Commit Graph

84712 Commits

Author SHA1 Message Date
Aaron Ballman d4cf4c66b5 Fix some typos (unkown -> unknown); NFC 2020-07-02 06:41:05 -04:00
Kazushi (Jam) Marukawa 804d968744 [VE] Rename VE toolchain source files
Summary:
Rename VE.cpp and VE.h to VEToolchain.cpp and VEToolchain.h respectively
in order to avoid link warning message.  Linker warns that VE.cpp.o and
Arch/VE.cpp.o have the same name.

Reviewers: simoll, k-ishizaka

Reviewed By: simoll

Subscribers: mgorny, cfe-commits

Tags: #llvm, #ve, #clang

Differential Revision: https://reviews.llvm.org/D82968
2020-07-02 18:45:16 +09:00
Sander de Smalen f255656a97 [SVE] ACLE: Fix builtins for svdup_lane_bf16 and svcvtnt_bf16_f32_x
bfloat16 variants of svdup_lane were missing, and svcvtnt_bf16_x
was implemented incorrectly (it takes an operand for the inactive
lanes)

Reviewers: fpetrogalli, efriedma

Reviewed By: fpetrogalli

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82908
2020-07-02 09:57:34 +01:00
Qiu Chaofan aa4fd7d848 [NFC] Fix typo in triples from unkown to unknown 2020-07-02 16:21:54 +08:00
Simon Tatham 9e6f19fd83 Fix missing build dependency on omp_gen.
Summary:
`include/llvm/Frontend/OpenMP/CMakeLists.txt` creates a new target
called `omp_gen` which builds the generated include file `OMP.h.inc`.
This target must therefore be a dependency of every compilation step
whose transitive #include dependencies contain `OMP.h.inc`, or else
it's possible for builds to fail if Ninja (or make or whatever)
schedules that compilation step before building `OMP.h.inc` at all.

A few of those dependencies are currently missing, which leads to
intermittent build failures, depending on the order that Ninja (or
whatever) happens to schedule its commands. As far as I can see,
compiles in `clang/lib/CodeGen`, `clang/lib/Frontend`, and
`clang/examples` all depend transitivily on `OMP.h.inc` (usually via
`clang/AST/AST.h`), but don't have the formal dependency in the ninja
graph.

Adding `omp_gen` to the dependencies of `clang-tablegen-targets` seems
to be the way to get the missing dependency into the `clang/examples`
subdirectory. This also fixes the other two clang subdirectories, as
far as I can see.

Reviewers: clementval, thakis, chandlerc, jdoerfert

Reviewed By: clementval

Subscribers: cfe-commits, jdenny, mgorny, sstefan1, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D82659
2020-07-02 09:16:15 +01:00
Alexander Belyaev 2a36f29fce [clang] Re-add deleted forward declaration. 2020-07-02 08:57:48 +02:00
Eduardo Caldas fdbd78333f Add parenthesized expression to SyntaxTree
Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82960
2020-07-02 06:28:41 +00:00
Biplob Mishra 88874f0746 [PowerPC]Implement Vector Shift Double Bit Immediate Builtins
Implement Vector Shift Double Bit Immediate Builtins in LLVM/Clang.
  * vec_sldb ();
  * vec_srdb ();

Differential Revision: https://reviews.llvm.org/D82440
2020-07-01 20:34:53 -05:00
Valentin Clement 2ddba3082c [flang][openmp] Use common Directive and Clause enum from llvm/Frontend
Summary:
This patch is removing the custom enumeration for OpenMP Directives and Clauses and replace them
with the newly tablegen generated one from llvm/Frontend. This is a first patch and some will follow to share the same
infrastructure where possible. The next patch should use the clauses allowance defined in the tablegen file.

Reviewers: jdoerfert, DavidTruby, sscalpone, kiranchandramohan, ichoyjx

Reviewed By: DavidTruby, ichoyjx

Subscribers: jholewinski, cfe-commits, dblaikie, MaskRay, ymandel, ichoyjx, mgorny, yaxunl, guansong, jfb, sstefan1, aaron.ballman, llvm-commits

Tags: #llvm, #flang, #clang

Differential Revision: https://reviews.llvm.org/D82906
2020-07-01 20:58:11 -04:00
Nico Weber ac8d059c8e typo fixes to cycle bots 2020-07-01 19:20:05 -04:00
Xun Li 9fc877213e clang CoverageMapping tests bot cleanup
Summary:
D82928 generated unexpected tmp files in the CoverageMapping test directory. This patch cleans it up and remove the file in the test bots.
It will be revered after a week.

