Summary:
1. Coroutine cannot be constexpr (added a check in SemaLambda.cpp not to mark coroutine as constexpr)
2. TransformCoroutineBodyStmt should transform ResultDecl and ReturnStmt
Reviewers: rsmith, GorNishanov
Reviewed By: GorNishanov
Subscribers: EricWF, cfe-commits
Differential Revision: https://reviews.llvm.org/D33498
llvm-svn: 303764
lambda capture used by the created block
The commit r288866 introduced guaranteed copy elision to C++ 17. This
unfortunately broke the lambda to block conversion in C++17 (the compiler
crashes when performing IRGen). This commit fixes the conversion by avoiding
copy elision for the capture that captures the lambda that's used in the block
created by the lambda to block conversion process.
rdar://31385153
Differential Revision: https://reviews.llvm.org/D31669
llvm-svn: 299646
- also replace direct equality checks against the ConstantEvaluated enumerator with isConstantEvaluted(), in anticipation of adding finer granularity to the various ConstantEvaluated contexts and reinstating certain restrictions on where lambda expressions can occur in C++17.
- update the clang tablegen backend that uses these Enumerators, and add the relevant scope where needed.
llvm-svn: 299316
Summary:
Don't warn about unused lambda captures that involve copying a
value of a type that cannot be trivially copied and destroyed.
Fixes PR31977
Reviewers: rsmith, aaron.ballman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D30327
llvm-svn: 296602
instantiation.
In preparation for converting the template stack to a more general context
stack (so we can include context notes for other kinds of context).
llvm-svn: 295686
Summary:
Warn when a lambda explicitly captures something that is not used in its body.
The warning is part of -Wunused and can be enabled with -Wunused-lambda-capture.
Reviewers: rsmith, arphaman, jbcoe, aaron.ballman
Subscribers: Quuxplusone, arphaman, cfe-commits
Differential Revision: https://reviews.llvm.org/D28467
llvm-svn: 291905
This patch has been sitting in review hell since july 2016 and our lack of constexpr lambda support is getting embarrassing (given that I've had a branch that implements the feature (modulo *this capture) for over a year. While in Issaquah I was enjoying shamelessly trying to convince folks of the lie that this was Richard's fault ;) I won't be able to do so in Kona since I won't be attending - so I'm going to aim to have this feature be implemented by then.
I'm quite confident of the approach in this patch, which simply maps the static-invoker 'thunk' back to the corresponding call-operator (specialization).
Thanks!
llvm-svn: 291397
This implements something like the current direction of DR1581: we use a narrow
syntactic check to determine the set of places where a constant expression
could be evaluated, and only instantiate a constexpr function or variable if
it's referenced in one of those contexts, or is odr-used.
It's not yet clear whether this is the right set of syntactic locations; we
currently consider all contexts within templates that would result in odr-uses
after instantiation, and contexts within list-initialization (narrowing
conversions take another victim...), as requiring instantiation. We could in
principle restrict the former cases more (only const integral / reference
variable initializers, and contexts in which a constant expression is required,
perhaps). However, this is sufficient to allow us to accept libstdc++ code,
which relies on GCC's behavior (which appears to be somewhat similar to this
approach).
llvm-svn: 291318
copy constructors of classes with array members, instead using
ArrayInitLoopExpr to represent the initialization loop.
This exposed a bug in the static analyzer where it was unable to differentiate
between zero-initialized and unknown array values, which has also been fixed
here.
llvm-svn: 289618
Reworked fix after comments from Richard Smith. We must skip all
CapturedDecl-based contexts when trying to get correct mangling number
context.
llvm-svn: 286953
Clang emits error message for the following code:
```
template <class F> void parallel_loop(F &&f) { f(0); }
int main() {
int x;
parallel_loop([&](auto y) {
{
x = y;
};
});
}
```
$ clang++ --std=gnu++14 clang_test.cc -o clang_test
clang_test.cc:9:7: error: reference to local variable 'x' declared in enclosing function 'main'
x = y;
^
clang_test.cc:2:48: note: in instantiation of function template specialization 'main()::(anonymous class)::operator()<int>' requested here
template <class F> void parallel_loop(F &&f) { f(0); }
^
clang_test.cc:6:3: note: in instantiation of function template specialization 'parallel_loop<(lambda at clang_test.cc:6:17)>' requested here parallel_loop([&](auto y) {
^
clang_test.cc:5:7: note: 'x' declared here
int x;
^
1 error generated.
