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[Sema] Add some basic lambda capture fix-its 

Adds fix-its when users forget to explicitly capture variables or this in lambdas

Addresses https://github.com/clangd/clangd/issues/697

Reviewed By: kbobyrev

Differential Revision: https://reviews.llvm.org/D96975
This commit is contained in:
Nathan James 2021-03-11 13:46:24 +00:00
parent 46354bac76
commit cb559c8d5e
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GPG Key ID: CC007AFCDA90AA5F
13 changed files with 211 additions and 78 deletions
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6
clang/include/clang/Basic/DiagnosticSemaKinds.td
View File

@ -7462,6 +7462,8 @@ let CategoryName = "Lambda Issue" in {
"duration">;
def err_this_capture : Error<
"'this' cannot be %select{implicitly |}0captured in this context">;
def note_lambda_this_capture_fixit : Note<
"explicitly capture 'this'">;
def err_lambda_capture_anonymous_var : Error<
"unnamed variable cannot be implicitly captured in a lambda expression">;
def err_lambda_capture_flexarray_type : Error<
@ -7470,6 +7472,10 @@ let CategoryName = "Lambda Issue" in {
def err_lambda_impcap : Error<
"variable %0 cannot be implicitly captured in a lambda with no "
"capture-default specified">;
def note_lambda_variable_capture_fixit : Note<
"capture %0 by %select{value|reference}1">;
def note_lambda_default_capture_fixit : Note<
"default capture by %select{value|reference}0">;
def note_lambda_decl : Note<"lambda expression begins here">;
def err_lambda_unevaluated_operand : Error<
"lambda expression in an unevaluated operand">;

