Commit Graph

1264 Commits

Author SHA1 Message Date
Hans Wennborg 8ba442bc21 Revert "Following up on PR48517, fix handling of template arguments that refer"
Combined with 'da98651 - Revert "DR2064:
decltype(E) is only a dependent', this change (5a391d3) caused verifier
errors when building Chromium. See https://crbug.com/1168494#c1 for a
reproducer.

Additionally it reverts changes that were dependent on this one, see
below.

> Following up on PR48517, fix handling of template arguments that refer
> to dependent declarations.
>
> Treat an id-expression that names a local variable in a templated
> function as being instantiation-dependent.
>
> This addresses a language defect whereby a reference to a dependent
> declaration can be formed without any construct being value-dependent.
> Fixing that through value-dependence turns out to be problematic, so
> instead this patch takes the approach (proposed on the core reflector)
> of allowing the use of pointers or references to (but not values of)
> dependent declarations inside value-dependent expressions, and instead
> treating template arguments as dependent if they evaluate to a constant
> involving such dependent declarations.
>
> This ends up affecting a bunch of OpenMP tests, due to OpenMP
> imprecisely handling instantiation-dependent constructs, bailing out
> early instead of processing dependent constructs to the extent possible
> when handling the template.
>
> Previously committed as 8c1f2d15b8, and
> reverted because a dependency commit was reverted.

This reverts commit 5a391d38ac.

It also restores clang/test/SemaCXX/coroutines.cpp to its state before
da986511fb.

Revert "[c++20] P1907R1: Support for generalized non-type template arguments of scalar type."

> Previously committed as 9e08e51a20, and
> reverted because a dependency commit was reverted. This incorporates the
> following follow-on commits that were also reverted:
>
> 7e84aa1b81 by Simon Pilgrim
> ed13d8c667 by me
> 95c7b6cadb by Sam McCall
> 430d5d8429 by Dave Zarzycki

This reverts commit 4b574008ae.

Revert "[msabi] Mangle a template argument referring to array-to-pointer decay"

> [msabi] Mangle a template argument referring to array-to-pointer decay
> applied to an array the same as the array itself.
>
> This follows MS ABI, and corrects a regression from the implementation
> of generalized non-type template parameters, where we "forgot" how to
> mangle this case.

This reverts commit 18e093faf7.
2021-01-20 15:55:35 +01:00
Richard Smith 4b574008ae [c++20] P1907R1: Support for generalized non-type template arguments of scalar type.
Previously committed as 9e08e51a20, and
reverted because a dependency commit was reverted. This incorporates the
following follow-on commits that were also reverted:

7e84aa1b81 by Simon Pilgrim
ed13d8c667 by me
95c7b6cadb by Sam McCall
430d5d8429 by Dave Zarzycki
2021-01-18 21:05:01 -08:00
Richard Smith 5a391d38ac Following up on PR48517, fix handling of template arguments that refer
to dependent declarations.

Treat an id-expression that names a local variable in a templated
function as being instantiation-dependent.

This addresses a language defect whereby a reference to a dependent
declaration can be formed without any construct being value-dependent.
Fixing that through value-dependence turns out to be problematic, so
instead this patch takes the approach (proposed on the core reflector)
of allowing the use of pointers or references to (but not values of)
dependent declarations inside value-dependent expressions, and instead
treating template arguments as dependent if they evaluate to a constant
involving such dependent declarations.

This ends up affecting a bunch of OpenMP tests, due to OpenMP
imprecisely handling instantiation-dependent constructs, bailing out
early instead of processing dependent constructs to the extent possible
when handling the template.

Previously committed as 8c1f2d15b8, and
reverted because a dependency commit was reverted.
2021-01-18 21:05:01 -08:00
Zequan Wu 4fffbc150c [clang][MSVC] Fix missing MSInheritanceAttr in template specialization.
Fix PR48687.

Differential Revision: https://reviews.llvm.org/D94646
2021-01-14 10:37:35 -08:00
Thorsten Schütt 2fd11e0b1e Revert "[NFC, Refactor] Modernize StorageClass from Specifiers.h to a scoped enum (II)"
This reverts commit efc82c4ad2.
2021-01-04 23:17:45 +01:00
Thorsten Schütt efc82c4ad2 [NFC, Refactor] Modernize StorageClass from Specifiers.h to a scoped enum (II)
Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D93765
2021-01-04 22:58:26 +01:00
Arthur Eubanks af0dbaaa38 Revert "Following up on PR48517, fix handling of template arguments that refer"
This reverts commit 8c1f2d15b8.

This is part of 5 commits being reverted due to https://crbug.com/1161059. See bug for repro.
2020-12-22 10:18:08 -08:00
Arthur Eubanks 2080232333 Revert "[c++20] P1907R1: Support for generalized non-type template arguments of scalar type."
This reverts commit 9e08e51a20.

This is part of 5 commits being reverted due to https://crbug.com/1161059. See bug for repro.
2020-12-22 10:18:08 -08:00
Arthur Eubanks ab7a60eb41 Revert "Fix MSVC "not all control paths return a value" warnings. NFCI."
This reverts commit 7e84aa1b81.

This is part of 5 commits being reverted due to https://crbug.com/1161059. See bug for repro.
2020-12-22 10:18:07 -08:00
Simon Pilgrim 7e84aa1b81 Fix MSVC "not all control paths return a value" warnings. NFCI.
Add missing llvm_unreachable()'s after each all-enums switch statement.
2020-12-20 11:32:40 +00:00
Richard Smith 9e08e51a20 [c++20] P1907R1: Support for generalized non-type template arguments of scalar type. 2020-12-18 01:08:41 -08:00
Richard Smith 8c1f2d15b8 Following up on PR48517, fix handling of template arguments that refer
to dependent declarations.

Treat an id-expression that names a local variable in a templated
function as being instantiation-dependent.

