https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79466
Bug ID: 79466
Summary: strange varargs warnings on superflous paranthesises
Product: gcc
Version: 5.4.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: martin at netbsd dot org
Target Milestone: ---
Created attachment 40719
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=40719&action=edit
Simple example triggering the warning
When compiled with g++ -std=gnu++14 the expression
__builtin_va_start ((ap), (fmt));
triggers a strange warning:
example.cc:4:37: warning: second parameter of 'va_start' not last named
argument [-Wvarargs]
__builtin_va_start ((ap), (fmt));
^
Removing the extra paranthesis makes it work. This does not happen with
-std=gnu++11.
Sample attached, compile with:
g++ -Wall -O2 -std=gnu++14 -c -o example.o example.cc
(warning and optimization settings do not make a difference, only std= is
important)
