diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
@@ -508,9 +508,6 @@ Sema::ActOnIfStmt(SourceLocation IfLoc, bool IsConstexpr, Stmt *InitStmt,
                   ConditionResult Cond,
                   Stmt *thenStmt, SourceLocation ElseLoc,
                   Stmt *elseStmt) {
-  if (InitStmt)
-    Diag(InitStmt->getLocStart(), diag::err_init_stmt_not_supported);
-
   if (Cond.isInvalid())
     Cond = ConditionResult(
         *this, nullptr,
@@ -528,12 +525,14 @@ Sema::ActOnIfStmt(SourceLocation IfLoc, bool IsConstexpr, Stmt *InitStmt,
     DiagnoseEmptyStmtBody(CondExpr->getLocEnd(), thenStmt,
                           diag::warn_empty_if_body);
 
-  return BuildIfStmt(IfLoc, IsConstexpr, Cond, thenStmt, ElseLoc, elseStmt);
+  return BuildIfStmt(IfLoc, IsConstexpr, InitStmt, Cond, thenStmt, ElseLoc,
+                     elseStmt);
 }
 
 StmtResult Sema::BuildIfStmt(SourceLocation IfLoc, bool IsConstexpr,
-                             ConditionResult Cond, Stmt *thenStmt,
-                             SourceLocation ElseLoc, Stmt *elseStmt) {
+                             Stmt *InitStmt, ConditionResult Cond,
+                             Stmt *thenStmt, SourceLocation ElseLoc,
+                             Stmt *elseStmt) {
   if (Cond.isInvalid())
     return StmtError();
 
@@ -543,8 +542,9 @@ StmtResult Sema::BuildIfStmt(SourceLocation IfLoc, bool IsConstexpr,
   DiagnoseUnusedExprResult(thenStmt);
   DiagnoseUnusedExprResult(elseStmt);
 
-  return new (Context) IfStmt(Context, IfLoc, IsConstexpr, Cond.get().first,
-                              Cond.get().second, thenStmt, ElseLoc, elseStmt);
+  return new (Context)
+      IfStmt(Context, IfLoc, IsConstexpr, InitStmt, Cond.get().first,
+             Cond.get().second, thenStmt, ElseLoc, elseStmt);
 }
 
 namespace {
@@ -668,13 +668,10 @@ StmtResult Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc,
   if (Cond.isInvalid())
     return StmtError();
 
-  if (InitStmt)
-    Diag(InitStmt->getLocStart(), diag::err_init_stmt_not_supported);
-
   getCurFunction()->setHasBranchIntoScope();
 
-  SwitchStmt *SS =
-      new (Context) SwitchStmt(Context, Cond.get().first, Cond.get().second);
+  SwitchStmt *SS = new (Context)
+      SwitchStmt(Context, InitStmt, Cond.get().first, Cond.get().second);
   getCurFunction()->SwitchStack.push_back(SS);
   return SS;
 }

diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
@@ -1174,19 +1174,19 @@ class TreeTransform {
   /// By default, performs semantic analysis to build the new statement.
   /// Subclasses may override this routine to provide different behavior.
   StmtResult RebuildIfStmt(SourceLocation IfLoc, bool IsConstexpr,
-                           Sema::ConditionResult Cond, Stmt *Then,
+                           Sema::ConditionResult Cond, Stmt *Init, Stmt *Then,
                            SourceLocation ElseLoc, Stmt *Else) {
-    return getSema().ActOnIfStmt(IfLoc, IsConstexpr, nullptr, Cond, Then,
+    return getSema().ActOnIfStmt(IfLoc, IsConstexpr, Init, Cond, Then,
                                  ElseLoc, Else);
   }
 
   /// \brief Start building a new switch statement.
   ///
   /// By default, performs semantic analysis to build the new statement.
   /// Subclasses may override this routine to provide different behavior.
-  StmtResult RebuildSwitchStmtStart(SourceLocation SwitchLoc,
+  StmtResult RebuildSwitchStmtStart(SourceLocation SwitchLoc, Stmt *Init,
                                     Sema::ConditionResult Cond) {
-    return getSema().ActOnStartOfSwitchStmt(SwitchLoc, nullptr, Cond);
+    return getSema().ActOnStartOfSwitchStmt(SwitchLoc, Init, Cond);
   }
 
