[clang][NFC] Introduce SemaBase

clang/include/clang/Sema/Sema.h

@@ -55,6 +55,7 @@
 #include "clang/Sema/ObjCMethodList.h"
 #include "clang/Sema/Ownership.h"
 #include "clang/Sema/Scope.h"
+#include "clang/Sema/SemaBase.h"
 #include "clang/Sema/SemaConcept.h"
 #include "clang/Sema/TypoCorrection.h"
 #include "clang/Sema/Weak.h"
@@ -422,7 +423,7 @@ enum class TemplateDeductionResult {
 
 /// Sema - This implements semantic analysis and AST building for C.
 /// \nosubgrouping
-class Sema final {
+class Sema final : public SemaBase {
   // Table of Contents
   // -----------------
   // 1. Semantic Analysis (Sema.cpp)
@@ -512,195 +513,6 @@ class Sema final {
   ///
   void addExternalSource(ExternalSemaSource *E);
 
-  /// Helper class that creates diagnostics with optional
-  /// template instantiation stacks.
-  ///
-  /// This class provides a wrapper around the basic DiagnosticBuilder
-  /// class that emits diagnostics. ImmediateDiagBuilder is
-  /// responsible for emitting the diagnostic (as DiagnosticBuilder
-  /// does) and, if the diagnostic comes from inside a template
-  /// instantiation, printing the template instantiation stack as
-  /// well.
-  class ImmediateDiagBuilder : public DiagnosticBuilder {
-    Sema &SemaRef;
-    unsigned DiagID;
-
-  public:
-    ImmediateDiagBuilder(DiagnosticBuilder &DB, Sema &SemaRef, unsigned DiagID)
-        : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) {}
-    ImmediateDiagBuilder(DiagnosticBuilder &&DB, Sema &SemaRef, unsigned DiagID)
-        : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) {}
-
-    // This is a cunning lie. DiagnosticBuilder actually performs move
-    // construction in its copy constructor (but due to varied uses, it's not
-    // possible to conveniently express this as actual move construction). So
-    // the default copy ctor here is fine, because the base class disables the
-    // source anyway, so the user-defined ~ImmediateDiagBuilder is a safe no-op
-    // in that case anwyay.
-    ImmediateDiagBuilder(const ImmediateDiagBuilder &) = default;
-
-    ~ImmediateDiagBuilder() {
-      // If we aren't active, there is nothing to do.
-      if (!isActive())
-        return;
-
-      // Otherwise, we need to emit the diagnostic. First clear the diagnostic
-      // builder itself so it won't emit the diagnostic in its own destructor.
-      //
-      // This seems wasteful, in that as written the DiagnosticBuilder dtor will
-      // do its own needless checks to see if the diagnostic needs to be
-      // emitted. However, because we take care to ensure that the builder
-      // objects never escape, a sufficiently smart compiler will be able to
-      // eliminate that code.
-      Clear();
-
-      // Dispatch to Sema to emit the diagnostic.
-      SemaRef.EmitCurrentDiagnostic(DiagID);
-    }
-
-    /// Teach operator<< to produce an object of the correct type.
-    template <typename T>
-    friend const ImmediateDiagBuilder &
-    operator<<(const ImmediateDiagBuilder &Diag, const T &Value) {
-      const DiagnosticBuilder &BaseDiag = Diag;
-      BaseDiag << Value;
-      return Diag;
-    }
-
-    // It is necessary to limit this to rvalue reference to avoid calling this
-    // function with a bitfield lvalue argument since non-const reference to
-    // bitfield is not allowed.
-    template <typename T,
-              typename = std::enable_if_t<!std::is_lvalue_reference<T>::value>>
-    const ImmediateDiagBuilder &operator<<(T &&V) const {
-      const DiagnosticBuilder &BaseDiag = *this;
-      BaseDiag << std::move(V);
-      return *this;
-    }
-  };
-
-  /// A generic diagnostic builder for errors which may or may not be deferred.
-  ///
-  /// In CUDA, there exist constructs (e.g. variable-length arrays, try/catch)
-  /// which are not allowed to appear inside __device__ functions and are
-  /// allowed to appear in __host__ __device__ functions only if the host+device
-  /// function is never codegen'ed.
-  ///
-  /// To handle this, we use the notion of "deferred diagnostics", where we
-  /// attach a diagnostic to a FunctionDecl that's emitted iff it's codegen'ed.
-  ///
-  /// This class lets you emit either a regular diagnostic, a deferred
-  /// diagnostic, or no diagnostic at all, according to an argument you pass to