Patch fixes this issue.
llvm-svn: 286584
aren't captured by lambdas with a default capture specifier
This commit is a follow-up to r286354. It avoids the -Wshadow warning for
variables which shadow variables that aren't captured by lambdas with a default
capture specifier. It provides an additional note that points to location of
the capture.
The old behaviour is preserved with -Wshadow-all or -Wshadow-uncaptured-local.
rdar://14984176
Differential Revision: https://reviews.llvm.org/D26448
llvm-svn: 286465
There was a bug in the implementation of captured statements. If it has
a lambda expression in it and the same lambda expression is used outside
the captured region, clang produced an error:
```
error: definition with same mangled name as another definition
```
Here is an example:
```
struct A {
template <typename L>
void g(const L&) { }
};
template<typename T>
void f() {
{
A().g([](){});
}
A().g([](){});
}
int main() {
f<void>();
}
```
Error report:
```
main.cpp:3:10: error: definition with same mangled name as another
definition
void g(const L&) { }
^
main.cpp:3:10: note: previous definition is here
```
Patch fixes this bug.
llvm-svn: 284229
I'm told that some optimizers like lambdas a lot more than mem_fn.
Given that the readability difference is basically nil, and we seem to
use lambdas basically everywhere else, it seems sensible to just use
lambdas.
llvm-svn: 276577
Summary:
Space for storing the //constraint-expression// of the
//requires-clause// associated with a `TemplateParameterList` is
arranged by taking a bit out of the `NumParams` field for the purpose
of determining whether there is a //requires-clause// or not, and by
adding to the trailing objects tied to the `TemplateParameterList`. An
accessor is provided.
An appropriate argument is supplied to `TemplateParameterList::Create`
at the various call sites.
Serialization changes will addressed as the Concepts implementation
becomes more solid.
Drive-by fix:
This change also replaces the custom
`FixedSizeTemplateParameterListStorage` implementation with one that
follows the interface provided by `llvm::TrailingObjects`.
Reviewers: aaron.ballman, faisalv, rsmith
Subscribers: cfe-commits, nwilson
Differential Revision: https://reviews.llvm.org/D19322
llvm-svn: 276069
These ExprWithCleanups are added for holding a RunCleanupsScope not
for destructor calls; rather, they are for lifetime marks. This requires
ExprWithCleanups to keep a bit to indicate whether it have cleanups with
side effects (e.g. dtor calls).
Differential Revision: http://reviews.llvm.org/D20498
llvm-svn: 272296
if we are parsing a template specialization.
This commit makes changes to clear the TemplateParamScope bit and set
the TemplateParamParent field of the current scope to null if a template
specialization is being parsed.
Before this commit, Sema::ActOnStartOfLambdaDefinition would check
whether the parent template scope had any decls to determine whether
or not a template specialization was being parsed. This wasn't correct
since it couldn't distinguish between a real template specialization and
a template defintion with an unnamed template parameter (only template
parameters with names are added to the scope's decl list). To fix the
bug, this commit changes the code to check the pointer to the parent
template scope rather than the decl list.
rdar://problem/23440346
Differential Revision: http://reviews.llvm.org/D19175
llvm-svn: 267975
Support the constexpr specifier on lambda expressions - and support its inference from the lambda call operator's body.
i.e.
auto L = [] () constexpr { return 5; };
static_assert(L() == 5); // OK
auto Implicit = [] (auto a) { return a; };
static_assert(Implicit(5) == 5);
We do not support evaluation of lambda's within constant expressions just yet.
Implementation Strategy:
- teach ParseLambdaExpressionAfterIntroducer to expect a constexpr specifier and mark the invented function call operator's declarator's decl-specifier with it; Have it emit fixits for multiple decl-specifiers (mutable or constexpr) in this location.
- for cases where constexpr is not explicitly specified, have buildLambdaExpr check whether the invented function call operator satisfies the requirements of a constexpr function, by calling CheckConstexprFunctionDecl/Body.
Much obliged to Richard Smith for his patience and his care, in ensuring the code is clang-worthy.
llvm-svn: 264513
lambda-expression. We don't actually instantiate the closure type / operator()
in the template in order to produce the closure type / operator() in the
instantiation, so this isn't caught by the normal path.
llvm-svn: 264184
Implement lambda capture of *this by copy.
