[clang] 0f5dbfd - Revert D123909 "[Clang] Use of decltype(capture) in parameter-declaration-clause"
Fangrui Song via cfe-commits
cfe-commits at lists.llvm.org
Wed Apr 20 10:32:48 PDT 2022
Author: Fangrui Song
Date: 2022-04-20T10:32:41-07:00
New Revision: 0f5dbfd29ae0df215a01aff80d29255bb799fed0
URL: https://github.com/llvm/llvm-project/commit/0f5dbfd29ae0df215a01aff80d29255bb799fed0
DIFF: https://github.com/llvm/llvm-project/commit/0f5dbfd29ae0df215a01aff80d29255bb799fed0.diff
LOG: Revert D123909 "[Clang] Use of decltype(capture) in parameter-declaration-clause"
This reverts commit daa6d7b250edb81ffef7770a71049d7af211698b.
It breaks valid code like https://reviews.llvm.org/D123909#3461716
Added:
Modified:
clang/docs/ReleaseNotes.rst
clang/include/clang/Parse/Parser.h
clang/include/clang/Sema/Sema.h
clang/lib/Parse/ParseDeclCXX.cpp
clang/lib/Parse/ParseExprCXX.cpp
clang/lib/Sema/SemaExpr.cpp
clang/test/SemaCXX/lambda-capture-type-deduction.cpp
Removed:
################################################################################
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 600185e3ddd84..eccbfa2daf27c 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -281,8 +281,6 @@ C++2b Feature Support
- Implemented `P2036R3: Change scope of lambda trailing-return-type <https://wg21.link/P2036R3>`_.
This proposal modifies how variables captured in lambdas can appear in trailing return type
expressions and how their types are deduced therein, in all C++ language versions.
- `CWG2569 <https://cplusplus.github.io/CWG/issues/2569.html>`_ is also partially implemented so that
- `[x](decltype(x)){}` doesn't become ill-formed with the adoption of P2036R3.
CUDA Language Changes in Clang
------------------------------
diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
index e9b1fa0f27451..3046962dddec4 100644
--- a/clang/include/clang/Parse/Parser.h
+++ b/clang/include/clang/Parse/Parser.h
@@ -1861,8 +1861,6 @@ class Parser : public CodeCompletionHandler {
Token &Replacement);
ExprResult ParseCXXIdExpression(bool isAddressOfOperand = false);
- ExprResult ParseCXXMaybeMutableAgnosticExpression();
-
bool areTokensAdjacent(const Token &A, const Token &B);
void CheckForTemplateAndDigraph(Token &Next, ParsedType ObjectTypePtr,
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 6298838d60855..a1eb22da0f5e2 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -787,23 +787,6 @@ class Sema final {
/// context.
unsigned FunctionScopesStart = 0;
- /// Whether we are currently in the context of a mutable agnostic identifier
- /// as described by CWG2569.
- /// We are handling the unqualified-id of a decltype or noexcept expression.
- bool InMutableAgnosticContext = false;
-
- /// RAII object used to change the value of \c InMutableAgnosticContext
- /// within a \c Sema object.
