Summary:
This is the second attempt of r333500 (Update NRVO logic to support early return).
The previous one was reverted for a miscompilation for an incorrect NRVO set up on templates such as:
```
struct Foo {};
template <typename T>
T bar() {
T t;
if (false)
return T();
return t;
}
```
Where, `t` is marked as non-NRVO variable before its instantiation. However, while its instantiation, it's left an NRVO candidate, turned into an NRVO variable later.
Reviewers: rsmith
Reviewed By: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D47586
llvm-svn: 335019
We were already performing checks on non-template variables,
but the checks on templated ones were missing.
Differential Revision: https://reviews.llvm.org/D45231
llvm-svn: 334143
This is similar to the LLVM change https://reviews.llvm.org/D46290.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
Differential Revision: https://reviews.llvm.org/D46320
llvm-svn: 331834
This patch is a tweak of changyu's patch: https://reviews.llvm.org/D40381. It differs in that the recognition of the 'concept' token is moved into the machinery that recognizes declaration-specifiers - this allows us to leverage the attribute handling machinery more seamlessly.
See the test file to get a sense of the basic parsing that this patch supports.
There is much more work to be done before concepts are usable...
Thanks Changyu!
llvm-svn: 330794
We were already performing checks on non-template variables,
but the checks on templated ones were missing.
Differential Revision: https://reviews.llvm.org/D45231
llvm-svn: 329127
The AST for the fragment
```
@interface I
@end
template <typename>
void decode(I *p) {
for (I *k in p) {}
}
void decode(I *p) {
decode<int>(p);
}
```
differs heavily when templatized and non-templatized:
```
|-FunctionTemplateDecl 0x7fbfe0863940 <line:4:1, line:7:1> line:5:6 decode
| |-TemplateTypeParmDecl 0x7fbfe0863690 <line:4:11> col:11 typename depth 0 index 0
| |-FunctionDecl 0x7fbfe08638a0 <line:5:1, line:7:1> line:5:6 decode 'void (I *__strong)'
| | |-ParmVarDecl 0x7fbfe08637a0 <col:13, col:16> col:16 referenced p 'I *__strong'
| | `-CompoundStmt 0x7fbfe0863b88 <col:19, line:7:1>
| | `-ObjCForCollectionStmt 0x7fbfe0863b50 <line:6:3, col:20>
| | |-DeclStmt 0x7fbfe0863a50 <col:8, col:13>
| | | `-VarDecl 0x7fbfe08639f0 <col:8, col:11> col:11 k 'I *const __strong'
| | |-ImplicitCastExpr 0x7fbfe0863a90 <col:16> 'I *' <LValueToRValue>
| | | `-DeclRefExpr 0x7fbfe0863a68 <col:16> 'I *__strong' lvalue ParmVar 0x7fbfe08637a0 'p' 'I *__strong'
| | `-CompoundStmt 0x7fbfe0863b78 <col:19, col:20>
| `-FunctionDecl 0x7fbfe0863f80 <line:5:1, line:7:1> line:5:6 used decode 'void (I *__strong)'
| |-TemplateArgument type 'int'
| |-ParmVarDecl 0x7fbfe0863ef8 <col:13, col:16> col:16 used p 'I *__strong'
| `-CompoundStmt 0x7fbfe0890cf0 <col:19, line:7:1>
| `-ObjCForCollectionStmt 0x7fbfe0890cc8 <line:6:3, col:20>
| |-DeclStmt 0x7fbfe0890c70 <col:8, col:13>
| | `-VarDecl 0x7fbfe0890c00 <col:8, col:11> col:11 k 'I *__strong' callinit
| | `-ImplicitValueInitExpr 0x7fbfe0890c60 <<invalid sloc>> 'I *__strong'
| |-ImplicitCastExpr 0x7fbfe0890cb0 <col:16> 'I *' <LValueToRValue>
| | `-DeclRefExpr 0x7fbfe0890c88 <col:16> 'I *__strong' lvalue ParmVar 0x7fbfe0863ef8 'p' 'I *__strong'
| `-CompoundStmt 0x7fbfe0863b78 <col:19, col:20>
```
Note how in the instantiated version ImplicitValueInitExpr unexpectedly appears.
While objects are auto-initialized under ARC, it does not make sense to
have an initializer for a for-loop variable, and it makes even less
sense to have such a different AST for instantiated and non-instantiated
version.
Digging deeper, I have found that there are two separate Sema* files for
dealing with templates and for dealing with non-templatized code.