For e.g.:
struct A {
int d = 10;
auto foo() { return [*this] (auto a) mutable { d+=a; return d; }; }
};
auto L = A{}.foo(); // A{}'s lifetime is gone.
// Below is still ok, because *this was captured by value.
assert(L(10) == 20);
assert(L(100) == 120);
If the capture was implicit, or [this] (i.e. *this was captured by reference), this code would be otherwise undefined.
Implementation Strategy:
- amend the parser to accept *this in the lambda introducer
- add a new king of capture LCK_StarThis
- teach Sema::CheckCXXThisCapture to handle by copy captures of the
enclosing object (i.e. *this)
- when CheckCXXThisCapture does capture by copy, the corresponding
initializer expression for the closure's data member
direct-initializes it thus making a copy of '*this'.
- in codegen, when assigning to CXXThisValue, if *this was captured by
copy, make sure it points to the corresponding field member, and
not, unlike when captured by reference, what the field member points
to.
- mark feature as implemented in svn
Much gratitude to Richard Smith for his carefully illuminating reviews!
llvm-svn: 263921
C++14 generic lambdas. It conflicts with the C++14 return type deduction
mechanism, and results in us failing to actually deduce the lambda's return
type in some cases.
llvm-svn: 259609
`pass_object_size` is our way of enabling `__builtin_object_size` to
produce high quality results without requiring inlining to happen
everywhere.
A link to the design doc for this attribute is available at the
Differential review link below.
Differential Revision: http://reviews.llvm.org/D13263
llvm-svn: 254554
std::initializer_list<T> type. Instead, the list must contain a single element
and the type is deduced from that.
In Clang 3.7, we warned by default on all the cases that would change meaning
due to this change. In Clang 3.8, we will support only the new rules -- per
the request in N3922, this change is applied as a Defect Report against earlier
versions of the C++ standard.
This change is not entirely trivial, because for lambda init-captures we
previously did not track the difference between direct-list-initialization and
copy-list-initialization. The difference was not previously observable, because
the two forms of initialization always did the same thing (the elements of the
initializer list were always copy-initialized regardless of the initialization
style used for the init-capture).
llvm-svn: 252688
Objective-C ARC lifetime qualifiers are dropped when canonicalizing
function types. Perform the same adjustment before comparing the
deduced result types of lambdas. Fixes rdar://problem/22344904.
llvm-svn: 249065
Previously we'd try to perform checks on the captures from the middle of
parsing the lambda's body, at the point where we detected that a variable
needed to be captured. This was wrong in a number of subtle ways. In
PR23334, we couldn't correctly handle the list of potential odr-uses
resulting from the capture, and our attempt to recover from that resulted
in a use-after-free.
We now defer building the initialization expression until we leave the lambda
body and return to the enclosing context, where the initialization does the
right thing. This patch only covers lambda-expressions, but we should apply
the same change to blocks and captured statements too.
llvm-svn: 235921
Update the test cases to pass when lambda call operators use thiscall.
Update the lambda-to-block conversion operator to use the default free
function calling convention instead of the call operator's convention.
This reverts commit r233082 and re-instates r233023.
llvm-svn: 233835
Changes diagnostic options, language standard options, diagnostic identifiers, diagnostic wording to use c++14 instead of c++1y. It also modifies related test cases to use the updated diagnostic wording.
llvm-svn: 215982
DR18 previously forebode typedefs to be used as parameter types if they
were of type 'void'. DR577 allows 'void' to be used as a function
parameter type regardless from where it came.
llvm-svn: 201631
A return type is the declared or deduced part of the function type specified in
the declaration.
A result type is the (potentially adjusted) type of the value of an expression
that calls the function.
Rule of thumb:
* Declarations have return types and parameters.
* Expressions have result types and arguments.
llvm-svn: 200082
Fix a perennial source of confusion in the clang type system: Declarations and
function prototypes have parameters to which arguments are supplied, so calling
these 'arguments' was a stretch even in C mode, let alone C++ where default
arguments, templates and overloading make the distinction important to get
right.
Readability win across the board, especially in the casting, ADL and
overloading implementations which make a lot more sense at a glance now.
Will keep an eye on the builders and update dependent projects shortly.
