Add FindIpopt.cmake module

find-external/Ipopt/FindIpopt.cmake

@@ -0,0 +1,35 @@
+find_package(Ipopt CONFIG QUIET)
+
+if(Ipopt_FOUND)
+  message(DEBUG "Found Ipopt (using IpoptConfig.cmake or ipopt-config.cmake)")
+else()
+  find_package(PkgConfig QUIET)
+  if(NOT PKG_CONFIG_FOUND)
+    message(FATAL_ERROR "pkg-config not found!")
+  endif()
+  pkg_check_modules(Ipopt REQUIRED ipopt)
+
+  include(FindPackageHandleStandardArgs)
+  find_package_handle_standard_args(
+    Ipopt
+    FAIL_MESSAGE DEFAULT_MSG
+    REQUIRED_VARS Ipopt_INCLUDE_DIRS Ipopt_LIBRARIES
+    VERSION_VAR Ipopt_VERSION
+  )
+
+  message(STATUS "  Ipopt library dirs: ${Ipopt_LIBRARY_DIRS}")
+  message(STATUS "  Ipopt include dirs: ${Ipopt_INCLUDE_DIRS}")
+  add_library(ipopt SHARED IMPORTED)
+  find_library(ipopt_lib_path NAMES ipopt PATHS ${Ipopt_LIBRARY_DIRS})
+  message(STATUS "  Ipopt library ipopt found at ${ipopt_lib_path}")
+  set_target_properties(ipopt PROPERTIES IMPORTED_LOCATION ${ipopt_lib_path})
+  target_include_directories(ipopt INTERFACE ${Ipopt_INCLUDE_DIRS})
+
+  if(${CMAKE_CXX_COMPILER_ID} STREQUAL "MSVC")
+  else()
+    target_compile_definitions(ipopt INTERFACE HAVE_CSTDDEF)
+  endif()
+  target_compile_options(ipopt INTERFACE ${Ipopt_CFLAGS_OTHER})
+
+  add_library(Ipopt::Ipopt ALIAS ipopt)
+endif()