Match MSVC's handling of commas during macro argument expansion
This allows clang to parse the type_traits header in Visual Studio 2012,
which is included widely in practice.
This is a rework of r163022 by João Matos. The original patch broke
preprocessing of gtest headers, which this patch addresses.
Patch by Will Wilson!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184968 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 13fdf85..06f14c2 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -458,7 +458,12 @@
}
} else if (Tok.is(tok::l_paren)) {
++NumParens;
- } else if (Tok.is(tok::comma) && NumParens == 0) {
+ } else if (Tok.is(tok::comma) && NumParens == 0 &&
+ !(Tok.getFlags() & Token::IgnoredComma)) {
+ // In Microsoft-compatibility mode, single commas from nested macro
+ // expansions should not be considered as argument separators. We test
+ // for this with the IgnoredComma token flag above.
+
// Comma ends this argument if there are more fixed arguments expected.
// However, if this is a variadic macro, and this is part of the
// variadic part, then the comma is just an argument token.