[coroutines] Switch to using std::experimental namespace per P0057R5

Summary:
Look for coroutine_traits and friends in std::experimental namespace.
Patch (mostly) by EricWF.

Reviewers: cfe-commits, EricWF, rsmith

Subscribers: majnemer, mehdi_amini

Differential Revision: https://reviews.llvm.org/D25068

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@283170 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index cd032b4a87bc8c14c52aa160dc2d34c508e4493d..06fa106ed0992dbd8ba46107a0f13d999678698b 100644 (file)
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -8572,9 +8572,9 @@ def ext_coroutine_without_co_await_co_yield : ExtWarn<
   "that uses neither 'co_await' nor 'co_yield'">,
   InGroup<DiagGroup<"coreturn-without-coawait">>;
 def err_implied_std_coroutine_traits_not_found : Error<
-  "you need to include <coroutine> before defining a coroutine">;
+  "you need to include <experimental/coroutine> before defining a coroutine">;
 def err_malformed_std_coroutine_traits : Error<
-  "'std::coroutine_traits' must be a class template">;
+  "'std::experimental::coroutine_traits' must be a class template">;
 def err_implied_std_coroutine_traits_promise_type_not_found : Error<
   "this function cannot be a coroutine: %q0 has no member named 'promise_type'">;
 def err_implied_std_coroutine_traits_promise_type_not_class : Error<

diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 74c4e41c4732d264e1d66455317cf1ad8f1415e4..f49b768ee67923431110b3b401f9a0a74dfc2d1f 100644 (file)
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -725,6 +725,10 @@ public:
   /// standard library.
   LazyDeclPtr StdAlignValT;
 
+  /// \brief The C++ "std::experimental" namespace, where the experimental parts
+  /// of the standard library resides.
+  NamespaceDecl *StdExperimentalNamespaceCache;
+
   /// \brief The C++ "std::initializer_list" template, which is defined in
   /// \<initializer_list>.
   ClassTemplateDecl *StdInitializerList;
@@ -4255,6 +4259,8 @@ public:
   NamespaceDecl *getStdNamespace() const;
   NamespaceDecl *getOrCreateStdNamespace();
 
+  NamespaceDecl *lookupStdExperimentalNamespace();
+
   CXXRecordDecl *getStdBadAlloc() const;
   EnumDecl *getStdAlignValT() const;
 

diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index 081d45b61eb7797b6b3d753936c7a5065d044bfe..9ea5cba94eec9444037cc0821fef276e3d2156c4 100644 (file)
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -88,8 +88,8 @@ Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
     VisContext(nullptr),
     IsBuildingRecoveryCallExpr(false),
     Cleanup{}, LateTemplateParser(nullptr),
-    LateTemplateParserCleanup(nullptr),
-    OpaqueParser(nullptr), IdResolver(pp), StdInitializerList(nullptr),
+    LateTemplateParserCleanup(nullptr), OpaqueParser(nullptr), IdResolver(pp),
+    StdExperimentalNamespaceCache(nullptr), StdInitializerList(nullptr),
     CXXTypeInfoDecl(nullptr), MSVCGuidDecl(nullptr),
     NSNumberDecl(nullptr), NSValueDecl(nullptr),
     NSStringDecl(nullptr), StringWithUTF8StringMethod(nullptr),

diff --git a/lib/Sema/SemaCoroutine.cpp b/lib/Sema/SemaCoroutine.cpp
index 461ca8eddcfec9ae7337285d62be0eb2868905cf..f9c3970e0219d891628b446e747a07afbf1a2539 100644 (file)
--- a/lib/Sema/SemaCoroutine.cpp
+++ b/lib/Sema/SemaCoroutine.cpp
@@ -26,15 +26,15 @@ using namespace sema;
 static QualType lookupPromiseType(Sema &S, const FunctionProtoType *FnType,
                                   SourceLocation Loc) {
   // FIXME: Cache std::coroutine_traits once we've found it.
-  NamespaceDecl *Std = S.getStdNamespace();
-  if (!Std) {
+  NamespaceDecl *StdExp = S.lookupStdExperimentalNamespace();
+  if (!StdExp) {
     S.Diag(Loc, diag::err_implied_std_coroutine_traits_not_found);
     return QualType();
   }
 
