From 658fa76c7ae2851ed3ba5dd0c99fa9b70a8063a5 Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev@redking.me.uk>
Date: Fri, 3 Apr 2020 18:53:38 +0100
Subject: [PATCH] [YAMLParser] Scanner::setError - ensure we use the
 StringRef::iterator argument (PR45043)

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.

Differential Revision: https://reviews.llvm.org/D76512
---
 lib/Support/YAMLParser.cpp | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/lib/Support/YAMLParser.cpp b/lib/Support/YAMLParser.cpp
index 4f9feee4a8a..ca8ffdc47af 100644
--- a/lib/Support/YAMLParser.cpp
+++ b/lib/Support/YAMLParser.cpp
@@ -268,8 +268,8 @@ public:
   }
 
   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)
@@ -278,14 +278,10 @@ public:
     // 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;
@@ -934,13 +930,13 @@ void Scanner::scan_ns_uri_char() {
 
 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) {
@@ -1763,7 +1759,7 @@ bool Scanner::fetchMoreTokens() {
                       && !isBlankOrBreak(Current + 2)))
     return scanPlainScalar();
 
-  setError("Unrecognized character while tokenizing.");
+  setError("Unrecognized character while tokenizing.", Current);
   return false;
 }