- class MutableAgnosticContextRAII {
- Sema &SemaRef;
-
- public:
- MutableAgnosticContextRAII(Sema &S) : SemaRef(S) {
- SemaRef.InMutableAgnosticContext = true;
- }
- ~MutableAgnosticContextRAII() { SemaRef.InMutableAgnosticContext = false; }
- };
-
ArrayRef<sema::FunctionScopeInfo*> getFunctionScopes() const {
return llvm::makeArrayRef(FunctionScopes.begin() + FunctionScopesStart,
FunctionScopes.end());
@@ -5287,9 +5270,6 @@ class Sema final {
CorrectionCandidateCallback *CCC = nullptr,
bool IsInlineAsmIdentifier = false, Token *KeywordReplacement = nullptr);
- ExprResult ActOnMutableAgnosticIdExpression(Scope *S, CXXScopeSpec &SS,
- UnqualifiedId &Id);
-
void DecomposeUnqualifiedId(const UnqualifiedId &Id,
TemplateArgumentListInfo &Buffer,
DeclarationNameInfo &NameInfo,
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index e367417410c86..9cf9f7cc4c371 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -1054,7 +1054,7 @@ SourceLocation Parser::ParseDecltypeSpecifier(DeclSpec &DS) {
Actions, Sema::ExpressionEvaluationContext::Unevaluated, nullptr,
Sema::ExpressionEvaluationContextRecord::EK_Decltype);
Result = Actions.CorrectDelayedTyposInExpr(
- ParseCXXMaybeMutableAgnosticExpression(), /*InitDecl=*/nullptr,
+ ParseExpression(), /*InitDecl=*/nullptr,
/*RecoverUncorrectedTypos=*/false,
[](Expr *E) { return E->hasPlaceholderType() ? ExprError() : E; });
if (Result.isInvalid()) {
diff --git a/clang/lib/Parse/ParseExprCXX.cpp b/clang/lib/Parse/ParseExprCXX.cpp
index 336b24942e07d..b03d4e3a90acb 100644
--- a/clang/lib/Parse/ParseExprCXX.cpp
+++ b/clang/lib/Parse/ParseExprCXX.cpp
@@ -685,34 +685,6 @@ ExprResult Parser::ParseCXXIdExpression(bool isAddressOfOperand) {
return Result;
}
-/// ParseCXXMaybeMutableAgnosticExpression - Handle expressions inside of
-/// sizeof, decltype, noexcept
-/// - unqualified-id
-/// - expression
-/// This serves to silence errors about captured variable referred in lambda
-/// parameter list, if they are used as the unqualified-id of a decltype,
-/// sizeof, or noexcept expression.
-ExprResult Parser::ParseCXXMaybeMutableAgnosticExpression() {
-
- if (!getLangOpts().CPlusPlus11)
- return ParseExpression();
-
- if (Tok.is(tok::identifier) && NextToken().is(tok::r_paren)) {
- UnqualifiedId Name;
- CXXScopeSpec SS;
- if (ParseUnqualifiedId(SS, /*ObjectType=*/nullptr,
- /*ObjectHadErrors=*/false,
- /*EnteringContext=*/false,
- /*AllowDestructorName=*/false,
- /*AllowConstructorName=*/false,
- /*AllowDeductionGuide=*/false,
- /*TemplateKWLoc=*/nullptr, Name))
- return ExprError();
- return Actions.ActOnMutableAgnosticIdExpression(getCurScope(), SS, Name);
- }
- return ParseExpression();
-}
-
/// ParseLambdaExpression - Parse a C++11 lambda expression.
///
/// lambda-expression:
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 59c1123749f54..7fbe083571e67 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -2699,18 +2699,6 @@ Sema::ActOnIdExpression(Scope *S, CXXScopeSpec &SS,
return BuildDeclarationNameExpr(SS, R, ADL);
}
-ExprResult Sema::ActOnMutableAgnosticIdExpression(Scope *S, CXXScopeSpec &SS,
- UnqualifiedId &Id) {
- MutableAgnosticContextRAII Ctx(*this);
- return ActOnIdExpression(S, SS, /*TemplateKwLoc*/
- SourceLocation(), Id,
- /*HasTrailingLParen*/ false,
- /*IsAddressOfOperand*/ false,
- /*CorrectionCandidateCallback*/ nullptr,
- /*IsInlineAsmIdentifier*/ false,
- /*KeywordReplacement*/ nullptr);
-}
-
/// BuildQualifiedDeclarationNameExpr - Build a C++ qualified
/// declaration name, generally during template instantiation.
/// There's a large number of things which don't need to be done along
@@ -18561,11 +18549,6 @@ static void buildLambdaCaptureFixit(Sema &Sema, LambdaScopeInfo *LSI,
static bool CheckCaptureUseBeforeLambdaQualifiers(Sema &S, VarDecl *Var,
SourceLocation ExprLoc,
LambdaScopeInfo *LSI) {
-
- // Allow `[a = 1](decltype(a)) {}` as per CWG2569.
