 3434.

on accessing an ivar inside a method. The assertion happens because
ivar belongs to one module while its containing interface belongs to
another module and then we fail to find the ivar inside the containing
interface. We already keep a single ObjCInterfaceDecl definition in
redecleration chain and in this case containing interface was correct.
The issue is with ObjCIvarDecl. IVar decl for IRGen is taken from
ObjCIvarRefExpr that is created in `Sema::BuildIvarRefExpr` using ivar
decl returned from `Sema::LookupIvarInObjCMethod`. And ivar lookup
returns a wrong decl because basically we take the first ObjCIvarDecl
found in `ASTReader::FindExternalVisibleDeclsByName` (called by
`DeclContext::lookup`). And in `ASTReader.Lookups` lookup table for a
wrong module comes first because `ASTReader::finishPendingActions`
processes `PendingUpdateRecords` in reverse order and the first
encountered ObjCIvarDecl will end up the last in `ASTReader.Lookups`.

Fix by merging ObjCIvarDecl from different modules correctly and by
using a canonical one in IRGen.

rdar://82854574

Differential Revision: https://reviews.llvm.org/D110280
2021-10-07 17:09:31 -07:00
Michael Kruse 2130117f92 [Clang][OpenMP] Allow loop-transformations with template parameters.
Clang would reject

    #pragma omp for
    #pragma omp tile sizes(P)
    for (int i = 0; i < 128; ++i) {}

where P is a template parameter, but the loop itself is not
template-dependent. Because P context-dependent, the TransformedStmt
cannot be generated and therefore is nullptr (until the template is
instantiated by TreeTransform). The OMPForDirective would still expect
the a loop is the dependent context and trigger an error.

Fix by introducing a NumGeneratedLoops field to OMPLoopTransformation.
This is used to distinguish the case where no TransformedStmt will be
generated at all (e.g. #pragma omp unroll full) and template
instantiation is needed. In the latter case, delay resolving the
iteration space like when the for-loop itself is template-dependent
until the template instatiation.

A more radical solution would always delay the iteration space analysis
until template instantiation, but would also break many test cases.

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D111124
2021-10-06 12:21:04 -05:00
Michael Kruse f37e8b0b83 [Clang][OpenMP] Infix OMPLoopTransformationDirective abstract class. NFC.
Insert OMPLoopTransformationDirective between OMPLoopBasedDirective and the loop transformations OMPTileDirective and OMPUnrollDirective. This simplifies handling of loop transformations not requiring distinguishing between OMPTileDirective and OMPUnrollDirective anymore.

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D111119
2021-10-06 10:49:07 -05:00
Simon Pilgrim b9b90bb542 [clang] Replace report_fatal_error(std::string) uses with report_fatal_error(Twine)
As described on D111049, we're trying to remove the <string> dependency from error handling and replace uses of report_fatal_error(const std::string&) with the Twine() variant which can be forward declared.
2021-10-06 11:43:19 +01:00
Corentin Jabot 424733c12a Implement if consteval (P1938)
Modify the IfStmt node to suppoort constant evaluated expressions.

Add a new ExpressionEvaluationContext::ImmediateFunctionContext to
keep track of immediate function contexts.

This proved easier/better/probably more efficient than walking the AST
backward as it allows diagnosing nested if consteval statements.
2021-10-05 08:04:14 -04:00
alokmishra.besu 000875c127 OpenMP 5.0 metadirective
This patch supports OpenMP 5.0 metadirective features.
It is implemented keeping the OpenMP 5.1 features like dynamic user condition in mind.

A new function, getBestWhenMatchForContext, is defined in llvm/Frontend/OpenMP/OMPContext.h

Currently this function return the index of the when clause with the highest score from the ones applicable in the Context.
But this function is declared with an array which can be used in OpenMP 5.1 implementation to select all the valid when clauses which can be resolved in runtime. Currently this array is set to null by default and its implementation is left for future.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D91944
2021-09-18 13:40:44 -05:00
Nico Weber 31cca21565 Revert "OpenMP 5.0 metadirective"
This reverts commit c7d7b98e52.
Breaks tests on macOS, see comment on https://reviews.llvm.org/D91944
2021-09-18 09:10:37 -04:00
alokmishra.besu 347f3c186d OpenMP 5.0 metadirective
This patch supports OpenMP 5.0 metadirective features.
It is implemented keeping the OpenMP 5.1 features like dynamic user condition in mind.