This addresses a language defect whereby a reference to a dependent
declaration can be formed without any construct being value-dependent.
Fixing that through value-dependence turns out to be problematic, so
instead this patch takes the approach (proposed on the core reflector)
of allowing the use of pointers or references to (but not values of)
dependent declarations inside value-dependent expressions, and instead
treating template arguments as dependent if they evaluate to a constant
involving such dependent declarations.

This ends up affecting a bunch of OpenMP tests, due to OpenMP
imprecisely handling instantiation-dependent constructs, bailing out
early instead of processing dependent constructs to the extent possible
when handling the template.
2020-12-17 23:54:37 -08:00
Richard Smith 4b388859f5 Ensure that we transform types into the current instantiation even if
they're only instantiation-dependent.
2020-12-17 23:23:05 -08:00
Richard Smith 71886c56f3 Where possible, don't try to ask whether a template argument is
dependent until it's been converted to match its parameter.

The type of a non-type template parameter can in general affect whether
the template argument is dependent.

Note that this is not always possible. For template arguments that name
static local variables in templates, the type of the template parameter
affects whether the argument is dependent, so the query is imprecise
until we know the parameter type. For example, in:

template<typename T> void f() {
  static const int n = 5;
  typename T::template X<n> x;
}

... we don't know whether 'n' is dependent until we know whether the
corresponding template parameter is of type 'int' or 'const int&'.
2020-12-17 23:23:05 -08:00
Richard Smith 6c365cd31e Consider reference, pointer, and pointer-to-member TemplateArguments to be different if they have different types.
For the Itanium ABI, this implements the mangling rule suggested in
https://github.com/itanium-cxx-abi/cxx-abi/issues/47, namely mangling
such template arguments as being cast to the parameter type in the case
where the template name is overloadable. This can cause a mangling
change for rare cases, where

 * the template argument declaration is converted from its declared type
   to the type of the template parameter, and
 * the template parameter either has a deduced type or is a parameter of
   a function template.

However, such changes are necessary to avoid mangling collisions. The
ABI changes can be reversed with -fclang-abi-compat=11 or earlier.

Re-commit with a fix for a couple of regressions.

Differential Revision: https://reviews.llvm.org/D91488
2020-12-15 12:00:57 -08:00
Richard Smith abbd57e558 Factor out and centralize repeated 'getExpandedPackSize'. 2020-12-13 22:43:23 -08:00
Richard Smith 2a2c228c7a Add new 'preferred_name' attribute.
This attribute permits a typedef to be associated with a class template
specialization as a preferred way of naming that class template
specialization. This permits us to specify that (for example) the
preferred way to express 'std::basic_string<char>' is as 'std::string'.

The attribute is applied to the various class templates in libc++ that have
corresponding well-known typedef names.

This is a re-commit. The previous commit was reverted because it exposed
a pre-existing bug that has since been fixed / worked around; see
PR48434.

Differential Revision: https://reviews.llvm.org/D91311
2020-12-09 12:22:35 -08:00
Richard Smith a1344779ab Revert "Add new 'preferred_name' attribute."
This change exposed a pre-existing issue with deserialization cycles
caused by a combination of attributes and template instantiations
violating the deserialization ordering restrictions; see PR48434 for
details.

A previous commit attempted to work around PR48434, but appears to have
only been a partial fix, and fixing this properly seems non-trivial.
Backing out for now to unblock things.

This reverts commit 98f76adf4e and
commit a64c26a47a.
2020-12-08 00:42:48 -08:00
Richard Smith 98f76adf4e Add new 'preferred_name' attribute.
This attribute permits a typedef to be associated with a class template
specialization as a preferred way of naming that class template
specialization. This permits us to specify that (for example) the
preferred way to express 'std::basic_string<char>' is as 'std::string'.

The attribute is applied to the various class templates in libc++ that have
corresponding well-known typedef names.

Differential Revision: https://reviews.llvm.org/D91311
2020-12-07 12:53:07 -08:00
Erich Keane 1c98f98410 Stop ExtractTypeForDeductionGuide from recursing on TypeSourceInfo
As reported in PR48177, the type-deduction extraction ends up going into
an infinite loop when the type referred to has a recursive definition.
This stops recursing and just substitutes the type-source-info the
TypeLocBuilder identified when transforming the base.
2020-12-07 11:29:57 -08:00
Fangrui Song 5755522b5a Sema.h: delete unused variables/functions/type aliases 2020-12-06 20:39:01 -08:00
Gabor Marton 1e14588d0f [Clang][Sema] Attempt to fix CTAD faulty copy of non-local typedefs
http://lists.llvm.org/pipermail/cfe-dev/2020-November/067252.html

Differential Revision: https://reviews.llvm.org/D92101
2020-12-03 11:35:47 +01:00
Ben Dunbobbin d5aaf60214 [windows-itanium] handle dllimport/export code paths separately and share with PS4
Similar to Windows Itanium, PS4 is also an Itanium C++ ABI variant
which shares the goal of semantic compatibility with Microsoft C++
code that uses dllimport/export.

This change introduces a new function to determine from the triple
if an environment aims for compatibility with MS C++ code w.r.t to
these attributes and guards the relevant code paths using that
function.

Differential Revision: https://reviews.llvm.org/D90299
2020-11-30 14:36:39 +00:00
Richard Smith af2f5f99bd Remove unused variable name. NFC. 2020-10-27 17:48:50 -07:00
Richard Smith e97e9851b2 [c++20] For P0732R2: permit class template argument deduction for non-type template parameters. 2020-10-21 15:03:22 -07:00
Richard Smith 0c417d4bef Add more test coverage for APValue serialization / deserialization and
fix a few exposed bugs.
2020-10-21 13:21:41 -07:00
Richard Smith ba4768c966 [c++20] For P0732R2 / P1907R1: Basic frontend support for class types as
non-type template parameters.

Create a unique TemplateParamObjectDecl instance for each such value,
representing the globally unique template parameter object to which the
template parameter refers.

No IR generation support yet; that will follow in a separate patch.
2020-10-21 13:21:41 -07:00
Richard Smith fc031d29be Switch the default of VerifyIntegerConstantExpression from constant
folding to not constant folding.