- if (S.InMutableAgnosticContext)
- return true;
-
if (Var->isInvalidDecl())
return false;
@@ -18648,7 +18631,7 @@ bool Sema::tryCaptureVariable(
LSI = dyn_cast_or_null<LambdaScopeInfo>(
FunctionScopes[FunctionScopesIndex]);
if (LSI && LSI->BeforeLambdaQualifiersScope) {
- if (isa<ParmVarDecl>(Var) && !Var->getDeclContext()->isFunctionOrMethod())
+ if (isa<ParmVarDecl>(Var))
return true;
IsInLambdaBeforeQualifiers = true;
if (!CheckCaptureUseBeforeLambdaQualifiers(*this, Var, ExprLoc, LSI)) {
diff --git a/clang/test/SemaCXX/lambda-capture-type-deduction.cpp b/clang/test/SemaCXX/lambda-capture-type-deduction.cpp
index ee5d872071cb7..90b26787ba313 100644
--- a/clang/test/SemaCXX/lambda-capture-type-deduction.cpp
+++ b/clang/test/SemaCXX/lambda-capture-type-deduction.cpp
@@ -87,23 +87,23 @@ void err() {
int y, z; // expected-note 2{{declared here}}
auto implicit_tpl = [=]( // expected-note {{variable 'y' is captured here}}
decltype(
- [&]<decltype((y))> { return 0; }) y) { // expected-error{{captured variable 'y' cannot appear here}}
+ [&]<decltype(y)> { return 0; }) y) { //expected-error{{captured variable 'y' cannot appear here}}
return y;
};
- auto init_tpl = [x = 1]( // expected-note{{explicitly captured here}}
- decltype([&]<decltype((x))> { return 0; }) y) { // expected-error {{captured variable 'x' cannot appear here}}
+ auto init_tpl = [x = 1]( // expected-note{{explicitly captured here}}
+ decltype([&]<decltype(x)> { return 0; }) y) { // expected-error {{captured variable 'x' cannot appear here}}
return x;
};
auto implicit = [=]( // expected-note {{variable 'z' is captured here}}
decltype(
- [&](decltype((z))) { return 0; }) z) { // expected-error{{captured variable 'z' cannot appear here}}
+ [&](decltype(z)) { return 0; }) z) { //expected-error{{captured variable 'z' cannot appear here}}
return z;
};
- auto init = [x = 1]( // expected-note{{explicitly captured here}}
- decltype([&](decltype((x))) { return 0; }) y) { // expected-error {{captured variable 'x' cannot appear here}}
+ auto init = [x = 1]( // expected-note{{explicitly captured here}}
+ decltype([&](decltype(x)) { return 0; }) y) { // expected-error {{captured variable 'x' cannot appear here}}
return x;
};
@@ -141,20 +141,20 @@ void nested() {
decltype([&](
decltype([=]( // expected-note {{variable 'x' is captured here}}
decltype([&](
- decltype([&](decltype((x))) {}) // expected-error{{captured variable 'x' cannot appear here}}
+ decltype([&](decltype(x)) {}) // expected-error{{captured variable 'x' cannot appear here}}
) {})) {})) {})){};
(void)[&](
decltype([&](
decltype([&](
decltype([&](
- decltype([&](decltype((y))) {})) {})) {})) {})){};
+ decltype([&](decltype(y)) {})) {})) {})) {})){};
(void)[=](
decltype([=](
decltype([=](
- decltype([=]( // expected-note {{variable 'z' is captured here}}
- decltype([&]<decltype((z))> {}) // expected-error{{captured variable 'z' cannot appear here}}
+ decltype([=]( // expected-note {{variable 'z' is captured here}}
+ decltype([&]<decltype(z)> {}) // expected-error{{captured variable 'z' cannot appear here}}
) {})) {})) {})){};
}
@@ -202,15 +202,3 @@ void test_dependent() {
dependent_init_capture(0);
dependent_variadic_capture(1, 2, 3, 4);
}
-
-void test_CWG2569_tpl(auto a) {
- (void)[=]<typename T = decltype(a)>(decltype(a) b = decltype(a)()){};
-}
-
-void test_CWG2569() {
- int a = 0;
- (void)[=]<typename T = decltype(a)>(decltype(a) b = decltype(a)()){};
- test_CWG2569_tpl(0);
-
- (void)[=]<typename T = decltype(not_a_thing)>(decltype(not_a_thing)){}; // expected-error 2{{use of undeclared identifier 'not_a_thing'}}
-}
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