[ARM] Fix bug in also_compatible_with attribute parser

[vhscampos]

Summary

Check ScopedPrinter pointer before attempting to print the attribute's
parsed information.

Patch by Michael Platings and Victor Campos

[pratlucas]

LGTM.

llvm/include/llvm/Support/ELFAttributeParser.h

protected:
   void printAttribute(unsigned tag, unsigned value, StringRef valueDesc);
 
   Error parseStringAttribute(const char *name, unsigned tag,
                              ArrayRef<const char *> strings);
   Error parseAttributeList(uint32_t length);
   void parseIndexList(SmallVectorImpl<uint8_t> &indexList);
   Error parseSubsection(uint32_t length);
 
+  void setAttributeString(unsigned tag, StringRef value) {
+    attributesStr.emplace(tag, value);
+  }
+
 public:
   virtual ~ELFAttributeParser() { static_cast<void>(!cursor.takeError()); }
   Error integerAttribute(unsigned tag);
   Error stringAttribute(unsigned tag);
 
   ELFAttributeParser(ScopedPrinter *sw, TagNameMap tagNameMap, StringRef vendor)
       : vendor(vendor), sw(sw), tagToStringMap(tagNameMap) {}
 

llvm/lib/Support/ARMAttributeParser.cpp

if (!ValidInnerTag) {
     default: {
       uint64_t InnerValue = de.getULEB128(cursor);
       DescStream << ELFAttrs::attrTypeAsString(InnerTag, tagToStringMap)
                  << " = " << InnerValue;
     }
     }
   }
 
+  setAttributeString(tag, RawStringValue);
+  if (sw) {
     DictScope scope(*sw, "Attribute");
     sw->printNumber("Tag", tag);
     sw->printString("TagName",
                     ELFAttrs::attrTypeAsString(tag, tagToStringMap, false));
     sw->printStringEscaped("Value", RawStringValue);
     if (!Description.empty()) {
       sw->printString("Description", Description);
     }
+  }
+
   cursor.seek(FinalOffset);
 
   return returnValue ? std::move(*returnValue) : Error::success();
 }
 
 Error ARMAttributeParser::handler(uint64_t tag, bool &handled) {
   handled = false;
   for (const auto &AH : displayRoutines) {

llvm/lib/Support/ELFAttributeParser.cpp

Error ELFAttributeParser::integerAttribute(unsigned tag) {
   }
   return Error::success();
 }
 
 Error ELFAttributeParser::stringAttribute(unsigned tag) {
   StringRef tagName =
       ELFAttrs::attrTypeAsString(tag, tagToStringMap, /*hasTagPrefix=*/false);
   StringRef desc = de.getCStrRef(cursor);
-  attributesStr.insert(std::make_pair(tag, desc));
+  setAttributeString(tag, desc);
 
   if (sw) {
     DictScope scope(*sw, "Attribute");
     sw->printNumber("Tag", tag);
     if (!tagName.empty())
       sw->printString("TagName", tagName);
     sw->printString("Value", desc);
   }