No functional change.
llvm-svn: 199686
encodes the canonical rules for LLVM's style. I noticed this had drifted
quite a bit when cleaning up LLVM, so wanted to clean up Clang as well.
llvm-svn: 198686
Add back the test that was triggering the assertion (which I removed mistakenly thinking it was triggering just a warning and not an assertion). My error was brought to my attention by Rafael (Thanks!).
llvm-svn: 196721
Employed the following refactorings:
- Renamed some functions
- Introduced explaining variables
- Cleaned up & added comments
- Used Optional<unsigned> for return value instead of an out parameter
- Added assertions
- Constified a few member functions
No functionality change.
All regressions pass.
llvm-svn: 196662
For an init capture, process the initialization expression
right away. For lambda init-captures such as the following:
const int x = 10;
auto L = [i = x+1](int a) {
return [j = x+2,
&k = x](char b) { };
};
keep in mind that each lambda init-capture has to have:
- its initialization expression executed in the context
of the enclosing/parent decl-context.
- but the variable itself has to be 'injected' into the
decl-context of its lambda's call-operator (which has
not yet been created).
Each init-expression is a full-expression that has to get
Sema-analyzed (for capturing etc.) before its lambda's
call-operator's decl-context, scope & scopeinfo are pushed on their
respective stacks. Thus if any variable is odr-used in the init-capture
it will correctly get captured in the enclosing lambda, if one exists.
The init-variables above are created later once the lambdascope and
call-operators decl-context is pushed onto its respective stack.
Since the lambda init-capture's initializer expression occurs in the
context of the enclosing function or lambda, therefore we can not wait
till a lambda scope has been pushed on before deciding whether the
variable needs to be captured. We also need to process all
lvalue-to-rvalue conversions and discarded-value conversions,
so that we can avoid capturing certain constant variables.
For e.g.,
void test() {
const int x = 10;
auto L = [&z = x](char a) { <-- don't capture by the current lambda
return [y = x](int i) { <-- don't capture by enclosing lambda
return y;
}
};
If x was not const, the second use would require 'L' to capture, and
that would be an error.
Make sure TranformLambdaExpr is also aware of this.
Patch approved by Richard (Thanks!!)
http://llvm-reviews.chandlerc.com/D2092
llvm-svn: 196454
Both Richard and I felt that the current wording in the working paper needed some tweaking - Please see http://llvm-reviews.chandlerc.com/D2035 for additional context and references to core-reflector messages that discuss wording tweaks.
What is implemented is what we had intended to specify in Bristol; but, recently felt that the specification might benefit from some tweaking and fleshing.
As a rough attempt to explain the semantics: If a nested lambda with a default-capture names a variable within its body, and if the enclosing full expression that contains the name of that variable is instantiation-dependent - then an enclosing lambda that is capture-ready (i.e. within a non-dependent context) must capture that variable, if all intervening nested lambdas can potentially capture that variable if they need to, and all intervening parent lambdas of the capture-ready lambda can and do capture the variable.
Of note, 'this' capturing is also currently underspecified in the working paper for generic lambdas. What is implemented here is if the set of candidate functions in a nested generic lambda includes both static and non-static member functions (regardless of viability checking - i.e. num and type of parameters/arguments) - and if all intervening nested-inner lambdas between the capture-ready lambda and the function-call containing nested lambda can capture 'this' and if all enclosing lambdas of the capture-ready lambda can capture 'this', then 'this' is speculatively captured by that capture-ready lambda.
Hopefully a paper for the C++ committee (that Richard and I had started some preliminary work on) is forthcoming.
This essentially makes generic lambdas feature complete, except for known bugs. The more prominent ones (and the ones I am currently aware of) being:
- generic lambdas and init-captures are broken - but a patch that fixes this is already in the works ...
- nested variadic expansions such as:
auto K = [](auto ... OuterArgs) {
vp([=](auto ... Is) {
decltype(OuterArgs) OA = OuterArgs;
return 0;
}(5)...);
return 0;
};
auto M = K('a', ' ', 1, " -- ", 3.14);
currently cause crashes. I think I know how to fix this (since I had done so in my initial implementation) - but it will probably take some work and back & forth with Doug and Richard.
A warm thanks to all who provided feedback - and especially to Doug Gregor and Richard Smith for their pivotal guidance: their insight and prestidigitation in such matters is boundless!
