diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 016c0f1..e925a70 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -251,13 +251,15 @@
                                                const Expr *IdxExpr,
                                                uint64_t &Idx)
 {
-  assert(isFunctionOrMethod(D) && hasFunctionProto(D));
+  assert(isFunctionOrMethod(D));
 
   // In C++ the implicit 'this' function parameter also counts.
   // Parameters are counted from one.
-  const bool HasImplicitThisParam = isInstanceMethod(D);
-  const unsigned NumArgs = getFunctionOrMethodNumArgs(D) + HasImplicitThisParam;
-  const unsigned FirstIdx = 1;
+  bool HP = hasFunctionProto(D);
+  bool HasImplicitThisParam = isInstanceMethod(D);
+  bool IV = HP && isFunctionOrMethodVariadic(D);
+  unsigned NumArgs = (HP ? getFunctionOrMethodNumArgs(D) : 0) +
+                     HasImplicitThisParam;
 
   llvm::APSInt IdxInt;
   if (IdxExpr->isTypeDependent() || IdxExpr->isValueDependent() ||
@@ -269,7 +271,7 @@
   }
 
   Idx = IdxInt.getLimitedValue();
-  if (Idx < FirstIdx || (!isFunctionOrMethodVariadic(D) && Idx > NumArgs)) {
+  if (Idx < 1 || (!IV && Idx > NumArgs)) {
     S.Diag(AttrLoc, diag::err_attribute_argument_out_of_bounds)
       << AttrName << AttrArgNum << IdxExpr->getSourceRange();
     return false;
@@ -1163,70 +1165,35 @@
 static void handleAllocSizeAttr(Sema &S, Decl *D, const AttributeList &Attr) {
   if (!isFunctionOrMethod(D)) {
     S.Diag(Attr.getLoc(), diag::warn_attribute_wrong_decl_type)
-    << "alloc_size" << ExpectedFunctionOrMethod;
+    << Attr.getName() << ExpectedFunctionOrMethod;
     return;
   }
 
   if (!checkAttributeAtLeastNumArgs(S, Attr, 1))
     return;
 
-  // In C++ the implicit 'this' function parameter also counts, and they are
-  // counted from one.
-  bool HasImplicitThisParam = isInstanceMethod(D);
-  unsigned NumArgs;
-  if (hasFunctionProto(D))
-    NumArgs = getFunctionOrMethodNumArgs(D) + HasImplicitThisParam;
-  else
-    NumArgs = 0;
-
   SmallVector<unsigned, 8> SizeArgs;
-
-  for (AttributeList::arg_iterator I = Attr.arg_begin(),
-       E = Attr.arg_end(); I!=E; ++I) {
-    // The argument must be an integer constant expression.
-    Expr *Ex = *I;
-    llvm::APSInt ArgNum;
-    if (Ex->isTypeDependent() || Ex->isValueDependent() ||
-        !Ex->isIntegerConstantExpr(ArgNum, S.Context)) {
-      S.Diag(Attr.getLoc(), diag::err_attribute_argument_not_int)
-      << "alloc_size" << Ex->getSourceRange();
+  for (unsigned i = 0; i < Attr.getNumArgs(); ++i) {
+    Expr *Ex = Attr.getArg(i);
+    uint64_t Idx;
+    if (!checkFunctionOrMethodArgumentIndex(S, D, Attr.getName()->getName(),
+                                            Attr.getLoc(), i + 1, Ex, Idx))
       return;
-    }
-
-    uint64_t x = ArgNum.getZExtValue();
-
-    if (x < 1 || x > NumArgs) {
-      S.Diag(Attr.getLoc(), diag::err_attribute_argument_out_of_bounds)
-      << "alloc_size" << I.getArgNum() << Ex->getSourceRange();
-      return;
-    }
-
-    --x;
-    if (HasImplicitThisParam) {
-      if (x == 0) {
-        S.Diag(Attr.getLoc(),
-               diag::err_attribute_invalid_implicit_this_argument)
-        << "alloc_size" << Ex->getSourceRange();
-        return;
-      }
-      --x;
-    }
 
