From 6887ff2c70f4afba4e521f8779d041e6d02df464 Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Thu, 27 Jun 2013 20:39:04 +0000
Subject: [PATCH] Simplify StmtIterator.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185098 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/clang/AST/StmtIterator.h | 27 +++++---------
 lib/AST/StmtIterator.cpp         | 63 ++++++--------------------------
 2 files changed, 20 insertions(+), 70 deletions(-)

diff --git a/include/clang/AST/StmtIterator.h b/include/clang/AST/StmtIterator.h
index fc25fa9a6e..fbc8e5d4ea 100644
--- a/include/clang/AST/StmtIterator.h
+++ b/include/clang/AST/StmtIterator.h
@@ -29,18 +29,14 @@ class VariableArrayType;
 
 class StmtIteratorBase {
 protected:
-  enum { DeclMode = 0x1, SizeOfTypeVAMode = 0x2, DeclGroupMode = 0x3,
+  enum { StmtMode = 0x0, SizeOfTypeVAMode = 0x1, DeclGroupMode = 0x2,
          Flags = 0x3 };
   
   Stmt **stmt;
-  union { Decl *decl; Decl **DGI; };
+  Decl **DGI;
   uintptr_t RawVAPtr;
   Decl **DGE;
   
-  bool inDecl() const {
-    return (RawVAPtr & Flags) == DeclMode;
-  }
-
   bool inDeclGroup() const {
     return (RawVAPtr & Flags) == DeclGroupMode;
   }
@@ -50,7 +46,7 @@ protected:
   }
 
   bool inStmt() const {
-    return (RawVAPtr & Flags) == 0;
+    return (RawVAPtr & Flags) == StmtMode;
   }
 
   const VariableArrayType *getVAPtr() const {
@@ -58,7 +54,7 @@ protected:
   }
 
   void setVAPtr(const VariableArrayType *P) {
-    assert (inDecl() || inDeclGroup() || inSizeOfTypeVA());
+    assert (inDeclGroup() || inSizeOfTypeVA());
     RawVAPtr = reinterpret_cast<uintptr_t>(P) | (RawVAPtr & Flags);
   }
 
@@ -68,11 +64,10 @@ protected:
 
   Stmt*& GetDeclExpr() const;
 
-  StmtIteratorBase(Stmt **s) : stmt(s), decl(0), RawVAPtr(0) {}
-  StmtIteratorBase(Decl *d, Stmt **s);
+  StmtIteratorBase(Stmt **s) : stmt(s), DGI(0), RawVAPtr(0) {}
   StmtIteratorBase(const VariableArrayType *t);
   StmtIteratorBase(Decl **dgi, Decl **dge);
-  StmtIteratorBase() : stmt(0), decl(0), RawVAPtr(0) {}
+  StmtIteratorBase() : stmt(0), DGI(0), RawVAPtr(0) {}
 };
 
 
@@ -87,7 +82,6 @@ public:
   StmtIteratorImpl() {}
   StmtIteratorImpl(Stmt **s) : StmtIteratorBase(s) {}
   StmtIteratorImpl(Decl **dgi, Decl **dge) : StmtIteratorBase(dgi, dge) {}
-  StmtIteratorImpl(Decl *d, Stmt **s) : StmtIteratorBase(d, s) {}
   StmtIteratorImpl(const VariableArrayType *t) : StmtIteratorBase(t) {}
 
   DERIVED& operator++() {
@@ -108,15 +102,15 @@ public:
   }
 
   bool operator==(const DERIVED& RHS) const {
-    return stmt == RHS.stmt && decl == RHS.decl && RawVAPtr == RHS.RawVAPtr;
+    return stmt == RHS.stmt && DGI == RHS.DGI && RawVAPtr == RHS.RawVAPtr;
   }
 
   bool operator!=(const DERIVED& RHS) const {
-    return stmt != RHS.stmt || decl != RHS.decl || RawVAPtr != RHS.RawVAPtr;
+    return stmt != RHS.stmt || DGI != RHS.DGI || RawVAPtr != RHS.RawVAPtr;
   }
 
   REFERENCE operator*() const {
-    return (REFERENCE) (inStmt() ? *stmt : GetDeclExpr());
+    return inStmt() ? *stmt : GetDeclExpr();
   }
 
   REFERENCE operator->() const { return operator*(); }
@@ -132,9 +126,6 @@ struct StmtIterator : public StmtIteratorImpl<StmtIterator,Stmt*&> {
 