111
clang/lib/Sema/SemaExpr.cpp
View File

@ -46,6 +46,7 @@
#include "clang/Sema/SemaFixItUtils.h"
#include "clang/Sema/SemaInternal.h"
#include "clang/Sema/Template.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/ConvertUTF.h"
#include "llvm/Support/SaveAndRestore.h"
using namespace clang;
@ -17431,6 +17432,107 @@ static bool captureInLambda(LambdaScopeInfo *LSI,
return !Invalid;
}
static bool canCaptureVariableByCopy(VarDecl *Var, const ASTContext &Context) {
// Offer a Copy fix even if the type is dependent.
if (Var->getType()->isDependentType())
return true;
QualType T = Var->getType().getNonReferenceType();
if (T.isTriviallyCopyableType(Context))
return true;
if (CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
if (!(RD = RD->getDefinition()))
return false;
if (RD->hasSimpleCopyConstructor())
return true;
if (RD->hasUserDeclaredCopyConstructor())
for (CXXConstructorDecl *Ctor : RD->ctors())
if (Ctor->isCopyConstructor())
return !Ctor->isDeleted();
}
return false;
}
/// Create up to 4 fix-its for explicit reference and value capture of \p Var or
/// default capture. Fixes may be omitted if they aren't allowed by the
/// standard, for example we can't emit a default copy capture fix-it if we
/// already explicitly copy capture capture another variable.
static void buildLambdaCaptureFixit(Sema &Sema, LambdaScopeInfo *LSI,
VarDecl *Var) {
assert(LSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_None);
// Don't offer Capture by copy of default capture by copy fixes if Var is
// known not to be copy constructible.
bool ShouldOfferCopyFix = canCaptureVariableByCopy(Var, Sema.getASTContext());
SmallString<32> FixBuffer;
StringRef Separator = LSI->NumExplicitCaptures > 0 ? ", " : "";
if (Var->getDeclName().isIdentifier() && !Var->getName().empty()) {
SourceLocation VarInsertLoc = LSI->IntroducerRange.getEnd();
if (ShouldOfferCopyFix) {
// Offer fixes to insert an explicit capture for the variable.
// [] -> [VarName]
// [OtherCapture] -> [OtherCapture, VarName]
FixBuffer.assign({Separator, Var->getName()});
Sema.Diag(VarInsertLoc, diag::note_lambda_variable_capture_fixit)
<< Var << /*value*/ 0
<< FixItHint::CreateInsertion(VarInsertLoc, FixBuffer);
}
// As above but capture by reference.
FixBuffer.assign({Separator, "&", Var->getName()});
Sema.Diag(VarInsertLoc, diag::note_lambda_variable_capture_fixit)
<< Var << /*reference*/ 1
<< FixItHint::CreateInsertion(VarInsertLoc, FixBuffer);
}
// Only try to offer default capture if there are no captures excluding this
// and init captures.
// [this]: OK.
// [X = Y]: OK.
// [&A, &B]: Don't offer.
// [A, B]: Don't offer.
if (llvm::any_of(LSI->Captures, [](Capture &C) {
return !C.isThisCapture() && !C.isInitCapture();
}))
return;
// The default capture specifiers, '=' or '&', must appear first in the
// capture body.
SourceLocation DefaultInsertLoc =
LSI->IntroducerRange.getBegin().getLocWithOffset(1);
if (ShouldOfferCopyFix) {
bool CanDefaultCopyCapture = true;
// [=, *this] OK since c++17
// [=, this] OK since c++20
if (LSI->isCXXThisCaptured() && !Sema.getLangOpts().CPlusPlus20)
CanDefaultCopyCapture = Sema.getLangOpts().CPlusPlus17
? LSI->getCXXThisCapture().isCopyCapture()
: false;
// We can't use default capture by copy if any captures already specified
// capture by copy.
if (CanDefaultCopyCapture && llvm::none_of(LSI->Captures, [](Capture &C) {
return !C.isThisCapture() && !C.isInitCapture() && C.isCopyCapture();
})) {
FixBuffer.assign({"=", Separator});
Sema.Diag(DefaultInsertLoc, diag::note_lambda_default_capture_fixit)
<< /*value*/ 0
<< FixItHint::CreateInsertion(DefaultInsertLoc, FixBuffer);
}
}
// We can't use default capture by reference if any captures already specified
// capture by reference.
if (llvm::none_of(LSI->Captures, [](Capture &C) {
return !C.isInitCapture() && C.isReferenceCapture() &&
!C.isThisCapture();
})) {
FixBuffer.assign({"&", Separator});
Sema.Diag(DefaultInsertLoc, diag::note_lambda_default_capture_fixit)
<< /*reference*/ 1
<< FixItHint::CreateInsertion(DefaultInsertLoc, FixBuffer);
}
}
bool Sema::tryCaptureVariable(
VarDecl *Var, SourceLocation ExprLoc, TryCaptureKind Kind,
SourceLocation EllipsisLoc, bool BuildAndDiagnose, QualType &CaptureType,
@ -17520,6 +17622,7 @@ bool Sema::tryCaptureVariable(
Diag(ExprLoc, diag::err_lambda_impcap) << Var;
Diag(Var->getLocation(), diag::note_previous_decl) << Var;
Diag(LSI->Lambda->getBeginLoc(), diag::note_lambda_decl);
buildLambdaCaptureFixit(*this, LSI, Var);
} else
diagnoseUncapturableValueReference(*this, ExprLoc, Var, DC);
}
@ -17598,9 +17701,11 @@ bool Sema::tryCaptureVariable(
if (BuildAndDiagnose) {
Diag(ExprLoc, diag::err_lambda_impcap) << Var;
Diag(Var->getLocation(), diag::note_previous_decl) << Var;
if (cast<LambdaScopeInfo>(CSI)->Lambda)
Diag(cast<LambdaScopeInfo>(CSI)->Lambda->getBeginLoc(),
diag::note_lambda_decl);
auto *LSI = cast<LambdaScopeInfo>(CSI);
if (LSI->Lambda) {
Diag(LSI->Lambda->getBeginLoc(), diag::note_lambda_decl);
buildLambdaCaptureFixit(*this, LSI, Var);
}
// FIXME: If we error out because an outer lambda can not implicitly
// capture a variable that an inner lambda explicitly captures, we
// should have the inner lambda do the explicit capture - because