-  /// its constructor, thus simplifying the process of creating these "maybe
-  /// deferred" diagnostics.
-  class SemaDiagnosticBuilder {
-  public:
-    enum Kind {
-      /// Emit no diagnostics.
-      K_Nop,
-      /// Emit the diagnostic immediately (i.e., behave like Sema::Diag()).
-      K_Immediate,
-      /// Emit the diagnostic immediately, and, if it's a warning or error, also
-      /// emit a call stack showing how this function can be reached by an a
-      /// priori known-emitted function.
-      K_ImmediateWithCallStack,
-      /// Create a deferred diagnostic, which is emitted only if the function
-      /// it's attached to is codegen'ed.  Also emit a call stack as with
-      /// K_ImmediateWithCallStack.
-      K_Deferred
-    };
-
-    SemaDiagnosticBuilder(Kind K, SourceLocation Loc, unsigned DiagID,
-                          const FunctionDecl *Fn, Sema &S);
-    SemaDiagnosticBuilder(SemaDiagnosticBuilder &&D);
-    SemaDiagnosticBuilder(const SemaDiagnosticBuilder &) = default;
-
-    // The copy and move assignment operator is defined as deleted pending
-    // further motivation.
-    SemaDiagnosticBuilder &operator=(const SemaDiagnosticBuilder &) = delete;
-    SemaDiagnosticBuilder &operator=(SemaDiagnosticBuilder &&) = delete;
-
-    ~SemaDiagnosticBuilder();
-
-    bool isImmediate() const { return ImmediateDiag.has_value(); }
-
-    /// Convertible to bool: True if we immediately emitted an error, false if
-    /// we didn't emit an error or we created a deferred error.
-    ///
-    /// Example usage:
-    ///
-    ///   if (SemaDiagnosticBuilder(...) << foo << bar)
-    ///     return ExprError();
-    ///
-    /// But see CUDADiagIfDeviceCode() and CUDADiagIfHostCode() -- you probably
-    /// want to use these instead of creating a SemaDiagnosticBuilder yourself.
-    operator bool() const { return isImmediate(); }
-
-    template <typename T>
-    friend const SemaDiagnosticBuilder &
-    operator<<(const SemaDiagnosticBuilder &Diag, const T &Value) {
-      if (Diag.ImmediateDiag)
-        *Diag.ImmediateDiag << Value;
-      else if (Diag.PartialDiagId)
-        Diag.S.DeviceDeferredDiags[Diag.Fn][*Diag.PartialDiagId].second
-            << Value;
-      return Diag;
-    }
-
-    // It is necessary to limit this to rvalue reference to avoid calling this
-    // function with a bitfield lvalue argument since non-const reference to
-    // bitfield is not allowed.
-    template <typename T,
-              typename = std::enable_if_t<!std::is_lvalue_reference<T>::value>>
-    const SemaDiagnosticBuilder &operator<<(T &&V) const {
-      if (ImmediateDiag)
-        *ImmediateDiag << std::move(V);
-      else if (PartialDiagId)
-        S.DeviceDeferredDiags[Fn][*PartialDiagId].second << std::move(V);
-      return *this;
-    }
-
-    friend const SemaDiagnosticBuilder &
-    operator<<(const SemaDiagnosticBuilder &Diag, const PartialDiagnostic &PD) {
-      if (Diag.ImmediateDiag)
-        PD.Emit(*Diag.ImmediateDiag);
-      else if (Diag.PartialDiagId)
-        Diag.S.DeviceDeferredDiags[Diag.Fn][*Diag.PartialDiagId].second = PD;
-      return Diag;
-    }
-
-    void AddFixItHint(const FixItHint &Hint) const {
-      if (ImmediateDiag)
-        ImmediateDiag->AddFixItHint(Hint);
-      else if (PartialDiagId)
-        S.DeviceDeferredDiags[Fn][*PartialDiagId].second.AddFixItHint(Hint);
-    }
-
-    friend ExprResult ExprError(const SemaDiagnosticBuilder &) {
-      return ExprError();
-    }
-    friend StmtResult StmtError(const SemaDiagnosticBuilder &) {
-      return StmtError();
-    }
-    operator ExprResult() const { return ExprError(); }
-    operator StmtResult() const { return StmtError(); }
-    operator TypeResult() const { return TypeError(); }
-    operator DeclResult() const { return DeclResult(true); }
-    operator MemInitResult() const { return MemInitResult(true); }
-
-  private:
-    Sema &S;
-    SourceLocation Loc;
-    unsigned DiagID;
-    const FunctionDecl *Fn;
-    bool ShowCallStack;
-
-    // Invariant: At most one of these Optionals has a value.
-    // FIXME: Switch these to a Variant once that exists.
-    std::optional<ImmediateDiagBuilder> ImmediateDiag;
-    std::optional<unsigned> PartialDiagId;
-  };
-
   void PrintStats() const;
 
