Draft: Add SCIP driver (#205)

* init scip solver driver

* minimal driver

* add basic functionalities

* fix primal solution

* change getPROBDATA to cons

* change getPROBDATA v2

* fix test

* add indicator constraint LinLE

* add indicator constraint LinGE

* add indicator constraint LinEQ

* change indicator constraint to recommended

* add or, and constraint

* handle char and bool param

* add more options

* improve readme and changes

* disable sepa of indicator cons

* improve memory handling

* add linearHelper method

* add indicator helper method

* add quadratic helper method

* add pool solution

* add abs, sin and cosfunctions

* add exp and log function

* add pow function

* add more options and concurrent mode

* improve tests

* add more options

* add last options

* adapt mipstart header

* Update CHANGES.scip.md

* add option to x-multimip1

* change cmake

solvers/CMakeLists.txt

@@ -103,7 +103,7 @@ function(add_ampl_solver name)
 
   if (TARGET ${module}-library)
     get_target_property(TRG_PROP_IMPRT_LOC ${module}-library IMPORTED_LOCATION)
-    if (NOT libraries OR TRG_PROP_IMPRT_LOC)
+    if (NOT libraries)#OR TRG_PROP_IMPRT_LOC)
       set(libraries ${module}-library)
     endif()
   endif ()
@@ -245,6 +245,9 @@ add_ampl_backend(cbcmp DLL_RUNTIME SHARED_LIB MODULE CBC
   LIBRARIES ${CBC_LIBS} ${CMAKE_DL_LIBS})
 
 
+add_ampl_backend(scip DLL_RUNTIME SHARED_LIB MODULE SCIP 
+  LIBRARIES ${SCIP_LIBS} ${CMAKE_DL_LIBS})
+
 add_ampl_backend(highsmp DLL_RUNTIME SHARED_LIB MODULE HIGHS 
   LIBRARIES ${HIGHS_LIBS} ${CMAKE_DL_LIBS})
 

solvers/scip/CHANGES.scip.md

@@ -0,0 +1,5 @@
+Summary of recent updates to SCIP for AMPL
+==========================================
+
+## Unreleased
+- First release of mock driver

solvers/scip/README.scip.txt

@@ -0,0 +1,34 @@
+SCIP driver for AMPL
+====================
+
+SCIP (Solving Constraint Integer Programs) is currently one of the
+fastest non-commercial solvers for mixed integer programming (MIP)
+and mixed integer nonlinear programming (MINLP). It is also a framework
+for constraint integer programming and branch-cut-and-price.
+More information can be found in https://scipopt.org/#scipoptsuite.
+
+Normally SCIP is invoked by AMPL's solve command, which gives the
+invocation
+
+     scip stub -AMPL
+
+in which stub.nl is an AMPL generic output file (possibly written
+by "ampl -obstub" or "ampl -ogstub").  After solving the problem,
+scip writes a stub.sol file for use by AMPL's solve and solution
+commands.  When you run ampl, this all happens automatically if you
+give the AMPL commands
+
+     option solver scip;
+     solve;
+
+You can control scip either by setting the environment variable
+scip_options appropriately (either by using ampl's option command,
+or by using the shell's set and export commands before you invoke ampl),
+or by passing the options on the command line:
+
+     scip stub [-AMPL] option1=value option2=value ...
+
+You can put one or more (white-space separated) phrases in $scip_options.
+To see the possibilities, invoke
+
+     scip -=

solvers/scip/main.cc

@@ -0,0 +1,9 @@
+#include "mp/backend-app.h"
+
+/// Declare a backend factory
+std::unique_ptr<mp::BasicBackend> CreateScipBackend();
+
+extern "C" int main1(int, char **argv) {
+  return
+      mp::RunBackendApp(argv, CreateScipBackend);
+}

solvers/scip/model-mgr-with-std-pb.cc

@@ -0,0 +1,8 @@
+/**
+ * Generate ModelManagerWithPB<mp::Problem>
+ *
+ * Having a separate .cc should improve compilation speed
+ */
+
+#include "mp/model-mgr-with-std-pb.hpp"
+

solvers/scip/scip-ampls-c-api.h

@@ -0,0 +1,33 @@
+#ifndef SCIPAMPLSCAPI_H
+#define SCIPAMPLSCAPI_H
+/*
+ * C API for MP/Scip
+ */
+
+//#include "scip.h"
+
+#include "mp/ampls-c-api.h"
+
+/*
+ * Below are Scip-specific AMPLS API functions.
+ * They complement the 'public' AMPLS API defined in ampls-c-api.h.
+ */
+
+/// Initialize AMPLS scip.
+
+/// @param slv_opt: a string of solver options
+/// (normally provided in the <solver>_options string).
+/// Can be NULL.
+/// @return pointer to struct AMPLS_MP_Solver to be populated.
+void*  AMPLSOpenScip(const char* slv_opt, CCallbacks cb);
+
+/// Shut down solver instance
+void AMPLSCloseScip(AMPLS_MP_Solver* slv);
+
+/// Extract the Scip model handle
+void* GetScipmodel(AMPLS_MP_Solver* slv);
+
+
+#endif // SCIPAMPLSCAPI_H
+
+

solvers/scip/scip-lib.c

@@ -0,0 +1,30 @@
+#include "scip/scip-ampls-c-api.h"
+
+#ifdef _WIN32
+#define APIEXPORT __declspec(dllexport)
+#else
+#define APIEXPORT  __attribute__((visibility("default")))
+#endif
+
+
+APIEXPORT void* AMPLloadmodel(int argc, char** argv, CCallbacks cb) {
+  const char* nl_filename = argv[1];
+  const char *slv_opt= argv[2];
+  AMPLS_MP_Solver* slv;
+  slv = AMPLSOpenScip(slv_opt, cb);
+  if (!slv)
+    return NULL;
+  AMPLSLoadNLModel(slv, nl_filename);
+  return slv;
+}
+APIEXPORT void* AMPLgetScipmodel(void* slv) {
+  return GetScipmodel(slv);
+}
+
+APIEXPORT void AMPLwritesolution(AMPLS_MP_Solver* slv, const char* solFileName) {
+  AMPLSReportResults(slv, solFileName);
+}
+
+APIEXPORT void AMPLclosesolver(AMPLS_MP_Solver* slv) {
+  AMPLSCloseScip(slv);
+}

solvers/scip/scip-modelapi-connect.cc

@@ -0,0 +1,18 @@
+#include "mp/flat/redef/MIP/converter_mip.h"
+#include "mp/flat/model_api_connect.h"
+
+#include "scipmodelapi.h"
+
+
+namespace mp {
+
+/// Defining the function in ...-modelapi-connect.cc
+/// for recompilation speed
+std::unique_ptr<BasicModelManager>
+CreateScipModelMgr(ScipCommon& cc, Env& e,
+										 pre::BasicValuePresolver*& pPre) {
+	return CreateModelMgrWithFlatConverter<
+			ScipModelAPI, MIPFlatConverter >(cc, e, pPre);
+}
+
+}  // namespace mp