20
clang/lib/Sema/SemaExprCXX.cpp
View File

@ -1226,6 +1226,18 @@ Sema::CXXThisScopeRAII::~CXXThisScopeRAII() {
}
}
static void buildLambdaThisCaptureFixit(Sema &Sema, LambdaScopeInfo *LSI) {
SourceLocation DiagLoc = LSI->IntroducerRange.getEnd();
assert(!LSI->isCXXThisCaptured());
// [=, this] {}; // until C++20: Error: this when = is the default
if (LSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByval &&
!Sema.getLangOpts().CPlusPlus20)
return;
Sema.Diag(DiagLoc, diag::note_lambda_this_capture_fixit)
<< FixItHint::CreateInsertion(
DiagLoc, LSI->NumExplicitCaptures > 0 ? ", this" : "this");
}
bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
bool BuildAndDiagnose, const unsigned *const FunctionScopeIndexToStopAt,
const bool ByCopy) {
@ -1274,9 +1286,12 @@ bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
LambdaScopeInfo *LSI = dyn_cast<LambdaScopeInfo>(CSI);
if (LSI && isGenericLambdaCallOperatorSpecialization(LSI->CallOperator)) {
// This context can't implicitly capture 'this'; fail out.
if (BuildAndDiagnose)
if (BuildAndDiagnose) {
Diag(Loc, diag::err_this_capture)
<< (Explicit && idx == MaxFunctionScopesIndex);
if (!Explicit)
buildLambdaThisCaptureFixit(*this, LSI);
}
return true;
}
if (CSI->ImpCaptureStyle == CapturingScopeInfo::ImpCap_LambdaByref ||
@ -1296,6 +1311,9 @@ bool Sema::CheckCXXThisCapture(SourceLocation Loc, const bool Explicit,
if (BuildAndDiagnose)
Diag(Loc, diag::err_this_capture)
<< (Explicit && idx == MaxFunctionScopesIndex);
if (!Explicit)
buildLambdaThisCaptureFixit(*this, LSI);
return true;
}
break;

2
clang/test/CXX/drs/dr6xx.cpp
View File

@ -1153,7 +1153,7 @@ namespace dr696 { // dr696: yes
};
#if __cplusplus >= 201103L
(void) [] { int arr[N]; (void)arr; };
(void) [] { f(&N); }; // expected-error {{cannot be implicitly captured}} expected-note {{here}}
(void)[] { f(&N); }; // expected-error {{cannot be implicitly captured}} expected-note {{here}} expected-note 2 {{capture 'N' by}} expected-note 2 {{default capture by}}
#endif
}
}

4
clang/test/CXX/expr/expr.prim/expr.prim.lambda/p12.cpp
View File

@ -42,7 +42,7 @@ void immediately_enclosing(int i) { // expected-note{{'i' declared here}}
[i] {}();
}();
[]() { // expected-note{{lambda expression begins here}}
[]() { // expected-note{{lambda expression begins here}} expected-note 2 {{capture 'i' by}} expected-note 2 {{default capture by}}
[i] {}(); // expected-error{{variable 'i' cannot be implicitly captured in a lambda with no capture-default specified}}
}();
}
@ -64,7 +64,7 @@ void f1(int i) { // expected-note{{declared here}}
void work(int n) { // expected-note{{declared here}}
int m = n*n;
int j = 40; // expected-note{{declared here}}
auto m3 = [this,m] { // expected-note 3{{lambda expression begins here}}
auto m3 = [this, m] { // expected-note 3{{lambda expression begins here}} expected-note 2 {{capture 'i' by}} expected-note 2 {{capture 'j' by}} expected-note 2 {{capture 'n' by}}
auto m4 = [&,j] { // expected-error{{variable 'j' cannot be implicitly captured in a lambda with no capture-default specified}}
int x = n; // expected-error{{variable 'n' cannot be implicitly captured in a lambda with no capture-default specified}}
x += m;

6
clang/test/CXX/expr/expr.prim/expr.prim.lambda/p2-generic-lambda-1y.cpp
View File

@ -19,7 +19,9 @@ void unevaluated_operand(P &p, int i) { //expected-note{{declared here}}
int i2 = sizeof([](auto a, auto b)->void{}(3, '4')); // expected-error{{lambda expression in an unevaluated operand}} \
// expected-error{{invalid application of 'sizeof'}}
const std::type_info &ti1 = typeid([](auto &a) -> P& { static P p; return p; }(i)); // expected-warning {{expression with side effects will be evaluated despite being used as an operand to 'typeid'}}
const std::type_info &ti2 = typeid([](auto) -> int { return i; }(i)); // expected-error{{lambda expression in an unevaluated operand}}\
const std::type_info &ti2 = typeid([](auto) -> int { return i; }(i)); // expected-error{{lambda expression in an unevaluated operand}}\
// expected-error{{cannot be implicitly captured}}\
// expected-note{{begins here}}
// expected-note{{begins here}}\
// expected-note 2 {{capture 'i' by}}\
// expected-note 2 {{default capture by}}
}

