[coroutines] Add serialization/deserialization of coroutines

[GorNishanov]

@rsmith, ping. Would be good to get this in for clang 5.0

[rsmith]

lib/Serialization/ASTWriterStmt.cpp

320–321

Please call this ASTStmtWriter::VisitCoroutineSuspendExpr, following the pattern we use in the rest of this visitor.

[GorNishanov]

Thank you for the review. Feedback implemented. Preparing to land

[dongAxis1944]

cfe/trunk/lib/AST/StmtCXX.cpp

107–108 ↗

(On Diff #108121)

hello, i have a question about that why clang commit info of parameters again in coroutine body?

include/clang/AST/StmtCXX.h

enum SubStmt {
     ResultDecl,    ///< Declaration holding the result of get_return_object.
     ReturnStmt,    ///< Return statement for the thunk function.
     ReturnStmtOnAllocFailure, ///< Return statement if allocation failed.
     FirstParamMove ///< First offset for move construction of parameter copies.
   };
   unsigned NumParams;
 
   friend class ASTStmtReader;
+  friend class ASTReader;
   friend TrailingObjects;
 
   Stmt **getStoredStmts() { return getTrailingObjects<Stmt *>(); }
 
   Stmt *const *getStoredStmts() const { return getTrailingObjects<Stmt *>(); }
 
 public:
 
public:
   };
 
 private:
 
   CoroutineBodyStmt(CtorArgs const& Args);
 
 public:
   static CoroutineBodyStmt *Create(const ASTContext &C, CtorArgs const &Args);
+  static CoroutineBodyStmt *Create(const ASTContext &C, EmptyShell,
+                                   unsigned NumParams);
 
   bool hasDependentPromiseType() const {
     return getPromiseDecl()->getType()->isDependentType();
   }
 
   /// \brief Retrieve the body of the coroutine as written. This will be either
   /// a CompoundStmt or a TryStmt.
   Stmt *getBody() const {
public:
   CoreturnStmt(SourceLocation CoreturnLoc, Stmt *Operand, Stmt *PromiseCall,
                bool IsImplicit = false)
       : Stmt(CoreturnStmtClass), CoreturnLoc(CoreturnLoc),
         IsImplicit(IsImplicit) {
     SubStmts[SubStmt::Operand] = Operand;
     SubStmts[SubStmt::PromiseCall] = PromiseCall;
   }
 
+  CoreturnStmt(EmptyShell) : CoreturnStmt({}, {}, {}) {}
+
   SourceLocation getKeywordLoc() const { return CoreturnLoc; }
 
   /// \brief Retrieve the operand of the 'co_return' statement. Will be nullptr
   /// if none was specified.
   Expr *getOperand() const { return static_cast<Expr*>(SubStmts[Operand]); }
 
   /// \brief Retrieve the promise call that results from this 'co_return'
   /// statement. Will be nullptr if either the coroutine has not yet been

include/clang/Serialization/ASTBitCodes.h

enum StmtCode {
       STMT_OMP_TARGET_TEAMS_DISTRIBUTE_DIRECTIVE,
       STMT_OMP_TARGET_TEAMS_DISTRIBUTE_PARALLEL_FOR_DIRECTIVE,
       STMT_OMP_TARGET_TEAMS_DISTRIBUTE_PARALLEL_FOR_SIMD_DIRECTIVE,
       STMT_OMP_TARGET_TEAMS_DISTRIBUTE_SIMD_DIRECTIVE,
       EXPR_OMP_ARRAY_SECTION,
 
       // ARC
       EXPR_OBJC_BRIDGED_CAST,     // ObjCBridgedCastExpr
-      
       STMT_MS_DEPENDENT_EXISTS,   // MSDependentExistsStmt
-      EXPR_LAMBDA                 // LambdaExpr
+      EXPR_LAMBDA,                // LambdaExpr
+      STMT_COROUTINE_BODY,
+      STMT_CORETURN,
+      EXPR_COAWAIT,
+      EXPR_COYIELD,
+      EXPR_DEPENDENT_COAWAIT,
     };
 
