On 06/08/2017 11:29 AM, Marek Polacek wrote:
> On Wed, Jun 07, 2017 at 08:02:42PM +0100, Pedro Alves wrote:
>> Hi Marek,
>>
>> Nice warning! Just to confirm, would the patch warn with code like:
>
> Thanks. BTW, if you (or anyone) could come up with a better name,
> I'm all ears.
AFAICS, the warning's intent is catching the case of a
a macro expanding to multiple (top level) statements, not lines.
Both the comments in the code and the description of the
warning talk in those terms:
+/* (....) This warning warns about
+ cases when a macro expands to multiple statements not wrapped in
+ do {} while (0) or ({ }) and is used as a body of if/else/for/while
+ conditionals. For example,
+Wmultiline-expansion
+C ObjC C++ ObjC++ Var(warn_multiline_expansion) Warning LangEnabledBy(C ObjC
C++ ObjC++,Wall)
+Warn about macros expanding to multiple statements in a body of a conditional
such as if, else, while, or for.
So it'd seem clearer to me if the warning was named around
"-Wmulti-statement-something" instead of "-Wmultiline-something"?
-Wmulti-statement-expansion
-Wmulti-statement-macros
-Wmulti-statement-macro
-Wmulti-statement-macro-expansion
Particularly when one could argue that "multiline expansion" in
context of macros doesn't make any sense, given macros always
expand to a single line:
#define SAME_LINE \
(__LINE__ \
== __LINE__)
static_assert (SAME_LINE, "");
> Nope, it doesn't warn (neither C nor C++). I should probably add this test.
Thanks for confirming. A test would be nice, to make sure we
don't regress.
Thanks,
Pedro Alves