A new function, getBestWhenMatchForContext, is defined in llvm/Frontend/OpenMP/OMPContext.h

Currently this function return the index of the when clause with the highest score from the ones applicable in the Context.
But this function is declared with an array which can be used in OpenMP 5.1 implementation to select all the valid when clauses which can be resolved in runtime. Currently this array is set to null by default and its implementation is left for future.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D91944
2021-09-17 16:30:06 -05:00
cchen 7efb825382 Revert "OpenMP 5.0 metadirective"
This reverts commit c7d7b98e52.
2021-09-17 16:14:16 -05:00
cchen c7d7b98e52 OpenMP 5.0 metadirective
This patch supports OpenMP 5.0 metadirective features.
It is implemented keeping the OpenMP 5.1 features like dynamic user condition in mind.

A new function, getBestWhenMatchForContext, is defined in llvm/Frontend/OpenMP/OMPContext.h

Currently this function return the index of the when clause with the highest score from the ones applicable in the Context.
But this function is declared with an array which can be used in OpenMP 5.1 implementation to select all the valid when clauses which can be resolved in runtime. Currently this array is set to null by default and its implementation is left for future.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D91944
2021-09-17 16:03:13 -05:00
Richard Howell e6020b2a42 [clang][NFC] refactor GlobalMethodPool to encapsulate its map
This refactor changes the GlobalMethodPool to a class that contains
the DenseMap of methods. This is to allow for the addition of a
separate DenseSet in a follow-up diff that will handle method
de-duplication when inserting methods into the global method pool.

Changes:
  - the `GlobalMethods` pair becomes `GlobalMethodPool::Lists`
  - the `GlobalMethodPool` becomes a class containing the `DenseMap` of methods
  - pass through methods are added to maintain most of the existing code without changing `MethodPool` -> `MethodPool.Methods` everywhere

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D109898
2021-09-16 14:02:14 -07:00
Erich Keane 720766a50c Remove trailing whitespace in ASTReaderDecl.cpp 2021-09-16 08:23:28 -07:00
Qiu Chaofan fae0dfa642 [Clang] Add __ibm128 type to represent ppc_fp128
Currently, we have no front-end type for ppc_fp128 type in IR. PowerPC
target generates ppc_fp128 type from long double now, but there's option
(-mabi=(ieee|ibm)longdouble) to control it and we're going to do
transition from IBM extended double-double ppc_fp128 to IEEE fp128 in
the future.

This patch adds type __ibm128 which always represents ppc_fp128 in IR,
as what GCC did for that type. Without this type in Clang, compilation
will fail if compiling against future version of libstdcxx (which uses
__ibm128 in headers).

Although all operations in backend for __ibm128 is done by software,
only PowerPC enables support for it.

There's something not implemented in this commit, which can be done in
future ones:

- Literal suffix for __ibm128 type. w/W is suitable as GCC documented.
- __attribute__((mode(IF))) should be for __ibm128.
- Complex __ibm128 type.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D93377
2021-09-06 18:00:58 +08:00
Alexandre Rames 655bea4226 [modules] Use `HashBuilder` and `MD5` for the module hash.
Per the comments, `hash_code` values "are not stable to save or
persist", so are unsuitable for the module hash, which must persist
across compilations for the implicit module hashes to match. Note that
in practice, today, `hash_code` are stable. But this is an
implementation detail, with a clear `FIXME` indicating we should switch
to a per-execution seed.

The stability of `MD5` also allows modules cross-compilation use-cases.
The `size_t` underlying storage for `hash_code` varying across platforms
could cause mismatching hashes when cross-compiling from a 64bit
target to a 32bit target.

Note that native endianness is still used for the hash computation. So hashes
will differ between platforms of different endianness.

Reviewed By: jansvoboda11

Differential Revision: https://reviews.llvm.org/D102943
2021-09-03 11:13:36 -07:00
Richard Smith 6eda66b0a9 PR50294: Fix a performance regression from 2c9dbcd.
Per the contract of ReadLateParsedTemplates, we should not be returning
the same results multiple times. No functionality change intended, other
than to runtime.

