Fix crash on end-of-file after \ in a char literal, fixes PR14369.

This makes LexCharConstant() look more like LexStringLiteral(), which doesn't
have this bug. Add tests for eof after \ for several other cases.

llvm-svn: 168269

clang/lib/Lex/Lexer.cpp

@@ -1823,16 +1823,18 @@ void Lexer::LexCharConstant(Token &Result, const char *CurPtr,
 
   while (C != '\'') {
     // Skip escaped characters.
-    if (C == '\\') {
-      // Skip the escaped character.
-      getAndAdvanceChar(CurPtr, Result);
-    } else if (C == '\n' || C == '\r' ||             // Newline.
+    if (C == '\\')
+      C = getAndAdvanceChar(CurPtr, Result);
+
+    if (C == '\n' || C == '\r' ||             // Newline.
         (C == 0 && CurPtr-1 == BufferEnd)) {  // End of file.
       if (!isLexingRawMode() && !LangOpts.AsmPreprocessor)
         Diag(BufferPtr, diag::ext_unterminated_char);
       FormTokenWithChars(Result, CurPtr-1, tok::unknown);
       return;
-    } else if (C == 0) {
+    }
+
+    if (C == 0) {
       if (isCodeCompletionPoint(CurPtr-1)) {
         PP->CodeCompleteNaturalLanguage();
         FormTokenWithChars(Result, CurPtr-1, tok::unknown);

clang/test/Lexer/eof-char.c

@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 %s -verify -fsyntax-only
+// vim: set binary noeol:
+
+// This file intentionally ends without a \n on the last line.  Make sure your
+// editor doesn't add one.
+
+// expected-warning@+1{{missing terminating ' character}} expected-error@+1{{expected expression}} expected-error@+1{{expected ';'}}
+char c = '\

clang/test/Lexer/eof-file.c

@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 %s -verify -fsyntax-only
+// vim: set binary noeol:
+
+// This file intentionally ends without a \n on the last line.  Make sure your
+// editor doesn't add one.
+
+// expected-error@+1{{expected expression}} expected-error@+1{{expected ';'}}
+char c = \

clang/test/Lexer/eof-string.c

@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 %s -verify -fsyntax-only
+// vim: set binary noeol:
+
+// This file intentionally ends without a \n on the last line.  Make sure your
+// editor doesn't add one.
+
+// expected-warning@+1{{missing terminating '"' character}} expected-error@+1{{expected expression}} expected-error@+1{{expected ';'}}
+char c = "\