It's a Frequently Asked Question
clang -cc1 and system includes
-
26-06-2022 - |
문제
I have the following file foo.cpp
:
#include <vector>
struct MyClass
{
std::vector<int> v;
};
It can be successfully compiled with clang (I'm using clang 3.3 on Ubuntu 13.04 32bit):
clang++ -c foo.cpp
Now I want to print AST:
clang++ -cc1 -ast-print foo.cpp
and I've got the following error
foo.cpp:1:10: fatal error: 'vector' file not found
#include <vector>
^
struct MyClass {
};
1 error generated.
It looks like clang++ -cc1
doesn't know about system include files etc.
I'm wondering how to set up includes for clang++ -cc1
?
해결책 2
다른 팁
You need to set up the right include paths. on my system I added
-I/usr/include/i386-linux-gnu/c++/4.8 -I/usr/include/c++/4.8
to the compiler flags. The first one was so that it could find bits/c++config.h Of course the 4.8 is due to the fact I am using a compiler compatible with g++-4.8
I also added
-std=c++11 -stdlib=libstdc++
as compiler options. Hope this helps
@john is correct. For posterity, the relevant portions of the FAQ are (with names tweaked to match the question) :
clang -cc1
is the frontend,clang
is the driver. The driver invokes the frontend with options appropriate for your system. To see these options, run:$ clang++ -### -c foo.cpp
Some clang command line options are driver-only options, some are frontend-only options. Frontend-only options are intended to be used only by clang developers. Users should not run
clang -cc1
directly, because-cc1
options are not guaranteed to be stable.If you want to use a frontend-only option (“a
-cc1
option”), for example-ast-dump
, then you need to take theclang -cc1
line generated by the driver and add the option you need. Alternatively, you can runclang -Xclang <option> ...
to force the driver [to] pass<option>
toclang -cc1
.
I did the latter (-Xclang
) for emitting precompiled headers:
/usr/bin/clang++ -x c++-header foo.hpp -Xclang -emit-pch -o foo.hpp.pch <other options>
^^^^^^^
Without the -Xclang
, clang++
ignored the -emit-pch
. When I tried -cc1
, I had the same problem as the OP — clang++
accepted -emit-pch
but didn't have the other options the driver normally provides.