4 files changed, 24 insertions, 9 deletions
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index 176aec53a2..b77977f7fd 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -651,6 +651,7 @@ CXXABI *ASTContext::createCXXABI(const TargetInfo &T) {
   case TargetCXXABI::GenericARM:
   case TargetCXXABI::iOS:
     return CreateARMCXXABI(*this);
+  case TargetCXXABI::Emscripten:     // Same as Itanium at this level
   case TargetCXXABI::GenericAArch64: // Same as Itanium at this level
   case TargetCXXABI::GenericItanium:
     return CreateItaniumCXXABI(*this);
@@ -7940,6 +7941,7 @@ MangleContext *ASTContext::createMangleContext() {
   case TargetCXXABI::GenericAArch64:
   case TargetCXXABI::GenericItanium:
   case TargetCXXABI::GenericARM:
+  case TargetCXXABI::Emscripten:
   case TargetCXXABI::iOS:
     return createItaniumMangleContext(*this, getDiagnostics());
   case TargetCXXABI::Microsoft:
diff --git a/lib/Basic/Targets.cpp b/lib/Basic/Targets.cpp
index b56b42c798..93da96f897 100644
--- a/lib/Basic/Targets.cpp
+++ b/lib/Basic/Targets.cpp
@@ -270,6 +270,11 @@ public:
     // beneficial.
     this->UserLabelPrefix = "";
     this->MaxAtomicPromoteWidth = this->MaxAtomicInlineWidth = 32;
+
+    // Emscripten uses the Itanium ABI mostly, but it uses ARM-style pointers
+    // to member functions so that it can avoid having to align function
+    // addresses.
+    this->TheCXXABI.set(TargetCXXABI::Emscripten);
   }
 };
 
diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 0b03a3c4b6..3fb7cba914 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -57,6 +57,7 @@ static CGCXXABI &createCXXABI(CodeGenModule &CGM) {
   switch (CGM.getTarget().getCXXABI().getKind()) {
   case TargetCXXABI::GenericAArch64:
   case TargetCXXABI::GenericARM:
+  case TargetCXXABI::Emscripten:
   case TargetCXXABI::iOS:
   case TargetCXXABI::GenericItanium:
     return *CreateItaniumCXXABI(CGM);
@@ -656,9 +657,11 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
   if (alignment)
     F->setAlignment(alignment);
 
-  // C++ ABI requires 2-byte alignment for member functions.
-  if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
-    F->setAlignment(2);
+  if (getTarget().getCXXABI().arePointersToMemberFunctionsAligned()) {
+    // C++ ABI requires 2-byte alignment for member functions.
+    if (F->getAlignment() < 2 && isa<CXXMethodDecl>(D))
+      F->setAlignment(2);
+  }
 }
 
 void CodeGenModule::SetCommonAttributes(const Decl *D,
diff --git a/lib/CodeGen/ItaniumCXXABI.cpp b/lib/CodeGen/ItaniumCXXABI.cpp
index 3767e4f278..1568284a7d 100644
--- a/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/lib/CodeGen/ItaniumCXXABI.cpp
@@ -231,18 +231,23 @@ CodeGen::CGCXXABI *CodeGen::CreateItaniumCXXABI(CodeGenModule &CGM) {
     return new ItaniumCXXABI(CGM, /* UseARMMethodPtrABI = */ true,
                              /* UseARMGuardVarABI = */ true);
 
+  case TargetCXXABI::Emscripten:
+    // Use ARM-style method pointers so that generated code
+    // does not assume anything about the alignment of function
+    // pointers.
+    return new ItaniumCXXABI(CGM, /* UseARMMethodPtrABI = */ true,
+                             /* UseARMGuardVarABI = */ false);
+
   case TargetCXXABI::GenericItanium:
-    switch (CGM.getContext().getTargetInfo().getTriple().getArch()) {
-    case llvm::Triple::le32:
-    case llvm::Triple::asmjs:
-      // Use ARM-style method pointers so that generated code
+    if (CGM.getContext().getTargetInfo().getTriple().getArch()
+        == llvm::Triple::le32) {
+      // For PNaCl, use ARM-style method pointers so that PNaCl code
       // does not assume anything about the alignment of function
       // pointers.
       return new ItaniumCXXABI(CGM, /* UseARMMethodPtrABI = */ true,
                                /* UseARMGuardVarABI = */ false);
-    default:
-      return new ItaniumCXXABI(CGM);
     }
+    return new ItaniumCXXABI(CGM);
 
   case TargetCXXABI::Microsoft:
     llvm_unreachable("Microsoft ABI is not Itanium-based");