Refactored duplicate string literal lexing code within Preprocessor, into a

common LexStringLiteral function.  In doing so, some consistency problems have
been ironed out (e.g. where the first token in the string literal was lexed
with macro expansion, but subsequent ones were not) and also an erroneous
diagnostic has been corrected.

LexStringLiteral is complemented by a FinishLexStringLiteral function which
can be used in the situation where the first token of the string literal has
already been lexed.

llvm-svn: 168266

1 files changed, 39 insertions, 0 deletions

diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index 3b070ce..52d6bb6a 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -37,6 +37,7 @@
 #include "clang/Lex/LexDiagnostic.h"
 #include "clang/Lex/CodeCompletionHandler.h"
 #include "clang/Lex/ModuleLoader.h"
+#include "clang/Lex/LiteralSupport.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/TargetInfo.h"
@@ -689,6 +690,44 @@ void Preprocessor::LexAfterModuleImport(Token &Result) {
   }
 }
 
+bool Preprocessor::FinishLexStringLiteral(Token &Result, std::string &String,
+                                          bool AllowMacroExpansion) {
+  // We need at least one string literal.
+  if (Result.isNot(tok::string_literal)) {
+    Diag(Result, diag::err_expected_string_literal);
+    return false;
+  }
+
+  // Lex string literal tokens, optionally with macro expansion.
+  SmallVector<Token, 4> StrToks;
+  do {
+    StrToks.push_back(Result);
+
+    if (Result.hasUDSuffix())
+      Diag(Result, diag::err_invalid_string_udl);
+
+    if (AllowMacroExpansion)
+      Lex(Result);
+    else
+      LexUnexpandedToken(Result);
+  } while (Result.is(tok::string_literal));
+
+  // Concatenate and parse the strings.
+  StringLiteralParser Literal(&StrToks[0], StrToks.size(), *this);
+  assert(Literal.isAscii() && "Didn't allow wide strings in");
+
+  if (Literal.hadError)
+    return false;
+
+  if (Literal.Pascal) {
+    Diag(StrToks[0].getLocation(), diag::err_expected_string_literal);
+    return false;
+  }
+
+  String = Literal.GetString();
+  return true;
+}
+
 void Preprocessor::addCommentHandler(CommentHandler *Handler) {
   assert(Handler && "NULL comment handler");
   assert(std::find(CommentHandlers.begin(), CommentHandlers.end(), Handler) ==