Use lexing mode based on FormatStyle.Standard.

Summary:
Some valid pre-C++11 constructs change meaning when lexed in C++11
mode, e.g.
#define x(_a) printf("foo"_a);
(example from http://llvm.org/bugs/show_bug.cgi?id=16342). "foo"_a is treated as
a user-defined string literal when parsed in C++11 mode.
In order to deal with this correctly, we need to set lexing mode according to
which standard the code conforms to. We already have a configuration value for
this (FormatStyle.Standard), which seems to be appropriate to use in this case
as well.

Reviewers: klimek

CC: cfe-commits, gribozavr

Differential Revision: http://llvm-reviews.chandlerc.com/D1028

llvm-svn: 185149

1 files changed, 4 insertions, 3 deletions

diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index 766be71bbdf..7d6bc14241e 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1660,7 +1660,8 @@ tooling::Replacements reformat(const FormatStyle &Style, StringRef Code,
   SourceMgr.overrideFileContents(Entry, Buf);
   FileID ID =
       SourceMgr.createFileID(Entry, SourceLocation(), clang::SrcMgr::C_User);
-  Lexer Lex(ID, SourceMgr.getBuffer(ID), SourceMgr, getFormattingLangOpts());
+  Lexer Lex(ID, SourceMgr.getBuffer(ID), SourceMgr,
+            getFormattingLangOpts(Style.Standard));
   SourceLocation StartOfFile = SourceMgr.getLocForStartOfFile(ID);
   std::vector<CharSourceRange> CharRanges;
   for (unsigned i = 0, e = Ranges.size(); i != e; ++i) {
@@ -1671,10 +1672,10 @@ tooling::Replacements reformat(const FormatStyle &Style, StringRef Code,
   return reformat(Style, Lex, SourceMgr, CharRanges);
 }
 
-LangOptions getFormattingLangOpts() {
+LangOptions getFormattingLangOpts(FormatStyle::LanguageStandard Standard) {
   LangOptions LangOpts;
   LangOpts.CPlusPlus = 1;
-  LangOpts.CPlusPlus11 = 1;
+  LangOpts.CPlusPlus11 = Standard == FormatStyle::LS_Cpp03 ? 0 : 1;
   LangOpts.LineComment = 1;
   LangOpts.Bool = 1;
   LangOpts.ObjC1 = 1;