[ADT] Make Twine's copy constructor private.

There's a lot of misuse of Twine scattered around LLVM.  This
ranges in severity from benign (returning a Twine from a function
by value that is just a string literal) to pretty sketchy (storing
a Twine by value in a class).  While there are some uses for
copying Twines, most of the very compelling ones are confined
to the Twine class implementation itself, and other uses are
either dubious or easily worked around.

This patch makes Twine's copy constructor private, and fixes up
all callsites.

Differential Revision: https://reviews.llvm.org/D38767

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@315530 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 7 deletions

diff --git a/unittests/Tooling/TestVisitor.h b/unittests/Tooling/TestVisitor.h
index fb6a76ccad..a3a50cf0d4 100644
--- a/unittests/Tooling/TestVisitor.h
+++ b/unittests/Tooling/TestVisitor.h
@@ -128,7 +128,7 @@ public:
   /// \brief Expect 'Match' *not* to occur at the given 'Line' and 'Column'.
   ///
   /// Any number of matches can be disallowed.
-  void DisallowMatch(Twine Match, unsigned Line, unsigned Column) {
+  void DisallowMatch(const Twine &Match, unsigned Line, unsigned Column) {
     DisallowedMatches.push_back(MatchCandidate(Match, Line, Column));
   }
 
@@ -138,7 +138,7 @@ public:
   /// Each is expected to be matched 'Times' number of times. (This is useful in
   /// cases in which different AST nodes can match at the same source code
   /// location.)
-  void ExpectMatch(Twine Match, unsigned Line, unsigned Column,
+  void ExpectMatch(const Twine &Match, unsigned Line, unsigned Column,
                    unsigned Times = 1) {
     ExpectedMatches.push_back(ExpectedMatch(Match, Line, Column, Times));
   }
@@ -180,10 +180,10 @@ protected:
     unsigned LineNumber;
     unsigned ColumnNumber;
 
-    MatchCandidate(Twine Name, unsigned LineNumber, unsigned ColumnNumber)
-      : ExpectedName(Name.str()), LineNumber(LineNumber),
-        ColumnNumber(ColumnNumber) {
-    }
+    MatchCandidate(const Twine &Name, unsigned LineNumber,
+                   unsigned ColumnNumber)
+        : ExpectedName(Name.str()), LineNumber(LineNumber),
+          ColumnNumber(ColumnNumber) {}
 
     bool Matches(StringRef Name, FullSourceLoc const &Location) const {
       return MatchesName(Name) && MatchesLocation(Location);
@@ -211,7 +211,7 @@ protected:
   };
 
   struct ExpectedMatch {
-    ExpectedMatch(Twine Name, unsigned LineNumber, unsigned ColumnNumber,
+    ExpectedMatch(const Twine &Name, unsigned LineNumber, unsigned ColumnNumber,
                   unsigned Times)
         : Candidate(Name, LineNumber, ColumnNumber), TimesExpected(Times),
           TimesSeen(0) {}