     // check if the function argument is of an integer type
-    QualType T = getFunctionOrMethodArgType(D, x).getNonReferenceType();
+    QualType T = getFunctionOrMethodArgType(D, Idx).getNonReferenceType();
     if (!T->isIntegerType()) {
       S.Diag(Attr.getLoc(), diag::err_attribute_argument_not_int)
-      << "alloc_size" << Ex->getSourceRange();
+        << "alloc_size" << Ex->getSourceRange();
       return;
     }
-
-    SizeArgs.push_back(x);
+    SizeArgs.push_back(Idx);
   }
 
   // check if the function returns a pointer
   if (!getFunctionType(D)->getResultType()->isAnyPointerType()) {
     S.Diag(Attr.getLoc(), diag::warn_ns_attribute_wrong_return_type)
-    << "alloc_size" << 0 /*function*/<< 1 /*pointer*/ << D->getSourceRange();
+    << Attr.getName() << 0 /*function*/<< 1 /*pointer*/ << D->getSourceRange();
   }
 
   D->addAttr(::new (S.Context)
@@ -1244,47 +1211,16 @@
     return;
   }
 
-  // In C++ the implicit 'this' function parameter also counts, and they are
-  // counted from one.
-  bool HasImplicitThisParam = isInstanceMethod(D);
-  unsigned NumArgs = getFunctionOrMethodNumArgs(D) + HasImplicitThisParam;
-
-  // The nonnull attribute only applies to pointers.
-  SmallVector<unsigned, 10> NonNullArgs;
-
-  for (AttributeList::arg_iterator I = Attr.arg_begin(),
-                                   E = Attr.arg_end(); I != E; ++I) {
-    // The argument must be an integer constant expression.
-    Expr *Ex = *I;
-    llvm::APSInt ArgNum(32);
-    if (Ex->isTypeDependent() || Ex->isValueDependent() ||
-        !Ex->isIntegerConstantExpr(ArgNum, S.Context)) {
-      S.Diag(Attr.getLoc(), diag::err_attribute_argument_not_int)
-        << "nonnull" << Ex->getSourceRange();
+  SmallVector<unsigned, 8> NonNullArgs;
+  for (unsigned i = 0; i < Attr.getNumArgs(); ++i) {
+    Expr *Ex = Attr.getArg(i);
+    uint64_t Idx;
+    if (!checkFunctionOrMethodArgumentIndex(S, D, Attr.getName()->getName(),
+                                            Attr.getLoc(), i + 1, Ex, Idx))
       return;
-    }
-
-    unsigned x = (unsigned) ArgNum.getZExtValue();
-
-    if (x < 1 || x > NumArgs) {
-      S.Diag(Attr.getLoc(), diag::err_attribute_argument_out_of_bounds)
-       << "nonnull" << I.getArgNum() << Ex->getSourceRange();
-      return;
-    }
-
-    --x;
-    if (HasImplicitThisParam) {
-      if (x == 0) {
-        S.Diag(Attr.getLoc(),
-               diag::err_attribute_invalid_implicit_this_argument)
-          << "nonnull" << Ex->getSourceRange();
-        return;
-      }
-      --x;
-    }
 
     // Is the function argument a pointer type?
-    QualType T = getFunctionOrMethodArgType(D, x).getNonReferenceType();
+    QualType T = getFunctionOrMethodArgType(D, Idx).getNonReferenceType();
     possibleTransparentUnionPointerType(T);
     
     if (!T->isAnyPointerType() && !T->isBlockPointerType()) {
@@ -1294,7 +1230,7 @@
       continue;
     }
 
-    NonNullArgs.push_back(x);
+    NonNullArgs.push_back(Idx);
   }
 
   // If no arguments were specified to __attribute__((nonnull)) then all pointer
@@ -1378,59 +1314,32 @@
     return;
   }
 