Constant folding of ICEs is done as a GCC compatibility measure, but new
code was picking it up, presumably by accident, due to the bad default.

While here, also switch the flag from a bool to an enum to make it more
obvious what it means at call sites. This highlighted a couple of places
where our behavior is different between C++11 and C++14 due to switching
from checking for an ICE to checking for a converted constant
expression (where there is no 'fold' codepath).
2020-10-15 16:58:47 -07:00
Bruno Cardoso Lopes cffb0dd54d [SemaTemplate] Stop passing insertion position around during VarTemplate instantiation
They can get stale at use time because of updates from other recursive
specializations. Instead, rely on the existence of previous declarations to add
the specialization.

Differential Revision: https://reviews.llvm.org/D87853
2020-10-12 16:48:50 -07:00
Haojian Wu af29591650 [AST] Reduce the size of TemplateArgumentLocInfo.
allocate the underlying data of Template kind separately, this would reduce AST
memory usage

- TemplateArgumentLocInfo 24 => 8 bytes
- TemplateArgumentLoc  48 => 32 bytes
- DynTypeNode 56 => 40 bytes

ASTContext::.getASTAllocatedMemory changes:
  SemaDecl.cpp 255.5 MB => 247.5MB
  SemaExpr.cpp 293.5 MB => 283.5MB

Differential Revision: https://reviews.llvm.org/D87080
2020-09-21 13:08:53 +02:00
Richard Smith 0cd73dbe2c [c++20] For P1907R1: Add checking for structural types for non-type
template parameters.

No support for the new kinds of non-type template argument yet.

This is not entirely NFC for prior language modes: we have historically
incorrectly accepted rvalue references as the types of non-type template
parameters. Such invalid code is now rejected.
2020-09-20 20:20:52 -07:00
Serge Pavlov f1cd6593da [AST][FPEnv] Keep FP options in trailing storage of CastExpr
This is recommit of 6c8041aa0f, reverted in de044f7562 because of some
fails. Original commit message is below.

This change allow a CastExpr to have optional FPOptionsOverride object,
stored in trailing storage. Of all cast nodes only ImplicitCastExpr,
CStyleCastExpr, CXXFunctionalCastExpr and CXXStaticCastExpr are allowed
to have FPOptions.

Differential Revision: https://reviews.llvm.org/D85960
2020-09-14 12:15:21 +07:00
Serge Pavlov de044f7562 Revert "[AST][FPEnv] Keep FP options in trailing storage of CastExpr"
This reverts commit 6c8041aa0f.
It caused some fails on buildbots.
2020-09-12 17:06:42 +07:00
Serge Pavlov 6c8041aa0f [AST][FPEnv] Keep FP options in trailing storage of CastExpr
This change allow a CastExpr to have optional FPOptionsOverride object,
stored in trailing storage. Of all cast nodes only ImplicitCastExpr,
CStyleCastExpr, CXXFunctionalCastExpr and CXXStaticCastExpr are allowed
to have FPOptions.

Differential Revision: https://reviews.llvm.org/D85960
2020-09-12 14:30:44 +07:00
Richard Smith 6f33936719 Explain why the array bound is non-constant in VLA diagnostics.
In passing, also use a more precise diagnostic to explain why an
expression is not an ICE if it's not of integral type.
2020-08-19 15:45:51 -07:00
Richard Smith 617007240c Improve modeling of variable template specializations with dependent
arguments.

Don't build a variable template specialization declaration until its
scope and template arguments are non-dependent.

No functionality change intended, but the AST representation is now more
consistent with how we model other templates.
2020-08-09 23:22:26 -07:00
Richard Smith fb943696cb PR47025, PR47043: Diagnose unexpanded parameter packs in concept
declarations and requires-expressions.
2020-08-07 18:19:39 -07:00
Richard Smith ed5a18fc03 PR30738: Implement two-phase name lookup for fold-expressions. 2020-08-06 16:56:39 -07:00
Richard Smith a648834313 PR46729: Reject explicit and partial specializations with C linkage. 2020-07-29 17:44:32 -07:00
Richard Smith e69138dad5 PR46859: Fix crash if declaring a template in a DeclScope with no DeclContext.
This can happen during error recovery; it could also happen at block
scope if we ever parsed a template declaration at block scope.
2020-07-29 12:02:55 -07:00
Haojian Wu 8c5133f185 [clang] Fix a null-NSS-access crash in DependentNameType.
The DependentNameType must have a non-null NSS. This property could be
violated during typo correction.

Differential Revision: https://reviews.llvm.org/D82738
2020-07-02 14:58:32 +02:00
Richard Smith d1446017f3 DR458: Search template parameter scopes in the right order.
C++ unqualified name lookup searches template parameter scopes
immediately after finishing searching the entity the parameters belong
to. (Eg, for a class template, you search the template parameter scope
after looking in that class template and its base classes and before
looking in the scope containing the class template.) This is complicated
by the fact that scope lookup within a template parameter scope looks in
a different sequence of places prior to reaching the end of the
declarator-id in the template declaration.

We used to approximate the proper lookup rule with a hack in the scope /
decl context walk inside name lookup. Now we instead compute the lookup
parent for each template parameter scope.

In order to get this right, we now make sure to enter a distinct Scope
for each template parameter scope, and make sure to re-enter the
enclosing class scopes properly when handling delay-parsed regions
within a class.
2020-06-23 17:14:33 -07:00
Richard Smith a6308c0ad9 When performing a substitution into a dependent alias template, mark the
outer levels as retained rather than omitting their arguments.

This better reflects what's going on (we're performing a substitution
while still inside a template), and in theory is more correct, but I've
not found a testcase where it matters in practice (largely because we
don't allow alias templates to be declared inside a function).

Fixed AST dumping of SubstNonTypeTemplateParm[Pack]Expr to demonstrate
that we're properly substituting through dependent alias templates. (We
can't deduce properly through these yet, but we can at least produce the
right input to template argument deduction.)