   /// \brief Attach the body to the switch statement.
@@ -6266,6 +6266,11 @@ StmtResult TreeTransform<Derived>::TransformAttributedStmt(AttributedStmt *S) {
 template<typename Derived>
 StmtResult
 TreeTransform<Derived>::TransformIfStmt(IfStmt *S) {
+  // Transform the initialization statement
+  StmtResult Init = getDerived().TransformStmt(S->getInit());
+  if (Init.isInvalid())
+    return StmtError();
+
   // Transform the condition
   Sema::ConditionResult Cond = getDerived().TransformCondition(
       S->getIfLoc(), S->getConditionVariable(), S->getCond(),
@@ -6298,18 +6303,25 @@ TreeTransform<Derived>::TransformIfStmt(IfStmt *S) {
   }
 
   if (!getDerived().AlwaysRebuild() &&
+      Init.get() == S->getInit() &&
       Cond.get() == std::make_pair(S->getConditionVariable(), S->getCond()) &&
       Then.get() == S->getThen() &&
       Else.get() == S->getElse())
     return S;
 
   return getDerived().RebuildIfStmt(S->getIfLoc(), S->isConstexpr(), Cond,
-                                    Then.get(), S->getElseLoc(), Else.get());
+                                    Init.get(), Then.get(), S->getElseLoc(),
+                                    Else.get());
 }
 
 template<typename Derived>
 StmtResult
 TreeTransform<Derived>::TransformSwitchStmt(SwitchStmt *S) {
+  // Transform the initialization statement
+  StmtResult Init = getDerived().TransformStmt(S->getInit());
+  if (Init.isInvalid())
+    return StmtError();
+
   // Transform the condition.
   Sema::ConditionResult Cond = getDerived().TransformCondition(
       S->getSwitchLoc(), S->getConditionVariable(), S->getCond(),
@@ -6319,7 +6331,8 @@ TreeTransform<Derived>::TransformSwitchStmt(SwitchStmt *S) {
 
   // Rebuild the switch statement.
   StmtResult Switch
-    = getDerived().RebuildSwitchStmtStart(S->getSwitchLoc(), Cond);
+    = getDerived().RebuildSwitchStmtStart(S->getSwitchLoc(),
+                                          S->getInit(), Cond);
   if (Switch.isInvalid())
     return StmtError();
 

diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -185,6 +185,7 @@ void ASTStmtReader::VisitAttributedStmt(AttributedStmt *S) {
 void ASTStmtReader::VisitIfStmt(IfStmt *S) {
   VisitStmt(S);
   S->setConstexpr(Record[Idx++]);
+  S->setInit(Reader.ReadSubStmt());
   S->setConditionVariable(Reader.getContext(),
                           ReadDeclAs<VarDecl>(Record, Idx));
   S->setCond(Reader.ReadSubExpr());
@@ -196,6 +197,7 @@ void ASTStmtReader::VisitIfStmt(IfStmt *S) {
 
 void ASTStmtReader::VisitSwitchStmt(SwitchStmt *S) {
   VisitStmt(S);
+  S->setInit(Reader.ReadSubStmt());
   S->setConditionVariable(Reader.getContext(),
                           ReadDeclAs<VarDecl>(Record, Idx));
   S->setCond(Reader.ReadSubExpr());

diff --git a/clang/lib/Serialization/ASTWriterStmt.cpp b/clang/lib/Serialization/ASTWriterStmt.cpp
@@ -129,6 +129,7 @@ void ASTStmtWriter::VisitAttributedStmt(AttributedStmt *S) {
 void ASTStmtWriter::VisitIfStmt(IfStmt *S) {
   VisitStmt(S);
   Record.push_back(S->isConstexpr());
+  Record.AddStmt(S->getInit());
   Record.AddDeclRef(S->getConditionVariable());
   Record.AddStmt(S->getCond());
   Record.AddStmt(S->getThen());
@@ -140,6 +141,7 @@ void ASTStmtWriter::VisitIfStmt(IfStmt *S) {
 
 void ASTStmtWriter::VisitSwitchStmt(SwitchStmt *S) {
   VisitStmt(S);
+  Record.AddStmt(S->getInit());
   Record.AddDeclRef(S->getConditionVariable());
   Record.AddStmt(S->getCond());
   Record.AddStmt(S->getBody());