   LookupResult Result(S, &S.PP.getIdentifierTable().get("coroutine_traits"),
                       Loc, Sema::LookupOrdinaryName);
-  if (!S.LookupQualifiedName(Result, Std)) {
+  if (!S.LookupQualifiedName(Result, StdExp)) {
     S.Diag(Loc, diag::err_implied_std_coroutine_traits_not_found);
     return QualType();
   }
@@ -86,7 +86,7 @@ static QualType lookupPromiseType(Sema &S, const FunctionProtoType *FnType,
   QualType PromiseType = S.Context.getTypeDeclType(Promise);
   if (!PromiseType->getAsCXXRecordDecl()) {
     // Use the fully-qualified name of the type.
-    auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, Std);
+    auto *NNS = NestedNameSpecifier::Create(S.Context, nullptr, StdExp);
     NNS = NestedNameSpecifier::Create(S.Context, NNS, false,
                                       CoroTrait.getTypePtr());
     PromiseType = S.Context.getElaboratedType(ETK_None, NNS, PromiseType);
@@ -345,6 +345,7 @@ StmtResult Sema::ActOnCoreturnStmt(SourceLocation Loc, Expr *E) {
   }
   return BuildCoreturnStmt(Loc, E);
 }
+
 StmtResult Sema::BuildCoreturnStmt(SourceLocation Loc, Expr *E) {
   auto *Coroutine = checkCoroutineContext(*this, Loc, "co_return");
   if (!Coroutine)

diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 133f1f47cc4e845de29d59d1d88b7bf0084487b3..2fe520b82380d1dc03ed66b0673b680d69719536 100644 (file)
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -8275,6 +8275,20 @@ NamespaceDecl *Sema::getStdNamespace() const {
                                  StdNamespace.get(Context.getExternalSource()));
 }
 
+NamespaceDecl *Sema::lookupStdExperimentalNamespace() {
+  if (!StdExperimentalNamespaceCache) {
+    if (auto Std = getStdNamespace()) {
+      LookupResult Result(*this, &PP.getIdentifierTable().get("experimental"),
+                          SourceLocation(), LookupNamespaceName);
+      if (!LookupQualifiedName(Result, Std) ||
+          !(StdExperimentalNamespaceCache =
+                Result.getAsSingle<NamespaceDecl>()))
+        Result.suppressDiagnostics();
+    }
+  }
+  return StdExperimentalNamespaceCache;
+}
+
 /// \brief Retrieve the special "std" namespace, which may require us to 
 /// implicitly define the namespace.
 NamespaceDecl *Sema::getOrCreateStdNamespace() {

diff --git a/test/SemaCXX/coroutines.cpp b/test/SemaCXX/coroutines.cpp
index 17bf5d0481925b5584c062a0cc3a5c0af0e20eb8..dd941237647e7065dfd4c1bcd8b45329a23429c1 100644 (file)
--- a/test/SemaCXX/coroutines.cpp
+++ b/test/SemaCXX/coroutines.cpp
@@ -1,18 +1,18 @@
 // RUN: %clang_cc1 -std=c++14 -fcoroutines-ts -verify %s
 
 void no_coroutine_traits_bad_arg_await() {
-  co_await a; // expected-error {{include <coroutine>}}
+  co_await a; // expected-error {{include <experimental/coroutine>}}
   // expected-error@-1 {{use of undeclared identifier 'a'}}
 }
 
 void no_coroutine_traits_bad_arg_yield() {
-  co_yield a; // expected-error {{include <coroutine>}}
+  co_yield a; // expected-error {{include <experimental/coroutine>}}
   // expected-error@-1 {{use of undeclared identifier 'a'}}
 }
 
 
 void no_coroutine_traits_bad_arg_return() {
-  co_return a; // expected-error {{include <coroutine>}}
+  co_return a; // expected-error {{include <experimental/coroutine>}}
   // expected-error@-1 {{use of undeclared identifier 'a'}}
 }
 