Reviewers: thakis

Reviewed By: thakis

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82992
2020-07-01 16:06:56 -07:00
Gabriel Matute ecfa0b2418 [libTooling] Fix `maybeExtendRange` to support `CharRange`s.
Currently, `maybeExtendRange` takes a `CharSourceRange`, but only works
correctly for the `TokenRange` case. This change adds proper support for the
`CharRange` case.

Reviewed By: gribozavr2

Differential Revision: https://reviews.llvm.org/D82901
2020-07-01 20:40:48 +00:00
Xun Li ddcf063dd5 [Coroutines] Fix test breakage in D82928
Summary: The test file in D82928 generated temp files within the test directory, causing test failures. Fix it.

Reviewers: modocache, fhahn

Reviewed By: modocache

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82986
2020-07-01 11:17:21 -07:00
zoecarver e7c5da57a5 [CodeGen] Add public function to emit C++ destructor call.
Adds `CodeGen::getCXXDestructorImplicitParam`, to retrieve a C++ destructor's implicit parameter (after the "this" pointer) based on the ABI in the given CodeGenModule.

This will allow other frontends (Swift, for example) to easily emit calls to object destructors with correct ABI semantics and calling convetions.

This is needed for Swift C++ interop. Here's the corresponding Swift change: https://github.com/apple/swift/pull/32291

Differential Revision: https://reviews.llvm.org/D82392
2020-07-01 11:01:23 -07:00
Xun Li 565e37c770 [Coroutines] Fix code coverage for coroutine
Summary:
Previously, source-based coverage analysis does not work properly for coroutine.
This patch adds processing of coroutine body and co_return in the coverage analysis, so that we can handle them properly.
For coroutine body, we should only look at the actual function body and ignore the compiler-generated things; for co_return, we need to terminate the region similar to return statement.
Added a test, and confirms that it now works properly. (without this patch, the statement after the if statement will be treated wrongly)

Reviewers: lewissbaker, modocache, junparser

Reviewed By: modocache

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82928
2020-07-01 10:11:40 -07:00
Erich Keane 19c35526d9 Limit x86 test to require target to fix buildbot (from 2831a317b)
The modification of the features apparently requires the backend to be
instantiated, so make sure this is required to fix the ARM build bots.
2020-07-01 07:35:39 -07:00
Erich Keane 2831a317b6 Implement AVX ABI Warning/error
The x86-64 "avx" feature changes how >128 bit vector types are passed,
instead of being passed in separate 128 bit registers, they can be
passed in 256 bit registers.

"avx512f" does the same thing, except it switches from 256 bit registers
to 512 bit registers.

The result of both of these is an ABI incompatibility between functions
compiled with and without these features.

This patch implements a warning/error pair upon an attempt to call a
function that would run afoul of this. First, if a function is called
that would have its ABI changed, we issue a warning.

Second, if said call is made in a situation where the caller and callee
are known to have different calling conventions (such as the case of
'target'), we instead issue an error.

Differential Revision: https://reviews.llvm.org/D82562
2020-07-01 07:14:31 -07:00
Simon Pilgrim 36aaffbf56 Fix Wdocumentation warnings due to outdated parameter list. NFC. 2020-07-01 12:01:18 +01:00
Adam Balogh c79745ed48 [Analyzer] Quick fix for broken tests on Windows 2020-07-01 12:52:47 +02:00
Daniel Kiss 070acb1d1e [Driver][ARM] parse version of arm/thumb architecture correctly
Summary:
If you execute the following commandline multiple times, the behavior was not always the same:
  clang++ --target=thumbv7em-none-windows-eabi-coff -march=armv7-m -mcpu=cortex-m7 -o temp.obj -c -x c++ empty.cpp

Most of the time the compilation succeeded, but sometimes clang reported this error:
  clang++: error: the target architecture 'thumbv7em' is not supported by the target 'thumbv7em-none-windows-eabi'

The cause of the inconsistent behavior was the uninitialized variable Version.

