GSoC 2022: Manas Sivakumar Week 6

[Manas23601]

Changes proposed in this pull request:

• Trying to make OR-Tools work with vrpRouting.

[Manas23601]

OR tools example : https://github.com/Manas23601/google-or-practise.

[Manas23601]

I tried asking for help in OR Tools official discord channel. I did whatever I could understand.
https://discord.com/invite/ENkQrdf (Discord Server)

so far I'm able to access the ortools library inside my repo repository (no header file undefined errors), but its failing when I use a function defined inside that library. I will attach the output log below.

After I build ortools. I am able to build and run a example.cc file perfectly with make run SOURCE=\path\to\file.cc in the root folder of ortools. Whereas with just g++ -std=c++17 it fails

Error Message:

manas@Fallen-Knight:~/Codes/GSOC-2022/MyFork$ g++ -std=c++17 bin_packing.cc
/usr/bin/ld: /tmp/ccNh7n0N.o: in function `operations_research::BinPackingMip()':
bin_packing.cc:(.text+0x59): undefined reference to `operations_research::MPSolver::CreateSolver(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/usr/bin/ld: bin_packing.cc:(.text+0x1bc): undefined reference to `operations_research::MPSolver::MakeIntVar(double, double, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/usr/bin/ld: bin_packing.cc:(.text+0x2ca): undefined reference to `operations_research::MPSolver::MakeIntVar(double, double, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
/usr/bin/ld: bin_packing.cc:(.text+0x33a): undefined reference to `operations_research::LinearExpr::LinearExpr()'
/usr/bin/ld: bin_packing.cc:(.text+0x395): undefined reference to `operations_research::LinearExpr::LinearExpr(operations_research::MPVariable const*)'
/usr/bin/ld: bin_packing.cc:(.text+0x3ab): undefined reference to `operations_research::LinearExpr::operator+=(operations_research::LinearExpr const&)'
/usr/bin/ld: bin_packing.cc:(.text+0x3ed): undefined reference to `operations_research::LinearExpr::LinearExpr(double)'
/usr/bin/ld: bin_packing.cc:(.text+0x40a): undefined reference to `operations_research::operator==(operations_research::LinearExpr const&, operations_research::LinearExpr const&)'
/usr/bin/ld: bin_packing.cc:(.text+0x419): undefined reference to `operations_research::MPSolver::MakeRowConstraint(operations_research::LinearRange const&)'
/usr/bin/ld: bin_packing.cc:(.text+0x47a): undefined reference to `operations_research::LinearExpr::LinearExpr()'
/usr/bin/ld: bin_packing.cc:(.text+0x4dc): undefined reference to `operations_research::LinearExpr::LinearExpr(operations_research::MPVariable const*)'
/usr/bin/ld: bin_packing.cc:(.text+0x515): undefined reference to `operations_research::operator*(double, operations_research::LinearExpr)'
/usr/bin/ld: bin_packing.cc:(.text+0x52b): undefined reference to `operations_research::LinearExpr::operator+=(operations_research::LinearExpr const&)'
/usr/bin/ld: bin_packing.cc:(.text+0x5a6): undefined reference to `operations_research::LinearExpr::LinearExpr(operations_research::MPVariable const*)'
/usr/bin/ld: bin_packing.cc:(.text+0x5c7): undefined reference to `operations_research::operator*(operations_research::LinearExpr, double)'
/usr/bin/ld: bin_packing.cc:(.text+0x5e4): undefined reference to `operations_research::operator<=(operations_research::LinearExpr const&, operations_research::LinearExpr const&)'
/usr/bin/ld: bin_packing.cc:(.text+0x5f3): undefined reference to `operations_research::MPSolver::MakeRowConstraint(operations_research::LinearRange const&)'
/usr/bin/ld: bin_packing.cc:(.text+0x665): undefined reference to `operations_research::LinearExpr::LinearExpr()'
/usr/bin/ld: bin_packing.cc:(.text+0x6aa): undefined reference to `operations_research::LinearExpr::LinearExpr(operations_research::MPVariable const*)'
/usr/bin/ld: bin_packing.cc:(.text+0x6c0): undefined reference to `operations_research::LinearExpr::operator+=(operations_research::LinearExpr const&)'
/usr/bin/ld: bin_packing.cc:(.text+0x705): undefined reference to `operations_research::MPSolver::Solve()'
/usr/bin/ld: bin_packing.cc:(.text+0x756): undefined reference to `operations_research::MPObjective::Value() const'
/usr/bin/ld: bin_packing.cc:(.text+0x7d6): undefined reference to `operations_research::MPVariable::solution_value() const'
/usr/bin/ld: bin_packing.cc:(.text+0x8b5): undefined reference to `operations_research::MPVariable::solution_value() const'
/usr/bin/ld: /tmp/ccNh7n0N.o: in function `absl::lts_20211102::container_internal::EmptyGroup()':
bin_packing.cc:(.text._ZN4absl12lts_2021110218container_internal10EmptyGroupEv[_ZN4absl12lts_2021110218container_internal10EmptyGroupEv]+0xb): undefined reference to `absl::lts_20211102::container_internal::kEmptyGroup'
/usr/bin/ld: /tmp/ccNh7n0N.o: in function `operations_research::MPObjective::MinimizeLinearExpr(operations_research::LinearExpr const&)':
bin_packing.cc:(.text._ZN19operations_research11MPObjective18MinimizeLinearExprERKNS_10LinearExprE[_ZN19operations_research11MPObjective18MinimizeLinearExprERKNS_10LinearExprE]+0x28): undefined reference to `operations_research::MPObjective::OptimizeLinearExpr(operations_research::LinearExpr const&, bool)'
collect2: error: ld returned 1 exit status

[Manas23601]

Please take a look at the discord conversation as well. ("general" room). To summarise OR tools when installed from source and built works with a make run SOURCE=\path\to\file.cc but not with g++ -std=c++17 file.cc

https://github.com/or-tools/cmake_or-tools Used this as a reference. I think I need to somehow compile my example while building.

[cvvergara]

something like

git mv  * test_or_tools

[cvvergara]

Instruction to "install google-or-tools in your local machine"

[Manas23601]

git clone -b stable --single-branch git@github.com:google/or-tools.git
cmake -S. -Bbuild -DBUILD_DEPS:BOOL=ON
cmake --build build