[YAMLParser] Scanner::setError - ensure we use the StringRef::iterator argument (PR45043)

[RKSimon]

Summary

As detailed on PR45043, static analysis was warning that the StringRef::iterator Position argument was being ignored and the function was hardwired to use the Current iterator.

This patch ensures we use the provided iterator and removes the (barely necessary) setError wrapper that always used Current.

[RKSimon]

ping?

[RKSimon]

ping?

[bkramer]

makes sense to me

llvm/lib/Support/YAMLParser.cpp

public:
   Token getNext();
 
   void printError(SMLoc Loc, SourceMgr::DiagKind Kind, const Twine &Message,
                   ArrayRef<SMRange> Ranges = None) {
     SM.PrintMessage(Loc, Kind, Message, Ranges, /* FixIts= */ None, ShowColors);
   }
 
   void setError(const Twine &Message, StringRef::iterator Position) {
-    if (Current >= End)
-      Current = End - 1;
+    if (Position >= End)
+      Position = End - 1;
 
     // propagate the error if possible
     if (EC)
       *EC = make_error_code(std::errc::invalid_argument);
 
     // Don't print out more errors after the first one we encounter. The rest
     // are just the result of the first, and have no meaning.
     if (!Failed)
-      printError(SMLoc::getFromPointer(Current), SourceMgr::DK_Error, Message);
+      printError(SMLoc::getFromPointer(Position), SourceMgr::DK_Error, Message);
     Failed = true;
   }
 
-  void setError(const Twine &Message) {
-    setError(Message, Current);
-  }
-
   /// Returns true if an error occurred while parsing.
   bool failed() {
     return Failed;
   }
 
 private:
   void init(MemoryBufferRef Buffer);
 
if ((   *Current == '%'
       ++Column;
     } else
       break;
   }
 }
 
 bool Scanner::consume(uint32_t Expected) {
   if (Expected >= 0x80) {
-    setError("Cannot consume non-ascii characters");
+    setError("Cannot consume non-ascii characters", Current);
     return false;
   }
   if (Current == End)
     return false;
   if (uint8_t(*Current) >= 0x80) {
-    setError("Cannot consume non-ascii characters");
+    setError("Cannot consume non-ascii characters", Current);
     return false;
   }
   if (uint8_t(*Current) == Expected) {
     ++Current;
     ++Column;
     return true;
   }
   return false;
if (!(isBlankOrBreak(Current)
       || (!FlowLevel && (*Current == '?' || *Current == ':')
           && isBlankOrBreak(Current + 1))
       || (!FlowLevel && *Current == ':'
                       && Current + 2 < End
                       && *(Current + 1) == ':'
                       && !isBlankOrBreak(Current + 2)))
     return scanPlainScalar();
 
-  setError("Unrecognized character while tokenizing.");
+  setError("Unrecognized character while tokenizing.", Current);
   return false;
 }
 
 Stream::Stream(StringRef Input, SourceMgr &SM, bool ShowColors,
                std::error_code *EC)
     : scanner(new Scanner(Input, SM, ShowColors, EC)), CurrentDoc() {}
 
 Stream::Stream(MemoryBufferRef InputBuffer, SourceMgr &SM, bool ShowColors,