With these commandline arguments, the variable Version was not set by getAsInteger(),
because it cannot parse a number from the substring "7em" (of "thumbv7em").
To get a consistent behaviour, it's enough to initialize the variable Version to zero.
Zero is smaller than 7, so the comparison will be true.
Then the command always fails with the error message seen above.

By using consumeInteger() instead of getAsInteger() we get 7 from the substring "7em"
and the command does not fail.

Reviewers: compnerd, danielkiss

Reviewed By: danielkiss

Subscribers: danielkiss, kristof.beyls, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75453
2020-07-01 12:13:52 +02:00
Endre Fülöp 52f6532366 [analyzer][CrossTU] Lower CTUImportThreshold default value
Summary:
The default value of 100 makes the analysis slow. Projects of considerable
size can take more time to finish than it is practical. The new default
setting of 8 is based on the analysis of LLVM itself. With the old default
value of 100 the analysis time was over a magnitude slower. Thresholding the
load of ASTUnits is to be extended in the future with a more fine-tuneable
solution that accomodates to the specifics of the project analyzed.

Reviewers: martong, balazske, Szelethus

Subscribers: whisperity, xazax.hun, baloghadamsoftware, szepet, rnkovacs, a.sidorin, mikhail.ramalho, Szelethus, donat.nagy, dkrupp, Charusso, steakhal, ASDenysPetrov, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82561
2020-07-01 10:08:52 +02:00
Hans Wennborg a8e582c830 [ThinLTO] Always parse module level inline asm with At&t dialect (PR46503)
clang-cl passes -x86-asm-syntax=intel to the cc1 invocation so that
assembly listings produced by the /FA flag are printed in Intel dialect.
That flag however should not affect the *parsing* of inline assembly in
the program. (See r322652)

When compiling normally, AsmPrinter::emitInlineAsm is used for
assembling and defaults to At&t dialect. However, when compiling for
ThinLTO, the code which parses module level inline asm to find symbols
for the symbol table was failing to set the dialect. This patch fixes
that. (See the bug for more details.)

Differential revision: https://reviews.llvm.org/D82862
2020-07-01 09:43:45 +02:00
Balázs Kéri f3b3446610 [clang][CrossTU] Invalidate parent map after get cross TU definition.
Summary:
Parent map of ASTContext is built once. If this happens and later
the TU is modified by getCrossTUDefinition the parent map does not
contain the newly imported objects and has to be re-created.

Invalidation of the parent map is added to the CrossTranslationUnitContext.
It could be added to ASTImporter as well but for now this task remains the
responsibility of the user of ASTImporter. Reason for this is mostly that
ASTImporter calls itself recursively.

Reviewers: gamesh411, martong

Reviewed By: gamesh411

Subscribers: rnkovacs, dkrupp, Szelethus, gamesh411, martong, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82568
2020-07-01 09:13:05 +02:00
Adam Balogh 9e63b190af [Analyzer] Handle pointer implemented as iterators in iterator checkers
Iterators are an abstraction of pointers and in some data structures
iterators may be implemented by pointers. This patch adds support for
iterators implemented as pointers in all the iterator checkers
(including iterator modeling).

Differential Revision: https://reviews.llvm.org/D82185
2020-07-01 09:04:28 +02:00
Adam Balogh ea563daae5 [Analyzer] Fix errors in iterator modeling
There is major a bug found in iterator modeling: upon adding a value
to or subtracting a value from an iterator the position of the original
iterator is also changed beside the result. This patch fixes this bug.

To catch such bugs in the future we also changed the tests to look for
regular expressions including an end-of-line symbol (`$`) so we can
prevent false matches where only the tested prefix matches.

Another minor bug is that when printing the state, all the iterator
positions are printed in a single line. This patch also fixes this.

Differential Revision: https://reviews.llvm.org/D82385
2020-07-01 09:04:28 +02:00
Adam Balogh 40c50bdee4 [Sema][NFC] Remove Redundant Condition
Condition `TypeQuals` is checked both in an outer and in an inner `if`
statement in static function `ConvertDeclSpecToType()` in file
`SemaType.cpp`. This patch removes the redundant inner check.

