clang: error: unsupported option '-fopenmp'

Question

clang: error: unsupported option '-fopenmp'

jounih opened this issue 8 years ago · comments

Hi, thanks for this great work.

I noticed it doesn't compile on OSX (using clang), "make" gives these errors:

[dep] third-party/lodepng/lodepng.cc ...
clang: error: unsupported option '-fopenmp'
[dep] stitch/warp.cc ...
clang: error: unsupported option '-fopenmp'
[dep] stitch/transform_estimate.cc ...
clang: error: unsupported option '-fopenmp'
[dep] stitch/stitcherbase.cc ...
clang: error: unsupported option '-fopenmp'

...and so on.

Compiling with gcc on Ubuntu (and probably OSX if installed gcc) works ok.

Any ideas what to fix in the makefile for clang?

Yuxin Wu commented 6 years ago

"src".

Yuxin Wu · Answer 1 · Thu Aug 04 2016 02:25:39 GMT+0800 (China Standard Time)

Clang starts supporting openmp at some version. Works for me with clang on
Linux.

On Aug 3, 2016 11:00 AM, "Jouni Helminen" notifications@github.com wrote:

Hi, thanks for this great work.

I noticed it doesn't compile on OSX (using clang), "make" gives these
errors:

[dep] third-party/lodepng/lodepng.cc ...
clang: error: unsupported option '-fopenmp'
[dep] stitch/warp.cc ...
clang: error: unsupported option '-fopenmp'
[dep] stitch/transform_estimate.cc ...
clang: error: unsupported option '-fopenmp'
[dep] stitch/stitcherbase.cc ...
clang: error: unsupported option '-fopenmp'

...and so on.

Compiling with gcc on Ubuntu (and probably OSX if installed gcc) works ok.

Any ideas what to fix in the makefile for clang?

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GitZChen · Answer 2 · Thu Aug 04 2016 12:18:26 GMT+0800 (China Standard Time)

From my dealings with it, the clang on OSX is an Apple-customized one one that doesn't have OpenMP support. Changing the makefile or even the build system entirely (e.g. to cmake) doesn't help at all. As you have suggested yourself, the only way you can get around this issue is to get another compiler (latest clang or gcc) as well as their associated libraries and then try building the project again.

Yuxin Wu · Answer 3 · Thu Aug 04 2016 15:09:24 GMT+0800 (China Standard Time)

Thanks @GitZChen ! I should add these to the readme.

Jouni Helminen · Answer 4 · Thu Aug 04 2016 21:48:06 GMT+0800 (China Standard Time)

You are right, latest clang should have OpenMP support, but doesn't (yet) on MacOS. I installed Xcode 8 Beta 4 and it didn't include any updates to clang/LLVM version (but perhaps MacOS Sierra will).

So after a bit of fiddling, here is how to successfully compile OpenPano on MacOS El Capitan:

Install brew (http://brew.sh/)
"brew install gcc --without-multilib" (grab a coffee, this takes quite a while - but needed because default brew installation of gcc doesn't have OpenMP support)
"export CXX=/usr/local/Cellar/gcc/6.1.0/bin/g++-6" (use the path from the output of brew gcc install. at the time of writing the above is correct, but may change. Do this or otherwise osx still uses clang to compile)
"brew install eigen"
run "make" in panorama /src - it compiles OK now

GitZChen · Answer 5 · Fri Aug 05 2016 00:27:12 GMT+0800 (China Standard Time)

For 3, you can maybe try using "brew ls gcc" to list all installed components in the gcc formula then determine the path of g++ binary.

Also, in case anyone really wants to use clang instead of gcc, just substitute "gcc" with "llvm" and the path to "g++-6" with the path to the brew-installed "clang++" in the above instructions.

Though @jounih, don't you still need libjpeg?

paranoidpixel · Answer 6 · Sun Aug 07 2016 05:40:34 GMT+0800 (China Standard Time)

Hi everyone,

I am following this thread, and tried the method suggested by @jounih, compiling . However I got many of these errors:

/var/folders/5_/k6wvp3594651b83cz4f_f4n80000gn/T//cc2ALrIr.s:1205:no such instruction: vmovaps %xmm0, -160(%rbp)' /var/folders/5_/k6wvp3594651b83cz4f_f4n80000gn/T//cc2ALrIr.s:1206:no such instruction:vmovaps %xmm1, -144(%rbp)'
/var/folders/5_/k6wvp3594651b83cz4f_f4n80000gn/T//cc2ALrIr.s:1207:no such instruction: vmovaps %xmm2, -128(%rbp)' /var/folders/5_/k6wvp3594651b83cz4f_f4n80000gn/T//cc2ALrIr.s:1208:no such instruction:vmovaps %xmm3, -112(%rbp)'

Did a quick look on Google, and looks like it is related to AVX on OSX problem. I've tried several methods suggested but no luck. Have you ever encountered this issue?