No functionality change intended.
2020-06-23 14:43:04 -07:00
Richard Smith 9f9373f86d Distinguish between template parameter substitutions that are forming
specializations and those that are done as part of rewrites.

Do not create Subst* nodes in the latter. We previously had a hybrid of
these two behaviors where we would only create some Subst* nodes but not
others during deduction guide rewrites.

No functional change intended, but the resulting ASTs are more
principled.
2020-06-22 19:34:52 -07:00
Richard Smith 973cfa9ef5 Revert "When performing a substitution into a dependent alias template, mark the"
This change depends on reverted change c7fbe2191b.

This reverts commit c851d6cf4a.
2020-06-17 16:07:58 -07:00
Richard Smith c851d6cf4a When performing a substitution into a dependent alias template, mark the
outer levels as retained rather than omitting their arguments.

This better reflects what's going on (we're performing a substitution
while still inside a template). In theory this is also more correct, but
I've not found a testcase where it matters in practice (largely because
we don't allow alias templates to be declared inside a function).
2020-06-17 15:12:04 -07:00
Richard Smith 02fccc26cf Revert "DR458: Search template parameter scopes in the right order."
We weren't re-entering template scopes in the right order, causing this
to break self-host with -fdelayed-template-parsing.

This reverts commit 237c2a23b6.
2020-06-16 23:53:44 -07:00
Richard Smith 237c2a23b6 DR458: Search template parameter scopes in the right order.
C++ unqualified name lookup searches template parameter scopes
immediately after finishing searching the entity the parameters belong
to. (Eg, for a class template, you search the template parameter scope
after looking in that class template and its base classes and before
looking in the scope containing the class template.) This is complicated
by the fact that scope lookup within a template parameter scope looks in
a different sequence of places prior to reaching the end of the
declarator-id in the template declaration.

We used to approximate the proper lookup rule with a hack in the scope /
decl context walk inside name lookup. Now we instead compute the lookup
parent for each template parameter scope. This gets the right answer and
as a bonus is substantially simpler and more uniform.

In order to get this right, we now make sure to enter a distinct Scope
for each template parameter scope. (The fact that we didn't before was
already a bug, but not really observable most of the time, since
template parameters can't shadow each other.)
2020-06-16 19:41:14 -07:00
Erich Keane 82a21229da (PR46111) Properly handle elaborated types in an implicit deduction guide
As reported in PR46111, implicit instantiation of a deduction guide
causes us to have an elaborated type as the parameter, rather than the
dependent type.

After review and feedback from @rsmith, this patch solves this problem
by wrapping the value in an uninstantiated typedef/type-alias that is
instantiated when required later.

Differential Revision: https://reviews.llvm.org/D80743
2020-06-12 05:32:13 -07:00
Florian Hahn 1065869195 [Matrix] Add matrix type to Clang.
This patch adds a matrix type to Clang as described in the draft
specification in clang/docs/MatrixSupport.rst. It introduces a new option
-fenable-matrix, which can be used to enable the matrix support.

The patch adds new MatrixType and DependentSizedMatrixType types along
with the plumbing required. Loads of and stores to pointers to matrix
values are lowered to memory operations on 1-D IR arrays. After loading,
the loaded values are cast to a vector. This ensures matrix values use
the alignment of the element type, instead of LLVM's large vector
alignment.

The operators and builtins described in the draft spec will will be added in
follow-up patches.

Reviewers: martong, rsmith, Bigcheese, anemet, dexonsmith, rjmccall, aaron.ballman

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D72281
2020-05-11 18:55:45 +01:00
Aaron Ballman 6a30894391 C++2a -> C++20 in some identifiers; NFC. 2020-04-21 15:37:19 -04:00
Erich Keane 5f0903e9be Reland Implement _ExtInt as an extended int type specifier.
I fixed the LLDB issue, so re-applying the patch.

This reverts commit a4b88c0449.
2020-04-17 10:45:48 -07:00
Sterling Augustine a4b88c0449 Revert "Implement _ExtInt as an extended int type specifier."
This reverts commit 61ba1481e2.

I'm reverting this because it breaks the lldb build with
incomplete switch coverage warnings. I would fix it forward,
but am not familiar enough with lldb to determine the correct
fix.

lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:3958:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
          ^
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:4633:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
          ^
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:4889:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
2020-04-17 10:29:40 -07:00
Erich Keane 61ba1481e2 Implement _ExtInt as an extended int type specifier.
Introduction/Motivation:
LLVM-IR supports integers of non-power-of-2 bitwidth, in the iN syntax.
Integers of non-power-of-two aren't particularly interesting or useful
on most hardware, so much so that no language in Clang has been
motivated to expose it before.

However, in the case of FPGA hardware normal integer types where the
full bitwidth isn't used, is extremely wasteful and has severe
performance/space concerns.  Because of this, Intel has introduced this
functionality in the High Level Synthesis compiler[0]
under the name "Arbitrary Precision Integer" (ap_int for short). This
has been extremely useful and effective for our users, permitting them
to optimize their storage and operation space on an architecture where
both can be extremely expensive.

We are proposing upstreaming a more palatable version of this to the
community, in the form of this proposal and accompanying patch.  We are
proposing the syntax _ExtInt(N).  We intend to propose this to the WG14
committee[1], and the underscore-capital seems like the active direction
for a WG14 paper's acceptance.  An alternative that Richard Smith
suggested on the initial review was __int(N), however we believe that
is much less acceptable by WG14.  We considered _Int, however _Int is
used as an identifier in libstdc++ and there is no good way to fall
back to an identifier (since _Int(5) is indistinguishable from an
unnamed initializer of a template type named _Int).

[0]https://www.intel.com/content/www/us/en/software/programmable/quartus-prime/hls-compiler.html)
[1]http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2472.pdf

Differential Revision: https://reviews.llvm.org/D73967
2020-04-17 07:10:57 -07:00
Richard Smith bab6df86ae Rework how UuidAttr, CXXUuidofExpr, and GUID template arguments and constants are represented.
Summary:
Previously, we treated CXXUuidofExpr as quite a special case: it was the
only kind of expression that could be a canonical template argument, it
could be a constant lvalue base object, and so on. In addition, we
represented the UUID value as a string, whose source form we did not
preserve faithfully, and that we partially parsed in multiple different
places.