   /// Warn that the stack is nearly exhausted.
@@ -742,14 +554,6 @@ class Sema final {
 
   void addImplicitTypedef(StringRef Name, QualType T);
 
-  /// Emit a diagnostic.
-  SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID,
-                             bool DeferHint = false);
-
-  /// Emit a partial diagnostic.
-  SemaDiagnosticBuilder Diag(SourceLocation Loc, const PartialDiagnostic &PD,
-                             bool DeferHint = false);
-
   /// Whether uncompilable error has occurred. This includes error happens
   /// in deferred diagnostics.
   bool hasUncompilableErrorOccurred() const;
@@ -13115,9 +12919,7 @@ class Sema final {
   /// Diagnostics that are emitted only if we discover that the given function
   /// must be codegen'ed.  Because handling these correctly adds overhead to
   /// compilation, this is currently only enabled for CUDA compilations.
-  llvm::DenseMap<CanonicalDeclPtr<const FunctionDecl>,
-                 std::vector<PartialDiagnosticAt>>
-      DeviceDeferredDiags;
+  SemaDiagnosticBuilder::DeferredDiagnosticsType DeviceDeferredDiags;
 
   /// A pair of a canonical FunctionDecl and a SourceLocation.  When used as the
   /// key in a hashtable, both the FD and location are hashed.