Now let's hope this commit doesn't upset the buildbot gods ;)
Thanks!
llvm-svn: 194188
This patch fixes the typelocs of the conversion-operator and the conversion-operator-name and adds the parameters of the call operator to the FunctionProtoTypeLoc of the respective entities. Thus, when the template declarations (conversion operators) undergo deduction and instantiation/transformation/substitution - they add themselves to the local instantiation scope if needed.
This patch supports the following:
auto L = [](auto b) {
return [](auto a) ->decltype(a) { return a; };
};
int (*fp)(int) = L(8);
Richard LGTM'd this patch: http://llvm-reviews.chandlerc.com/D1831
Thanks!
llvm-svn: 193294
A prior commit of this patch was reverted because it was within the blamelist's purview of a failing test. The failure of that test has been addressed here: http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20131021/091546.html. Therefore I am recommitting this patch (all tests pass on windows, except for the usual modules & index suspects that never pass on my box).
Some background: Both Doug and Richard had asked me in Chicago to remove the circular reference in CXXRecordDecl to LambdaExpr by factoring out and storing the needed information from LambdaExpr directly into CXXRecordDecl.
In addition, I have added an IsGenericLambda flag - this makes life a little easier when we implement capturing, and are Sema-analyzing the body of a lambda (and the calloperator hasn't been wired to the closure class yet). Any inner lambdas can have potential captures that could require walking up the scope chain and checking if any generic lambdas are capture-ready. This 'bit' makes some of that checking easier.
No change in functionality.
This patch was approved by Doug with minor modifications (comments were cleaned up, and all data members were converted from bool/enum to unsigned, as requested):
http://llvm-reviews.chandlerc.com/D1856
Thanks!
llvm-svn: 193246
They were causing CodeGenCXX/mangle-exprs.cpp to fail.
Revert "Remove the circular reference to LambdaExpr in CXXRecordDecl."
Revert "Again: Teach TreeTransform and family how to transform generic lambdas nested within templates and themselves."
llvm-svn: 193226
Both Doug and Richard had asked me to remove the circular reference in CXXRecordDecl to LambdaExpr by factoring out and storing the needed information from LambdaExpr directly into CXXRecordDecl.
No change in functionality.
In addition, I have added an IsGenericLambda flag - this makes life a little easier when we implement capturing, and are Sema-analyzing the body of a lambda (and the calloperator hasn't been wired to the closure class yet). Any inner lambdas can have potential captures that could require walking up the scope chain and checking if any generic lambdas are capture-ready. This 'bit' makes some of that checking easier.
This patch was approved by Doug with minor modifications (comments were cleaned up, and all data members were converted from bool/enum to unsigned, as requested):
http://llvm-reviews.chandlerc.com/D1856
Thanks!
llvm-svn: 193223
The general strategy is to create template versions of the conversion function and static invoker and then during template argument deduction of the conversion function, create the corresponding call-operator and static invoker specializations, and when the conversion function is marked referenced generate the body of the conversion function using the corresponding static-invoker specialization. Similarly, Codegen does something similar - when asked to emit the IR for a specialized static invoker of a generic lambda, it forwards emission to the corresponding call operator.
This patch has been reviewed in person both by Doug and Richard. Richard gave me the LGTM.
A few minor changes:
- per Richard's request i added a simple check to gracefully inform that captures (init, explicit or default) have not been added to generic lambdas just yet (instead of the assertion violation).
- I removed a few lines of code that added the call operators instantiated parameters to the currentinstantiationscope. Not only did it not handle parameter packs, but it is more relevant in the patch for nested lambdas which will follow this one, and fix that problem more comprehensively.
- Doug had commented that the original implementation strategy of using the TypeSourceInfo of the call operator to create the static-invoker was flawed and allowed const as a member qualifier to creep into the type of the static-invoker. I currently kludge around it - but after my initial discussion with Doug, with a follow up session with Richard, I have added a FIXME so that a more elegant solution that involves the use of TrivialTypeSourceInfo call followed by the correct wiring of the template parameters to the functionprototypeloc is forthcoming.