With this patch, we create an MSGuidDecl object to represent the
implicit object of type 'struct _GUID' created by a UuidAttr. Each
UuidAttr holds a pointer to its 'struct _GUID' and its original
(as-written) UUID string. A non-value-dependent CXXUuidofExpr behaves
like a DeclRefExpr denoting that MSGuidDecl object. We cache an APValue
representation of the GUID on the MSGuidDecl and use it from constant
evaluation where needed.

This allows removing a lot of the special-case logic to handle these
expressions. Unfortunately, many parts of Clang assume there are only
a couple of interesting kinds of ValueDecl, so the total amount of
special-case logic is not really reduced very much.

This fixes a few bugs and issues:
 * PR38490: we now support reading from GUID objects returned from
   __uuidof during constant evaluation.
 * Our Itanium mangling for a non-instantiation-dependent template
   argument involving __uuidof no longer depends on which CXXUuidofExpr
   template argument we happened to see first.
 * We now predeclare ::_GUID, and permit use of __uuidof without
   any header inclusion, better matching MSVC's behavior. We do not
   predefine ::__s_GUID, though; that seems like a step too far.
 * Our IR representation for GUID constants now uses the correct IR type
   wherever possible. We will still fall back to using the
      {i32, i16, i16, [8 x i8]}
   layout if a definition of struct _GUID is not available. This is not
   ideal: in principle the two layouts could have different padding.

Reviewers: rnk, jdoerfert

Subscribers: arphaman, cfe-commits, aeubanks

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78171
2020-04-15 12:20:42 -07:00
Richard Smith a5458bb0d6 Don't claim template names that name non-templates are undeclared. 2020-03-29 13:15:30 -07:00
Richard Smith 499b2a8d63 PR45294: Fix handling of assumed template names looked up in the lexical
scope.

There are a few contexts in which we assume a name is a template name;
if such a context is one where we should perform an unqualified lookup,
and lookup finds nothing, we would form a dependent template name even
if the name is not dependent. This happens in particular for the lookup
of a pseudo-destructor.

In passing, rename ActOnDependentTemplateName to just ActOnTemplateName
given that we apply it for non-dependent template names too.
2020-03-27 21:07:06 -07:00
Richard Smith 88c7ffaf94 Form invalid template-id annotations when parsing a construct that is
required to be a template-id but names an undeclared identifier.
2020-03-27 20:27:42 -07:00
Haojian Wu bd763e2cf7 [clang] Fix crash on visiting null nestedNameSpecifier.
Summary: Fix https://github.com/clangd/clangd/issues/293

Reviewers: sammccall

Subscribers: ilya-biryukov, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76320
2020-03-18 09:15:02 +01:00
Saar Raz 19fccc52ff [Concepts] Fix incorrect control flow when TryAnnotateTypeConstraint annotates an invalid template-id
TryAnnotateTypeConstraint could annotate a template-id which doesn't end up being a type-constraint,
in which case control flow would incorrectly flow into ParseImplicitInt.

Reenter the loop in this case.
Enable relevant tests for C++20. This required disabling typo-correction during TryAnnotateTypeConstraint
and changing a test case which is broken due to a separate bug (will be reported and handled separately).
2020-03-17 01:49:42 +02:00
Richard Smith 44c3a63c74 PR45063: Fix crash on invalid processing an elaborated class template-id
with an invalid scope specifier.
2020-03-13 18:53:49 -07:00
Richard Smith 5c845c1c50 PR45083: Mark statement expressions as being dependent if they appear in
a dependent context.

This matches the GCC behavior.

We track the enclosing template depth when determining whether a
statement expression is within a dependent context; there doesn't appear
to be any other reliable way to determine this.

We previously assumed they were neither value- nor
instantiation-dependent under any circumstances, which would lead to
crashes and other misbehavior.
2020-03-10 14:45:04 -07:00
Richard Smith 6d894afdea PR45124: Don't leave behind pending cleanups when declaring implicit
deduction guides.

Previously if an implicit deduction guide had a default argument with a
cleanup, we'd leave the 'pending cleanup' flag set after declaring the
implicit guide. But it turns out that there's no reason to even
substitute into the default argument when declaring an implicit
deduction guide: we only need to record that the default argument
exists, not what it is, since we never actually form a call to a
deduction guide.
2020-03-06 13:22:10 -08:00
Jim Lin 466f8843f5 [NFC] Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h,td}
2020-02-18 10:49:13 +08:00
Benjamin Kramer adcd026838 Make llvm::StringRef to std::string conversions explicit.
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.
2020-01-28 23:25:25 +01:00
Saar Raz a8d096aff6 [Concepts] Add missing null check to transformConstructor
Caused bug 44671 when transforming a constructor with a type-constraint with no explicit template args.
2020-01-27 00:15:42 +02:00
Saar Raz 67c608a969 [Concepts] Deprecate -fconcepts-ts, enable Concepts under -std=c++2a
Now with concepts support merged and mostly complete, we do not need -fconcepts-ts
(which was also misleading as we were not implementing the TS) and can enable
concepts features under C++2a. A warning will be generated if users still attempt
to use -fconcepts-ts.
2020-01-24 00:48:59 +02:00
Saar Raz d42d5eb8ea [Concepts] Implement P1616R1 - Using unconstrained template template parameters with constrained templates
Summary: Allow unconstrained template template parameters to accept constrainted templates as arguments.

Reviewers: rsmith

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73155
2020-01-23 23:32:03 +02:00
Saar Raz b481f02814 [Concepts] Placeholder constraints and abbreviated templates
This patch implements P1141R2 "Yet another approach for constrained declarations".