Thanks to Luboš Luňák for identifying the cause of the regression!
2021-09-01 18:00:07 -07:00
Volodymyr Sapsai 93764ff6e2 [modules] Fix miscompilation when using two RecordDecl definitions with the same name.
When deserializing a RecordDecl we don't enforce that redeclaration
chain contains only a single definition. So if the canonical decl is not
a definition itself, `RecordType::getDecl` can return different objects
before and after an include. It means we can build CGRecordLayout for
one RecordDecl with its set of FieldDecl but try to use it with
FieldDecl belonging to a different RecordDecl. With assertions enabled
it results in

> Assertion failed: (FieldInfo.count(FD) && "Invalid field for record!"),
> function getLLVMFieldNo, file llvm-project/clang/lib/CodeGen/CGRecordLayout.h, line 199.

and with assertions disabled a bunch of fields are treated as their
memory is located at offset 0.

Fix by keeping the first encountered RecordDecl definition and marking
the subsequent ones as non-definitions. Also need to merge FieldDecl
properly, so that `getPrimaryMergedDecl` works correctly and during name
lookup we don't treat fields from same-name RecordDecl as ambiguous.

rdar://80184238

Differential Revision: https://reviews.llvm.org/D106994
2021-08-30 17:51:38 -07:00
Ben Barham a4a5c00b53 [Modules] Change result of reading AST block to llvm::Error instead
Reading the AST block can never fail with a recoverable error as modules
cannot be removed during this phase. Change the return type of these
functions to return an llvm::Error instead, ie. either success or
failure.

NFC other than the wording of some of the errors.

Differential Revision: https://reviews.llvm.org/D108268
2021-08-27 20:16:20 -07:00
Chuanqi Xu a52cfb3523 [NFC] [ASTReader] Remove unused variables 2021-08-27 14:00:03 +08:00
Richard Smith df7b6b9142 Extend diagnostic for out of date AST input file.
If the size has changed, list the old and new sizes; if the mtime has
changed, list the old and new mtimes (as raw time_t values).
2021-08-24 17:03:06 -07:00
Ben Barham 32208555af [Modules] Do not remove failed modules after the control block phase
Reading modules first reads each control block in the chain and then all
AST blocks.

The first phase is intended to find recoverable errors, eg. an out of
date or missing module. If any error occurs during this phase, it is
safe to remove all modules in the chain as no references to them will
exist.

While reading the AST blocks, however, various fields in ASTReader are
updated with references to the module. Removing modules at this point
can cause dangling pointers which can be accessed later. These would be
otherwise harmless, eg. a binary search over `GlobalSLocEntryMap` may
access a failed module that could error, but shouldn't crash. Do not
remove modules in this phase, regardless of failures.

Since this is the case, it also doesn't make sense to return OutOfDate
during this phase, so remove the two cases where this happens.

When they were originally added these checks would return a failure when
the serialized and current path didn't match up. That was updated to an
OutOfDate as it was found to be hit when using VFS and overriding the
umbrella. Later on the path was changed to instead be the name as
written in the module file, resolved using the serialized base
directory. At this point the check is really only comparing the name of
the umbrella and only works for frameworks since those don't include
`Headers/` in the name (which means the resolved path will never exist)

Given all that, it seems safe to ignore this case entirely for now.
This makes the handling of an umbrella header/directory the same as
regular headers, which also don't check for differences in the path
caused by VFS.

Resolves rdar://79329355

Differential Revision: https://reviews.llvm.org/D107690
2021-08-17 16:46:51 -07:00
Simon Tatham 21401a7262 [clang] Introduce SourceLocation::[U]IntTy typedefs.
This is part of a patch series working towards the ability to make
SourceLocation into a 64-bit type to handle larger translation units.

NFC: this patch introduces typedefs for the integer type used by
SourceLocation and makes all the boring changes to use the typedefs
everywhere, but for the moment, they are unconditionally defined to
uint32_t.

Patch originally by Mikhail Maltsev.