clang/include/clang/Sema/SemaBase.h

@@ -0,0 +1,224 @@
+//===--- SemaBase.h - Common utilities for semantic analysis-----*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the SemaBase class, which provides utilities for Sema
+// and its parts like SemaOpenACC.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_SEMA_SEMABASE_H
+#define LLVM_CLANG_SEMA_SEMABASE_H
+
+#include "clang/AST/Decl.h"
+#include "clang/AST/Redeclarable.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/PartialDiagnostic.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Sema/Ownership.h"
+#include "llvm/ADT/DenseMap.h"
+#include <optional>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+namespace clang {
+
+class ASTContext;
+class DiagnosticsEngine;
+class LangOptions;
+class Sema;
+
+class SemaBase {
+public:
+  SemaBase(Sema &S);
+
+  Sema &SemaRef;
+
+  ASTContext &getASTContext() const;
+  DiagnosticsEngine &getDiagnostics() const;
+  const LangOptions &getLangOpts() const;
+
+  /// Helper class that creates diagnostics with optional
+  /// template instantiation stacks.
+  ///
+  /// This class provides a wrapper around the basic DiagnosticBuilder
+  /// class that emits diagnostics. ImmediateDiagBuilder is
+  /// responsible for emitting the diagnostic (as DiagnosticBuilder
+  /// does) and, if the diagnostic comes from inside a template
+  /// instantiation, printing the template instantiation stack as
+  /// well.
+  class ImmediateDiagBuilder : public DiagnosticBuilder {
+    Sema &SemaRef;
+    unsigned DiagID;
+
+  public:
+    ImmediateDiagBuilder(DiagnosticBuilder &DB, Sema &SemaRef, unsigned DiagID)
+        : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) {}
+    ImmediateDiagBuilder(DiagnosticBuilder &&DB, Sema &SemaRef, unsigned DiagID)
+        : DiagnosticBuilder(DB), SemaRef(SemaRef), DiagID(DiagID) {}
+
+    // This is a cunning lie. DiagnosticBuilder actually performs move
+    // construction in its copy constructor (but due to varied uses, it's not
+    // possible to conveniently express this as actual move construction). So
+    // the default copy ctor here is fine, because the base class disables the
+    // source anyway, so the user-defined ~ImmediateDiagBuilder is a safe no-op
+    // in that case anwyay.
+    ImmediateDiagBuilder(const ImmediateDiagBuilder &) = default;
+
+    ~ImmediateDiagBuilder();
+
+    /// Teach operator<< to produce an object of the correct type.
+    template <typename T>
+    friend const ImmediateDiagBuilder &
+    operator<<(const ImmediateDiagBuilder &Diag, const T &Value) {
+      const DiagnosticBuilder &BaseDiag = Diag;
+      BaseDiag << Value;
+      return Diag;
+    }
+
+    // It is necessary to limit this to rvalue reference to avoid calling this
+    // function with a bitfield lvalue argument since non-const reference to
+    // bitfield is not allowed.
+    template <typename T,
+              typename = std::enable_if_t<!std::is_lvalue_reference<T>::value>>
+    const ImmediateDiagBuilder &operator<<(T &&V) const {
+      const DiagnosticBuilder &BaseDiag = *this;
+      BaseDiag << std::move(V);
+      return *this;
+    }
+  };
+
+  /// A generic diagnostic builder for errors which may or may not be deferred.
+  ///
+  /// In CUDA, there exist constructs (e.g. variable-length arrays, try/catch)
+  /// which are not allowed to appear inside __device__ functions and are
+  /// allowed to appear in __host__ __device__ functions only if the host+device
+  /// function is never codegen'ed.
+  ///
+  /// To handle this, we use the notion of "deferred diagnostics", where we
+  /// attach a diagnostic to a FunctionDecl that's emitted iff it's codegen'ed.
+  ///
+  /// This class lets you emit either a regular diagnostic, a deferred
+  /// diagnostic, or no diagnostic at all, according to an argument you pass to
+  /// its constructor, thus simplifying the process of creating these "maybe
+  /// deferred" diagnostics.
+  class SemaDiagnosticBuilder {
+  public:
+    enum Kind {
+      /// Emit no diagnostics.
+      K_Nop,
+      /// Emit the diagnostic immediately (i.e., behave like Sema::Diag()).