88
clang/test/SemaCXX/cxx1y-generic-lambdas-capturing.cpp
View File

@ -1,7 +1,7 @@
// RUN: %clang_cc1 -std=c++1y -verify -fsyntax-only -fblocks -emit-llvm-only %s
// RUN: %clang_cc1 -std=c++2a -verify -fsyntax-only -fblocks -emit-llvm-only %s
// RUN: %clang_cc1 -std=c++2a -verify -verify=expected-cxx2a -fsyntax-only -fblocks -emit-llvm-only %s
// RUN: %clang_cc1 -std=c++1y -verify -fsyntax-only -fblocks -emit-llvm-only -triple i386-windows-pc %s
// RUN: %clang_cc1 -std=c++2a -verify -fsyntax-only -fblocks -emit-llvm-only -triple i386-windows-pc %s
// RUN: %clang_cc1 -std=c++2a -verify -verify=expected-cxx2a -fsyntax-only -fblocks -emit-llvm-only -triple i386-windows-pc %s
// DONTRUNYET: %clang_cc1 -std=c++1y -verify -fsyntax-only -fblocks -fdelayed-template-parsing %s -DDELAYED_TEMPLATE_PARSING
// DONTRUNYET: %clang_cc1 -std=c++1y -verify -fsyntax-only -fblocks -fms-extensions %s -DMS_EXTENSIONS
// DONTRUNYET: %clang_cc1 -std=c++1y -verify -fsyntax-only -fblocks -fdelayed-template-parsing -fms-extensions %s -DMS_EXTENSIONS -DDELAYED_TEMPLATE_PARSING
@ -77,13 +77,14 @@ void doit() {
{
int a; //expected-note{{declared here}}
auto B = []() { return ^{ return a; }; }; //expected-error{{cannot be implicitly capture}}\
//expected-note{{begins here}}
//expected-note{{begins here}}\
//expected-note 2 {{capture 'a' by}}\
//expected-note 2 {{default capture by}}
//[](){ return ({int b = 5; return 'c'; 'x';}); };
//auto X = ^{ return a; };
//auto Y = []() -> auto { return 3; return 'c'; };
}
}
}
@ -102,7 +103,7 @@ void doit() {
}
{
// should not capture 'x' - even though certain instantiations require
auto L = [](auto a) { //expected-note{{begins here}}
auto L = [](auto a) { //expected-note{{begins here}} expected-note 2 {{capture 'x' by}} expected-note 2 {{default capture by}}
DEFINE_SELECTOR(a);
F_CALL(x, a); //expected-error{{'x' cannot be implicitly captured}}
};
@ -137,7 +138,7 @@ void doit() {
}
{
int j = 0; //expected-note{{declared}}
auto L = [](auto a) { //expected-note{{begins here}}
auto L = [](auto a) { //expected-note{{begins here}} expected-note 2 {{capture 'j' by}} expected-note 2 {{default capture by}}
return j + 1; //expected-error{{cannot be implicitly captured}}
};
}
@ -366,10 +367,10 @@ template<class T> struct Y {
T t2{t};
return [](auto b) {
const int y = 0; //expected-note{{declared here}}
return [](auto c) { //expected-note 2{{lambda expression begins here}}
return [](auto c) { //expected-note 2{{lambda expression begins here}} expected-note 2 {{capture 'x' by}} expected-note 2 {{capture 'y' by}} expected-note 4 {{default capture by}}
f(x, c); //expected-error{{variable 'x'}}
f(y, c); //expected-error{{variable 'y'}}
return 0;
return 0;
};
};
};
@ -530,7 +531,7 @@ struct X {
L(3.13);
}
{
auto L = [](auto a) {
auto L = [](auto a) { // expected-note {{explicitly capture 'this'}}
f(a); //expected-error{{this}}
};
L(3.13);
@ -561,8 +562,8 @@ struct X {
static void f(double) { }
int g() {
auto L = [=](auto a) {
return [](int i) {
auto L = [=](auto a) {
return [](int i) { // expected-note {{explicitly capture 'this'}}
return [=](auto b) {
f(decltype(a){}); //expected-error{{this}}
int x = i;
@ -585,8 +586,8 @@ struct X {
static void f(double) { }
int g() {
auto L = [=](auto a) {
return [](auto b) {
auto L = [=](auto a) {
return [](auto b) { // expected-note {{explicitly capture 'this'}}
return [=](int i) {
f(b);
f(decltype(a){}); //expected-error{{this}}
@ -609,8 +610,8 @@ struct X {
static void f(double) { }
int g() {
auto L = [=](auto a) {
return [](auto b) {
auto L = [=](auto a) {
return [](auto b) { // expected-note {{explicitly capture 'this'}}
return [=](int i) {
f(b); //expected-error{{this}}
f(decltype(a){});
@ -632,9 +633,9 @@ struct X {
static void f(double) { }
int g() {
auto L = [=](auto a) {
auto L = [=](auto a) {
return [](int i) {
return [=](auto b) {
return [=](auto b) { // expected-cxx2a-note {{explicitly capture 'this'}}
f(b); //expected-error{{'this' cannot}}
int x = i;
};
@ -655,8 +656,8 @@ int foo()
{ // This variable is used and must be caught early, do not need instantiation
const int x = 0; //expected-note{{declared}}
auto L = [](auto a) { //expected-note{{begins}}
const int &r = x; //expected-error{{variable}}
auto L = [](auto a) { //expected-note{{begins}} expected-note 2 {{capture 'x' by}} expected-note 2 {{default capture by}}
const int &r = x; //expected-error{{variable}}
};
}
{ // This variable is not used
