A few more tweaks to the blocks AST representation:

  - BlockDeclRefExprs always store VarDecls
  - BDREs no longer store copy expressions
  - BlockDecls now store a list of captured variables, information about
    how they're captured, and a copy expression if necessary
    
With that in hand, change IR generation to use the captures data in       
blocks instead of walking the block independently.        

Additionally, optimize block layout by emitting fields in descending
alignment order, with a heuristic for filling in words when alignment
of the end of the block header is insufficient for the most aligned
field.

llvm-svn: 125005

4 files changed, 28 insertions, 13 deletions

diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 311ce7b5b11..2c304326bf1 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -698,13 +698,20 @@ void ASTDeclReader::VisitBlockDecl(BlockDecl *BD) {
   BD->setParams(Params.data(), NumParams);
 
   bool capturesCXXThis = Record[Idx++];
-  unsigned numCapturedDecls = Record[Idx++];
-  llvm::SmallVector<VarDecl*, 16> capturedDecls;
-  capturedDecls.reserve(numCapturedDecls);
-  for (unsigned i = 0; i != numCapturedDecls; ++i)
-    capturedDecls.push_back(cast<VarDecl>(Reader.GetDecl(Record[Idx++])));
-  BD->setCapturedDecls(*Reader.getContext(), capturedDecls.begin(),
-                       capturedDecls.end(), capturesCXXThis);
+  unsigned numCaptures = Record[Idx++];
+  llvm::SmallVector<BlockDecl::Capture, 16> captures;
+  captures.reserve(numCaptures);
+  for (unsigned i = 0; i != numCaptures; ++i) {
+    VarDecl *decl = cast<VarDecl>(Reader.GetDecl(Record[Idx++]));
+    unsigned flags = Record[Idx++];
+    bool byRef = (flags & 1);
+    bool nested = (flags & 2);
+    Expr *copyExpr = ((flags & 4) ? Reader.ReadExpr(F) : 0);
+
+    captures.push_back(BlockDecl::Capture(decl, byRef, nested, copyExpr));
+  }
+  BD->setCaptures(*Reader.getContext(), captures.begin(),
+                  captures.end(), capturesCXXThis);
 }
 
 void ASTDeclReader::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 4335ff97068..8bd94b48ce2 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -798,11 +798,10 @@ void ASTStmtReader::VisitBlockExpr(BlockExpr *E) {
 
 void ASTStmtReader::VisitBlockDeclRefExpr(BlockDeclRefExpr *E) {
   VisitExpr(E);
-  E->setDecl(cast<ValueDecl>(Reader.GetDecl(Record[Idx++])));
+  E->setDecl(cast<VarDecl>(Reader.GetDecl(Record[Idx++])));
   E->setLocation(ReadSourceLocation(Record, Idx));
   E->setByRef(Record[Idx++]);
   E->setConstQualAdded(Record[Idx++]);
-  E->setCopyConstructorExpr(Reader.ReadSubExpr());
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index 1fe6398b733..3e57de11c83 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -624,10 +624,20 @@ void ASTDeclWriter::VisitBlockDecl(BlockDecl *D) {
        P != PEnd; ++P)
     Writer.AddDeclRef(*P, Record);
   Record.push_back(D->capturesCXXThis());
-  Record.push_back(D->getNumCapturedDecls());
+  Record.push_back(D->getNumCaptures());
   for (BlockDecl::capture_iterator
-         i = D->capture_begin(), e = D->capture_end(); i != e; ++i)
-    Writer.AddDeclRef(*i, Record);
+         i = D->capture_begin(), e = D->capture_end(); i != e; ++i) {
+    const BlockDecl::Capture &capture = *i;
+    Writer.AddDeclRef(capture.getVariable(), Record);
+
+    unsigned flags = 0;
+    if (capture.isByRef()) flags |= 1;
+    if (capture.isNested()) flags |= 2;
+    if (capture.hasCopyExpr()) flags |= 4;
+    Record.push_back(flags);
+
+    if (capture.hasCopyExpr()) Writer.AddStmt(capture.getCopyExpr());
+  }
 
   Code = serialization::DECL_BLOCK;
 }
diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
index 4a3bea5aaeb..d721c18022e 100644
--- a/clang/lib/Serialization/ASTWriterStmt.cpp
+++ b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -769,7 +769,6 @@ void ASTStmtWriter::VisitBlockDeclRefExpr(BlockDeclRefExpr *E) {
   Writer.AddSourceLocation(E->getLocation(), Record);
   Record.push_back(E->isByRef());
   Record.push_back(E->isConstQualAdded());
-  Writer.AddStmt(E->getCopyConstructorExpr());
   Code = serialization::EXPR_BLOCK_DECL_REF;
 }