General strategy for this patch was:

- Expand AutoType to include optional type-constraint, reflecting the wording and easing the integration of constraints.
- Replace autos in parameter type specifiers with invented parameters in GetTypeSpecTypeForDeclarator, using the same logic
  previously used for generic lambdas, now unified with abbreviated templates, by:
  - Tracking the template parameter lists in the Declarator object
  - Tracking the template parameter depth before parsing function declarators (at which point we can match template
    parameters against scope specifiers to know if we have an explicit template parameter list to append invented parameters
    to or not).
- When encountering an AutoType in a parameter context we check a stack of InventedTemplateParameterInfo structures that
  contain the info required to create and accumulate invented template parameters (fields that were already present in
  LambdaScopeInfo, which now inherits from this class and is looked up when an auto is encountered in a lambda context).

Resubmit after fixing MSAN failures caused by incomplete initialization of AutoTypeLocs in TypeSpecLocFiller.

Differential Revision: https://reviews.llvm.org/D65042
2020-01-23 19:39:43 +02:00
Sam McCall 5c02fe1faa Revert "[Concepts] Placeholder constraints and abbreviated templates"
This reverts commit e57a9abc4b.

Parser/cxx2a-placeholder-type-constraint.cpp has MSan failures.

Present at 7b81c3f8793d30a4285095a9b67dcfca2117916c:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-msan/builds/17133/steps/check-clang%20msan/logs/stdio
not present at eaa594f4ec54eba52b03fd9f1c789b214c66a753:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-msan/builds/17132/steps/check-clang%20msan/logs/stdio

Stack trace:
```
==57032==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0xccfe016 in clang::AutoTypeLoc::getLocalSourceRange() const /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/include/clang/AST/TypeLoc.h:2036:19
    #1 0xcc56758 in CheckDeducedPlaceholderConstraints(clang::Sema&, clang::AutoType const&, clang::AutoTypeLoc, clang::QualType) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Sema/SemaTemplateDeduction.cpp:4505:56
    #2 0xcc550ce in clang::Sema::DeduceAutoType(clang::TypeLoc, clang::Expr*&, clang::QualType&, llvm::Optional<unsigned int>, bool) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Sema/SemaTemplateDeduction.cpp:4707:11
    #3 0xcc52407 in clang::Sema::DeduceAutoType(clang::TypeSourceInfo*, clang::Expr*&, clang::QualType&, llvm::Optional<unsigned int>, bool) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Sema/SemaTemplateDeduction.cpp:4457:10
    #4 0xba38332 in clang::Sema::deduceVarTypeFromInitializer(clang::VarDecl*, clang::DeclarationName, clang::QualType, clang::TypeSourceInfo*, clang::SourceRange, bool, clang::Expr*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Sema/SemaDecl.cpp:11351:7
    #5 0xba3a8a9 in clang::Sema::DeduceVariableDeclarationType(clang::VarDecl*, bool, clang::Expr*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Sema/SemaDecl.cpp:11385:26
    #6 0xba3c520 in clang::Sema::AddInitializerToDecl(clang::Decl*, clang::Expr*, bool) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Sema/SemaDecl.cpp:11725:9
    #7 0xb39c498 in clang::Parser::ParseDeclarationAfterDeclaratorAndAttributes(clang::Declarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::ForRangeInit*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:2399:17
    #8 0xb394d80 in clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::SourceLocation*, clang::Parser::ForRangeInit*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:2128:21
    #9 0xb383bbf in clang::Parser::ParseSimpleDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::Parser::ParsedAttributesWithRange&, bool, clang::Parser::ForRangeInit*, clang::SourceLocation*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:1848:10
    #10 0xb383129 in clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::Parser::ParsedAttributesWithRange&, clang::SourceLocation*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/include/llvm/ADT/PointerUnion.h
    #11 0xb53a388 in clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::Parser::ParsedAttributesWithRange&) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/ParseStmt.cpp:221:13
    #12 0xb539309 in clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/ParseStmt.cpp:106:20
    #13 0xb55610e in clang::Parser::ParseCompoundStatementBody(bool) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/ParseStmt.cpp:1079:11
    #14 0xb559529 in clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/ParseStmt.cpp:2204:21
    #15 0xb33c13e in clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/Parser.cpp:1339:10
    #16 0xb394703 in clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::SourceLocation*, clang::Parser::ForRangeInit*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/ParseDecl.cpp:2068:11
    #17 0xb338e52 in clang::Parser::ParseDeclOrFunctionDefInternal(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec&, clang::AccessSpecifier) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/Parser.cpp:1099:10
    #18 0xb337674 in clang::Parser::ParseDeclarationOrFunctionDefinition(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*, clang::AccessSpecifier) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/Parser.cpp:1115:12
    #19 0xb334a96 in clang::Parser::ParseExternalDeclaration(clang::Parser::ParsedAttributesWithRange&, clang::ParsingDeclSpec*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/Parser.cpp:935:12
    #20 0xb32f12a in clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, bool) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/Parser.cpp:686:12
    #21 0xb31e193 in clang::ParseAST(clang::Sema&, bool, bool) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Parse/ParseAST.cpp:158:20
    #22 0x80263f0 in clang::FrontendAction::Execute() /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Frontend/FrontendAction.cpp:936:8
    #23 0x7f2a257 in clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/Frontend/CompilerInstance.cpp:965:33
    #24 0x8288bef in clang::ExecuteCompilerInvocation(clang::CompilerInstance*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/lib/FrontendTool/ExecuteCompilerInvocation.cpp:290:25
    #25 0xad44c2 in cc1_main(llvm::ArrayRef<char const*>, char const*, void*) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/tools/driver/cc1_main.cpp:239:15
    #26 0xacd76a in ExecuteCC1Tool(llvm::ArrayRef<char const*>) /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/tools/driver/driver.cpp:325:12
    #27 0xacc9fd in main /b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/clang/tools/driver/driver.cpp:398:12
    #28 0x7f7d82cdb2e0 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
    #29 0xa4dde9 in _start (/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm_build_msan/bin/clang-11+0xa4dde9)
```
2020-01-23 10:38:59 +01:00
Saar Raz e57a9abc4b [Concepts] Placeholder constraints and abbreviated templates
This patch implements P1141R2 "Yet another approach for constrained declarations".