@ -670,7 +671,7 @@ int foo()
const int x = 0; //expected-note{{declared}}
auto L = [=](auto a) { // <-- #A
const int y = 0;
return [](auto b) { //expected-note{{begins}}
return [](auto b) { //expected-note{{begins}} expected-note 2 {{capture 'x' by}} expected-note 2 {{default capture by}}
int c[sizeof(b)];
f(x, c);
f(y, c);
@ -716,7 +717,7 @@ int foo() {
int x;
auto L = [](auto a) { //expected-note {{declared here}}
int y = 10; //expected-note {{declared here}}
return [](int b) { //expected-note 2{{expression begins here}}
return [](int b) { //expected-note 2{{expression begins here}} expected-note 2 {{capture 'a' by}} expected-note 2 {{capture 'y' by}} expected-note 4 {{default capture by}}
return [=] (auto c) {
return a + y; //expected-error 2{{cannot be implicitly captured}}
};
@ -908,7 +909,7 @@ struct X {
return 0;
}
int g2() {
auto lam = [](auto a) { f(a); }; // expected-error{{'this'}}
auto lam = [](auto a) { f(a); }; // expected-error{{'this'}} expected-note {{explicitly capture 'this'}}
lam(0); // expected-note{{in instantiation of}}
lam(0.0); // ok.
return 0;
@ -941,9 +942,10 @@ template<class T> struct YUnresolvable {
template<class T> struct YUnresolvable2 {
void f(int) { }
static void f(double) { }
T t = [](auto a) { f(a); return a; }; //expected-error{{'this'}} \
//expected-note{{in instantiation of}}
//expected-note{{in instantiation of}}\
//expected-note {{explicitly capture 'this'}}
T t2 = [=](auto b) { f(b); return b; };
};
@ -961,8 +963,8 @@ template<class T> struct YOnlyStatic {
YOnlyStatic<FunctorDouble> yos;
template<class T> struct YOnlyNonStatic {
void f(int) { }
T t = [](auto a) { f(a); return a; }; //expected-error{{'this'}}
T t = [](auto a) { f(a); return a; }; //expected-error{{'this'}} expected-note {{explicitly capture 'this'}}
};
@ -980,8 +982,8 @@ struct FunctorInt {
template<class T> struct YThisCapture {
const int x = 10;
static double d;
T t = [](auto a) { return x; }; //expected-error{{'this'}}
static double d;
T t = [](auto a) { return x; }; //expected-error{{'this'}} expected-note {{explicitly capture 'this'}}
T t2 = [](auto b) { return d; };
T t3 = [this](auto a) {
return [=](auto b) {
@ -993,10 +995,10 @@ template<class T> struct YThisCapture {
return x;
};
};
T t5 = [](auto a) {
return [=](auto b) {
return x; //expected-error{{'this'}}
};
T t5 = [](auto a) { // expected-note {{explicitly capture 'this'}}
return [=](auto b) {
return x; //expected-error{{'this'}}
};
};
};
@ -1020,8 +1022,8 @@ template void foo(int); //expected-note{{in instantiation of}}
#else
template<class T> void foo(T t) { //expected-note{{declared here}}
auto L = []() //expected-note{{begins here}}
{ return t; }; //expected-error{{cannot be implicitly captured}}
auto L = []() //expected-note{{begins here}} expected-note 2 {{capture 't' by}} expected-note 2 {{default capture by}}
{ return t; }; //expected-error{{cannot be implicitly captured}}
}
#endif
@ -1049,9 +1051,9 @@ struct X {
void f(double) { }
int g() {
auto L = [=](auto a) { f(a); };
L(0);
auto L2 = [](auto a) { f(a); }; //expected-error {{cannot be implicitly captured}}
auto L = [=](auto a) { f(a); };
L(0);
auto L2 = [](auto a) { f(a); }; //expected-error {{cannot be implicitly captured}} expected-note {{explicitly capture 'this'}}
return 0;
}
};
@ -1080,7 +1082,7 @@ struct X {
static void f(double) { }
template<class T>
int g(T t) {
auto L = [](auto a) { f(a); }; //expected-error{{'this'}}
auto L = [](auto a) { f(a); }; //expected-error{{'this'}} expected-note {{explicitly capture 'this'}}
L(t); // expected-note{{in instantiation of}}
return 0;
}
@ -1099,7 +1101,7 @@ struct X {
void f(int) { }
template<class T>
int g(T t) {
auto L = [](auto a) { f(a); }; //expected-error{{'this'}}
auto L = [](auto a) { f(a); }; //expected-error{{'this'}} expected-note {{explicitly capture 'this'}}
L(t);
return 0;
}
@ -1209,9 +1211,9 @@ struct X {
static void f(double) { }
int g() {
auto L = [=](auto a) {
auto L = [=](auto a) {
return [](int i) {
return [=](auto b) {
return [=](auto b) { // expected-cxx2a-note {{explicitly capture 'this'}}
f(b); //expected-error {{'this' cannot}}
int x = i;
};
@ -1235,9 +1237,9 @@ struct X {
static void f(double) { }
int g() {
auto L = [](auto a) {
auto L = [](auto a) {
return [=](auto i) {
return [=](auto b) {
return [=](auto b) { // expected-cxx2a-note {{explicitly capture 'this'}}
f(b); //expected-error {{'this' cannot}}
int x = i;
};