     /// \brief The kinds of designators that can occur in a
     /// DesignatedInitExpr.
     enum DesignatorTypes {
       /// \brief Field designator where only the field name is known.
       DESIG_FIELD_NAME  = 0,
       /// \brief Field designator where the field has been resolved to

lib/AST/StmtCXX.cpp

CoroutineBodyStmt *CoroutineBodyStmt::Create(
     const ASTContext &C, CoroutineBodyStmt::CtorArgs const &Args) {
   std::size_t Size = totalSizeToAlloc<Stmt *>(
       CoroutineBodyStmt::FirstParamMove + Args.ParamMoves.size());
 
   void *Mem = C.Allocate(Size, alignof(CoroutineBodyStmt));
   return new (Mem) CoroutineBodyStmt(Args);
 }
 
+CoroutineBodyStmt *CoroutineBodyStmt::Create(const ASTContext &C, EmptyShell,
+                                             unsigned NumParams) {
+  std::size_t Size = totalSizeToAlloc<Stmt *>(
+      CoroutineBodyStmt::FirstParamMove + NumParams);
+
+  void *Mem = C.Allocate(Size, alignof(CoroutineBodyStmt));
+  auto *Result = new (Mem) CoroutineBodyStmt(CtorArgs());
+  Result->NumParams = NumParams;
+  auto *ParamBegin = Result->getStoredStmts() + SubStmt::FirstParamMove;
+  std::uninitialized_fill(ParamBegin, ParamBegin + NumParams,
+                          static_cast<Stmt *>(nullptr));
+  return Result;
+}
+
 CoroutineBodyStmt::CoroutineBodyStmt(CoroutineBodyStmt::CtorArgs const &Args)
     : Stmt(CoroutineBodyStmtClass), NumParams(Args.ParamMoves.size()) {
   Stmt **SubStmts = getStoredStmts();
   SubStmts[CoroutineBodyStmt::Body] = Args.Body;
   SubStmts[CoroutineBodyStmt::Promise] = Args.Promise;
   SubStmts[CoroutineBodyStmt::InitSuspend] = Args.InitialSuspend;
   SubStmts[CoroutineBodyStmt::FinalSuspend] = Args.FinalSuspend;
   SubStmts[CoroutineBodyStmt::OnException] = Args.OnException;

lib/Serialization/ASTReaderStmt.cpp

for (unsigned i = 0; i != NumOperands; ++i) {
     Constraints.push_back(ConstraintsData.back());
   }
 
   S->initialize(Record.getContext(), AsmStr, AsmToks,
                 Constraints, Exprs, Clobbers);
 }
 
 void ASTStmtReader::VisitCoroutineBodyStmt(CoroutineBodyStmt *S) {
-  // FIXME: Implement coroutine serialization.
-  llvm_unreachable("unimplemented");
+  VisitStmt(S);
+  assert(Record.peekInt() == S->NumParams);
+  Record.skipInts(1);
+  auto *StoredStmts = S->getStoredStmts();
+  for (unsigned i = 0;
+       i < CoroutineBodyStmt::SubStmt::FirstParamMove + S->NumParams; ++i)
+    StoredStmts[i] = Record.readSubStmt();
 }
 
 void ASTStmtReader::VisitCoreturnStmt(CoreturnStmt *S) {
-  // FIXME: Implement coroutine serialization.
-  llvm_unreachable("unimplemented");
+  VisitStmt(S);
+  S->CoreturnLoc = Record.readSourceLocation();
+  for (auto &SubStmt: S->SubStmts)
+    SubStmt = Record.readSubStmt();
+  S->IsImplicit = Record.readInt() != 0;
 }
 
-void ASTStmtReader::VisitCoawaitExpr(CoawaitExpr *S) {
-  // FIXME: Implement coroutine serialization.
-  llvm_unreachable("unimplemented");
+void ASTStmtReader::VisitCoawaitExpr(CoawaitExpr *E) {
+  VisitExpr(E);
+  E->KeywordLoc = ReadSourceLocation();
+  for (auto &SubExpr: E->SubExprs)
+    SubExpr = Record.readSubStmt();
+  E->OpaqueValue = cast_or_null<OpaqueValueExpr>(Record.readSubStmt());
+  E->setIsImplicit(Record.readInt() != 0);
 }
 
-void ASTStmtReader::VisitDependentCoawaitExpr(DependentCoawaitExpr *S) {
-  // FIXME: Implement coroutine serialization.
-  llvm_unreachable("unimplemented");
+void ASTStmtReader::VisitCoyieldExpr(CoyieldExpr *E) {
+  VisitExpr(E);
+  E->KeywordLoc = ReadSourceLocation();
+  for (auto &SubExpr: E->SubExprs)
+    SubExpr = Record.readSubStmt();
+  E->OpaqueValue = cast_or_null<OpaqueValueExpr>(Record.readSubStmt());
 }
 