The issue was found using `clang-tidy` check under review
`misc-redundant-condition`. See https://reviews.llvm.org/D81272.

Differential Revision: https://reviews.llvm.org/D82563
2020-07-01 09:04:27 +02:00
lh123 83fae3f762 [CodeComplete] Add code completion after function equals
Summary:
Provide `default` and `delete` completion after the function equals.

Reviewers: kadircet, sammccall

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82548
2020-07-01 12:51:25 +08:00
Richard Smith 4eff2beefb [c++20] consteval functions don't get vtable slots.
For the Itanium C++ ABI, this implements the rule added in
https://github.com/itanium-cxx-abi/cxx-abi/pull/83

For the MS C++ ABI, this implements the direction that seemed most
plausible based on personal correspondence with MSVC developers, but is
subject to change as they decide their ABI rule.
2020-06-30 18:22:09 -07:00
Richard Smith b6c490349d A constexpr virtual function is implicitly inline so should never be a
key function.
2020-06-30 16:07:50 -07:00
Zixu Wang 89a0c4066b [clang][diagnostics] Add '-Wundef-prefix' warning option
Summary:
Add an `-Wundef-prefix=<arg1>,<arg2>...` option, which is similar to `-Wundef`, but only give warnings for undefined macros with the given prefixes.

Reviewers: ributzka, steven_wu, cishida, bruno, arphaman, rsmith

Reviewed By: ributzka, arphaman

Subscribers: riccibruno, dexonsmith, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D80751

This patch was authored by Zixu Wang <zixu_wang@apple.com>
2020-06-30 13:57:47 -07:00
Vince Bridgers ecae672ac2 [ASTImporter] Fix AST import crash for a friend decl
Summary:
Running CTU testing, we found that VisitFriendDecl in
ASTImporterLookup.cpp was not handling a particular non-dependent case,
so we reached the llvm_unreachable case.

The FriendDecl and QualType not handled were:

(gdb) p D->dump()
FriendDecl 0x7ffff5cf1958
< <<srcfile>>, 'nlohmann::basic_json<std::map, std::vector,
   std::basic_string<char>, bool, long long, unsigned long long, double,
   std::allocator, adl_serializer, std::vector<unsigned char,
   std::allocator<unsigned char>>>':'nlohmann::basic_json<std::map,
   std::vector, std::basic_string<char>, bool, long long, unsigned long
   long, double, std::allocator, adl_serializer, std::vector<unsigned char,
   std::allocator<unsigned char>>>'

(gdb) p Ty->dump()
SubstTemplateTypeParmType 0x7ffff5cf0df0 'class
nlohmann::basic_json<std::map, std::vector, class
   std::basic_string<char>, _Bool, long long, unsigned long long, double,
   std::allocator, adl_serializer, class std::vector<unsigned char, class
   std::allocator<unsigned char> > >' sugar
|-TemplateTypeParmType 0x7ffff643ea40 'BasicJsonType' dependent depth 0
index 0
| `-TemplateTypeParm 0x7ffff643e9e8 'BasicJsonType'
`-RecordType 0x1012ad20 'class nlohmann::basic_json<std::map,
std::vector, class std::basic_string<char>, _Bool, long long, unsigned
long long, double, std::allocator, adl_serializer, class
std::vector<unsigned char, class std::allocator<unsigned char> > >'
  `-ClassTemplateSpecialization 0x1012ab68 'basic_json'

Reviewers: martong, a.sidorin

Reviewed By: martong

Subscribers: kristof.beyls, rnkovacs, teemperor, cfe-commits, dkrupp

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82882
2020-06-30 15:57:01 -05:00
Craig Topper 3537939cda [X86] Move frontend CPU feature initialization to a look up table based implementation. NFCI
This replaces the switch statement implementation in the clang's
X86.cpp with a lookup table in X86TargetParser.cpp.

I've used constexpr and copy of the FeatureBitset from
SubtargetFeature.h to store the features in a lookup table.
After the lookup the bitset is translated into strings for use
by the rest of the frontend code.