+      K_Immediate,
+      /// Emit the diagnostic immediately, and, if it's a warning or error, also
+      /// emit a call stack showing how this function can be reached by an a
+      /// priori known-emitted function.
+      K_ImmediateWithCallStack,
+      /// Create a deferred diagnostic, which is emitted only if the function
+      /// it's attached to is codegen'ed.  Also emit a call stack as with
+      /// K_ImmediateWithCallStack.
+      K_Deferred
+    };
+
+    SemaDiagnosticBuilder(Kind K, SourceLocation Loc, unsigned DiagID,
+                          const FunctionDecl *Fn, Sema &S);
+    SemaDiagnosticBuilder(SemaDiagnosticBuilder &&D);
+    SemaDiagnosticBuilder(const SemaDiagnosticBuilder &) = default;
+
+    // The copy and move assignment operator is defined as deleted pending
+    // further motivation.
+    SemaDiagnosticBuilder &operator=(const SemaDiagnosticBuilder &) = delete;
+    SemaDiagnosticBuilder &operator=(SemaDiagnosticBuilder &&) = delete;
+
+    ~SemaDiagnosticBuilder();
+
+    bool isImmediate() const { return ImmediateDiag.has_value(); }
+
+    /// Convertible to bool: True if we immediately emitted an error, false if
+    /// we didn't emit an error or we created a deferred error.
+    ///
+    /// Example usage:
+    ///
+    ///   if (SemaDiagnosticBuilder(...) << foo << bar)
+    ///     return ExprError();
+    ///
+    /// But see CUDADiagIfDeviceCode() and CUDADiagIfHostCode() -- you probably
+    /// want to use these instead of creating a SemaDiagnosticBuilder yourself.
+    operator bool() const { return isImmediate(); }
+
+    template <typename T>
+    friend const SemaDiagnosticBuilder &
+    operator<<(const SemaDiagnosticBuilder &Diag, const T &Value) {
+      if (Diag.ImmediateDiag)
+        *Diag.ImmediateDiag << Value;
+      else if (Diag.PartialDiagId)
+        Diag.getDeviceDeferredDiags()[Diag.Fn][*Diag.PartialDiagId].second
+            << Value;
+      return Diag;
+    }
+
+    // It is necessary to limit this to rvalue reference to avoid calling this
+    // function with a bitfield lvalue argument since non-const reference to
+    // bitfield is not allowed.
+    template <typename T,
+              typename = std::enable_if_t<!std::is_lvalue_reference<T>::value>>
+    const SemaDiagnosticBuilder &operator<<(T &&V) const {
+      if (ImmediateDiag)
+        *ImmediateDiag << std::move(V);
+      else if (PartialDiagId)
+        getDeviceDeferredDiags()[Fn][*PartialDiagId].second << std::move(V);
+      return *this;
+    }
+
+    friend const SemaDiagnosticBuilder &
+    operator<<(const SemaDiagnosticBuilder &Diag, const PartialDiagnostic &PD);
+
+    void AddFixItHint(const FixItHint &Hint) const;
+
+    friend ExprResult ExprError(const SemaDiagnosticBuilder &) {
+      return ExprError();
+    }
+    friend StmtResult StmtError(const SemaDiagnosticBuilder &) {
+      return StmtError();
+    }
+    operator ExprResult() const { return ExprError(); }
+    operator StmtResult() const { return StmtError(); }
+    operator TypeResult() const { return TypeError(); }
+    operator DeclResult() const { return DeclResult(true); }
+    operator MemInitResult() const { return MemInitResult(true); }
+
+    using DeferredDiagnosticsType =
+        llvm::DenseMap<CanonicalDeclPtr<const FunctionDecl>,
+                       std::vector<PartialDiagnosticAt>>;
+
+  private:
+    Sema &S;
+    SourceLocation Loc;
+    unsigned DiagID;
+    const FunctionDecl *Fn;
+    bool ShowCallStack;
+
+    // Invariant: At most one of these Optionals has a value.
+    // FIXME: Switch these to a Variant once that exists.
+    std::optional<ImmediateDiagBuilder> ImmediateDiag;
+    std::optional<unsigned> PartialDiagId;
+
+    DeferredDiagnosticsType &getDeviceDeferredDiags() const;
+  };
+
+  /// Emit a diagnostic.
+  SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID,
+                             bool DeferHint = false);
+
+  /// Emit a partial diagnostic.
+  SemaDiagnosticBuilder Diag(SourceLocation Loc, const PartialDiagnostic &PD,
+                             bool DeferHint = false);
+};
+
+} // namespace clang
+
+#endif