-void ASTStmtReader::VisitCoyieldExpr(CoyieldExpr *S) {
-  // FIXME: Implement coroutine serialization.
-  llvm_unreachable("unimplemented");
+void ASTStmtReader::VisitDependentCoawaitExpr(DependentCoawaitExpr *E) {
+  VisitExpr(E);
+  E->KeywordLoc = ReadSourceLocation();
+  for (auto &SubExpr: E->SubExprs)
+    SubExpr = Record.readSubStmt();
 }
 
 void ASTStmtReader::VisitCapturedStmt(CapturedStmt *S) {
   VisitStmt(S);
   Record.skipInts(1);
   S->setCapturedDecl(ReadDeclAs<CapturedDecl>());
   S->setCapturedRegionKind(static_cast<CapturedRegionKind>(Record.readInt()));
   S->setCapturedRecordDecl(ReadDeclAs<RecordDecl>());
case EXPR_ATOMIC:
       S = new (Context) AtomicExpr(Empty);
       break;
 
     case EXPR_LAMBDA: {
       unsigned NumCaptures = Record[ASTStmtReader::NumExprFields];
       S = LambdaExpr::CreateDeserialized(Context, NumCaptures);
       break;
     }
+
+    case STMT_COROUTINE_BODY: {
+      unsigned NumParams = Record[ASTStmtReader::NumStmtFields];
+      S = CoroutineBodyStmt::Create(Context, Empty, NumParams);
+      break;
+    }
+
+    case STMT_CORETURN:
+      S = new (Context) CoreturnStmt(Empty);
+      break;
+
+    case EXPR_COAWAIT:
+      S = new (Context) CoawaitExpr(Empty);
+      break;
+
+    case EXPR_COYIELD:
+      S = new (Context) CoyieldExpr(Empty);
+      break;
+
+    case EXPR_DEPENDENT_COAWAIT:
+      S = new (Context) DependentCoawaitExpr(Empty);
+      break;
+
     }
 
     // We hit a STMT_STOP, so we're done with this expression.
     if (Finished)
       break;
 
     ++NumStatementsRead;
 

lib/Serialization/ASTWriterStmt.cpp

void ASTStmtWriter::VisitMSAsmStmt(MSAsmStmt *S) {
   }
 
   // Clobbers
   for (unsigned I = 0, N = S->getNumClobbers(); I != N; ++I) {
     Record.AddString(S->getClobber(I));
   }
 
   // Outputs
-  for (unsigned I = 0, N = S->getNumOutputs(); I != N; ++I) {      
+  for (unsigned I = 0, N = S->getNumOutputs(); I != N; ++I) {
     Record.AddStmt(S->getOutputExpr(I));
     Record.AddString(S->getOutputConstraint(I));
   }
 
   // Inputs
   for (unsigned I = 0, N = S->getNumInputs(); I != N; ++I) {
     Record.AddStmt(S->getInputExpr(I));
     Record.AddString(S->getInputConstraint(I));
   }
 
   Code = serialization::STMT_MSASM;
 }
 
-void ASTStmtWriter::VisitCoroutineBodyStmt(CoroutineBodyStmt *S) {
-  // FIXME: Implement coroutine serialization.
-  llvm_unreachable("unimplemented");
+void ASTStmtWriter::VisitCoroutineBodyStmt(CoroutineBodyStmt *CoroStmt) {
+  VisitStmt(CoroStmt);
+  Record.push_back(CoroStmt->getParamMoves().size());
+  for (Stmt *S : CoroStmt->children())
+    Record.AddStmt(S);
+  Code = serialization::STMT_COROUTINE_BODY;
 }
 
 void ASTStmtWriter::VisitCoreturnStmt(CoreturnStmt *S) {
-  // FIXME: Implement coroutine serialization.
-  llvm_unreachable("unimplemented");
+  VisitStmt(S);
+  Record.AddSourceLocation(S->getKeywordLoc());
+  Record.AddStmt(S->getOperand());
+  Record.AddStmt(S->getPromiseCall());
+  Record.push_back(S->isImplicit());
+  Code = serialization::STMT_CORETURN;
 }
 
