http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58138
Bug ID: 58138
Summary: #include <random> gives warning: macro
"__code_model_small__" is not used
Product: gcc
Version: 4.9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: sbergman at redhat dot com
At least with a trunk revision 201654 (aka LATEST-4.9) build (on Fedora 18
x86_64):
> $ cat test1.cc
> #include <random>
> namespace {}
> $ ~/gcc/LATEST-4.9/inst/bin/g++ -std=gnu++11 -Wunused-macros -c test1.cc
> test1.cc:2:12: warning: macro "__code_model_small__" is not used
> [-Wunused-macros]
> namespace {}
> ^
I was able to strip that down to the following excerpt of
~/gcc/LATEST-4.9/inst/lib/gcc/x86_64-unknown-linux-gnu/4.9.0/include/ia32intrin.h:
> $ cat test2.cc
> #include "test2.h"
> namespace {}
> $ cat test2.h
> #pragma GCC system_header
> #pragma GCC push_options
> #pragma GCC target("sse4.2")
> #pragma GCC pop_options
> $ ~/gcc/LATEST-4.9/inst/bin/g++ -Wunused-macros -c test2.cc test2.cc:2:12:
> warning: macro "__code_model_small__" is not used [-Wunused-macros]
> namespace {}
> ^
With a build of tags/gcc_4_8_1_release, compiling test1.cc does not give a
warning while test2.cc does. And with a random old build of
branches/gcc-4_6-branch, compiling neither test1.cc nor test2.cc gives a
warning (replacing -std=gnu++11 with -std=gnu++0x when compiling test1.cc).
