Compiling problems

[gabrielepalloni98]

Good evening,
I would like to ask for some clarification regarding the compilation of GRTresna. In the Wiki (in the Compiling GRTresna section) it states that “To compile the solver, navigate to the GRTresna folder (with the file 'GNUmakefile') and run make all -j 8.”
However, this file is not present in the main GRTresna directory, it only appears inside the following folders: /Examples/ScalarFieldCosmo/GNUmakefile;
/Examples/ScalarFieldBH/GNUmakefile;
/Tests/PeriodicScalarFieldTest/GNUmakefile).
We were wondering how we should proceed with the compilation in this case.

[JCAurre]

Hi!

Thanks for pointing this out. The wiki is misleading, the user should compile GRTresna within the specific example folder to be used. I will amend the wiki.

Josu

[gabrielepalloni98]

Thank you. Following your suggestions, I still encountered some compilation problems. It turned out that, since GRTresna requires C++14, Chombo must be compiled accordingly. To ensure consistency, depending on the chosen compiler, the following changes are required:

• In lib/mk/Make.defs.local, add the flag CXXSTD = 14 (or 17). By default, lib/mk/compiler/Make.defs.GNU sets C++11, see the lines:

ifeq ($(CXXSTD),11)
  _cxxbaseflags := -std=c++11
else ifeq ($(CXXSTD),14)
  _cxxbaseflags := -std=c++14
else ifeq ($(CXXSTD),17)
  _cxxbaseflags := -std=c++17
else
  _cxxbaseflags := -std=c++11
endif

• In lib/mk/compiler/Make.defs.clang++, replace:

defcxxdbgflags = -std=c++11 -g -Wall -Wno-overloaded-virtual -Wno-sign-compare
defcxxoptflags = -std=c++11 -O3 -ffast-math -march=native -Rpass=loop-vectorize -Wno-sign-compare

with

defcxxdbgflags = -std=c++14 -g -Wall -Wno-overloaded-virtual -Wno-sign-compare
defcxxoptflags = -std=c++14 -O3 -ffast-math -march=native -Rpass=loop-vectorize -Wno-sign-compare

• In lib/mk/compiler/Make.defs.Intel, modify:

_cxxbaseflags = -restrict -m64 -std=c++11

with

_cxxbaseflags = -restrict -m64 -std=c++14

After applying these changes, GRTresna compiles correctly. I think this information should be added to the Wiki.

Gabriele

[JCAurre]

Thank you! Indeed all our codes based on Chombo (e.g. GRTresna, GRChombo, GRDzadhza...) require at least C++14, see here. As the Make.defs.local is a system-dependent file, we could put yours in a folder where we store many of the ones we have used over the years. These can be found here.