diff --git a/clang/test/CodeGenCXX/cxx1z-init-statement.cpp b/clang/test/CodeGenCXX/cxx1z-init-statement.cpp
@@ -0,0 +1,70 @@
+// RUN: %clang_cc1 -std=c++1z -triple x86_64-apple-macosx10.7.0 -emit-llvm -o - %s -w | FileCheck %s
+
+typedef int T;
+void f() {
+  // CHECK:      %[[A:.*]] = alloca i32, align 4
+  // CHECK-NEXT: store i32 5, i32* %[[A]], align 4
+  // CHECK-NEXT: %[[B:.*]] = load i32, i32* %[[A]], align 4
+  // CHECK-NEXT  %[[C:.*]] = icmp slt i32 %[[B]], 8
+  if (int a = 5; a < 8)
+    ;
+}
+
+void f1() {
+  // CHECK:      %[[A:.*]] = alloca i32, align 4
+  // CHECK-NEXT: %[[B:.*]] = alloca i32, align 4
+  // CHECK-NEXT: %[[C:.*]] = alloca i32, align 4
+  // CHECK-NEXT: store i32 5, i32* %[[B]], align 4
+  // CHECK-NEXT: store i32 7, i32* %[[C]], align 4
+  if (int a, b = 5; int c = 7)
+    ;
+}
+
+int f2() {
+  // CHECK:      %[[A:.*]] = alloca i32, align 4
+  // CHECK-NEXT: %[[B:.*]] = call i32 @_Z2f2v()
+  // CHECK-NEXT: store i32 7, i32* %[[A]], align 4
+  // CHECK-NEXT: %[[C:.*]] = load i32, i32* %[[A]], align 4
+  // CHECK-NEXT: %[[D:.*]] = icmp ne i32 %[[C]], 0
+  if (T{f2()}; int c = 7)
+    ;
+  return 2;
+}
+
+void g() {
+  // CHECK:      %[[A:.*]] = alloca i32, align 4
+  // CHECK-NEXT: store i32 5, i32* %[[A]], align 4
+  // CHECK-NEXT: %[[B:.*]] = load i32, i32* %[[A]], align 4
+  // CHECK-NEXT: switch i32 %[[B]], label %[[C:.*]] [
+  switch (int a = 5; a) {
+    case 0:
+      break;
+  }
+}
+
+void g1() {
+  // CHECK:      %[[A:.*]] = alloca i32, align 4
+  // CHECK-NEXT: %[[B:.*]] = alloca i32, align 4
+  // CHECK-NEXT: %[[C:.*]] = alloca i32, align 4
+  // CHECK-NEXT: store i32 5, i32* %[[B]], align 4
+  // CHECK-NEXT: store i32 7, i32* %[[C]], align 4
+  // CHECK-NEXT: %[[D:.*]] = load i32, i32* %[[C]], align 4
+  // CHECK-NEXT: switch i32 %[[D]], label %[[E:.*]] [
+  switch (int a, b = 5; int c = 7) {
+    case 0:
+      break;
+  }
+}
+
+int g2() {
+  // CHECK:      %[[A:.*]] = alloca i32, align 4
+  // CHECK-NEXT: %[[B:.*]] = call i32 @_Z2f2v()
+  // CHECK-NEXT: store i32 7, i32* %[[A]], align 4
+  // CHECK-NEXT: %[[C:.*]] = load i32, i32* %[[A]], align 4
+  // CHECK-NEXT: switch i32 %[[C]], label %[[E:.*]] [
+  switch (T{f2()}; int c = 7) {
+    case 0:
+      break;
+  }
+  return 2;
+}
diff --git a/clang/test/Misc/ast-dump-invalid.cpp b/clang/test/Misc/ast-dump-invalid.cpp
@@ -34,14 +34,14 @@ int g(int i) {
 // CHECK-NEXT:   `-CompoundStmt
 // CHECK-NEXT:     `-IfStmt {{.*}} <line:25:3, line:28:12>
 // CHECK-NEXT:       |-<<<NULL>>>
+// CHECK-NEXT:       |-<<<NULL>>>
 // CHECK-NEXT:       |-OpaqueValueExpr {{.*}} <<invalid sloc>> '_Bool'
 // CHECK-NEXT:       |-ReturnStmt {{.*}} <line:26:5, col:12>
 // CHECK-NEXT:       | `-IntegerLiteral {{.*}} <col:12> 'int' 4
 // CHECK-NEXT:       `-ReturnStmt {{.*}} <line:28:5, col:12>
 // CHECK-NEXT:         `-ImplicitCastExpr {{.*}} <col:12> 'int' <LValueToRValue>
 // CHECK-NEXT:           `-DeclRefExpr {{.*}} <col:12> 'int' lvalue ParmVar {{.*}} 'i' 'int'
 