2
clang/test/SemaCXX/cxx1y-generic-lambdas.cpp
View File

@ -258,7 +258,7 @@ int test() {
{
int i = 10; //expected-note 3{{declared here}}
auto L = [](auto a) {
return [](auto b) { //expected-note 3{{begins here}}
return [](auto b) { //expected-note 3{{begins here}} expected-note 6 {{capture 'i' by}} expected-note 6 {{default capture by}}
i = b; //expected-error 3{{cannot be implicitly captured}}
return b;
};

15
clang/test/SemaCXX/cxx1y-init-captures.cpp
View File

@ -21,10 +21,10 @@ namespace variadic_expansion {
return a;
}() ...);
};
auto N2 = [x = y, //expected-note3{{begins here}}
auto N2 = [x = y, //expected-note3{{begins here}} expected-note 6 {{default capture by}}
&z = y, n = f(t...),
o = f([&a(t)](T& ... t)->decltype(auto) { return a; }(t...)...)](T& ... s) {
fv([&a(t)]()->decltype(auto) { //expected-error 3{{captured}}
o = f([&a(t)](T& ... t)->decltype(auto) { return a; }(t...)...)](T& ... s) { // expected-note 6 {{capture 't' by}}
fv([&a(t)]()->decltype(auto) { //expected-error 3{{captured}}
return a;
}() ...);
};
@ -57,8 +57,8 @@ int test() {
}
{
const int x = 10;
auto L = [k = x](char a) { //expected-note {{declared}}
return [](int b) { //expected-note {{begins}}
auto L = [k = x](char a) { //expected-note {{declared}}
return [](int b) { //expected-note {{begins}} expected-note 2 {{capture 'k' by}} expected-note 2 {{default capture by}}
return [j = k](int c) { //expected-error {{cannot be implicitly captured}}
return c;
};
@ -117,13 +117,12 @@ int test(T t = T{}) {
}
{ // will need to capture x in outer lambda
const T x = 10; //expected-note {{declared}}
auto L = [z = x](char a) { //expected-note {{begins}}
auto L = [z = x](char a) { //expected-note {{begins}} expected-note 2 {{capture 'x' by}} expected-note 2 {{default capture by}}
auto M = [&y = x](T b) { //expected-error {{cannot be implicitly captured}}
return y;
};
return M;
};
}
{ // will need to capture x in outer lambda
const T x = 10;
@ -146,7 +145,7 @@ int test(T t = T{}) {
}
{ // will need to capture x in outer lambda
const int x = 10; //expected-note {{declared}}
auto L = [z = x](char a) { //expected-note {{begins}}
auto L = [z = x](char a) { //expected-note {{begins}} expected-note 2 {{capture 'x' by}} expected-note 2 {{default capture by}}
auto M = [&y = x](T b) { //expected-error {{cannot be implicitly captured}}
return y;
};