I had to modify the implementation of the FeatureBitset to avoid
bugs in gcc 5.5 constexpr handling. It seems to not like the
same array entry to be used on the left side and right hand side
of an assignment or &= or |=. I've also used uint32_t instead of
uint64_t and sized based on the X86::CPU_FEATURE_MAX.

I've initialized the features for different CPUs outside of the
table so that we can express inheritance in an adhoc way. This
was one of the big limitations of the switch and we had resorted
to labels and gotos.

Differential Revision: https://reviews.llvm.org/D82731
2020-06-30 12:04:58 -07:00
Craig Topper f886f07248 [X86] Some CHECK-NOTs for FMA4/TBM/XOP for znver1/znver2 in predefined-arch-macros.c
These features exist in earlier CPUs, but were deprecated on
znver1/znver2. While working on D82731 I accidentally copied
them from the earlier CPU. And nothing caught my mistake. Having
these additional checks would have helped.
2020-06-30 12:04:26 -07:00
Francesco Petrogalli d54e4dded7 [sve][acle] Enable feature macros for SVE ACLE extensions.
Summary:
The following feature macros have been added:

__ARM_FEATURE_SVE_BF16

__ARM_FEATURE_SVE_MATMUL_INT8

__ARM_FEATURE_SVE_MATMUL_FP32

__ARM_FEATURE_SVE_MATMUL_FP64

The driver has been updated to enable them accordingly to the value of
the target feature passed at command line.

The SVE ACLE tests using the macros have been modified to work with
the target feature instead of passing the macro at command line.

Reviewers: sdesmalen, efriedma, c-rhodes, kmclaughlin, SjoerdMeijer, rengolin

Subscribers: tschuett, kristof.beyls, rkruppe, psnobl, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82623
2020-06-30 18:33:03 +00:00
Philippe Blain a1f4e48c4a [clang][docs] Add note about using `-flto` with `-g` on macOS
If -Wl,object_path_lto,<lto-filename>.o is not passed at link time
when compiling and linking in separate steps with -flto and -g, the
temporary file used for Link Time Optimization is deleted by the linker,
so the executable is missing debug symbols and can't be easily debugged,
and dsymutil can't be run.

Document this behaviour.

Differential revision: https://reviews.llvm.org/D82733
2020-06-30 09:33:20 -07:00
Nathan James 8ba4867c27
[CodeComplete] Tweak completion for else.
If an `if` statement uses braces for its `then` block, suggest braces for the `else` and `else if` completion blocks, Otherwise don't suggest them.

Reviewed By: sammccall

Differential Revision: https://reviews.llvm.org/D82626
2020-06-30 16:48:24 +01:00
Andy Soffer 9945bd5911 Add Metadata to Transformer tooling
This change adds a Metadata field to ASTEdit, Edit, and AtomicChange so that
edits can have associated metadata and that metadata can be constructed with
Transformer-based RewriteRules. Metadata is ignored when applying edits to
source, but other consumers of AtomicChange can use this metadata to direct how
they want to consume each edit.

Reviewed By: ymandel, gribozavr2

Differential Revision: https://reviews.llvm.org/D82226
2020-06-30 15:03:07 +00:00
Haojian Wu d285f29317 [AST][RecoveryExpr] Avoid spurious 'missing typename' diagnostic when the NNS contains errors.
Differential Revision: https://reviews.llvm.org/D82631
2020-06-30 16:18:32 +02:00
Haojian Wu 9f865246a8 [ASTMatcher] Fix a performance regression: memorize the child match.
D80025 introduced a performance regression: in some cases, it makes
clang-tidy readability-container-size-empty ~80x slower (running on an internal
huge TU, before that patch 12s vs after 950s).

after this patch, we go back to 12s.

Differential Revision: https://reviews.llvm.org/D82771
2020-06-30 15:43:51 +02:00
serge-sans-paille 05c479491c Make it possible for client code to consume CLANG_LINK_CLANG_DYLIB
If a client code wants to consume clang libraries, it needs to know
CLANG_LINK_CLANG_DYLIB value in order to decide whether to use the DYLIB or
individual components.