My machine is an 2013 MBP with i5. I did a check and it does have AVX1.0.

Thanks!

GitZChen · Answer 7 · Sun Aug 07 2016 10:11:30 GMT+0800 (China Standard Time)

Never encountered that problem before compiling GCC. Though isn't this question off-topic for OpenPano? Maybe you'll have better luck asking it on SO instead?

Keon-Woong Moon · Answer 8 · Tue Sep 05 2017 09:43:42 GMT+0800 (China Standard Time)

How can I perform step 5 of jounih 's comment?

ermiaswalelgne · Answer 9 · Fri Sep 29 2017 05:53:16 GMT+0800 (China Standard Time)

I know this is a bit old, but just in case someone is still looking for the solution, I want to say that the solution given by @jounih fixed the same problem I had. Just make sure that you get the right path of '/usr/local/Cellar/gcc/6.1.0/bin/g++-6' for the export. By the time of commenting, mine was "export CXX="/usr/local/Cellar/gcc/7.2.0/bin/g++-7"

tpsmahal · Answer 10 · Fri Sep 21 2018 14:27:58 GMT+0800 (China Standard Time)

In jounih's commented on Aug 4, 2016 •
In step 5 "run "make" in panorama /src - it compiles OK now"

what is panorama ? where is /src ?
When I run "make" , I get "make: *** No targets specified and no makefile found. Stop."

Yuxin Wu · Answer 11 · Fri Sep 21 2018 14:29:38 GMT+0800 (China Standard Time)

https://github.com/ppwwyyxx/OpenPano/tree/master/src

tpsmahal · Answer 12 · Fri Sep 21 2018 14:31:02 GMT+0800 (China Standard Time)

what is above link referring to ?

tpsmahal · Answer 13 · Fri Sep 21 2018 14:34:40 GMT+0800 (China Standard Time)

Hello ppwwyyxx , I need to run step 5 as i stated above.
Sorry I am unable to following from link you gave. Could you please describe what should I do now ?

tpsmahal · Answer 14 · Fri Sep 21 2018 14:43:47 GMT+0800 (China Standard Time)

You are right, latest clang should have OpenMP support, but doesn't (yet) on MacOS. I installed Xcode 8 Beta 4 and it didn't include any updates to clang/LLVM version (but perhaps MacOS Sierra will).

So after a bit of fiddling, here is how to successfully compile OpenPano on MacOS El Capitan:

Install brew (http://brew.sh/)

"brew install gcc --without-multilib" (grab a coffee, this takes quite a while - but needed because default brew installation of gcc doesn't have OpenMP support)

"export CXX=/usr/local/Cellar/gcc/6.1.0/bin/g++-6" (use the path from the output of brew gcc install. at the time of writing the above is correct, but may change. Do this or otherwise osx still uses clang to compile)

"brew install eigen"

run "make" in panorama /src - it compiles OK now

Could you please help me run step 5 ? I did till 4. No clue about step 5 ?
I get below
"make: *** No targets specified and no makefile found. Stop."
No clue where is "panorama /src" ?

Gláuber Brennon · Answer 15 · Tue Oct 30 2018 12:54:25 GMT+0800 (China Standard Time)

@ppwwyyxx dude, I did all 5 steps but it still is returning the error "unsupported option -fopenmp" :(
I've reiinstalled the gcc and set the env variable but it is still returning the error

After runing "make -C src" this is the error:

make: Entering directory '/Users/gbrennon/Documents/Prog/Github/OpenPano/src'
[cc] lib/debugutils.cc ...
clang: error: unsupported option '-fopenmp'
make: *** [Makefile:71: obj/lib/debugutils.o] Error 1
make: Leaving directory '/Users/gbrennon/Documents/Prog/Github/OpenPano/src'

Answering @tpsmahal step 5 can be executed with: "make -C src"

Trung Hoang · Answer 16 · Wed Sep 13 2023 09:30:25 GMT+0800 (China Standard Time)

hi, brew install gcc error: Invalid options: --without-multilib