2
clang/test/SemaCXX/cxx1z-constexpr-lambdas.cpp
View File

@ -93,7 +93,7 @@ void f() {
}
void f(char c) { //expected-note{{declared here}}
auto L = [] { return c; }; //expected-error{{cannot be implicitly captured}} expected-note{{lambda expression begins here}}
auto L = [] { return c; }; //expected-error{{cannot be implicitly captured}} expected-note{{lambda expression begins here}} expected-note 2 {{capture 'c' by}} expected-note 2 {{default capture by}}
int I = L();
}

29
clang/test/SemaCXX/lambda-expressions.cpp
View File

@ -12,17 +12,17 @@ namespace ExplicitCapture {
virtual C& Overload(float);
void ImplicitThisCapture() {
[](){(void)Member;}; // expected-error {{'this' cannot be implicitly captured in this context}}
const int var = [](){(void)Member; return 0;}(); // expected-error {{'this' cannot be implicitly captured in this context}}
[]() { (void)Member; }; // expected-error {{'this' cannot be implicitly captured in this context}} expected-note {{explicitly capture 'this'}}
const int var = []() {(void)Member; return 0; }(); // expected-error {{'this' cannot be implicitly captured in this context}} expected-note {{explicitly capture 'this'}}
[&](){(void)Member;};
[this](){(void)Member;};
[this]{[this]{};};
[]{[this]{};};// expected-error {{'this' cannot be implicitly captured in this context}}
[]{Overload(3);};
[]{Overload();}; // expected-error {{'this' cannot be implicitly captured in this context}}
[] { Overload(); }; // expected-error {{'this' cannot be implicitly captured in this context}} expected-note {{explicitly capture 'this'}}
[]{(void)typeid(Overload());};
[]{(void)typeid(Overload(.5f));};// expected-error {{'this' cannot be implicitly captured in this context}}
[] { (void)typeid(Overload(.5f)); }; // expected-error {{'this' cannot be implicitly captured in this context}} expected-note {{explicitly capture 'this'}}
}
};
@ -47,14 +47,14 @@ namespace ReturnDeduction {
namespace ImplicitCapture {
void test() {
int a = 0; // expected-note 5 {{declared}}
[]() { return a; }; // expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{begins here}}
[]() { return a; }; // expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{begins here}} expected-note 2 {{capture 'a' by}} expected-note 2 {{default capture by}}
[&]() { return a; };
[=]() { return a; };
[=]() { int* b = &a; }; // expected-error {{cannot initialize a variable of type 'int *' with an rvalue of type 'const int *'}}
[=]() { return [&]() { return a; }; };
[]() { return [&]() { return a; }; }; // expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
[]() { return ^{ return a; }; };// expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
[]() { return [&a] { return a; }; }; // expected-error 2 {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note 2 {{lambda expression begins here}}
[]() { return [&]() { return a; }; }; // expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}} expected-note 2 {{capture 'a' by}} expected-note 2 {{default capture by}}
[]() { return ^{ return a; }; };// expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}} expected-note 2 {{capture 'a' by}} expected-note 2 {{default capture by}}
[]() { return [&a] { return a; }; }; // expected-error 2 {{variable 'a' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note 2 {{lambda expression begins here}} expected-note 4 {{capture 'a' by}} expected-note 4 {{default capture by}}
[=]() { return [&a] { return a; }; }; //
const int b = 2;
@ -74,7 +74,7 @@ namespace ImplicitCapture {
int f[10]; // expected-note {{declared}}
[&]() { return f[2]; };
(void) ^{ return []() { return f[2]; }; }; // expected-error {{variable 'f' cannot be implicitly captured in a lambda with no capture-default specified}} \
// expected-note{{lambda expression begins here}}
