diff options
Diffstat (limited to 'clang')
| -rw-r--r-- | clang/lib/Lex/PPMacroExpansion.cpp | 28 | ||||
| -rw-r--r-- | clang/test/Preprocessor/microsoft-ext.c | 13 |
2 files changed, 31 insertions, 10 deletions
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp index dfbcaedcacf..c13515280b7 100644 --- a/clang/lib/Lex/PPMacroExpansion.cpp +++ b/clang/lib/Lex/PPMacroExpansion.cpp @@ -820,18 +820,26 @@ MacroArgs *Preprocessor::ReadMacroCallArgumentList(Token &MacroName, } } else if (Tok.is(tok::l_paren)) { ++NumParens; - } else if (Tok.is(tok::comma) && NumParens == 0 && - !(Tok.getFlags() & Token::IgnoredComma)) { + } else if (Tok.is(tok::comma)) { // 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. - if (!isVariadic) break; - if (NumFixedArgsLeft > 1) - break; + // for this with the IgnoredComma token flag. + if (Tok.getFlags() & Token::IgnoredComma) { + // However, in MSVC's preprocessor, subsequent expansions do treat + // these commas as argument separators. This leads to a common + // workaround used in macros that need to work in both MSVC and + // compliant preprocessors. Therefore, the IgnoredComma flag can only + // apply once to any given token. + Tok.clearFlag(Token::IgnoredComma); + } else if (NumParens == 0) { + // 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. + if (!isVariadic) + break; + if (NumFixedArgsLeft > 1) + break; + } } else if (Tok.is(tok::comment) && !KeepMacroComments) { // If this is a comment token in the argument list and we're just in // -C mode (not -CC mode), discard the comment. diff --git a/clang/test/Preprocessor/microsoft-ext.c b/clang/test/Preprocessor/microsoft-ext.c index cb3cf4f1537..aae52a84b62 100644 --- a/clang/test/Preprocessor/microsoft-ext.c +++ b/clang/test/Preprocessor/microsoft-ext.c @@ -23,6 +23,19 @@ ACTION_TEMPLATE(InvokeArgument, HAS_1_TEMPLATE_PARAMS(int, k), AND_2_VALUE_PARAMS(p0, p1)); +// Regression test for PR43282; check that we match MSVC's failure to unpack +// __VA_ARGS__ unless forwarded through another macro. +#define THIRD_ARGUMENT(A, B, C, ...) C +#define TEST(...) THIRD_ARGUMENT(__VA_ARGS__, 1, 2) +#define COMBINE(...) __VA_ARGS__ +#define WRAPPED_TEST(...) COMBINE(THIRD_ARGUMENT(__VA_ARGS__, 1, 2)) +// Check that we match MSVC's failure to unpack __VA_ARGS__, unless forwarded +// through another macro +auto packed = TEST(,); +auto unpacked = WRAPPED_TEST(,); +// CHECK: auto packed = 2; +// CHECK: auto unpacked = 1; + // This tests compatibility with behaviour needed for type_traits in VS2012 // Test based on _VARIADIC_EXPAND_0X macros in xstddef of VS2012 #define _COMMA , |