-  // In C++ the implicit 'this' function parameter also counts, and they are
-  // counted from one.
-  bool HasImplicitThisParam = isInstanceMethod(D);
-  unsigned NumArgs  = getFunctionOrMethodNumArgs(D) + HasImplicitThisParam;
-
   StringRef Module = AL.getParameterName()->getName();
 
   // Normalize the argument, __foo__ becomes foo.
   if (Module.startswith("__") && Module.endswith("__"))
     Module = Module.substr(2, Module.size() - 4);
 
-  SmallVector<unsigned, 10> OwnershipArgs;
 
-  for (AttributeList::arg_iterator I = AL.arg_begin(), E = AL.arg_end(); I != E;
-       ++I) {
-
-    Expr *IdxExpr = *I;
-    llvm::APSInt ArgNum(32);
-    if (IdxExpr->isTypeDependent() || IdxExpr->isValueDependent()
-        || !IdxExpr->isIntegerConstantExpr(ArgNum, S.Context)) {
-      S.Diag(AL.getLoc(), diag::err_attribute_argument_not_int)
-          << AL.getName()->getName() << IdxExpr->getSourceRange();
-      continue;
-    }
-
-    unsigned x = (unsigned) ArgNum.getZExtValue();
-
-    if (x > NumArgs || x < 1) {
-      S.Diag(AL.getLoc(), diag::err_attribute_argument_out_of_bounds)
-          << AL.getName()->getName() << x << IdxExpr->getSourceRange();
-      continue;
-    }
-    --x;
-    if (HasImplicitThisParam) {
-      if (x == 0) {
-        S.Diag(AL.getLoc(), diag::err_attribute_invalid_implicit_this_argument)
-          << "ownership" << IdxExpr->getSourceRange();
-        return;
-      }
-      --x;
-    }
+  SmallVector<unsigned, 8> OwnershipArgs;
+  for (unsigned i = 0; i < AL.getNumArgs(); ++i) {
+    Expr *Ex = AL.getArg(i);
+    uint64_t Idx;
+    if (!checkFunctionOrMethodArgumentIndex(S, D, AL.getName()->getName(),
+                                            AL.getLoc(), i + 1, Ex, Idx))
+      return;
 
     switch (K) {
     case OwnershipAttr::Takes:
     case OwnershipAttr::Holds: {
       // Is the function argument a pointer type?
-      QualType T = getFunctionOrMethodArgType(D, x);
+      QualType T = getFunctionOrMethodArgType(D, Idx);
       if (!T->isAnyPointerType() && !T->isBlockPointerType()) {
         // FIXME: Should also highlight argument in decl.
         S.Diag(AL.getLoc(), diag::err_ownership_type)
             << ((K==OwnershipAttr::Takes)?"ownership_takes":"ownership_holds")
             << "pointer"
-            << IdxExpr->getSourceRange();
+            << Ex->getSourceRange();
         continue;
       }
       break;
@@ -1460,14 +1369,14 @@
       if ((*i)->getOwnKind() != K) {
         for (const unsigned *I = (*i)->args_begin(), *E = (*i)->args_end();
              I!=E; ++I) {
-          if (x == *I) {
+          if (Idx == *I) {
             S.Diag(AL.getLoc(), diag::err_attributes_are_not_compatible)
                 << AL.getName()->getName() << "ownership_*";
           }
         }
       }
     }
-    OwnershipArgs.push_back(x);
+    OwnershipArgs.push_back(Idx);
   }
 
   unsigned* start = OwnershipArgs.data();
@@ -3043,39 +2952,11 @@
     return;
   }
 