   StmtIterator(const VariableArrayType *t)
     : StmtIteratorImpl<StmtIterator,Stmt*&>(t) {}
-
-  StmtIterator(Decl* D, Stmt **s = 0)
-    : StmtIteratorImpl<StmtIterator,Stmt*&>(D, s) {}
 };
 
 struct ConstStmtIterator : public StmtIteratorImpl<ConstStmtIterator,
diff --git a/lib/AST/StmtIterator.cpp b/lib/AST/StmtIterator.cpp
index 9bf4aeaae8..6e85375ed2 100644
--- a/lib/AST/StmtIterator.cpp
+++ b/lib/AST/StmtIterator.cpp
@@ -40,14 +40,7 @@ void StmtIteratorBase::NextVA() {
   if (p)
     return;
 
-  if (inDecl()) {
-    if (VarDecl* VD = dyn_cast<VarDecl>(decl))
-      if (VD->Init)
-        return;
-
-    NextDecl();
-  }
-  else if (inDeclGroup()) {
+  if (inDeclGroup()) {
     if (VarDecl* VD = dyn_cast<VarDecl>(*DGI))
       if (VD->Init)
         return;
@@ -55,40 +48,26 @@ void StmtIteratorBase::NextVA() {
     NextDecl();
   }
   else {
-    assert (inSizeOfTypeVA());
-    assert(!decl);
+    assert(inSizeOfTypeVA());
     RawVAPtr = 0;
   }
 }
 
 void StmtIteratorBase::NextDecl(bool ImmediateAdvance) {
   assert (getVAPtr() == NULL);
+  assert(inDeclGroup());
 
-  if (inDecl()) {
-    assert(decl);
+  if (ImmediateAdvance)
+    ++DGI;
 
-    // FIXME: SIMPLIFY AWAY.
-    if (ImmediateAdvance)
-      decl = 0;
-    else if (HandleDecl(decl))
+  for ( ; DGI != DGE; ++DGI)
+    if (HandleDecl(*DGI))
       return;
-  }
-  else {
-    assert(inDeclGroup());
-
-    if (ImmediateAdvance)
-      ++DGI;
-
-    for ( ; DGI != DGE; ++DGI)
-      if (HandleDecl(*DGI))
-        return;
-  }
 
   RawVAPtr = 0;
 }
 
 bool StmtIteratorBase::HandleDecl(Decl* D) {
-
   if (VarDecl* VD = dyn_cast<VarDecl>(D)) {
     if (const VariableArrayType* VAPtr = FindVA(VD->getType().getTypePtr())) {
       setVAPtr(VAPtr);
@@ -113,43 +92,23 @@ bool StmtIteratorBase::HandleDecl(Decl* D) {
   return false;
 }
 
-StmtIteratorBase::StmtIteratorBase(Decl *d, Stmt **s)
-  : stmt(s), decl(d), RawVAPtr(d ? DeclMode : 0) {
-  if (decl)
-    NextDecl(false);
-}
-
 StmtIteratorBase::StmtIteratorBase(Decl** dgi, Decl** dge)
   : stmt(0), DGI(dgi), RawVAPtr(DeclGroupMode), DGE(dge) {
   NextDecl(false);
 }
 
 StmtIteratorBase::StmtIteratorBase(const VariableArrayType* t)
-  : stmt(0), decl(0), RawVAPtr(SizeOfTypeVAMode) {
+  : stmt(0), DGI(0), RawVAPtr(SizeOfTypeVAMode) {
   RawVAPtr |= reinterpret_cast<uintptr_t>(t);
 }
 
 Stmt*& StmtIteratorBase::GetDeclExpr() const {
-
   if (const VariableArrayType* VAPtr = getVAPtr()) {
     assert (VAPtr->SizeExpr);
     return const_cast<Stmt*&>(VAPtr->SizeExpr);
   }
 
-  assert (inDecl() || inDeclGroup());
-
-  if (inDeclGroup()) {
-    VarDecl* VD = cast<VarDecl>(*DGI);
-    return *VD->getInitAddress();
-  }
-
-  assert (inDecl());
-
-  if (VarDecl* VD = dyn_cast<VarDecl>(decl)) {
-    assert (VD->Init);
-    return *VD->getInitAddress();
-  }
-
-  EnumConstantDecl* ECD = cast<EnumConstantDecl>(decl);
-  return ECD->Init;
+  assert (inDeclGroup());
+  VarDecl* VD = cast<VarDecl>(*DGI);
+  return *VD->getInitAddress();
 }
-- 
2.40.0