In a non-templatized version, an initialization was performed only for
variables which are not loop variables for an Objective-C loop and not
variables for a C++ for-in loop:
```
if (FRI && (Tok.is(tok::colon) || isTokIdentifier_in())) {
bool IsForRangeLoop = false;
if (TryConsumeToken(tok::colon, FRI->ColonLoc)) {
IsForRangeLoop = true;
if (Tok.is(tok::l_brace))
FRI->RangeExpr = ParseBraceInitializer();
else
FRI->RangeExpr = ParseExpression();
}
Decl *ThisDecl = Actions.ActOnDeclarator(getCurScope(), D);
if (IsForRangeLoop)
Actions.ActOnCXXForRangeDecl(ThisDecl);
Actions.FinalizeDeclaration(ThisDecl);
D.complete(ThisDecl);
return Actions.FinalizeDeclaratorGroup(getCurScope(), DS, ThisDecl);
}
SmallVector<Decl *, 8> DeclsInGroup;
Decl *FirstDecl = ParseDeclarationAfterDeclaratorAndAttributes(
D, ParsedTemplateInfo(), FRI);
```
However the code in SemaTemplateInstantiateDecl was inconsistent,
guarding only against C++ for-in loops.
rdar://38391075
Differential Revision: https://reviews.llvm.org/D44989
llvm-svn: 328749
Summary:
This fixes PR33561 and PR34185.
Don't store pending template instantiations for late-parsed templates in
the normal PendingInstantiations queue. Instead, use a separate list
that will only be parsed and instantiated at end of TU when late
template parsing actually works and doesn't infinite loop.
Reviewers: rsmith, thakis, hans
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D44846
llvm-svn: 328567
Digging through commit logs, it appears the checks in this block predate
`inline` class variables. With them, we fail to emit dynamic
initializers for members that don't have an explicit initializer, and we
won't go out of our way to instantiate the class denoted by
`Var->getType()`.
Fixes PR35599.
llvm-svn: 327945
More generally, this permits a template to be specialized in any scope in which
it could be defined, so this also supersedes DR44 and DR374 (the latter of
which we previously only implemented in C++11 mode onwards due to unclarity as
to whether it was a DR).
llvm-svn: 327705
Use an enum parameter instead of a bool for more control on how the copy elision
functions work. Extract the move initialization code from the move or copy
initialization block.
Patch by: Arthur O'Dwyer
Differential Revision: https://reviews.llvm.org/D43898
llvm-svn: 327598
Summary:
By calling ActOnFinishFunctionBody(). Previously we were only calling
ActOnSkippedFunctionBody, which didn't pop the function scope.
This causes a crash when running on our internal code. No test-case,
though, since I couldn't come up with a small example in reasonable
time.
The bug was introduced in r321174.
Reviewers: bkramer, sammccall, sepavloff, aaron.ballman
Reviewed By: sammccall, aaron.ballman
Subscribers: aaron.ballman, cfe-commits
Differential Revision: https://reviews.llvm.org/D44439
llvm-svn: 327504
template parameter that is an expanded parameter pack, only substitute into the
current slice, not the entire pack.
This reduces the checking of N template template arguments for an expanded
parameter pack containing N parameters from quadratic time to linear time in
the length of the pack. This is important because one (and possibly the only?)
general technique for splitting a template parameter pack in linear time
depends on doing this.
llvm-svn: 326973
The patch fixes a number of bugs related to parameter indexing in
attributes:
* Parameter indices in some attributes (argument_with_type_tag,
pointer_with_type_tag, nonnull, ownership_takes, ownership_holds,
and ownership_returns) are specified in source as one-origin
including any C++ implicit this parameter, were stored as
zero-origin excluding any this parameter, and were erroneously
printing (-ast-print) and confusingly dumping (-ast-dump) as the
stored values.
* For alloc_size, the C++ implicit this parameter was not subtracted
correctly in Sema, leading to assert failures or to silent failures
of __builtin_object_size to compute a value.
* For argument_with_type_tag, pointer_with_type_tag, and
ownership_returns, the C++ implicit this parameter was not added
back to parameter indices in some diagnostics.
This patch fixes the above bugs and aims to prevent similar bugs in
the future by introducing careful mechanisms for handling parameter
indices in attributes. ParamIdx stores a parameter index and is
designed to hide the stored encoding while providing accessors that
require each use (such as printing) to make explicit the encoding that
is needed. Attribute declarations declare parameter index arguments
as [Variadic]ParamIdxArgument, which are exposed as ParamIdx[*]. This
patch rewrites all attribute arguments that are processed by
checkFunctionOrMethodParameterIndex in SemaDeclAttr.cpp to be declared
as [Variadic]ParamIdxArgument. The only exception is xray_log_args's
argument, which is encoded as a count not an index.