General strategy for this patch was:

- Expand AutoType to include optional type-constraint, reflecting the wording and easing the integration of constraints.
- Replace autos in parameter type specifiers with invented parameters in GetTypeSpecTypeForDeclarator, using the same logic
  previously used for generic lambdas, now unified with abbreviated templates, by:
  - Tracking the template parameter lists in the Declarator object
  - Tracking the template parameter depth before parsing function declarators (at which point we can match template
    parameters against scope specifiers to know if we have an explicit template parameter list to append invented parameters
    to or not).
- When encountering an AutoType in a parameter context we check a stack of InventedTemplateParameterInfo structures that
  contain the info required to create and accumulate invented template parameters (fields that were already present in
  LambdaScopeInfo, which now inherits from this class and is looked up when an auto is encountered in a lambda context).

Resubmit after incorrect check in NonTypeTemplateParmDecl broke lldb.

Differential Revision: https://reviews.llvm.org/D65042
2020-01-22 12:09:13 +02:00
Jonas Devlieghere 62e4b501ab Revert "[Concepts] Placeholder constraints and abbreviated templates"
This temporarily reverts commit e03ead6771
because it breaks LLDB.

http://lab.llvm.org:8011/builders/lldb-x86_64-debian/builds/3356
http://lab.llvm.org:8011/builders/lldb-x64-windows-ninja/builds/12872
http://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/6407/
2020-01-21 19:03:52 -08:00
Saar Raz e03ead6771 [Concepts] Placeholder constraints and abbreviated templates
This patch implements P1141R2 "Yet another approach for constrained declarations".

General strategy for this patch was:

- Expand AutoType to include optional type-constraint, reflecting the wording and easing the integration of constraints.
- Replace autos in parameter type specifiers with invented parameters in GetTypeSpecTypeForDeclarator, using the same logic
  previously used for generic lambdas, now unified with abbreviated templates, by:
  - Tracking the template parameter lists in the Declarator object
  - Tracking the template parameter depth before parsing function declarators (at which point we can match template
    parameters against scope specifiers to know if we have an explicit template parameter list to append invented parameters
    to or not).
- When encountering an AutoType in a parameter context we check a stack of InventedTemplateParameterInfo structures that
  contain the info required to create and accumulate invented template parameters (fields that were already present in
  LambdaScopeInfo, which now inherits from this class and is looked up when an auto is encountered in a lambda context).

Differential Revision: https://reviews.llvm.org/D65042
2020-01-22 02:03:05 +02:00
Richard Smith 13fa4e2e5a PR42108 Consistently diagnose binding a reference template parameter to
a temporary.

We previously failed to materialize a temporary when performing an
implicit conversion to a reference type, resulting in our thinking the
argument was a value rather than a reference in some cases.
2020-01-19 18:16:36 -08:00
Saar Raz a0f50d7316 [Concepts] Requires Expressions
Implement support for C++2a requires-expressions.

Re-commit after compilation failure on some platforms due to alignment issues with PointerIntPair.

Differential Revision: https://reviews.llvm.org/D50360
2020-01-19 00:23:26 +02:00
Saar Raz baa84d8cde Revert "[Concepts] Requires Expressions"
This reverts commit 0279318997.

There have been some failing tests on some platforms, reverting while investigating.
2020-01-18 14:58:01 +02:00
Saar Raz 0279318997 [Concepts] Requires Expressions
Implement support for C++2a requires-expressions.

Differential Revision: https://reviews.llvm.org/D50360
2020-01-18 09:15:36 +02:00
Richard Smith a42fd84cff Remove redundant CXXScopeSpec from TemplateIdAnnotation.
A TemplateIdAnnotation represents only a template-id, not a
nested-name-specifier plus a template-id. Don't make a redundant copy of
the CXXScopeSpec and store it on the template-id annotation.

This slightly improves error recovery by more properly handling the case
where we would form an invalid CXXScopeSpec while parsing a typename
specifier, instead of accidentally putting the token stream into a
broken "annot_template_id with a scope specifier, but with no preceding
annot_cxxscope token" state.
2020-01-17 15:47:21 -08:00
Saar Raz ff1e0fce81 [Concepts] Type Constraints
Add support for type-constraints in template type parameters.
Also add support for template type parameters as pack expansions (where the type constraint can now contain an unexpanded parameter pack).

Differential Revision: https://reviews.llvm.org/D44352
2020-01-15 04:02:39 +02:00
Simon Pilgrim 1d6b964ed1 Fix "pointer is null" static analyzer warning. NFCI.
Remove Ctx null test as clang static analyzer assumes that this can fail - replace it with an assertion as the pointer is always dereferenced below.
2020-01-14 14:00:38 +00:00
Simon Pilgrim 591cd40584 Fix "pointer is null" static analyzer warnings. NFCI.
Use cast<> instead of cast_or_null<> since the pointers are always dereferenced and cast<> will perform the null assertion for us.
2020-01-14 14:00:38 +00:00
Saar Raz b65b1f322b [Concepts] Function trailing requires clauses
Function trailing requires clauses now parsed, supported in overload resolution and when calling, referencing and taking the address of functions or function templates.

Differential Revision: https://reviews.llvm.org/D43357
2020-01-09 15:07:51 +02:00
Saar Raz df061c3e2b [Concepts] Constrained partial specializations and function overloads.
Added support for constraint satisfaction checking and partial ordering of constraints in constrained partial specialization and function template overloads.
Re-commit after fixing another crash (added regression test).

Differential Revision: https://reviews.llvm.org/D41910
2019-12-23 08:37:35 +02:00
Reid Kleckner 79cc9e9b30 Revert "[Concepts] Constrained partial specializations and function overloads."
This reverts commit d3f5769d5e.

Causes crashes on Chromium. Have reproducer, will reduce and send along.
2019-12-22 11:40:07 -08:00
Saar Raz d3f5769d5e [Concepts] Constrained partial specializations and function overloads.
Added support for constraint satisfaction checking and partial ordering of constraints in constrained partial specialization and function template overloads.
Re-commit after fixing some crashes and warnings.

