[LibTooling] Add retrieval of extended AST-node source to FixIt library

Summary:
Introduces variants of `getText` and `getSourceRange` that extract the source text of an AST node potentially with a trailing token.

Some of the new functions manipulate `CharSourceRange`s, rather than `SourceRange`s, because they document and dynamically enforce their type.  So, this revision also updates the corresponding existing FixIt functions to manipulate `CharSourceRange`s.  This change is not strictly necessary, but seems like the correct choice, to keep the API self-consistent.

This revision is the first in a series intended to improve the abstractions available to users for writing source-to-source transformations.  A full discussion of the end goal can be found on the cfe-dev list with subject "[RFC] Easier source-to-source transformations with clang tooling".

Reviewers: ilya-biryukov

Reviewed By: ilya-biryukov

Subscribers: kimgr, riccibruno, JonasToth, jdoerfert, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58556

llvm-svn: 356095

1 files changed, 12 insertions, 4 deletions

diff --git a/clang/lib/Tooling/FixIt.cpp b/clang/lib/Tooling/FixIt.cpp
index c828c18871f..ca12a5642a1 100644
--- a/clang/lib/Tooling/FixIt.cpp
+++ b/clang/lib/Tooling/FixIt.cpp
@@ -18,12 +18,20 @@ namespace tooling {
 namespace fixit {
 
 namespace internal {
-StringRef getText(SourceRange Range, const ASTContext &Context) {
-  return Lexer::getSourceText(CharSourceRange::getTokenRange(Range),
-                              Context.getSourceManager(),
+StringRef getText(CharSourceRange Range, const ASTContext &Context) {
+  return Lexer::getSourceText(Range, Context.getSourceManager(),
                               Context.getLangOpts());
 }
-} // end namespace internal
+
+CharSourceRange maybeExtendRange(CharSourceRange Range, tok::TokenKind Next,
+                                 ASTContext &Context) {
+  Optional<Token> Tok = Lexer::findNextToken(
+      Range.getEnd(), Context.getSourceManager(), Context.getLangOpts());
+  if (!Tok || !Tok->is(Next))
+    return Range;
+  return CharSourceRange::getTokenRange(Range.getBegin(), Tok->getLocation());
+}
+} // namespace internal
 
 } // end namespace fixit
 } // end namespace tooling