-void ASTStmtWriter::VisitCoawaitExpr(CoawaitExpr *S) {
-  // FIXME: Implement coroutine serialization.
-  llvm_unreachable("unimplemented");
+static void serializeSuspendExpr(ASTStmtWriter &Writer, ASTRecordWriter &Record,
+                                 CoroutineSuspendExpr *E) {
+  Writer.VisitExpr(E);
+  Record.AddSourceLocation(E->getKeywordLoc());
+  for (Stmt *S : E->children())
+    Record.AddStmt(S);
+  Record.AddStmt(E->getOpaqueValue());
 }
 
-void ASTStmtWriter::VisitDependentCoawaitExpr(DependentCoawaitExpr *S) {
-  // FIXME: Implement coroutine serialization.
-  llvm_unreachable("unimplemented");
+void ASTStmtWriter::VisitCoawaitExpr(CoawaitExpr *E) {
+  serializeSuspendExpr(*this, Record, E);
+  Record.push_back(E->isImplicit());
+  Code = serialization::EXPR_COAWAIT;
 }
 
-void ASTStmtWriter::VisitCoyieldExpr(CoyieldExpr *S) {
-  // FIXME: Implement coroutine serialization.
-  llvm_unreachable("unimplemented");
+void ASTStmtWriter::VisitCoyieldExpr(CoyieldExpr *E) {
+  serializeSuspendExpr(*this, Record, E);
+  Code = serialization::EXPR_COYIELD;
+}
+
+void ASTStmtWriter::VisitDependentCoawaitExpr(DependentCoawaitExpr *E) {
+  VisitExpr(E);
+  Record.AddSourceLocation(E->getKeywordLoc());
+  for (Stmt *S : E->children())
+    Record.AddStmt(S);
+  Code = serialization::EXPR_DEPENDENT_COAWAIT;
 }
 
 void ASTStmtWriter::VisitCapturedStmt(CapturedStmt *S) {
   VisitStmt(S);
   // NumCaptures
   Record.push_back(std::distance(S->capture_begin(), S->capture_end()));
 
   // CapturedDecl and captured region kind

test/PCH/coroutines.cpp

+// Test this without pch.
+// RUN: %clang_cc1 -include %s -verify -std=c++1z -fcoroutines-ts %s
+
+// Test with pch.
+// RUN: %clang_cc1 -std=c++1z -fcoroutines-ts  -emit-pch -o %t %s
+// RUN: %clang_cc1 -include-pch %t -verify -std=c++1z -fcoroutines-ts %s
+
+#ifndef HEADER
+#define HEADER
+
+namespace std::experimental {
+template <typename... T> struct coroutine_traits;
+
+template <class Promise = void> struct coroutine_handle {
+  coroutine_handle() = default;
+  static coroutine_handle from_address(void *) noexcept;
+};
+template <> struct coroutine_handle<void> {
+  static coroutine_handle from_address(void *) noexcept;
+  coroutine_handle() = default;
+  template <class PromiseType>
+  coroutine_handle(coroutine_handle<PromiseType>) noexcept;
+};
+}
+
+struct suspend_always {
+  bool await_ready() noexcept;
+  void await_suspend(std::experimental::coroutine_handle<>) noexcept;
+  void await_resume() noexcept;
+};
+
+template <typename... Args> struct std::experimental::coroutine_traits<void, Args...> {
+  struct promise_type {
+    void get_return_object() noexcept;
+    suspend_always initial_suspend() noexcept;
+    suspend_always final_suspend() noexcept;
+    void return_void() noexcept;
+    suspend_always yield_value(int) noexcept;
+    promise_type();
+    ~promise_type() noexcept;
+    void unhandled_exception() noexcept;
+  };
+};
+
+template <typename... Args> struct std::experimental::coroutine_traits<int, Args...> {
+  struct promise_type {
+    int get_return_object() noexcept;
+    suspend_always initial_suspend() noexcept;
+    suspend_always final_suspend() noexcept;
+    void return_value(int) noexcept;
+    promise_type();
+    ~promise_type() noexcept;
+    void unhandled_exception() noexcept;
+  };
+};
+
+template <typename T>
+void f(T x) {  // checks coawait_expr and coroutine_body_stmt
+  co_yield 42; // checks coyield_expr
+  co_await x;  // checks dependent_coawait
+  co_return;   // checks coreturn_stmt
+}
+
+template <typename T>
+int f2(T x) {  // checks coawait_expr and coroutine_body_stmt
+  co_return x;   // checks coreturn_stmt with expr
+}
+
+#else
+
+// expected-no-diagnostics
+void g() {
+  f(suspend_always{});
+  f2(42);
+}
+
+#endif