clang/include/clang/Sema/SemaOpenACC.h

@@ -18,24 +18,14 @@
 #include "clang/Basic/OpenACCKinds.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Sema/Ownership.h"
+#include "clang/Sema/SemaBase.h"
 
 namespace clang {
 
-class ASTContext;
-class DiagnosticEngine;
-class LangOptions;
-class Sema;
-
-class SemaOpenACC {
+class SemaOpenACC : public SemaBase {
 public:
   SemaOpenACC(Sema &S);
 
-  ASTContext &getASTContext() const;
-  DiagnosticsEngine &getDiagnostics() const;
-  const LangOptions &getLangOpts() const;
-
-  Sema &SemaRef;
-
   /// Called after parsing an OpenACC Clause so that it can be checked.
   bool ActOnClause(OpenACCClauseKind ClauseKind, SourceLocation StartLoc);
 

clang/lib/Sema/CMakeLists.txt

@@ -29,6 +29,7 @@ add_clang_library(clangSema
   SemaAttr.cpp
   SemaAPINotes.cpp
   SemaAvailability.cpp
+  SemaBase.cpp
   SemaCXXScopeSpec.cpp
   SemaCast.cpp
   SemaChecking.cpp

clang/lib/Sema/Sema.cpp

@@ -190,14 +190,15 @@ const uint64_t Sema::MaximumAlignment;
 
 Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer,
            TranslationUnitKind TUKind, CodeCompleteConsumer *CodeCompleter)
-    : CollectStats(false), TUKind(TUKind), CurFPFeatures(pp.getLangOpts()),
-      LangOpts(pp.getLangOpts()), PP(pp), Context(ctxt), Consumer(consumer),
-      Diags(PP.getDiagnostics()), SourceMgr(PP.getSourceManager()),
-      APINotes(SourceMgr, LangOpts), AnalysisWarnings(*this),
-      ThreadSafetyDeclCache(nullptr), LateTemplateParser(nullptr),
-      LateTemplateParserCleanup(nullptr), OpaqueParser(nullptr),
-      CurContext(nullptr), ExternalSource(nullptr), CurScope(nullptr),
-      Ident_super(nullptr), OpenACCPtr(std::make_unique<SemaOpenACC>(*this)),
+    : SemaBase(*this), CollectStats(false), TUKind(TUKind),
+      CurFPFeatures(pp.getLangOpts()), LangOpts(pp.getLangOpts()), PP(pp),
+      Context(ctxt), Consumer(consumer), Diags(PP.getDiagnostics()),
+      SourceMgr(PP.getSourceManager()), APINotes(SourceMgr, LangOpts),
+      AnalysisWarnings(*this), ThreadSafetyDeclCache(nullptr),
+      LateTemplateParser(nullptr), LateTemplateParserCleanup(nullptr),
+      OpaqueParser(nullptr), CurContext(nullptr), ExternalSource(nullptr),
+      CurScope(nullptr), Ident_super(nullptr),
+      OpenACCPtr(std::make_unique<SemaOpenACC>(*this)),
       MSPointerToMemberRepresentationMethod(
           LangOpts.getMSPointerToMemberRepresentationMethod()),
       MSStructPragmaOn(false), VtorDispStack(LangOpts.getVtorDispMode()),
@@ -1612,11 +1613,6 @@ void Sema::EmitCurrentDiagnostic(unsigned DiagID) {
     PrintContextStack();
 }
 
-Sema::SemaDiagnosticBuilder
-Sema::Diag(SourceLocation Loc, const PartialDiagnostic &PD, bool DeferHint) {
-  return Diag(Loc, PD.getDiagID(), DeferHint) << PD;
-}
-
 bool Sema::hasUncompilableErrorOccurred() const {
   if (getDiagnostics().hasUncompilableErrorOccurred())
     return true;
@@ -1911,29 +1907,6 @@ Sema::targetDiag(SourceLocation Loc, unsigned DiagID, const FunctionDecl *FD) {
                                FD, *this);
 }
 