Differential Revision: https://reviews.llvm.org/D82291
2020-06-30 15:13:53 +02:00
Bevin Hansson 33bae9c265 [AST] Fix handling of some edge cases in fixed-point division.
Division by zero was not being handled, and division of
-EPSILON / MAX did not perform rounding correctly.
2020-06-30 13:47:12 +02:00
Haojian Wu d28267f981 [AST][RecoveryExpr] Add error-bit to NestNameSpecifierDependence and TemplateNameDependence.
Summary:
We might lose the error-bit if the error-bit goes through the code path
"error type/expr" -> "error template argument" -> "nested name specifier" ->
... -> "template Specialization type"

Template name also needs this, as a template can be nested into
an error specifier, e.g. templateName apply in
`TC<decltype(<recovery-expr>(Foo, int()))>::template apply`

Reviewers: sammccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D82526
2020-06-30 11:56:24 +02:00
David Sherwood c02332a693 [CodeGen] Fix warning in getNode for EXTRACT_SUBVECTOR
Fix a warning in getNode() when extracting a subvector from a
concat vector. We can simply replace the call to getVectorNumElements
with getVectorMinNumElements as this follows the defined behaviour
for EXTRACT_SUBVECTOR.

Differential Revision: https://reviews.llvm.org/D82746
2020-06-30 08:11:41 +01:00
Alex Lorenz bb162dfe25 [clang] attempt to fix a linux test failure for the darwin-ld-platform-version-macos.c test
Clang should use explicit -target to ensure that the Darwin driver is used.
Also drop arm64e test-case for now.
2020-06-29 20:13:41 -07:00
Alex Lorenz 6792a60778 [darwin][driver] pass the minimum supported OS version to the linker
if it's newer than the target version

This change ensures that the arm64-apple-macOS slice is linked for
macOS 11 even if the deployment target is earlier than macOS 11.
2020-06-29 19:03:57 -07:00
Richard Smith 5a5f5350e1 [c++20] Fix handling of operator rewrites naming consteval operator<=>. 2020-06-29 19:02:47 -07:00
David Blaikie 31c689e694 Move Sema::PragmaStack<ValueType>::Act into Sema.h so it can be instantiated as needed
Found by linker failures in ThinLTO where the definition wasn't
available when it needed to be. (eg: ThinLTO may've eliminated the one
caller in the same TU and dropped the definition - breaking accidental
implicit depenednce on that definition from elsewhere)
2020-06-29 18:02:12 -07:00
James Y Knight 4772b99dff Clang Driver: refactor support for writing response files to be
specified at Command creation, rather than as part of the Tool.

This resolves the hack I just added to allow Darwin toolchain to vary
its level of support based on `-mlinker-version=`.

The change preserves the _current_ settings for response-file support.
Some tools look likely to be declaring that they don't support
response files in error, however I kept them as-is in order for this
change to be a simple refactoring.

Differential Revision: https://reviews.llvm.org/D82782
2020-06-29 18:27:02 -04:00
James Y Knight 381df1653c Clang Driver: Use Apple ld64's new @response-file support.
In XCode 12, ld64 got support for @files, in addition to the old
-filelist mechanism. Response files allow passing all command-line
arguments to the linker via a file, rather than just filenames, and is
therefore preferred.

Because of the way response-file support is currently implemented as
part of the Tool class in Clang, this change requires an ugly backdoor
function to access Args. A follow-up commit fixes this, but I've
ordered this change first, for easier backportability.

I've added no tests here, because unfortunately, there don't appear to
be _any_ response-file emission automated tests, and I don't see an
obvious way to add them. I've tested that this change works as
expected locally.

Differential Revision: https://reviews.llvm.org/D82777
2020-06-29 18:26:53 -04:00
Richard Smith 4d1b7e9820 Fix a few cases that were incorrectly parsed as unary-expressions
instead of postfix-expressions, and improve error recovery for postfix
operators after unary-expressions.

This covers nullptr, __null, and some calls to type traits with special
parsing rules. We would previously not parse a postfix-expression suffix
for these expressions, so would reject expressions such as
__is_trivial(int)["foo"].

For the case where a postfix-expression suffix is *not* permitted after
a unary-expression (for example, after a new-expression or sizeof
expression), produce a diagnostic if one appears there anyway. That's
always ill-formed, but previously produced very bad diagnostics.
2020-06-29 14:33:21 -07:00