PCH support for return statements.

Optimize PCH encoding for switch-case statements slightly, by making
the switch-case numbering local to a particular statement.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@69355 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 58 insertions, 4 deletions

diff --git a/include/clang/AST/Stmt.h b/include/clang/AST/Stmt.h
index 0f489d2291..fbb5552ca7 100644
--- a/include/clang/AST/Stmt.h
+++ b/include/clang/AST/Stmt.h
@@ -931,9 +931,16 @@ class ReturnStmt : public Stmt {
 public:
   ReturnStmt(SourceLocation RL, Expr *E = 0) : Stmt(ReturnStmtClass), 
     RetExpr((Stmt*) E), RetLoc(RL) {}
-  
+
+  /// \brief Build an empty return expression.
+  explicit ReturnStmt(EmptyShell Empty) : Stmt(ReturnStmtClass, Empty) { }
+
   const Expr *getRetValue() const;
   Expr *getRetValue();
+  void setRetValue(Expr *E) { RetExpr = reinterpret_cast<Stmt*>(E); }
+
+  SourceLocation getReturnLoc() const { return RetLoc; }
+  void setReturnLoc(SourceLocation L) { RetLoc = L; }
 
   virtual SourceRange getSourceRange() const;
   
diff --git a/include/clang/Frontend/PCHBitCodes.h b/include/clang/Frontend/PCHBitCodes.h
index 06c120e465..7c316c691c 100644
--- a/include/clang/Frontend/PCHBitCodes.h
+++ b/include/clang/Frontend/PCHBitCodes.h
@@ -397,6 +397,8 @@ namespace clang {
       STMT_CONTINUE,
       /// \brief A BreakStmt record.
       STMT_BREAK,
+      /// \brief A ReturnStmt record.
+      STMT_RETURN,
       /// \brief A PredefinedExpr record.
       EXPR_PREDEFINED,
       /// \brief A DeclRefExpr record.
diff --git a/lib/Frontend/PCHReader.cpp b/lib/Frontend/PCHReader.cpp
index d2fb8ab3cb..0dcdf8d3fd 100644
--- a/lib/Frontend/PCHReader.cpp
+++ b/lib/Frontend/PCHReader.cpp
@@ -256,6 +256,7 @@ namespace {
     unsigned VisitForStmt(ForStmt *S);
     unsigned VisitContinueStmt(ContinueStmt *S);
     unsigned VisitBreakStmt(BreakStmt *S);
+    unsigned VisitReturnStmt(ReturnStmt *S);
     unsigned VisitExpr(Expr *E);
     unsigned VisitPredefinedExpr(PredefinedExpr *E);
     unsigned VisitDeclRefExpr(DeclRefExpr *E);
@@ -398,6 +399,13 @@ unsigned PCHStmtReader::VisitBreakStmt(BreakStmt *S) {
   return 0;
 }
 
+unsigned PCHStmtReader::VisitReturnStmt(ReturnStmt *S) {
+  VisitStmt(S);
+  S->setRetValue(cast_or_null<Expr>(StmtStack.back()));
+  S->setReturnLoc(SourceLocation::getFromRawEncoding(Record[Idx++]));
+  return 1;
+}
+
 unsigned PCHStmtReader::VisitExpr(Expr *E) {
   VisitStmt(E);
   E->setType(Reader.GetType(Record[Idx++]));
@@ -2172,6 +2180,10 @@ Stmt *PCHReader::ReadStmt() {
       S = new (Context) BreakStmt(Empty);
       break;
 
+    case pch::STMT_RETURN:
+      S = new (Context) ReturnStmt(Empty);
+      break;
+
     case pch::EXPR_PREDEFINED:
       // FIXME: untested (until we can serialize function bodies).
       S = new (Context) PredefinedExpr(Empty);
@@ -2311,6 +2323,7 @@ Stmt *PCHReader::ReadStmt() {
     StmtStack.push_back(S);
   }
   assert(StmtStack.size() == 1 && "Extra expressions on stack!");
+  SwitchCaseStmts.clear();
   return StmtStack.back();
 }
 
diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index 29c9eb81f4..91490549ea 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -458,6 +458,7 @@ namespace {
     void VisitForStmt(ForStmt *S);
     void VisitContinueStmt(ContinueStmt *S);
     void VisitBreakStmt(BreakStmt *S);
+    void VisitReturnStmt(ReturnStmt *S);
     void VisitExpr(Expr *E);
     void VisitPredefinedExpr(PredefinedExpr *E);
     void VisitDeclRefExpr(DeclRefExpr *E);
@@ -592,6 +593,13 @@ void PCHStmtWriter::VisitBreakStmt(BreakStmt *S) {
   Code = pch::STMT_BREAK;
 }
 
+void PCHStmtWriter::VisitReturnStmt(ReturnStmt *S) {
+  VisitStmt(S);
+  Writer.WriteSubStmt(S->getRetValue());
+  Writer.AddSourceLocation(S->getReturnLoc(), Record);
+  Code = pch::STMT_RETURN;
+}
+
 void PCHStmtWriter::VisitExpr(Expr *E) {
   VisitStmt(E);
   Writer.AddTypeRef(E->getType(), Record);
@@ -1822,6 +1830,7 @@ void PCHWriter::FlushStmts() {
   }
 
   StmtsToEmit.clear();
+  SwitchCaseIDs.clear();
 }
 
 unsigned PCHWriter::RecordSwitchCaseID(SwitchCase *S) {
diff --git a/test/PCH/stmts.c b/test/PCH/stmts.c
index b71db63e67..e9d03e8774 100644
--- a/test/PCH/stmts.c
+++ b/test/PCH/stmts.c
@@ -1,8 +1,9 @@
 // Test this without pch.
-// RUN: clang-cc -fblocks -include %S/stmts.h -fsyntax-only -emit-llvm -o - %s
+// RUN: clang-cc -fblocks -include %S/stmts.h -fsyntax-only -ast-print -o - %s
 
 // Test with pch.
 // RUN: clang-cc -emit-pch -fblocks -o %t %S/stmts.h &&
-// RUN: clang-cc -fblocks -include-pch %t -fsyntax-only -emit-llvm -o - %s 
+// RUN: clang-cc -fblocks -include-pch %t -fsyntax-only -ast-print -o - %s 
 
 void g0(void) { f0(5); }
+int g1(int x) { return f1(x); }
diff --git a/test/PCH/stmts.h b/test/PCH/stmts.h
index d67ae187bb..7290d2efcb 100644
--- a/test/PCH/stmts.h
+++ b/test/PCH/stmts.h
@@ -17,6 +17,13 @@ void f0(int x) {
     break;
 
   default:
+    switch (x >> 1) {
+    case 7:
+      // fall through
+    case 9:
+      break;
+    }
+    x += 2;
     break;
   }
 
@@ -32,5 +39,20 @@ void f0(int x) {
     x++;
   } while (x < 10);
 
-  for (; x < 20; ++x) ;
+  for (; x < 20; ++x) {
+    if (x == 12)
+      return;
+  }
+}
+
+int f1(int x) {
+  switch (x) {
+  case 17:
+    return 12;
+
+  default:
+    break;
+  }
+
+  return x*2;
 }