Differential Revision: https://reviews.llvm.org/D43248
llvm-svn: 326602
Current implementation of `FunctionDecl::isDefined` does not take into
account redeclarations that do not have bodies, but the bodies can be
instantiated from corresponding templated definition. This behavior does
not allow to detect function redefinition in the cases where friend
functions is defined in class templates. For instance, the code:
```
template<typename T> struct X { friend void f() {} };
X<int> xi;
void f() {}
```
compiles successfully but must fail due to redefinition of `f`. The
declaration of the friend `f` is created when the containing template
`X` is instantiated, but it does not have a body as per 14.5.4p4
because `f` is not odr-used.
With this change the function `Sema::CheckForFunctionRedefinition`
considers functions with uninstantiated bodies as definitions.
Differential Revision: https://reviews.llvm.org/D30170
llvm-svn: 326419
So I wrote a clang-tidy check to lint out redundant `isa`, `cast`, and
`dyn_cast`s for fun. This is a portion of what it found for clang; I
plan to do similar cleanups in LLVM and other subprojects when I find
time.
Because of the volume of changes, I explicitly avoided making any change
that wasn't highly local and obviously correct to me (e.g. we still have
a number of foo(cast<Bar>(baz)) that I didn't touch, since overloading
is a thing and the cast<Bar> did actually change the type -- just up the
class hierarchy).
I also tried to leave the types we were cast<>ing to somewhere nearby,
in cases where it wasn't locally obvious what we were dealing with
before.
llvm-svn: 326416
Summary:
This fixes a flaw in our AST: PR27098
MSVC always gives plain enums the underlying type 'int'. Clang does this
as well, but we claim the enum is "fixed", as if the user actually wrote
': int'. It means we end up emitting spurious -Wsign-compare warnings on
code like this:
enum Vals { E1, E2, E3 };
bool f(unsigned v1, Vals v2) {
return v1 == v2;
}
We think 'v2' can take on negative values because we think 'Vals' is
fixed. This fixes that.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D43110
llvm-svn: 324913
This patch adds a base-class called TemplateInstantiationObserver which gets
notified whenever a template instantiation is entered or exited during
semantic analysis. This is a base class used to implement the template
profiling and debugging tool called
Templight (https://github.com/mikael-s-persson/templight).
The patch also makes a few more changes:
* ActiveTemplateInstantiation class is moved out of the Sema class (so it can be used with inclusion of Sema.h).
* CreateFrontendAction function in front-end utilities is given external linkage (not longer a hidden static function).
* TemplateInstObserverChain data member added to Sema class to hold the list of template-inst observers.
* Notifications to the template-inst observer are added at the key places where templates are instantiated.
Patch by: Abel Sinkovics!
Differential Revision: https://reviews.llvm.org/D5767
llvm-svn: 324808
each kind.
Attribute instantiation would previously default to instantiating each kind of
attribute only once. This was overridden by a flag whose intended purpose was
to permit attributes from a prior declaration to be inherited onto a new
declaration even if that new declaration had its own copy of the attribute.
This is the wrong behavior: when instantiating attributes from a template, we
should always instantiate all the attributes that were written on that
template.
This patch renames the flag in the Attr class (and TableGen sources) to more
clearly identify what it's actually for, and removes the usage of the flag from
template instantiation. I also removed the flag from AlignedAttr, which was
only added to work around the incorrect suppression of duplicate attribute
instantiation.
llvm-svn: 321834
Previously, we would:
* compute the type of the conversion function and static invoker as a
side-effect of template argument deduction for a conversion
* re-compute the type as part of deduced return type deduction when building
the conversion function itself
Neither of these turns out to be quite correct. There are other ways to reach a
declaration of the conversion function than in a conversion (such as an
explicit call or friend declaration), and performing auto deduction causes the
function type to be rebuilt in the context of the lambda closure type (which is
different from the context in which it originally appeared, resulting in
spurious substitution failures for constructs that are valid in one context but
not the other, such as the use of an enclosing class's "this" pointer).
This patch switches us to use a different strategy: as before, we use the
declared type of the operator() to form the type of the conversion function and
invoker, but we now populate that type as part of return type deduction for the
conversion function. And the invoker is now treated as simply being an
implementation detail of building the conversion function, and isn't given
special treatment by template argument deduction for the conversion function
any more.
llvm-svn: 321683
The way to fix an undefined-template warning is to add lines to the header file that defines the template pattern. We should suppress the warnings when the template pattern is in a system header because we don't expect users to edit those.
llvm-svn: 321665
Summary:
Previsouly clang tried instantiating member initializers even if ctor
body was skipped, this caused spurious errors (see the test).
Reviewers: sepavloff, klimek
Reviewed By: sepavloff
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D41492
llvm-svn: 321520
Summary:
- Fixed an assert in Sema::InstantiateFunctionDefinition and added
support for instantiating a function template with skipped body.
- Properly call setHasSkippedBody for FunctionTemplateDecl passed to
Sema::ActOnSkippedFunctionBody.