Reviewed By: tmatheson

Differential Revision: https://reviews.llvm.org/D105492
2021-07-21 10:45:46 +01:00
Ben Barham 766a08df12 [Frontend] Only compile modules if not already finalized
It was possible to re-add a module to a shared in-memory module cache
when search paths are changed. This can eventually cause a crash if the
original module is referenced after this occurs.
  1. Module A depends on B
  2. B exists in two paths C and D
  3. First run only has C on the search path, finds A and B and loads
     them
  4. Second run adds D to the front of the search path. A is loaded and
     contains a reference to the already compiled module from C. But
     searching finds the module from D instead, causing a mismatch
  5. B and the modules that depend on it are considered out of date and
     thus rebuilt
  6. The recompiled module A is added to the in-memory cache, freeing
     the previously inserted one

This can never occur from a regular clang process, but is very easy to
do through the API - whether through the use of a shared case or just
running multiple compilations from a single `CompilerInstance`. Update
the compilation to return early if a module is already finalized so that
the pre-condition in the in-memory module cache holds.

Resolves rdar://78180255

Differential Revision: https://reviews.llvm.org/D105328
2021-07-15 18:27:08 -07:00
Vassil Vassilev 11b47c103a Reland "[clang-repl] Implement partial translation units and error recovery."
Original commit message:

[clang-repl] Implement partial translation units and error recovery.

https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:

Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.

The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.

The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.

Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.

It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.

We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.

We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.

This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:

```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
            ^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```

Differential revision: https://reviews.llvm.org/D104918
2021-07-12 15:21:22 +00:00
Vassil Vassilev 5922f234c8 Revert "[clang-repl] Implement partial translation units and error recovery."
This reverts commit 6775fc6ffa.

It also reverts "[lldb] Fix compilation by adjusting to the new ASTContext signature."

This reverts commit 03a3f86071.

We see some failures on the lldb infrastructure, these changes might play a role
in it. Let's revert it now and see if the bots will become green.

Ref: https://reviews.llvm.org/D104918
2021-07-11 14:40:10 +00:00
Vassil Vassilev 6775fc6ffa [clang-repl] Implement partial translation units and error recovery.
https://reviews.llvm.org/D96033 contained a discussion regarding efficient
modeling of error recovery. @rjmccall has outlined the key ideas:

Conceptually, we can split the translation unit into a sequence of partial
translation units (PTUs). Every declaration will be associated with a unique PTU
that owns it.

The first key insight here is that the owning PTU isn't always the "active"
(most recent) PTU, and it isn't always the PTU that the declaration
"comes from". A new declaration (that isn't a redeclaration or specialization of
anything) does belong to the active PTU. A template specialization, however,
belongs to the most recent PTU of all the declarations in its signature - mostly
that means that it can be pulled into a more recent PTU by its template
arguments.

The second key insight is that processing a PTU might extend an earlier PTU.
Rolling back the later PTU shouldn't throw that extension away. For example, if
the second PTU defines a template, and the third PTU requires that template to
be instantiated at float, that template specialization is still part of the
second PTU. Similarly, if the fifth PTU uses an inline function belonging to the
fourth, that definition still belongs to the fourth. When we go to emit code in
a new PTU, we map each declaration we have to emit back to its owning PTU and
emit it in a new module for just the extensions to that PTU. We keep track of
all the modules we've emitted for a PTU so that we can unload them all if we
decide to roll it back.

Most declarations/definitions will only refer to entities from the same or
earlier PTUs. However, it is possible (primarily by defining a
previously-declared entity, but also through templates or ADL) for an entity
that belongs to one PTU to refer to something from a later PTU. We will have to
keep track of this and prevent unwinding to later PTU when we recognize it.
Fortunately, this should be very rare; and crucially, we don't have to do the
bookkeeping for this if we've only got one PTU, e.g. in normal compilation.
Otherwise, PTUs after the first just need to record enough metadata to be able
to revert any changes they've made to declarations belonging to earlier PTUs,
e.g. to redeclaration chains or template specialization lists.

It should even eventually be possible for PTUs to provide their own slab
allocators which can be thrown away as part of rolling back the PTU. We can
maintain a notion of the active allocator and allocate things like Stmt/Expr
nodes in it, temporarily changing it to the appropriate PTU whenever we go to do
something like instantiate a function template. More care will be required when
allocating declarations and types, though.

We would want the PTU to be efficiently recoverable from a Decl; I'm not sure
how best to do that. An easy option that would cover most declarations would be
to make multiple TranslationUnitDecls and parent the declarations appropriately,
but I don't think that's good enough for things like member function templates,
since an instantiation of that would still be parented by its original class.
Maybe we can work this into the DC chain somehow, like how lexical DCs are.

We add a different kind of translation unit `TU_Incremental` which is a
complete translation unit that we might nonetheless incrementally extend later.
Because it is complete (and we might want to generate code for it), we do
perform template instantiation, but because it might be extended later, we don't
warn if it declares or uses undefined internal-linkage symbols.

This patch teaches clang-repl how to recover from errors by disconnecting the
most recent PTU and update the primary PTU lookup tables. For instance:

