Fix PR2477 - clang misparses "//*" in C89 mode
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62368 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index 0eb439a..fa29d0a 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -1300,7 +1300,8 @@
// If the next token is obviously a // or /* */ comment, skip it efficiently
// too (without going through the big switch stmt).
- if (CurPtr[0] == '/' && CurPtr[1] == '/' && !inKeepCommentMode()) {
+ if (CurPtr[0] == '/' && CurPtr[1] == '/' && !inKeepCommentMode() &&
+ Features.BCPLComment) {
SkipBCPLComment(Result, CurPtr+2);
goto SkipIgnoredUnits;
} else if (CurPtr[0] == '/' && CurPtr[1] == '*' && !inKeepCommentMode()) {
@@ -1480,18 +1481,32 @@
// 6.4.9: Comments
Char = getCharAndSize(CurPtr, SizeTmp);
if (Char == '/') { // BCPL comment.
- if (SkipBCPLComment(Result, ConsumeChar(CurPtr, SizeTmp, Result)))
- return; // KeepCommentMode
+ // Even if BCPL comments are disabled (e.g. in C89 mode), we generally
+ // want to lex this as a comment. There is one problem with this though,
+ // that in one particular corner case, this can change the behavior of the
+ // resultant program. For example, In "foo //**/ bar", C89 would lex
+ // this as "foo / bar" and langauges with BCPL comments would lex it as
+ // "foo". Check to see if the character after the second slash is a '*'.
+ // If so, we will lex that as a "/" instead of the start of a comment.
+ if (Features.BCPLComment ||
+ getCharAndSize(CurPtr+SizeTmp, SizeTmp2) != '*') {
+ if (SkipBCPLComment(Result, ConsumeChar(CurPtr, SizeTmp, Result)))
+ return; // KeepCommentMode
- // It is common for the tokens immediately after a // comment to be
- // whitespace (indentation for the next line). Instead of going through
- // the big switch, handle it efficiently now.
- goto SkipIgnoredUnits;
- } else if (Char == '*') { // /**/ comment.
+ // It is common for the tokens immediately after a // comment to be
+ // whitespace (indentation for the next line). Instead of going through
+ // the big switch, handle it efficiently now.
+ goto SkipIgnoredUnits;
+ }
+ }
+
+ if (Char == '*') { // /**/ comment.
if (SkipBlockComment(Result, ConsumeChar(CurPtr, SizeTmp, Result)))
return; // KeepCommentMode
goto LexNextToken; // GCC isn't tail call eliminating.
- } else if (Char == '=') {
+ }
+
+ if (Char == '=') {
CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
Kind = tok::slashequal;
} else {