Thanks!
llvm-svn: 191634
putting them in the call operator's DeclContext. This better matches the
language wording and avoids some cases where code gets confused by them for
namespace-scope lambdas and the like.
llvm-svn: 191606
Specifically, the following features are not included in this commit:
- any sort of capturing within generic lambdas
- generic lambdas within template functions and nested
within other generic lambdas
- conversion operator for captureless lambdas
- ensuring all visitors are generic lambda aware
(Although I have gotten some useful feedback on my patches of the above and will be incorporating that as I submit those patches for commit)
As an example of what compiles through this commit:
template <class F1, class F2>
struct overload : F1, F2 {
using F1::operator();
using F2::operator();
overload(F1 f1, F2 f2) : F1(f1), F2(f2) { }
};
auto Recursive = [](auto Self, auto h, auto ... rest) {
return 1 + Self(Self, rest...);
};
auto Base = [](auto Self, auto h) {
return 1;
};
overload<decltype(Base), decltype(Recursive)> O(Base, Recursive);
int num_params = O(O, 5, 3, "abc", 3.14, 'a');
Please see attached tests for more examples.
This patch has been reviewed by Doug and Richard. Minor changes (non-functionality affecting) have been made since both of them formally looked at it, but the changes involve removal of supernumerary return type deduction changes (since they are now redundant, with richard having committed a recent patch to address return type deduction for C++11 lambdas using C++14 semantics).
Some implementation notes:
- Add a new Declarator context => LambdaExprParameterContext to
clang::Declarator to allow the use of 'auto' in declaring generic
lambda parameters
- Add various helpers to CXXRecordDecl to facilitate identifying
and querying a closure class
- LambdaScopeInfo (which maintains the current lambda's Sema state)
was augmented to house the current depth of the template being
parsed (id est the Parser calls Sema::RecordParsingTemplateParameterDepth)
so that SemaType.cpp::ConvertDeclSpecToType may use it to immediately
generate a template-parameter-type when 'auto' is parsed in a generic
lambda parameter context. (i.e we do NOT use AutoType deduced to
a template parameter type - Richard seemed ok with this approach).
We encode that this template type was generated from an auto by simply
adding $auto to the name which can be used for better diagnostics if needed.
- SemaLambda.h was added to hold some common lambda utility
functions (this file is likely to grow ...)
- Teach Sema::ActOnStartOfFunctionDef to check whether it
is being called to instantiate a generic lambda's call
operator, and if so, push an appropriately prepared
LambdaScopeInfo object on the stack.
- various tests were added - but much more will be needed.
There is obviously more work to be done, and both Richard (weakly) and Doug (strongly)
have requested that LambdaExpr be removed form the CXXRecordDecl LambdaDefinitionaData
in a future patch which is forthcoming.
A greatful thanks to all reviewers including Eli Friedman, James Dennett,
and especially the two gracious wizards (Richard Smith and Doug Gregor)
who spent hours providing feedback (in person in Chicago and on the mailing lists).
And yet I am certain that I have allowed unidentified bugs to creep in; bugs, that I will do my best to slay, once identified!
Thanks!
llvm-svn: 191453
Static locals requiring initialization are not thread safe on Windows.
Unfortunately, it's possible to create static locals that are actually
externally visible with inline functions and templates. As a result, we
have to implement an initialization guard scheme that is compatible with
TUs built by MSVC, which makes thread safety prohibitively difficult.
MSVC's scheme is that every function that requires a guard gets an i32
bitfield. Each static local is assigned a bit that indicates if it has
been initialized, up to 32 bits, at which point a new bitfield is
created. MSVC rejects inline functions with more than 32 static locals,
and the externally visible mangling (?_B) only allows for one guard
variable per function.
On Eli's recommendation, I used MangleNumberingContext to track which
bit each static corresponds to.
Implements PR16888.
Reviewers: rjmccall, eli.friedman
Differential Revision: http://llvm-reviews.chandlerc.com/D1416
llvm-svn: 190427
When an AST file is built based on another AST file, it can use a decl from
the fist file, and therefore mark the "isUsed" bit. We need to note this in
the AST file so that the bit is set correctly when the second AST file is
loaded.
This patch introduces the distinction between setIsUsed() and markUsed() so
that we don't call into the ASTMutationListener callback when it wouldn't
be appropriate.
Fixes PR16635.
llvm-svn: 190016
Summary:
Makes functions with implicit calling convention compatible with
function types with a matching explicit calling convention. This fixes
things like calls to qsort(), which has an explicit __cdecl attribute on
the comparator in Windows headers.
