Help! Can not disable -Wsign-conversion!

Clang Frontend Using Clang
1

Hi, I got a problem when using clang++ 3.2 at my C++ project.

I use CXXFLAGS like :

– CXX_FLAGS = -g -D_FILE_OFFSET_BITS=64 -Wall -Wextra -Werror -Wno-error=sign-conversion -Wconversion -Wno-sign-conversion -Wno-unused-parameter -Wold-style-cast -Woverloaded-virtual -Wpointer-arith -Wshadow -Wwrite-strings -march=native -Wno-null-conversion -Wno-tautological-compare -Wno-unused-function -std=c++0x -O0

I use -Wno-sign-conversion to disable the warning, but I still got the error, How can I disable it, anyone can help me? thank you

/home/ubuntu/claire/claire-common/claire/common/eventloop/poller/EPollPoller.cc:112:13: error: implicit conversion changes signedness: ‘int’ to ‘unsigned int’
[-Werror,-Wsign-conversion]
if (channel->events() & ~(got))
^~~~~~~~~~~~~~~~~ ~
/home/ubuntu/claire/claire-common/claire/common/eventloop/poller/EPollPoller.cc:132:41: error: implicit conversion changes signedness: ‘uint32_t’ (aka ‘unsigned int’) to ‘int’
[-Werror,-Wsign-conversion]
channel->set_revents(events_[i].events);

/home/ubuntu/claire/claire-common/claire/common/eventloop/poller/EPollPoller.cc:138:27: error: implicit conversion changes signedness: 'int' to 'size_type' (aka 'unsigned long')
[-Werror,-Wsign-conversion]
events_.resize(cnt*2);
~~~~~~~ ~~~^~
/home/ubuntu/claire/claire-common/claire/common/eventloop/poller/EPollPoller.cc:143:73: error: implicit conversion changes signedness: 'const int' to 'size_type'
(aka 'unsigned long') [-Werror,-Wsign-conversion]
if (static_cast<size_t>((*it)) < channels_.size() && !channels_[*it].channel->IsNoneEvent())
~~~~~~~~~ ^~~
/home/ubuntu/claire/claire-common/claire/common/eventloop/poller/EPollPoller.cc:145:42: error: implicit conversion changes signedness: 'const int' to 'size_type'
(aka 'unsigned long') [-Werror,-Wsign-conversion]
actives->push_back(channels_[*it].channel);
~~~~~~~~~ ^~~
2

Hi, I got a problem when using clang++ 3.2 at my C++ project.

I use CXXFLAGS like :

-- CXX_FLAGS = -g -D_FILE_OFFSET_BITS=64 -Wall -Wextra -Werror
-Wno-error=sign-conversion -Wconversion -Wno-sign-conversion
-Wno-unused-parameter -Wold-style-cast -Woverloaded-virtual -Wpointer-arith
-Wshadow -Wwrite-strings -march=native -Wno-null-conversion
-Wno-tautological-compare -Wno-unused-function -std=c++0x -O0

Are you sure those flags are actually getting passed to your compile
command?

3

yes，the flags passed to the clang

发自我的 iPhone

在 2013-9-8，0:04，David Blaikie <dblaikie@gmail.com> 写道：

4

Works for me:

$ cat > sign.cpp
#include
int main() {
std::vector v;
int cnt = 3;
v.resize(cnt * 3);
}
blaikie@blaikie:~/dev/scratch$ clang++ sign.cpp -Wsign-conversion
sign.cpp:5:16: warning: implicit conversion changes signedness: ‘int’ to ‘size_type’ (aka ‘unsigned long’) [-Wsign-conversion]
v.resize(cnt * 3);
~ ~~^
1 warning generated.
blaikie@blaikie:~/dev/scratch$ clang++ sign.cpp -g -D_FILE_OFFSET_BITS=64 -Wall -Wextra -Werror -Wno-error=sign-conversion -Wconversion -Wno-sign-conversion -Wno-unused-parameter -Wold-style-cast -Woverloaded-virtual -Wpointer-arith -Wshadow -Wwrite-strings -march=native -Wno-null-conversion -Wno-tautological-compare -Wno-unused-function -std=c++0x -O0

So I assume your build system is putting your CXX_FLAGS before some other flags that are re-enabling this warning/error.