-
 namespace TestInvalidFunctionDecl {
 struct Str {
    double foo1(double, invalid_type);

diff --git a/clang/test/PCH/cxx1z-init-statement.cpp b/clang/test/PCH/cxx1z-init-statement.cpp
@@ -0,0 +1,17 @@
+// Test this without pch.
+// RUN: %clang_cc1 -std=c++1z -include %S/cxx1z-init-statement.h -fsyntax-only -emit-llvm -o - %s
+
+// Test with pch.
+// RUN: %clang_cc1 -x c++ -std=c++1z -emit-pch -o %t %S/cxx1z-init-statement.h
+// RUN: %clang_cc1 -std=c++1z -include-pch %t -fsyntax-only -emit-llvm -o - %s 
+
+void g0(void) {
+  static_assert(test_if(-1) == -1, "");
+  static_assert(test_if(0) == 0, "");
+}
+
+void g1(void) {
+  static_assert(test_switch(-1) == -1, "");
+  static_assert(test_switch(0) == 0, "");
+  static_assert(test_switch(1) == 1, "");
+}
diff --git a/clang/test/PCH/cxx1z-init-statement.h b/clang/test/PCH/cxx1z-init-statement.h
@@ -0,0 +1,22 @@
+// Header for PCH test cxx1z-init-statement.cpp
+
+constexpr int test_if(int x) { 
+  if (int a = ++x; a == 0) {
+    return -1;
+  } else if (++a; a == 2) {
+    return 0;
+  }
+  return 2;
+}
+
+constexpr int test_switch(int x) {
+  switch (int a = ++x; a) {
+    case 0:
+      return -1;
+    case 1:
+      return 0;
+    case 2:
+      return 1;
+  }
+  return 2;
+}
diff --git a/clang/test/Parser/cxx1z-init-statement.cpp b/clang/test/Parser/cxx1z-init-statement.cpp
@@ -4,18 +4,18 @@ int g, h;
 typedef int T;
 int f() {
   // init-statement declarations
-  if (T n = 0; n != 0) {} // expected-error {{not yet supported}}
-  if (T f(); f()) {} // expected-error {{not yet supported}}
-  if (T(f()); f()) {} // expected-error {{not yet supported}}
-  if (T(f()), g, h; f()) {} // expected-error {{not yet supported}}
-  if (T f(); f()) {} // expected-error {{not yet supported}}
-  if (T f(), g, h; f()) {} // expected-error {{not yet supported}}
-  if (T(n) = 0; n) {} // expected-error {{not yet supported}}
+  if (T n = 0; n != 0) {}
+  if (T f(); f()) {}
+  if (T(f()); f()) {}
+  if (T(f()), g, h; f()) {}
+  if (T f(); f()) {}
+  if (T f(), g, h; f()) {}
+  if (T(n) = 0; n) {}
 
   // init-statement expressions
-  if (T{f()}; f()) {} // expected-error {{not yet supported}}
-  if (T{f()}, g, h; f()) {} // expected-error {{not yet supported}} expected-warning 2{{unused}}
-  if (T(f()), g, h + 1; f()) {} // expected-error {{not yet supported}} expected-warning 2{{unused}}
+  if (T{f()}; f()) {}
+  if (T{f()}, g, h; f()) {} // expected-warning 2{{unused}}
+  if (T(f()), g, h + 1; f()) {} // expected-warning 2{{unused}}
 
   // condition declarations
   if (T(n){g}) {}
@@ -34,10 +34,10 @@ int f() {
   if (T(n)(int())) {} // expected-error {{undeclared identifier 'n'}}
 
   // Likewise for 'switch'
-  switch (int n; n) {} // expected-error {{not yet supported}}
-  switch (g; int g = 5) {} // expected-error {{not yet supported}}
+  switch (int n; n) {}
+  switch (g; int g = 5) {}
 