-  // In C++ the implicit 'this' function parameter also counts, and they are
-  // counted from one.
-  bool HasImplicitThisParam = isInstanceMethod(D);
-  unsigned NumArgs  = getFunctionOrMethodNumArgs(D) + HasImplicitThisParam;
-  unsigned FirstIdx = 1;
-
-  // checks for the 2nd argument
   Expr *IdxExpr = Attr.getArg(0);
-  llvm::APSInt Idx(32);
-  if (IdxExpr->isTypeDependent() || IdxExpr->isValueDependent() ||
-      !IdxExpr->isIntegerConstantExpr(Idx, S.Context)) {
-    S.Diag(Attr.getLoc(), diag::err_attribute_argument_n_type)
-      << Attr.getName() << 2 << ArgumentIntegerConstant
-      << IdxExpr->getSourceRange();
+  uint64_t ArgIdx;
+  if (!checkFunctionOrMethodArgumentIndex(S, D, Attr.getName()->getName(),
+                                          Attr.getLoc(), 1, IdxExpr, ArgIdx))
     return;
-  }
-
-  if (Idx.getZExtValue() < FirstIdx || Idx.getZExtValue() > NumArgs) {
-    S.Diag(Attr.getLoc(), diag::err_attribute_argument_out_of_bounds)
-    << "format" << 2 << IdxExpr->getSourceRange();
-    return;
-  }
-
-  unsigned ArgIdx = Idx.getZExtValue() - 1;
-
-  if (HasImplicitThisParam) {
-    if (ArgIdx == 0) {
-      S.Diag(Attr.getLoc(), diag::err_attribute_invalid_implicit_this_argument)
-        << "format_arg" << IdxExpr->getSourceRange();
-      return;
-    }
-    ArgIdx--;
-  }
 
   // make sure the format string is really a string
   QualType Ty = getFunctionOrMethodArgType(D, ArgIdx);
@@ -3103,8 +2984,14 @@
     return;
   }
 
+  // We cannot use the ArgIdx returned from checkFunctionOrMethodArgumentIndex
+  // because that has corrected for the implicit this parameter, and is zero-
+  // based.  The attribute expects what the user wrote explicitly.
+  llvm::APSInt Val;
+  IdxExpr->EvaluateAsInt(Val, S.Context);
+
   D->addAttr(::new (S.Context)
-             FormatArgAttr(Attr.getRange(), S.Context, Idx.getZExtValue(),
+             FormatArgAttr(Attr.getRange(), S.Context, Val.getZExtValue(),
                            Attr.getAttributeSpellingListIndex()));
 }
 
diff --git a/test/Sema/alloc_size.c b/test/Sema/alloc_size.c
index 46d94f7..2e9c304 100644
--- a/test/Sema/alloc_size.c
+++ b/test/Sema/alloc_size.c
@@ -5,7 +5,7 @@
 void* my_realloc(void*, unsigned) __attribute__((alloc_size(2)));
 
 
-void* fn1(int) __attribute__((alloc_size("xpto"))); // expected-error{{attribute requires integer constant}}
+void* fn1(int) __attribute__((alloc_size("xpto"))); // expected-error{{'alloc_size' attribute requires parameter 1 to be an integer constant}}
 
 void* fn2(void*) __attribute__((alloc_size(1))); // expected-error{{attribute requires integer constant}}
 
diff --git a/test/Sema/attr-format.c b/test/Sema/attr-format.c
index a223e08..21d9585 100644
--- a/test/Sema/attr-format.c
+++ b/test/Sema/attr-format.c
@@ -78,3 +78,5 @@
   __attribute__ ((__format__(__gcc_cxxdiag__, 1, 2)));
 extern void gcc_tformat (const char *, ...)
   __attribute__ ((__format__(__gcc_tdiag__, 1, 2)));
+
+const char *foo3(const char *format) __attribute__((format_arg("foo")));  // expected-error{{'format_arg' attribute requires parameter 1 to be an integer constant}}
diff --git a/test/Sema/nonnull.c b/test/Sema/nonnull.c
index 1544be5..4e61711 100644
--- a/test/Sema/nonnull.c
+++ b/test/Sema/nonnull.c
@@ -19,3 +19,4 @@
 	Class_init(obj, "Hello World");
 }
 
+void foo(const char *str) __attribute__((nonnull("foo"))); // expected-error{{'nonnull' attribute requires parameter 1 to be an integer constant}}