update cmake to build library

CMakeLists.txt

@@ -21,6 +21,7 @@ SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -fopenmp -O2 -std=c++11")
 
 SET(LightGBM_HEADER_DIR ${PROJECT_SOURCE_DIR}/include)
 SET(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR})
+SET(LIBRARY_OUTPUT_PATH ${PROJECT_SOURCE_DIR})
 
 ADD_SUBDIRECTORY(src)
 

include/LightGBM/c_api.h

@@ -67,10 +67,10 @@ DllExport int LGBM_CreateDatasetFromBinaryFile(const char* filename,
 /*!
 * \brief create a dataset from CSR format
 * \param indptr pointer to row headers
-* \param indptr_type 0:int_32 1:int_64
+* \param indptr_type
 * \param indices findex
 * \param data fvalue
-* \param data_type 0 for float_32 1 for float_64
+* \param data_type
 * \param nindptr number of rows in the matix + 1
 * \param nelem number of nonzero elements in the matrix
 * \param num_col number of columns; when it's set to 0, then guess from data
@@ -94,10 +94,10 @@ DllExport int LGBM_CreateDatasetFromCSR(const void* indptr,
 /*!
 * \brief create a dataset from CSC format
 * \param col_ptr pointer to col headers
-* \param col_ptr_type 0:int_32 1:int_64
+* \param col_ptr_type
 * \param indices findex
 * \param data fvalue
-* \param data_type 0 for float_32 1 for float_64
+* \param data_type
 * \param ncol_ptr number of rows in the matix + 1
 * \param nelem number of nonzero elements in the matrix
 * \param num_row number of rows; when it's set to 0, then guess from data
@@ -121,7 +121,7 @@ DllExport int LGBM_CreateDatasetFromCSC(const void* col_ptr,
 /*!
 * \brief create dataset from dense matrix
 * \param data pointer to the data space
-* \param data_type 0 for float_32 1 for float_64
+* \param data_type 0
 * \param nrow number of rows
 * \param ncol number columns
 * \param is_row_major 1 for row major, 0 for column major
@@ -302,10 +302,10 @@ DllExport int LGBM_BoosterGetPredict(BoosterHandle handle,
 * \brief make prediction for an new data set
 * \param handle handle
 * \param indptr pointer to row headers
-* \param indptr_type 0:int_32 1:int_64
+* \param indptr_type 
 * \param indices findex
 * \param data fvalue
-* \param data_type 0:float_32 1:float64
+* \param data_type
 * \param nindptr number of rows in the matix + 1
 * \param nelem number of nonzero elements in the matrix
 * \param num_col number of columns; when it's set to 0, then guess from data
@@ -334,7 +334,7 @@ DllExport int LGBM_BoosterPredictForCSR(BoosterHandle handle,
 * \brief make prediction for an new data set
 * \param handle handle
 * \param data pointer to the data space
-* \param data_type 0:float_32 1:float64
+* \param data_type
 * \param nrow number of rows
 * \param ncol number columns
 * \param is_row_major 1 for row major, 0 for column major
@@ -369,6 +369,8 @@ DllExport int LGBM_BoosterSaveModel(BoosterHandle handle,
 
 
 
+// some help functions used to convert data
+
 std::function<std::vector<double>(int row_idx)>
 RowFunctionFromDenseMatric(const void* data, int num_row, int num_col, int data_type, int is_row_major);
 

src/CMakeLists.txt

@@ -14,6 +14,8 @@ AUX_SOURCE_DIRECTORY(./treelearner/ TREELEARNER_SRC)
 
 add_executable(lightgbm main.cpp ${APPLICATION_SRC} ${BOOSTING_SRC} ${IO_SRC} ${METRIC_SRC} ${OBJECTIVE_SRC} ${NETWORK_SRC} ${TREELEARNER_SRC})
 
+add_library(_lightgbm SHARED c_api.cpp ${APPLICATION_SRC} ${BOOSTING_SRC} ${IO_SRC} ${METRIC_SRC} ${OBJECTIVE_SRC} ${NETWORK_SRC} ${TREELEARNER_SRC})
+
 if(USE_MPI)
   TARGET_LINK_LIBRARIES(lightgbm ${MPI_CXX_LIBRARIES})
 endif(USE_MPI)

src/c_api.cpp

@@ -558,7 +558,7 @@ DllExport int LGBM_BoosterSaveModel(BoosterHandle handle,
   return 0;
 }
 
-
+// ---- start of some help functions
 
 std::function<std::vector<double>(int row_idx)>
 RowFunctionFromDenseMatric(const void* data, int num_row, int num_col, int data_type, int is_row_major) {
@@ -609,6 +609,7 @@ RowFunctionFromDenseMatric(const void* data, int num_row, int num_col, int data_
   } else {
     Log::Fatal("unknown data type in RowFunctionFromDenseMatric");
   }
+  return nullptr;
 }
 
 std::function<std::vector<std::pair<int, double>>(int row_idx)>
@@ -660,6 +661,7 @@ RowPairFunctionFromDenseMatric(const void* data, int num_row, int num_col, int d
   } else {
     Log::Fatal("unknown data type in RowPairFunctionFromDenseMatric");
   }
+  return nullptr;
 }
 
 std::function<std::vector<std::pair<int, double>>(int idx)>
@@ -729,6 +731,7 @@ RowFunctionFromCSR(const void* indptr, int indptr_type, const int32_t* indices,
   } else {
     Log::Fatal("unknown data type in RowFunctionFromCSR");
   }
+  return nullptr;
 }
 
 std::function<std::vector<std::pair<int, double>>(int idx)>
@@ -798,6 +801,7 @@ ColumnFunctionFromCSC(const void* col_ptr, int col_ptr_type, const int32_t* indi
   } else {
     Log::Fatal("unknown data type in ColumnFunctionFromCSC");
   }
+  return nullptr;
 }
 
 std::vector<double> SampleFromOneColumn(const std::vector<std::pair<int, double>>& data, const std::vector<size_t>& indices) {