// expected-note{{lambda expression begins here}} expected-note 2 {{capture 'f' by}} expected-note 2 {{default capture by}}
struct G { G(); G(G&); int a; }; // expected-note 6 {{not viable}}
G g;
@ -83,13 +83,13 @@ namespace ImplicitCapture {
(void)^{ return [=]{ const G* gg = &g; return gg->a; }(); }; // expected-error 2 {{no matching constructor for initialization of 'const G'}}
const int h = a; // expected-note {{declared}}
[]() { return h; }; // expected-error {{variable 'h' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
[]() { return h; }; // expected-error {{variable 'h' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}} expected-note 2 {{capture 'h' by}} expected-note 2 {{default capture by}}
// References can appear in constant expressions if they are initialized by
// reference constant expressions.
int i;
int &ref_i = i; // expected-note {{declared}}
[] { return ref_i; }; // expected-error {{variable 'ref_i' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}}
[] { return ref_i; }; // expected-error {{variable 'ref_i' cannot be implicitly captured in a lambda with no capture-default specified}} expected-note {{lambda expression begins here}} expected-note 2 {{capture 'ref_i' by}} expected-note 2 {{default capture by}}
static int j;
int &ref_j = j;
@ -259,7 +259,8 @@ namespace VariadicPackExpansion {
// instantiation backtrace.
f([&ts] { return (int)f(ts...); } ()...); // \
// expected-error 2{{'ts' cannot be implicitly captured}} \
// expected-note 2{{lambda expression begins here}}
// expected-note 2{{lambda expression begins here}} \
// expected-note 4 {{capture 'ts' by}}
}
template void nested2(int); // ok
template void nested2(int, int); // expected-note {{in instantiation of}}
@ -375,7 +376,7 @@ namespace PR18128 {
int a = [=]{ return n; }(); // ok
int b = [=]{ return [=]{ return n; }(); }(); // ok
int c = []{ int k = 0; return [=]{ return k; }(); }(); // ok
int d = []{ return [=]{ return n; }(); }(); // expected-error {{'this' cannot be implicitly captured in this context}}
int d = [] { return [=] { return n; }(); }(); // expected-error {{'this' cannot be implicitly captured in this context}} expected-note {{explicitly capture 'this'}}
};
}
@ -661,6 +662,6 @@ void Test() {
};
[] { return i; }; // expected-error {{variable '' cannot be implicitly captured in a lambda with no capture-default specified}}
// expected-note@-1 {{lambda expression begins here}}
// expected-note@-2 2 {{default capture by}}
}
};

2
clang/test/SemaCXX/lambda-invalid-capture.cpp
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@ -18,7 +18,7 @@ void captures_invalid_array_type() {
}
int pr43080(int i) { // expected-note {{declared here}}
return [] { // expected-note {{begins here}}
return [] { // expected-note {{begins here}} expected-note 2 {{capture 'i' by}} expected-note 2 {{default capture by}}
return sizeof i <
i; // expected-error {{variable 'i' cannot be implicitly captured in a lambda with no capture-default specified}}
}();

2
clang/test/SemaObjCXX/capturing-flexible-array-in-block.mm
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@ -5,5 +5,5 @@ void f() {
struct { int x; int y[]; } a; // expected-note 3 {{'a' declared here}}
^{return a.x;}(); // expected-error {{cannot refer to declaration of structure variable with flexible array member inside block}}
[=] {return a.x;}(); // expected-error {{variable 'a' with flexible array member cannot be captured in a lambda expression}}
[] {return a.x;}(); // expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default}} expected-note {{here}}
[] {return a.x;}(); // expected-error {{variable 'a' cannot be implicitly captured in a lambda with no capture-default}} expected-note {{here}} expected-note 2 {{capture 'a' by}} expected-note 2 {{default capture by}}
}