Revert "Suppress non-conforming GNU paste extension in all standard-conforming modes"
This reverts commit f4537935dcdbf390c863591cf556e76c3abab9c1.
This reverts commit b43c26d036dcbf7a6881f39e4434cf059364022a.
This GNU and MSVC extension turns out to be very popular. Most projects
are not using C++20, so cannot use the new __VA_OPT__ feature to be
standards conformant. The other workaround, using -std=gnu*, enables too
many language extensions and isn't viable.
Until there is a way for users to get the behavior provided by the
`, ## __VA_ARGS__` extension in the -std=c++17 and earlier language
modes, we need to revert this.
(cherry picked from commit 61a66e4b5ec18e9e73c2f6334f6b7f7dd4bca77e)
diff --git a/clang/lib/Lex/TokenLexer.cpp b/clang/lib/Lex/TokenLexer.cpp
index 97cb2cf..da5681a 100644
--- a/clang/lib/Lex/TokenLexer.cpp
+++ b/clang/lib/Lex/TokenLexer.cpp
@@ -148,12 +148,12 @@
return false;
// GCC removes the comma in the expansion of " ... , ## __VA_ARGS__ " if
- // __VA_ARGS__ is empty, but not in strict mode where there are no
- // named arguments, where it remains. With GNU extensions, it is removed
- // regardless of named arguments.
+ // __VA_ARGS__ is empty, but not in strict C99 mode where there are no
+ // named arguments, where it remains. In all other modes, including C99
+ // with GNU extensions, it is removed regardless of named arguments.
// Microsoft also appears to support this extension, unofficially.
- if (!PP.getLangOpts().GNUMode && !PP.getLangOpts().MSVCCompat &&
- Macro->getNumParams() < 2)
+ if (PP.getLangOpts().C99 && !PP.getLangOpts().GNUMode
+ && Macro->getNumParams() < 2)
return false;
// Is a comma available to be removed?
diff --git a/clang/test/Preprocessor/macro_fn_comma_swallow2.c b/clang/test/Preprocessor/macro_fn_comma_swallow2.c
index 4e4960c..93ab2b8 100644
--- a/clang/test/Preprocessor/macro_fn_comma_swallow2.c
+++ b/clang/test/Preprocessor/macro_fn_comma_swallow2.c
@@ -1,16 +1,11 @@
// Test the __VA_ARGS__ comma swallowing extensions of various compiler dialects.
// RUN: %clang_cc1 -E %s | FileCheck -check-prefix=GCC -strict-whitespace %s
-// RUN: %clang_cc1 -E -std=c90 %s | FileCheck -check-prefix=C99 -strict-whitespace %s
// RUN: %clang_cc1 -E -std=c99 %s | FileCheck -check-prefix=C99 -strict-whitespace %s
// RUN: %clang_cc1 -E -std=c11 %s | FileCheck -check-prefix=C99 -strict-whitespace %s
// RUN: %clang_cc1 -E -x c++ %s | FileCheck -check-prefix=GCC -strict-whitespace %s
-// RUN: %clang_cc1 -E -x c++ -std=c++03 %s | FileCheck -check-prefix=C99 -strict-whitespace %s
-// RUN: %clang_cc1 -E -x c++ -std=c++11 %s | FileCheck -check-prefix=C99 -strict-whitespace %s
// RUN: %clang_cc1 -E -std=gnu99 %s | FileCheck -check-prefix=GCC -strict-whitespace %s
// RUN: %clang_cc1 -E -fms-compatibility %s | FileCheck -check-prefix=MS -strict-whitespace %s
-// RUN: %clang_cc1 -E -x c++ -fms-compatibility %s | FileCheck -check-prefix=MS -strict-whitespace %s
-// RUN: %clang_cc1 -E -x c++ -std=c++11 -fms-compatibility %s | FileCheck -check-prefix=MS -strict-whitespace %s
// RUN: %clang_cc1 -E -DNAMED %s | FileCheck -check-prefix=GCC -strict-whitespace %s
// RUN: %clang_cc1 -E -std=c99 -DNAMED %s | FileCheck -check-prefix=C99 -strict-whitespace %s