-Sema::SemaDiagnosticBuilder Sema::Diag(SourceLocation Loc, unsigned DiagID,
-                                       bool DeferHint) {
-  bool IsError = Diags.getDiagnosticIDs()->isDefaultMappingAsError(DiagID);
-  bool ShouldDefer = getLangOpts().CUDA && LangOpts.GPUDeferDiag &&
-                     DiagnosticIDs::isDeferrable(DiagID) &&
-                     (DeferHint || DeferDiags || !IsError);
-  auto SetIsLastErrorImmediate = [&](bool Flag) {
-    if (IsError)
-      IsLastErrorImmediate = Flag;
-  };
-  if (!ShouldDefer) {
-    SetIsLastErrorImmediate(true);
-    return SemaDiagnosticBuilder(SemaDiagnosticBuilder::K_Immediate, Loc,
-                                 DiagID, getCurFunctionDecl(), *this);
-  }
-
-  SemaDiagnosticBuilder DB = getLangOpts().CUDAIsDevice
-                                 ? CUDADiagIfDeviceCode(Loc, DiagID)
-                                 : CUDADiagIfHostCode(Loc, DiagID);
-  SetIsLastErrorImmediate(DB.isImmediate());
-  return DB;
-}
-
 void Sema::checkTypeSupport(QualType Ty, SourceLocation Loc, ValueDecl *D) {
   if (isUnevaluatedContext() || Ty.isNull())
     return;

clang/lib/Sema/SemaBase.cpp

@@ -0,0 +1,85 @@
+#include "clang/Sema/SemaBase.h"
+#include "clang/Sema/Sema.h"
+
+namespace clang {
+
+SemaBase::SemaBase(Sema &S) : SemaRef(S) {}
+
+ASTContext &SemaBase::getASTContext() const { return SemaRef.Context; }
+DiagnosticsEngine &SemaBase::getDiagnostics() const { return SemaRef.Diags; }
+const LangOptions &SemaBase::getLangOpts() const { return SemaRef.LangOpts; }
+
+SemaBase::ImmediateDiagBuilder::~ImmediateDiagBuilder() {
+  // If we aren't active, there is nothing to do.
+  if (!isActive())
+    return;
+
+  // Otherwise, we need to emit the diagnostic. First clear the diagnostic
+  // builder itself so it won't emit the diagnostic in its own destructor.
+  //
+  // This seems wasteful, in that as written the DiagnosticBuilder dtor will
+  // do its own needless checks to see if the diagnostic needs to be
+  // emitted. However, because we take care to ensure that the builder
+  // objects never escape, a sufficiently smart compiler will be able to
+  // eliminate that code.
+  Clear();
+
+  // Dispatch to Sema to emit the diagnostic.
+  SemaRef.EmitCurrentDiagnostic(DiagID);
+}
+
+const SemaBase::SemaDiagnosticBuilder &
+operator<<(const SemaBase::SemaDiagnosticBuilder &Diag,
+           const PartialDiagnostic &PD) {
+  if (Diag.ImmediateDiag)
+    PD.Emit(*Diag.ImmediateDiag);
+  else if (Diag.PartialDiagId)
+    Diag.S.DeviceDeferredDiags[Diag.Fn][*Diag.PartialDiagId].second = PD;
+  return Diag;
+}
+
+void SemaBase::SemaDiagnosticBuilder::AddFixItHint(
+    const FixItHint &Hint) const {
+  if (ImmediateDiag)
+    ImmediateDiag->AddFixItHint(Hint);
+  else if (PartialDiagId)
+    S.DeviceDeferredDiags[Fn][*PartialDiagId].second.AddFixItHint(Hint);
+}
+
+llvm::DenseMap<CanonicalDeclPtr<const FunctionDecl>,
+               std::vector<PartialDiagnosticAt>> &
+SemaBase::SemaDiagnosticBuilder::getDeviceDeferredDiags() const {
+  return S.DeviceDeferredDiags;
+}
+
+Sema::SemaDiagnosticBuilder SemaBase::Diag(SourceLocation Loc, unsigned DiagID,
+                                           bool DeferHint) {
+  bool IsError =
+      getDiagnostics().getDiagnosticIDs()->isDefaultMappingAsError(DiagID);
+  bool ShouldDefer = getLangOpts().CUDA && getLangOpts().GPUDeferDiag &&
+                     DiagnosticIDs::isDeferrable(DiagID) &&
+                     (DeferHint || SemaRef.DeferDiags || !IsError);
+  auto SetIsLastErrorImmediate = [&](bool Flag) {
+    if (IsError)
+      SemaRef.IsLastErrorImmediate = Flag;
+  };
+  if (!ShouldDefer) {
+    SetIsLastErrorImmediate(true);
+    return SemaDiagnosticBuilder(SemaDiagnosticBuilder::K_Immediate, Loc,
+                                 DiagID, SemaRef.getCurFunctionDecl(), SemaRef);
+  }
+
+  SemaDiagnosticBuilder DB = getLangOpts().CUDAIsDevice
+                                 ? SemaRef.CUDADiagIfDeviceCode(Loc, DiagID)
+                                 : SemaRef.CUDADiagIfHostCode(Loc, DiagID);
+  SetIsLastErrorImmediate(DB.isImmediate());
+  return DB;
+}
+
+Sema::SemaDiagnosticBuilder SemaBase::Diag(SourceLocation Loc,
+                                           const PartialDiagnostic &PD,
+                                           bool DeferHint) {
+  return Diag(Loc, PD.getDiagID(), DeferHint) << PD;
+}
+
+} // namespace clang

