From 3772c9abf9651da1f77c83ec937c96e10a353c6a Mon Sep 17 00:00:00 2001
From: Jordan Rose <jordan_rose@apple.com>
Date: Fri, 8 Jun 2012 21:14:19 +0000
Subject: [PATCH] If fixits appear to overlap, move the second one over in the
 output.

This occurs when you have two insertions and the first one is so long that the
second fixit's column is before the first fixit ends. The edits themselves
don't actually overlap, but our command-line preview does.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@158229 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Frontend/TextDiagnostic.cpp | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/lib/Frontend/TextDiagnostic.cpp b/lib/Frontend/TextDiagnostic.cpp
index 99e89f246b..5c8da05c7b 100644
--- a/lib/Frontend/TextDiagnostic.cpp
+++ b/lib/Frontend/TextDiagnostic.cpp
@@ -1090,6 +1090,7 @@ std::string TextDiagnostic::buildFixItInsertionLine(
   std::string FixItInsertionLine;
   if (Hints.empty() || !DiagOpts.ShowFixits)
     return FixItInsertionLine;
+  unsigned PrevHintEnd = 0;
 
   for (ArrayRef<FixItHint>::iterator I = Hints.begin(), E = Hints.end();
        I != E; ++I) {
@@ -1107,6 +1108,16 @@ std::string TextDiagnostic::buildFixItInsertionLine(
         assert(HintColNo<static_cast<unsigned>(map.bytes())+1);
         HintColNo = map.byteToColumn(HintColNo);
 
+        // If we inserted a long previous hint, push this one forwards, and add
+        // an extra space to show that this is not part of the previous
+        // completion. This is sort of the best we can do when two hints appear
+        // to overlap.
+        //
+        // Note that if this hint is located immediately after the previous
+        // hint, no space will be added, since the location is more important.
+        if (HintColNo < PrevHintEnd)
+          HintColNo = PrevHintEnd + 1;
+
         // FIXME: if the fixit includes tabs or other characters that do not
         //  take up a single column per byte when displayed then
         //  I->CodeToInsert.size() is not a column number and we're mixing
@@ -1115,19 +1126,16 @@ std::string TextDiagnostic::buildFixItInsertionLine(
         unsigned LastColumnModified
           = HintColNo + I->CodeToInsert.size();
 
-        if (LastColumnModified > static_cast<unsigned>(map.bytes())) {
-          unsigned LastExistingColumn = map.byteToColumn(map.bytes());
-          unsigned AddedColumns = LastColumnModified-LastExistingColumn;
-          LastColumnModified = LastExistingColumn + AddedColumns;
-        } else {
+        if (LastColumnModified <= static_cast<unsigned>(map.bytes()))
           LastColumnModified = map.byteToColumn(LastColumnModified);
-        }
 
         if (LastColumnModified > FixItInsertionLine.size())
           FixItInsertionLine.resize(LastColumnModified, ' ');
         assert(HintColNo+I->CodeToInsert.size() <= FixItInsertionLine.size());
         std::copy(I->CodeToInsert.begin(), I->CodeToInsert.end(),
                   FixItInsertionLine.begin() + HintColNo);
+
+        PrevHintEnd = LastColumnModified;
       } else {
         FixItInsertionLine.clear();
         break;
-- 
2.50.1