CodeGen for CapturedStmts

EmitCapturedStmt creates a captured struct containing all of the captured
variables, and then emits a call to the outlined function.  This is similar in
principle to EmitBlockLiteral.

GenerateCapturedFunction actually produces the outlined function.  It is based
on GenerateBlockFunction, but is much simpler.  The function type is determined
by the parameters that are in the CapturedDecl.

Some changes have been added to this patch that were reviewed as part of the
serialization patch and moving the parameters to the captured decl.

Differential Revision: http://llvm-reviews.chandlerc.com/D640

llvm-svn: 181536

1 files changed, 64 insertions, 1 deletions

diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index ff74c15c38c..6caf1689a9d 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -23,6 +23,7 @@
 #include "clang/AST/ExprObjC.h"
 #include "clang/AST/Type.h"
 #include "clang/Basic/ABI.h"
+#include "clang/Basic/CapturedStmt.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Frontend/CodeGenOptions.h"
 #include "llvm/ADT/ArrayRef.h"
@@ -606,6 +607,65 @@ public:
   /// we prefer to insert allocas.
   llvm::AssertingVH<llvm::Instruction> AllocaInsertPt;
 
+  /// \brief API for captured statement code generation.
+  class CGCapturedStmtInfo {
+  public:
+    explicit CGCapturedStmtInfo(const CapturedStmt &S,
+                                CapturedRegionKind K = CR_Default)
+      : Kind(K), ThisValue(0), CXXThisFieldDecl(0) {
+
+      RecordDecl::field_iterator Field =
+        S.getCapturedRecordDecl()->field_begin();
+      for (CapturedStmt::const_capture_iterator I = S.capture_begin(),
+                                                E = S.capture_end();
+           I != E; ++I, ++Field) {
+        if (I->capturesThis())
+          CXXThisFieldDecl = *Field;
+        else
+          CaptureFields[I->getCapturedVar()] = *Field;
+      }
+    }
+
+    virtual ~CGCapturedStmtInfo();
+
+    CapturedRegionKind getKind() const { return Kind; }
+
+    void setContextValue(llvm::Value *V) { ThisValue = V; }
+    // \brief Retrieve the value of the context parameter.
+    llvm::Value *getContextValue() const { return ThisValue; }
+
+    /// \brief Lookup the captured field decl for a variable.
+    const FieldDecl *lookup(const VarDecl *VD) const {
+      return CaptureFields.lookup(VD);
+    }
+
+    bool isCXXThisExprCaptured() const { return CXXThisFieldDecl != 0; }
+    FieldDecl *getThisFieldDecl() const { return CXXThisFieldDecl; }
+
+    /// \brief Emit the captured statement body.
+    virtual void EmitBody(CodeGenFunction &CGF, Stmt *S) {
+      CGF.EmitStmt(S);
+    }
+
+    /// \brief Get the name of the capture helper.
+    virtual StringRef getHelperName() const { return "__captured_stmt"; }
+
+  private:
+    /// \brief The kind of captured statement being generated.
+    CapturedRegionKind Kind;
+
+    /// \brief Keep the map between VarDecl and FieldDecl.
+    llvm::SmallDenseMap<const VarDecl *, FieldDecl *> CaptureFields;
+
+    /// \brief The base address of the captured record, passed in as the first
+    /// argument of the parallel region function.
+    llvm::Value *ThisValue;
+
+    /// \brief Captured 'this' type.
+    FieldDecl *CXXThisFieldDecl;
+  };
+  CGCapturedStmtInfo *CapturedStmtInfo;
+
   /// BoundsChecking - Emit run-time bounds checks. Higher values mean
   /// potentially higher performance penalties.
   unsigned char BoundsChecking;
@@ -2188,7 +2248,6 @@ public:
   void EmitCaseStmt(const CaseStmt &S);
   void EmitCaseStmtRange(const CaseStmt &S);
   void EmitAsmStmt(const AsmStmt &S);
-  void EmitCapturedStmt(const CapturedStmt &S);
 
   void EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S);
   void EmitObjCAtTryStmt(const ObjCAtTryStmt &S);
@@ -2204,6 +2263,10 @@ public:
   void EmitCXXTryStmt(const CXXTryStmt &S);
   void EmitCXXForRangeStmt(const CXXForRangeStmt &S);
 
+  llvm::Function *EmitCapturedStmt(const CapturedStmt &S, CapturedRegionKind K);
+  llvm::Function *GenerateCapturedStmtFunction(const CapturedDecl *CD,
+                                               const RecordDecl *RD);
+
   //===--------------------------------------------------------------------===//
   //                         LValue Expression Emission
   //===--------------------------------------------------------------------===//