clang/lib/Sema/SemaOpenACC.cpp

@@ -11,8 +11,8 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#include "clang/AST/StmtOpenACC.h"
 #include "clang/Sema/SemaOpenACC.h"
+#include "clang/AST/StmtOpenACC.h"
 #include "clang/Basic/DiagnosticSema.h"
 #include "clang/Sema/Sema.h"
 
@@ -31,19 +31,14 @@ bool diagnoseConstructAppertainment(SemaOpenACC &S, OpenACCDirectiveKind K,
   case OpenACCDirectiveKind::Serial:
   case OpenACCDirectiveKind::Kernels:
     if (!IsStmt)
-      return S.SemaRef.Diag(StartLoc, diag::err_acc_construct_appertainment)
-             << K;
+      return S.Diag(StartLoc, diag::err_acc_construct_appertainment) << K;
     break;
   }
   return false;
 }
 } // namespace
 
-SemaOpenACC::SemaOpenACC(Sema &S) : SemaRef(S) {}
-
-ASTContext &SemaOpenACC::getASTContext() const { return SemaRef.Context; }
-DiagnosticsEngine &SemaOpenACC::getDiagnostics() const { return SemaRef.Diags; }
-const LangOptions &SemaOpenACC::getLangOpts() const { return SemaRef.LangOpts; }
+SemaOpenACC::SemaOpenACC(Sema &S) : SemaBase(S) {}
 
 bool SemaOpenACC::ActOnClause(OpenACCClauseKind ClauseKind,
                               SourceLocation StartLoc) {
@@ -53,8 +48,7 @@ bool SemaOpenACC::ActOnClause(OpenACCClauseKind ClauseKind,
   // whatever it can do. This function will eventually need to start returning
   // some sort of Clause AST type, but for now just return true/false based on
   // success.
-  return SemaRef.Diag(StartLoc, diag::warn_acc_clause_unimplemented)
-         << ClauseKind;
+  return Diag(StartLoc, diag::warn_acc_clause_unimplemented) << ClauseKind;
 }
 void SemaOpenACC::ActOnConstruct(OpenACCDirectiveKind K,
                                  SourceLocation StartLoc) {
@@ -72,7 +66,7 @@ void SemaOpenACC::ActOnConstruct(OpenACCDirectiveKind K,
     // here as these constructs do not take any arguments.
     break;
   default:
-    SemaRef.Diag(StartLoc, diag::warn_acc_construct_unimplemented) << K;
+    Diag(StartLoc, diag::warn_acc_construct_unimplemented) << K;
     break;
   }
 }