-  if (int a, b; int c = a) { // expected-error {{not yet supported}} expected-note 6{{previous}}
+  if (int a, b; int c = a) { // expected-note 6{{previous}}
     int a; // expected-error {{redefinition}}
     int b; // expected-error {{redefinition}}
     int c; // expected-error {{redefinition}}
@@ -46,4 +46,6 @@ int f() {
     int b; // expected-error {{redefinition}}
     int c; // expected-error {{redefinition}}
   }
+
+  return 0;
 }
diff --git a/clang/test/SemaCXX/cxx1z-init-statement-warn-unused.cpp b/clang/test/SemaCXX/cxx1z-init-statement-warn-unused.cpp
@@ -0,0 +1,26 @@
+// RUN: %clang_cc1 -std=c++1z -verify -Wuninitialized %s
+
+void testIf() {
+  if (bool b; b) // expected-warning {{uninitialized}} expected-note {{to silence}}
+    ;
+  if (int a, b = 2; a) // expected-warning {{uninitialized}} expected-note {{to silence}}
+    ;
+  int a;
+  if (a = 0; a) {} // OK
+}
+
+void testSwitch() {
+  switch (bool b; b) { // expected-warning {{uninitialized}} expected-warning {{boolean value}} expected-note {{to silence}}
+    case 0:
+      break;
+  }
+  switch (int a, b = 7; a) { // expected-warning {{uninitialized}} expected-note {{to silence}}
+    case 0:
+      break;
+  }
+  int c;
+  switch (c = 0; c) { // OK
+    case 0:
+      break;
+  }
+}
diff --git a/clang/test/SemaCXX/cxx1z-init-statement.cpp b/clang/test/SemaCXX/cxx1z-init-statement.cpp
@@ -0,0 +1,91 @@
+// RUN: %clang_cc1 -std=c++1z -verify %s
+
+void testIf() {
+  int x = 0;
+  if (x; x) ++x;
+  if (int t = 0; t) ++t; else --t;
+
+  if (int x, y = 0; y) // expected-note 2 {{previous definition is here}}
+    int x = 0; // expected-error {{redefinition of 'x'}}
+  else
+    int x = 0; // expected-error {{redefinition of 'x'}}
+
+  if (x; int a = 0) ++a;
+  if (x, +x; int a = 0) // expected-note 2 {{previous definition is here}} expected-warning {{unused}}
+    int a = 0; // expected-error {{redefinition of 'a'}}
+  else
+    int a = 0; // expected-error {{redefinition of 'a'}}
+
+  if (int b = 0; b)
+    ;
+  b = 2; // expected-error {{use of undeclared identifier}}
+}
+
+void testSwitch() {
+  int x = 0;
+  switch (x; x) {
+    case 1:
+      ++x;
+  }
+
+  switch (int x, y = 0; y) {
+    case 1:
+      ++x;
+    default:
+      ++y;
+  }
+
+  switch (int x, y = 0; y) { // expected-note 2 {{previous definition is here}}
+    case 0:
+      int x = 0; // expected-error {{redefinition of 'x'}}
+    case 1:
+      int y = 0; // expected-error {{redefinition of 'y'}}
+  };
+
+  switch (x; int a = 0) {
+    case 0:
+      ++a;
+  }
+
+  switch (x, +x; int a = 0) { // expected-note {{previous definition is here}} expected-warning {{unused}}
+    case 0:
+      int a = 0; // expected-error {{redefinition of 'a'}} // expected-note {{previous definition is here}}
+    case 1:
+      int a = 0; // expected-error {{redefinition of 'a'}}
+  }
+
+  switch (int b = 0; b) {
+    case 0:
+      break;
+  }
+  b = 2; // expected-error {{use of undeclared identifier}}
+}
+
+constexpr bool constexpr_if_init(int n) {
+  if (int a = n; ++a > 0)
+    return true;
+  else
+    return false;
+}
+
+constexpr int constexpr_switch_init(int n) {
+  switch (int p = n + 2; p) {
+    case 0:
+      return 0;
+    case 1:
+      return 1;
+    default:
+      return -1;
+  }
+}
+
+void test_constexpr_init_stmt() {
+  constexpr bool a = constexpr_if_init(-2);
+  static_assert(!a, "");
+  static_assert(constexpr_if_init(1), "");
+
+  constexpr int b = constexpr_switch_init(-1);
+  static_assert(b == 1, "");
+  static_assert(constexpr_switch_init(-2) == 0, "");
+  static_assert(constexpr_switch_init(-5) == -1, "");
+}
diff --git a/clang/www/cxx_status.html b/clang/www/cxx_status.html
@@ -725,7 +725,7 @@ <h2 id="cxx17">C++1z implementation status</h2>
     <tr>
       <td>Separate variable and condition for <tt>if</tt> and <tt>switch</tt></td>
       <td><a href="http://wg21.link/p0305r1">P0305R1</a></td>
-      <td class="none" align="center">No</td>
+      <td class="svn" align="center">SVN</td>
     </tr>
 </table>