Reviewers: sepavloff, bkramer
Reviewed By: sepavloff
Subscribers: klimek, cfe-commits
Differential Revision: https://reviews.llvm.org/D41237
llvm-svn: 321174
whether they have an initializer.
We cannot distinguish between a declaration of a variable template
specialization and a definition of one that lacks an initializer without this,
and would previously mistake the latter for the former.
llvm-svn: 319605
In order to identify the copy deduction candidate, I considered two approaches:
- attempt to determine whether an implicit guide is a copy deduction candidate by checking certain properties of its subsituted parameter during overload-resolution.
- using one of the many bits (WillHaveBody) from FunctionDecl (that CXXDeductionGuideDecl inherits from) that are otherwise irrelevant for deduction guides
After some brittle gymnastics w the first strategy, I settled on the second, although to avoid confusion and to give that bit a better name, i turned it into a member of an anonymous union.
Given this identification 'bit', the tweak to overload resolution was a simple reordering of the deduction guide checks (in SemaOverload.cpp::isBetterOverloadCandidate), in-line with Jason Merrill's p0620r0 drafting which made it into the working paper. Concordant with that, I made sure the copy deduction candidate is always added.
References:
See https://bugs.llvm.org/show_bug.cgi?id=34970
See http://wg21.link/p0620r0
llvm-svn: 316292
instantiation declarations if they are usable from constant expressions.
We are permitted to instantiate in these cases, and required to do so in order
to have an initializer available for use within constant evaluation.
llvm-svn: 316136
When declaring an entity in the "purview" of a module, it's never a
redeclaration of an entity in the purview of a default module or in no module
("in the global module"). Don't consider those other declarations as possible
redeclaration targets if they're not visible, and reject any cases where we
pick a prior visible declaration that violates this rule.
This reinstates r315251 and r315256, reverted in r315309 and r315308
respectively, tweaked to avoid triggering a linkage calculation when declaring
implicit special members (this exposed our pre-existing issue with typedef
names for linkage changing the linkage of types whose linkage has already been
computed and cached in more cases). A testcase for that regression has been
added in r315366.
llvm-svn: 315379
When declaring an entity in the "purview" of a module, it's never a
redeclaration of an entity in the purview of a default module or in no module
("in the global module"). Don't consider those other declarations as possible
redeclaration targets if they're not visible, and reject any cases where we
pick a prior visible declaration that violates this rule.
llvm-svn: 315251
This implements the proposed approach in https://github.com/itanium-cxx-abi/cxx-abi/issues/33
This reinstates r313827, reverted in r313856, with a fix for the 'out-of-bounds
enumeration value' ubsan error in that change.
llvm-svn: 313955
move constructor.
Previously user-defined reduction initializer was considered as an
assignment expression, not as initializer. Fixed this by treating the
initializer expression as an initializer.
llvm-svn: 312638
the class becoming complete and its inline methods being parsed.
This replaces the hack of using the "late parsed template" flag to track member
functions with bodies we've not parsed yet; instead we now use the "will have
body" flag, which carries the desired implication that the function declaration
*is* a definition, and that we've just not parsed its body yet.
llvm-svn: 310776
declarations that are owned but unconditionally visible.
This allows us to set declarations as visible even if they have a local owning
module, without losing information. In turn, that means that our Objective-C
support can keep on incorrectly assuming the "hidden" bit on the declaration is
the whole story with regard to name visibility. This will also be useful once
we support the C++ Modules TS export semantics.
Objective-C name visibility is still incorrect in any case where the "hidden"
bit is not the complete story: for instance, in Objective-C++ the set of
visible categories will be wrong during template instantiation, and with local
submodule visibility enabled it will be wrong when building modules. Fixing that
will require a major overhaul of how visibility is handled for Objective-C (and
particularly for categories).
llvm-svn: 306075
While a function body is being parsed, the function declaration is not considered
as a definition because it does not have a body yet. In some cases it leads to
incorrect interpretation, the case is presented in
https://bugs.llvm.org/show_bug.cgi?id=14785:
```
template<typename T> struct Somewhat {
void internal() const {}
friend void operator+(int const &, Somewhat<T> const &) {}
};
void operator+(int const &, Somewhat<char> const &x) { x.internal(); }
```
When statement `x.internal()` in the body of global `operator+` is parsed, the type
of `x` must be completed, so the instantiation of `Somewhat<char>` is started. It
instantiates the declaration of `operator+` defined inline, and makes a check for
redefinition. The check does not detect another definition because the declaration
of `operator+` is still not defining as does not have a body yet.
To solves this problem the function `isThisDeclarationADefinition` considers
a function declaration as a definition if it has flag `WillHaveBody` set.
This change fixes PR14785.
Differential Revision: https://reviews.llvm.org/D30375
This is a recommit of 305379, reverted in 305381, with small changes.
llvm-svn: 305903