Lex: Require that '#' be followed by a macro parameter name when preceded by '##'
After lexing a '##', we would look ahead and check to see if it was
followed by '__VA_ARGS__'. After doing so, we would then go ahead and
lex the token.
However we would fail in the case where the '##' was followed by a '#'
followed by an identifier because we would have lexed the '#' separately
from the identifier, bypassing our parameter validation logic.
Instead, lex the tokens coming after the '##' later.
This fixes PR17804.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194059 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index a952b2e..9ba65a5 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -2005,13 +2005,8 @@
MI->getReplacementToken(NumTokens-1).is(tok::comma))
MI->setHasCommaPasting();
- // Things look ok, add the '##' and param name tokens to the macro.
+ // Things look ok, add the '##' token to the macro.
MI->AddTokenToBody(LastTok);
- MI->AddTokenToBody(Tok);
- LastTok = Tok;
-
- // Get the next token of the macro.
- LexUnexpandedToken(Tok);
continue;
}
diff --git a/test/Preprocessor/macro_paste_bad.c b/test/Preprocessor/macro_paste_bad.c
index 0a028a4..2114654 100644
--- a/test/Preprocessor/macro_paste_bad.c
+++ b/test/Preprocessor/macro_paste_bad.c
@@ -32,3 +32,5 @@
#define VA __VA_ ## ARGS__
int VA; // expected-warning {{__VA_ARGS__ can only appear in the expansion of a C99 variadic macro}}
+#define LOG_ON_ERROR(lvl) ::X x## #__LINE__; // expected-error {{'#' is not followed by a macro parameter}}
+LOG_ON_ERROR(0);