```./clang-repl
clang-repl> int i = 12; error;
In file included from <<< inputs >>>:1:
input_line_0:1:13: error: C++ requires a type specifier for all declarations
int i = 12; error;
            ^
error: Parsing failed.
clang-repl> int i = 13; extern "C" int printf(const char*,...);
clang-repl> auto r1 = printf("i=%d\n", i);
i=13
clang-repl> quit
```

Differential revision: https://reviews.llvm.org/D104918
2021-07-11 10:23:41 +00:00
Richard Smith 9ab5f76117 Support for merging UsingPackDecls across modules.
Fixes a false-positive error if the same std::variant<...> type is
instantiated across multiple modules.
2021-07-01 18:43:49 -07:00
Volodymyr Sapsai 722c51473c [clang][AST] Make `getLocalOrImportedSubmoduleID` work with const `Module*`. NFC.
Differential Revision: https://reviews.llvm.org/D104350
2021-06-17 17:29:12 -07:00
Jan Svoboda 78668c822a [clang][modules][pch] Allow loading PCH with different modules cache path
It's useful to be able to load explicitly-built PCH files into an implicit build (e.g. during dependency scanning). That's currently impossible, since the explicitly-built PCH has an empty modules cache path, while the current compilation has (and needs to have) a valid path, triggering an error in the `PCHValidator`.

This patch adds a preprocessor option and command-line flag that can be used to omit this check.

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D103802
2021-06-14 11:04:56 +02:00
Sterling Augustine 1d3873d41e Move variable only used inside an assert into the assert.
This prevents build failures with -Wunused.
2021-06-10 13:14:45 -07:00
Michael Kruse a22236120f [OpenMP] Implement '#pragma omp unroll'.
Implementation of the unroll directive introduced in OpenMP 5.1. Follows the approach from D76342 for the tile directive (i.e. AST-based, not using the OpenMPIRBuilder). Tries to use `llvm.loop.unroll.*` metadata where possible, but has to fall back to an AST representation of the outer loop if the partially unrolled generated loop is associated with another directive (because it needs to compute the number of iterations).

Reviewed By: ABataev

Differential Revision: https://reviews.llvm.org/D99459
2021-06-10 14:30:17 -05:00
Nathan Sidwell b2d0c16e91 [clang] p1099 using enum part 2
This implements the 'using enum maybe-qualified-enum-tag ;' part of
1099. It introduces a new 'UsingEnumDecl', subclassed from
'BaseUsingDecl'. Much of the diff is the boilerplate needed to get the
new class set up.

There is one case where we accept ill-formed, but I believe this is
merely an extended case of an existing bug, so consider it
orthogonal. AFAICT in class-scope the c++20 rule is that no 2 using
decls can bring in the same target decl ([namespace.udecl]/8). But we
already accept:

struct A { enum { a }; };
struct B : A { using A::a; };
struct C : B { using A::a;
using B::a; }; // same enumerator

this patch permits mixtures of 'using enum Bob;' and 'using Bob::member;' in the same way.

Differential Revision: https://reviews.llvm.org/D102241
2021-06-08 11:11:46 -07:00
Erik Pilkington 369c648399 [clang] Implement the using_if_exists attribute
This attribute applies to a using declaration, and permits importing a
declaration without knowing if that declaration exists. This is useful
for libc++ C wrapper headers that re-export declarations in std::, in
cases where the base C library doesn't provide all declarations.

This attribute was proposed in http://lists.llvm.org/pipermail/cfe-dev/2020-June/066038.html.

rdar://69313357

Differential Revision: https://reviews.llvm.org/D90188
2021-06-02 10:30:24 -04:00