Commit Graph

1215 Commits

Author SHA1 Message Date
Adam Czachorowski 4e1c487004 [clang] Fix crash when creating deduction guide.
We used to trigger assertion when transforming c-tor with unparsed
default argument. Now we ignore such constructors for this purpose.

Differential Revision: https://reviews.llvm.org/D97965
2021-03-09 16:57:56 +01:00
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