Compiler Flags For C++11 - chrono file not found

Question

I am trying to make a project I downloaded from github. After setting up all the dependencies, it asks me to run 'make'. However, 'make' fails and complains about chrono file not being found.
I understand that it is a compiler related issue and I have to enable c++11 support. More specifically, pass the compiler flag -stdlib=libc++.
However, adding this flag to my Makefile still produces the same error. Can anyone explain where/how this flag needs to be set?

this is the content of the Makefile:

TARGETS = \ 
    ptools \ 
    feature \ 
    libsvm \ 
    wrapper 

all: 
    -for dir in $(TARGETS); do \ 
    cd $${dir}; $(MAKE); cd ..; \ 
    done cd libsvm; $(MAKE) lib; cd ..; 

clean: 
    -for dir in $(TARGETS); do \ 
    cd $${dir}; $(MAKE) clean; cd ..; \ 
    done 

test: 
    @echo hello; 

.PHONY: clean $(TARGETS)

Update1: After running brew install gcc, it starts downloading the dependencies. However, it always breaks when it's downloading one of the dependencies, mpfr, with this error: Error: mpfr cannot be built with any available compilers. Install GNU's GCC.

Update2: I managed to update gcc and the version it returns is 6.2.0. However, I am still seeing the same error. I added CXXFLAGS += -stdlib=libc++ -std=gnu++11 to my Makefile, bust still see the same result.

What compiler (and version) are you using in your dev environment? — πάντα ῥεῖ, Nov 23 '16 at 20:47
Are you passing `-std=c++11`? You had to do this in GCC and Clang to use C++11 stuff when last i used them. — cHao, Nov 23 '16 at 20:48
I had to download xCode, so I believe it is using gcc. the version is 4.2.1. — Amin Abed, Nov 23 '16 at 20:54
Here is the link to the project: https://github.com/Netflix/vmaf — Amin Abed, Nov 23 '16 at 20:56
this is the content of the Makefile:TARGETS = \ ptools \ feature \ libsvm \ wrapper all: -for dir in $(TARGETS); do \ cd $${dir}; $(MAKE); cd ..; \ done cd libsvm; $(MAKE) lib; cd ..; clean: -for dir in $(TARGETS); do \ cd $${dir}; $(MAKE) clean; cd ..; \ done test: @echo hello; .PHONY: clean $(TARGETS) — Amin Abed, Nov 23 '16 at 20:57
I can read on project page : it requires gcc and g++ (>=4.8). — SR_, Nov 23 '16 at 21:08
@AminAbed Add additional information (like the makefile changes you made) [into your question](http://stackoverflow.com/posts/40773879/edit) please. As comments that's not very useful as you can see. — πάντα ῥεῖ, Nov 23 '16 at 21:38
@Amin Abed: have a look at http://stackoverflow.com/questions/28970935/osx-replace-gcc-version-4-2-1-with-4-9-installed-via-homebrew — SR_, Nov 23 '16 at 21:40
@AminAbed _"How do I update the gcc?"_ Depends on your dev environment. — πάντα ῥεῖ, Nov 23 '16 at 21:40
Put the lines of the error in your message, and enough lines before the error in order to see what's happening. — SR_, Nov 25 '16 at 07:08

score 1 · Answer 1 · edited May 23 '17 at 10:32

You should add

CXXFLAGS += -std=c++11

to your makefile (somewhere prior to the rules).

Supposed you have a up to date enough toolchain.

Older compilers support the flags

-std=c++0x

may be.

How to update your toolchain (as you asked for in your comment), depends on your OS environment and software managing system.

At least an option would be to compile the latest (stable) version of your toolchain yourself.

Compiler Flags For C++11 - chrono file not found

1 Answers1