Add some helpers for attribute lookup

This CL adds helpers to CXFA_Node to convert from strings to attributes
and from attributes to their string names. A static_assert was added to
make sure the list of attributes is the same size as the attribute data
so the checks can be removed.

Change-Id: Idebc65021d71f604bcf498e4cf42252af00d802b
Reviewed-on: https://pdfium-review.googlesource.com/19270
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

8 files changed, 52 insertions, 20 deletions

diff --git a/xfa/fxfa/fxfa_basic.h b/xfa/fxfa/fxfa_basic.h
index e2d4056095..cdd53a965b 100644
--- a/xfa/fxfa/fxfa_basic.h
+++ b/xfa/fxfa/fxfa_basic.h
@@ -618,7 +618,7 @@ enum class XFA_Attribute : uint8_t {
   Intact,
   XdpContent,
   DecipherOnly,
-
+  LastAttributePlaceholder,
   Unknown = 255,
 };
 
diff --git a/xfa/fxfa/parser/cxfa_dataexporter.cpp b/xfa/fxfa/parser/cxfa_dataexporter.cpp
index f28649fffa..edb7e1e186 100644
--- a/xfa/fxfa/parser/cxfa_dataexporter.cpp
+++ b/xfa/fxfa/parser/cxfa_dataexporter.cpp
@@ -87,7 +87,7 @@ WideString ExportEncodeContent(const WideString& str) {
 
 void SaveAttribute(CXFA_Node* pNode,
                    XFA_Attribute eName,
-                   const WideStringView& wsName,
+                   const WideString& wsName,
                    bool bProto,
                    WideString& wsOutput) {
   if (!bProto && !pNode->JSNode()->HasAttribute(eName))
@@ -175,13 +175,13 @@ void RegenerateFormFile_Changed(CXFA_Node* pNode,
     if (attr == XFA_Attribute::Unknown)
       break;
 
-    const XFA_ATTRIBUTEINFO* pAttr = XFA_GetAttributeByID(attr);
-    if (pAttr->eName == XFA_Attribute::Name ||
-        (AttributeSaveInDataModel(pNode, pAttr->eName) && !bSaveXML)) {
+    if (attr == XFA_Attribute::Name ||
+        (AttributeSaveInDataModel(pNode, attr) && !bSaveXML)) {
       continue;
     }
     WideString wsAttr;
-    SaveAttribute(pNode, pAttr->eName, pAttr->pName, bSaveXML, wsAttr);
+    SaveAttribute(pNode, attr, CXFA_Node::AttributeToName(attr), bSaveXML,
+                  wsAttr);
     wsAttrs += wsAttr;
   }
 
@@ -360,13 +360,11 @@ void RegenerateFormFile_Container(
     XFA_Attribute attr = pNode->GetAttribute(i);
     if (attr == XFA_Attribute::Unknown)
       break;
-
-    const XFA_ATTRIBUTEINFO* pAttr = XFA_GetAttributeByID(attr);
-    if (pAttr->eName == XFA_Attribute::Name)
+    if (attr == XFA_Attribute::Name)
       continue;
 
     WideString wsAttr;
-    SaveAttribute(pNode, pAttr->eName, pAttr->pName, false, wsAttr);
+    SaveAttribute(pNode, attr, CXFA_Node::AttributeToName(attr), false, wsAttr);
     wsOutput += wsAttr;
   }
 
diff --git a/xfa/fxfa/parser/cxfa_node.cpp b/xfa/fxfa/parser/cxfa_node.cpp
index ccbf31048d..4402208900 100644
--- a/xfa/fxfa/parser/cxfa_node.cpp
+++ b/xfa/fxfa/parser/cxfa_node.cpp
@@ -138,6 +138,19 @@ const XFA_ATTRIBUTEENUMINFO* GetAttributeEnumByID(XFA_ATTRIBUTEENUM eName) {
   return g_XFAEnumData + eName;
 }
 
+// static
+WideString CXFA_Node::AttributeToName(XFA_Attribute attr) {
+  return XFA_GetAttributeByID(attr)->pName;
+}
+
+// static
+XFA_Attribute CXFA_Node::NameToAttribute(const WideStringView& name) {
+  const XFA_ATTRIBUTEINFO* attr = XFA_GetAttributeByName(name);
+  if (!attr)
+    return XFA_Attribute::Unknown;
+  return attr->eName;
+}
+
 CXFA_Node::CXFA_Node(CXFA_Document* pDoc,
                      uint16_t ePacket,
                      uint32_t validPackets,
diff --git a/xfa/fxfa/parser/cxfa_node.h b/xfa/fxfa/parser/cxfa_node.h
index 7b7086ecb5..e5f47a1828 100644
--- a/xfa/fxfa/parser/cxfa_node.h
+++ b/xfa/fxfa/parser/cxfa_node.h
@@ -53,6 +53,8 @@ class CXFA_Node : public CXFA_Object {
     uint8_t flags;
   };
 