Differential Revision: https://reviews.llvm.org/D41910
2019-12-22 13:15:38 +02:00
Vedant Kumar 5094e6dad6 Revert concepts changes from D41910
These changes caused LibcxxVariantDataFormatterTestCase in lldb to fail
with an assert:

Assertion failed: (Idx < size() && "Out-of-bounds Bit access."),
function operator[], file
/Users/buildslave/jenkins/workspace/lldb-cmake/llvm-project/llvm/include/llvm/ADT/SmallBitVector.h,
line 452.

In:

7  clang-10                 0x00000001094b79d9 isAtLeastAsSpecializedAs(clang::Sema&, clang::SourceLocation, clang::FunctionTemplateDecl*, clang::FunctionTemplateDecl*, clang::TemplatePartialOrderingContext, unsigned int) + 1865
8  clang-10                 0x00000001094b7111 clang::Sema::getMoreSpecializedTemplate(clang::FunctionTemplateDecl*, clang::FunctionTemplateDecl*, clang::SourceLocation, clang::TemplatePartialOrderingContext, unsigned int, unsigned int) + 97
9  clang-10                 0x000000010939bf88 clang::isBetterOverloadCandidate(clang::Sema&, clang::OverloadCandidate const&, clang::OverloadCandidate const&, clang::SourceLocation, clang::OverloadCandidateSet::CandidateSetKind) + 1128

Revert "[Concepts] Fix incorrect move out of temporary in D41910"

This reverts commit 11d5fa6e87.

Revert "[Concepts] Fix crash in D41910"

This reverts commit 12038be20e.

Revert "[Concepts] Constrained partial specializations and function overloads."

This reverts commit fc0731b98a.
2019-12-18 15:02:39 -08:00
Saar Raz fc0731b98a [Concepts] Constrained partial specializations and function overloads.
Added support for constraint satisfaction checking and partial ordering of constraints in constrained partial specialization and function template overloads.

Phabricator: D41910
2019-12-18 21:01:31 +02:00
Saar Raz fdf80e86a5 [Concepts] Constraint Enforcement & Diagnostics
Part of the C++20 concepts implementation effort.
- Associated constraints (requires clauses, currently) are now enforced when instantiating/specializing templates and when considering partial specializations and function overloads.
- Elaborated diagnostics give helpful insight as to why the constraints were not satisfied.
Phabricator: D41569

Re-commit, after fixing some memory bugs.
2019-12-06 01:34:20 +02:00
Richard Smith b220662a45 Properly convert all declaration non-type template arguments when
forming non-type template parameter values.

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

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

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

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

The diagnostic is incorrect: adding the address-of operator also fails ("cannot
take the address of an rvalue of type 'uint32_t (*)()' (aka 'unsigned int
(*)()')").
2019-12-04 22:12:15 -08:00
Richard Smith 11d1052785 Properly convert all declaration non-type template arguments when
forming non-type template parameter values.
2019-12-04 18:55:24 -08:00
Richard Smith a1d2611c04 [c++17] Fix assert / wrong code when passing a noexcept pointer to
member function to a non-noexcept pointer to member non-type template
parameter.
2019-12-04 18:55:23 -08:00
Mark de Wever 743461090a [Sema] Fixes templated friend member assertion
Fixes PR41792: Clang assertion failure on templated friend member function

Differential Revision: https://reviews.llvm.org/D69481
2019-11-05 21:46:42 +01:00
Vlad Tsyrklevich 38839d08b8 Revert "[Concepts] Constraint Enforcement & Diagnostics"
This reverts commit ffa214ef22, it was
causing ASAN test failures on sanitizer-x86_64-linux-bootstrap.
2019-10-28 15:00:40 -07:00
Saar Raz ffa214ef22 [Concepts] Constraint Enforcement & Diagnostics
Part of the C++20 concepts implementation effort.
- Associated constraints (requires clauses, currently) are now enforced when instantiating/specializing templates and when considering partial specializations and function overloads.
- Elaborated diagnostics give helpful insight as to why the constraints were not satisfied.
Phabricator: D41569
2019-10-25 00:19:51 +03:00
Richard Smith 974c8b7e2f [c++20] Add rewriting from comparison operators to <=> / ==.
This adds support for rewriting <, >, <=, and >= to a normal or reversed
call to operator<=>, for rewriting != to a normal or reversed call to
operator==, and for rewriting <=> and == to reversed forms of those same
operators.

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

llvm-svn: 375306
2019-10-19 00:04:43 +00:00
Saar Raz f567b00880 [Concepts] ConceptSpecializationExprs mangling
Implement mangling for CSEs to match regular template-ids.
Reviewed as part of D41569 <https://reviews.llvm.org/D41569>.

Re-commit fixing failing test.

llvm-svn: 375063
2019-10-17 00:16:01 +00:00
Nico Weber b13d257028 Revert 374967 "[Concepts] ConceptSpecializationExprs mangling"
This reverts commit 5e34ad109c.

The mangling test fails on Windows:
http://lab.llvm.org:8011/builders/clang-x64-ninja-win7/builds/15944

It also fails on ppc64le:
http://lab.llvm.org:8011/builders/clang-ppc64le-linux-lnt/builds/21092

Also revert follow-up  374971 "Fix failing mangle-concept.cpp test."
(it did not help on Win/ppc64le).

llvm-svn: 374985
2019-10-16 10:23:53 +00:00
Saar Raz 5e34ad109c [Concepts] ConceptSpecializationExprs mangling
Implement mangling for CSEs to match regular template-ids.
Reviewed as part of D41569.

llvm-svn: 374967
2019-10-16 02:33:41 +00:00
Saar Raz 0330fba6e1 [Concept] Associated Constraints Infrastructure
Add code to correctly calculate the associated constraints of a template (no enforcement yet).
D41284 on Phabricator.

llvm-svn: 374938
2019-10-15 18:44:06 +00:00