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| author | Jakub Jelinek <jakub@redhat.com> | 2016-10-08 12:48:54 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2016-10-08 12:48:54 +0200 |
| commit | 7bad794aa005aa3ee52fc9c872051d8346c09a24 (patch) | |
| tree | dbcbde73147d32631dd626a01571e5964d9ff5fe /gcc/doc/invoke.texi | |
| parent | 6dc29c6db124fab32ab9b69cfb283e078cc881fc (diff) | |
| download | gcc-7bad794aa005aa3ee52fc9c872051d8346c09a24.tar.gz | |
c-lex.c (c_lex_with_flags): For CPP_COMMENT token with PREV_FALLTHROUGH...
* c-lex.c (c_lex_with_flags) <case CPP_COMMENT>: For CPP_COMMENT
token with PREV_FALLTHROUGH, skip all following CPP_PADDING and
CPP_COMMENT tokens and set add_flags to PREV_FALLTHROUGH afterwards.
* doc/invoke.texi (-Wimplicit-fallthrough): Document the accepted
FALLTHRU comment styles.
* lex.c (fallthrough_comment_p): Fix off-by-one size comparison
errors, cleanup.
(_cpp_lex_direct): Allow arbitrary comments in between
fallthrough_comment_p comment and following token.
* c-c++-common/Wimplicit-fallthrough-23.c: New test.
* c-c++-common/Wimplicit-fallthrough-24.c: New test.
From-SVN: r240884
Diffstat (limited to 'gcc/doc/invoke.texi')
| -rw-r--r-- | gcc/doc/invoke.texi | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 22af6e45673..e1a3e5f291f 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -4170,10 +4170,26 @@ C++17 provides a standard way to suppress the @option{-Wimplicit-fallthrough} warning using @code{[[fallthrough]];} instead of the GNU attribute. In C++11 or C++14 users can use @code{[[gnu::fallthrough]];}, which is a GNU extension. Instead of the these attributes, it is also possible to add a "falls through" -comment to silence the warning. GCC accepts a wide range of such comments, -for example all of "Falls through.", "fallthru", "FALLS-THROUGH" work. This -comment needs to consist of two words merely, optionally followed by periods -or whitespaces. +comment to silence the warning. The whole body of the C or C++ style comment +should match one of the following regular expressions: + +@itemize @bullet + +@item @code{-fallthrough} + +@item @code{@@fallthrough@@} + +@item @code{[ \t]*FALL(S | |-)?THR(OUGH|U)\.?[ \t]*} + +@item @code{[ \t]*Fall((s | |-)[Tt]|t)hr(ough|u)\.?[ \t]*} + +@item @code{[ \t]*fall(s | |-)?thr(ough|u)\.?[ \t]*} + +@end itemize + +and the comment needs to be followed after optional whitespace and other comments +by @code{case} or @code{default} keywords or by a user label that preceeds some +@code{case} or @code{default} label. @smallexample @group |