+  static WideString AttributeToName(XFA_Attribute attr);
+  static XFA_Attribute NameToAttribute(const WideStringView& name);
   static XFA_Element NameToElement(const WideString& name);
   static std::unique_ptr<CXFA_Node> Create(CXFA_Document* doc,
                                            XFA_Element element,
diff --git a/xfa/fxfa/parser/cxfa_node_unittest.cpp b/xfa/fxfa/parser/cxfa_node_unittest.cpp
new file mode 100644
index 0000000000..93df084391
--- /dev/null
+++ b/xfa/fxfa/parser/cxfa_node_unittest.cpp
@@ -0,0 +1,17 @@
+// Copyright 2017 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "xfa/fxfa/parser/cxfa_node.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/test_support.h"
+
+TEST(CXFA_NodeTest, NameToAttribute) {
+  EXPECT_EQ(XFA_Attribute::Unknown, CXFA_Node::NameToAttribute(L""));
+  EXPECT_EQ(XFA_Attribute::Unknown, CXFA_Node::NameToAttribute(L"nonesuch"));
+  EXPECT_EQ(XFA_Attribute::H, CXFA_Node::NameToAttribute(L"h"));
+  EXPECT_EQ(XFA_Attribute::Short, CXFA_Node::NameToAttribute(L"short"));
+  EXPECT_EQ(XFA_Attribute::DecipherOnly,
+            CXFA_Node::NameToAttribute(L"decipherOnly"));
+}
diff --git a/xfa/fxfa/parser/cxfa_simple_parser.cpp b/xfa/fxfa/parser/cxfa_simple_parser.cpp
index 4ee9ca76b3..453ae8d059 100644
--- a/xfa/fxfa/parser/cxfa_simple_parser.cpp
+++ b/xfa/fxfa/parser/cxfa_simple_parser.cpp
@@ -898,17 +898,17 @@ CXFA_Node* CXFA_SimpleParser::NormalLoader(CXFA_Node* pXFANode,
           if (wsAttrName == L"nil" && it.second == L"true")
             IsNeedValue = false;
 
-          const XFA_ATTRIBUTEINFO* lpAttrInfo =
-              XFA_GetAttributeByName(wsAttrName.AsStringView());
-          if (!lpAttrInfo)
+          XFA_Attribute attr =
+              CXFA_Node::NameToAttribute(wsAttrName.AsStringView());
+          if (attr == XFA_Attribute::Unknown)
             continue;
 
-          if (!bUseAttribute && lpAttrInfo->eName != XFA_Attribute::Name &&
-              lpAttrInfo->eName != XFA_Attribute::Save) {
+          if (!bUseAttribute && attr != XFA_Attribute::Name &&
+              attr != XFA_Attribute::Save) {
             continue;
           }
-          pXFAChild->JSNode()->SetAttribute(lpAttrInfo->eName,
-                                            it.second.AsStringView(), false);
+          pXFAChild->JSNode()->SetAttribute(attr, it.second.AsStringView(),
+                                            false);
         }
         pXFANode->InsertChild(pXFAChild, nullptr);
         if (eType == XFA_Element::Validate || eType == XFA_Element::Locale) {
diff --git a/xfa/fxfa/parser/xfa_basic_data_attributes.cpp b/xfa/fxfa/parser/xfa_basic_data_attributes.cpp
index 66f5c893ba..7b371a0239 100644
--- a/xfa/fxfa/parser/xfa_basic_data_attributes.cpp
+++ b/xfa/fxfa/parser/xfa_basic_data_attributes.cpp
@@ -704,6 +704,9 @@ const XFA_ATTRIBUTEINFO g_XFAAttributeData[] = {
 };
 const int32_t g_iXFAAttributeCount =
     sizeof(g_XFAAttributeData) / sizeof(XFA_ATTRIBUTEINFO);
+static_assert(g_iXFAAttributeCount ==
+                  static_cast<int32_t>(XFA_Attribute::LastAttributePlaceholder),
+              "Attribute count mismatch");
 
 const XFA_NOTSUREATTRIBUTE g_XFANotsureAttributes[] = {
     {XFA_Element::SubformSet, XFA_Attribute::Relation, XFA_AttributeType::Enum,
diff --git a/xfa/fxfa/parser/xfa_utils.cpp b/xfa/fxfa/parser/xfa_utils.cpp
index b17a7535eb..03b8943a1f 100644
--- a/xfa/fxfa/parser/xfa_utils.cpp
+++ b/xfa/fxfa/parser/xfa_utils.cpp
@@ -284,9 +284,8 @@ const XFA_ATTRIBUTEINFO* XFA_GetAttributeByName(const WideStringView& wsName) {
 }
 
 const XFA_ATTRIBUTEINFO* XFA_GetAttributeByID(XFA_Attribute eName) {
-  return (static_cast<uint8_t>(eName) < g_iXFAAttributeCount)
-             ? (g_XFAAttributeData + static_cast<uint8_t>(eName))
-             : nullptr;
+  ASSERT(static_cast<uint8_t>(eName) < g_iXFAAttributeCount);
+  return g_XFAAttributeData + static_cast<uint8_t>(eName);
 }
 
 const XFA_ATTRIBUTEENUMINFO* XFA_GetAttributeEnumByName(