@@ -36,45 +36,59 @@ struct suspend_never {
 };
 
 void no_coroutine_traits() {
-  co_await a; // expected-error {{need to include <coroutine>}}
+  co_await a; // expected-error {{need to include <experimental/coroutine>}}
 }
 
 namespace std {
-  template<typename ...T> struct coroutine_traits; // expected-note {{declared here}}
-};
+namespace experimental {
+template <typename... T>
+struct coroutine_traits; // expected-note {{declared here}}
+}
+}
 
 template<typename Promise> struct coro {};
-template<typename Promise, typename... Ps>
-struct std::coroutine_traits<coro<Promise>, Ps...> {
+template <typename Promise, typename... Ps>
+struct std::experimental::coroutine_traits<coro<Promise>, Ps...> {
   using promise_type = Promise;
 };
 
 void no_specialization() {
-  co_await a; // expected-error {{implicit instantiation of undefined template 'std::coroutine_traits<void>'}}
+  co_await a; // expected-error {{implicit instantiation of undefined template 'std::experimental::coroutine_traits<void>'}}
 }
 
-template<typename ...T> struct std::coroutine_traits<int, T...> {};
+template <typename... T>
+struct std::experimental::coroutine_traits<int, T...> {};
 
 int no_promise_type() {
-  co_await a; // expected-error {{this function cannot be a coroutine: 'std::coroutine_traits<int>' has no member named 'promise_type'}}
+  co_await a; // expected-error {{this function cannot be a coroutine: 'std::experimental::coroutine_traits<int>' has no member named 'promise_type'}}
 }
 
-template<> struct std::coroutine_traits<double, double> { typedef int promise_type; };
+template <>
+struct std::experimental::coroutine_traits<double, double> { typedef int promise_type; };
 double bad_promise_type(double) {
-  co_await a; // expected-error {{this function cannot be a coroutine: 'std::coroutine_traits<double, double>::promise_type' (aka 'int') is not a class}}
+  co_await a; // expected-error {{this function cannot be a coroutine: 'experimental::coroutine_traits<double, double>::promise_type' (aka 'int') is not a class}}
 }
 
-template<> struct std::coroutine_traits<double, int> {
+template <>
+struct std::experimental::coroutine_traits<double, int> {
   struct promise_type {};
 };
 double bad_promise_type_2(int) {
-  co_yield 0; // expected-error {{no member named 'yield_value' in 'std::coroutine_traits<double, int>::promise_type'}}
+  co_yield 0; // expected-error {{no member named 'yield_value' in 'std::experimental::coroutine_traits<double, int>::promise_type'}}
 }
 
 struct promise; // expected-note 2{{forward declaration}}
-template<typename ...T> struct std::coroutine_traits<void, T...> { using promise_type = promise; };
+template <typename... T>
+struct std::experimental::coroutine_traits<void, T...> { using promise_type = promise; };
+
+namespace std {
+namespace experimental {
+template <typename Promise = void>
+struct coroutine_handle;
+}
+}
 
-  // FIXME: This diagnostic is terrible.
+// FIXME: This diagnostic is terrible.
 void undefined_promise() { // expected-error {{variable has incomplete type 'promise_type'}}
   // FIXME: This diagnostic doesn't make any sense.
   // expected-error@-2 {{incomplete definition of type 'promise'}}
@@ -200,7 +214,8 @@ namespace dependent_operator_co_await_lookup {
 }
 
 struct yield_fn_tag {};
-template<> struct std::coroutine_traits<void, yield_fn_tag> {
+template <>
+struct std::experimental::coroutine_traits<void, yield_fn_tag> {
   struct promise_type {
     // FIXME: add an await_transform overload for functions
     awaitable yield_value(int());
@@ -285,7 +300,7 @@ coro<bad_promise_5> bad_final_suspend() { // expected-error {{no member named 'a
 }
 
 
-template<> struct std::coroutine_traits<int, int, const char**>
+template<> struct std::experimental::coroutine_traits<int, int, const char**>
 { using promise_type = promise; };
 
 int main(int, const char**) { // expected-error {{'main' cannot be a coroutine}}