Clang will now infer the calling convention from the declarator. There
are two cases when the CC must be adjusted during redeclaration:
1. When defining a non-inline static method.
2. When redeclaring a function with an implicit or mismatched
convention.
Fixes PR13457, and allows clang to compile CommandLine.cpp for the
Microsoft C++ ABI.
Excellent test cases provided by Alexander Zinenko!
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D1231
llvm-svn: 189412
Specifically, the following features are not included in this commit:
- any sort of capturing within generic lambdas
- nested lambdas
- conversion operator for captureless lambdas
- ensuring all visitors are generic lambda aware
As an example of what compiles:
template <class F1, class F2>
struct overload : F1, F2 {
using F1::operator();
using F2::operator();
overload(F1 f1, F2 f2) : F1(f1), F2(f2) { }
};
auto Recursive = [](auto Self, auto h, auto ... rest) {
return 1 + Self(Self, rest...);
};
auto Base = [](auto Self, auto h) {
return 1;
};
overload<decltype(Base), decltype(Recursive)> O(Base, Recursive);
int num_params = O(O, 5, 3, "abc", 3.14, 'a');
Please see attached tests for more examples.
Some implementation notes:
- Add a new Declarator context => LambdaExprParameterContext to
clang::Declarator to allow the use of 'auto' in declaring generic
lambda parameters
- Augment AutoType's constructor (similar to how variadic
template-type-parameters ala TemplateTypeParmDecl are implemented) to
accept an IsParameterPack to encode a generic lambda parameter pack.
- Add various helpers to CXXRecordDecl to facilitate identifying
and querying a closure class
- LambdaScopeInfo (which maintains the current lambda's Sema state)
was augmented to house the current depth of the template being
parsed (id est the Parser calls Sema::RecordParsingTemplateParameterDepth)
so that Sema::ActOnLambdaAutoParameter may use it to create the
appropriate list of corresponding TemplateTypeParmDecl for each
auto parameter identified within the generic lambda (also stored
within the current LambdaScopeInfo). Additionally,
a TemplateParameterList data-member was added to hold the invented
TemplateParameterList AST node which will be much more useful
once we teach TreeTransform how to transform generic lambdas.
- SemaLambda.h was added to hold some common lambda utility
functions (this file is likely to grow ...)
- Teach Sema::ActOnStartOfFunctionDef to check whether it
is being called to instantiate a generic lambda's call
operator, and if so, push an appropriately prepared
LambdaScopeInfo object on the stack.
- Teach Sema::ActOnStartOfLambdaDefinition to set the
return type of a lambda without a trailing return type
to 'auto' in C++1y mode, and teach the return type
deduction machinery in SemaStmt.cpp to process either
C++11 and C++14 lambda's correctly depending on the flag.
- various tests were added - but much more will be needed.
A greatful thanks to all reviewers including Eli Friedman,
James Dennett and the ever illuminating Richard Smith. And
yet I am certain that I have allowed unidentified bugs to creep in;
bugs, that I will do my best to slay, once identified!
Thanks!
llvm-svn: 188977
Summary:
Source-centric tools need access to the location of a C++11
lambda expression's capture-default ('&' or '=') when it's present.
It's possible for them to find it by re-lexing and re-implementing
rules that Clang's parser has already applied, but the cost of storing
the SourceLocation and making it available to them is 32 bits per
LambdaExpr (a small delta, proportionally), and the simplification in
client code is significant.
Reviewers: rsmith
Reviewed By: rsmith
CC: cfe-commits, klimek, revane
Differential Revision: http://llvm-reviews.chandlerc.com/D1192
llvm-svn: 188121
Compute mangling numbers for externally visible local variables and tags.
Change the mangler to consistently use discriminators where necessary.
Tweak the scheme we use to number decls which are not externally visible
to avoid unnecessary discriminators in common cases now that we request
them more consistently.
Fixes <rdar://problem/14204721>.
llvm-svn: 185986
Blocks, like lambdas, can be written in contexts which are required to be
treated as the same under ODR. Unlike lambdas, it isn't possible to actually
take the address of a block, so the mangling of the block itself doesn't
matter. However, objects like static variables inside a block do need to
be mangled in a consistent way.
There are basically three components here. One, block literals need a
consistent numbering. Two, objects/types inside a block literal need
to be mangled using it. Three, objects/types inside a block literal need
to have their linkage computed correctly.
llvm-svn: 185372
Hiroshi Inoue