cmake: Use FindPython3. (#7019)

`FindPythonInterp` has been deprecated for a long time and is more
verbal about that deprecation now.

The build system no longer uses `PYTHON_EXECUTABLE` but instead uses
`Python3_EXECUTABLE`.

CMakeLists.txt

@@ -153,8 +153,8 @@ list(APPEND Z3_COMPONENT_CXX_DEFINES $<$<CONFIG:RelWithDebInfo>:_EXTERNAL_RELEAS
 ################################################################################
 # Find Python
 ################################################################################
-find_package(PythonInterp 3 REQUIRED)
-message(STATUS "PYTHON_EXECUTABLE: ${PYTHON_EXECUTABLE}")
+find_package(Python3 REQUIRED COMPONENTS Interpreter)
+message(STATUS "Python3_EXECUTABLE: ${Python3_EXECUTABLE}")
 
 ################################################################################
 # Target architecture detection

README-CMake.md

@@ -277,7 +277,7 @@ The following useful options can be passed to CMake whilst configuring.
 * ``CMAKE_INSTALL_PYTHON_PKG_DIR`` - STRING. The path to install the z3 python bindings. This can be relative (to ``CMAKE_INSTALL_PREFIX``) or absolute.
 * ``CMAKE_INSTALL_Z3_CMAKE_PACKAGE_DIR`` - STRING. The path to install CMake package files (e.g. ``/usr/lib/cmake/z3``).
 * ``CMAKE_INSTALL_API_BINDINGS_DOC`` - STRING. The path to install documentation for API bindings.
-* ``PYTHON_EXECUTABLE`` - STRING. The python executable to use during the build.
+* ``Python3_EXECUTABLE`` - STRING. The python executable to use during the build.
 * ``Z3_ENABLE_TRACING_FOR_NON_DEBUG`` - BOOL. If set to ``TRUE`` enable tracing in non-debug builds, if set to ``FALSE`` disable tracing in non-debug builds. Note in debug builds tracing is always enabled.
 * ``Z3_BUILD_LIBZ3_SHARED`` - BOOL. If set to ``TRUE`` build libz3 as a shared library otherwise build as a static library.
 * ``Z3_ENABLE_EXAMPLE_TARGETS`` - BOOL. If set to ``TRUE`` add the build targets for building the API examples.

cmake/z3_add_component.cmake

@@ -116,7 +116,7 @@ macro(z3_add_component component_name)
     set(_full_output_file_path "${CMAKE_CURRENT_BINARY_DIR}/${_output_file}")
     message(STATUS "Adding rule to generate \"${_output_file}\"")
     add_custom_command(OUTPUT "${_output_file}"
-      COMMAND "${PYTHON_EXECUTABLE}" "${PROJECT_SOURCE_DIR}/scripts/pyg2hpp.py" "${_full_pyg_file_path}" "${CMAKE_CURRENT_BINARY_DIR}"
+      COMMAND "${Python3_EXECUTABLE}" "${PROJECT_SOURCE_DIR}/scripts/pyg2hpp.py" "${_full_pyg_file_path}" "${CMAKE_CURRENT_BINARY_DIR}"
       MAIN_DEPENDENCY "${_full_pyg_file_path}"
       DEPENDS "${PROJECT_SOURCE_DIR}/scripts/pyg2hpp.py"
               ${Z3_GENERATED_FILE_EXTRA_DEPENDENCIES}
@@ -275,7 +275,7 @@ macro(z3_add_install_tactic_rule)
   string(REPLACE ";" "\n" _tactic_header_files "${_tactic_header_files}")
   file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/install_tactic.deps" ${_tactic_header_files})
   add_custom_command(OUTPUT "install_tactic.cpp"
-    COMMAND "${PYTHON_EXECUTABLE}"
+    COMMAND "${Python3_EXECUTABLE}"
     "${PROJECT_SOURCE_DIR}/scripts/mk_install_tactic_cpp.py"
     "${CMAKE_CURRENT_BINARY_DIR}"
     "${CMAKE_CURRENT_BINARY_DIR}/install_tactic.deps"
@@ -313,7 +313,7 @@ macro(z3_add_memory_initializer_rule)
   endforeach()
 
   add_custom_command(OUTPUT "mem_initializer.cpp"
-    COMMAND "${PYTHON_EXECUTABLE}"
+    COMMAND "${Python3_EXECUTABLE}"
     "${PROJECT_SOURCE_DIR}/scripts/mk_mem_initializer_cpp.py"
     "${CMAKE_CURRENT_BINARY_DIR}"
     ${_mem_init_finalize_headers}
@@ -349,7 +349,7 @@ macro(z3_add_gparams_register_modules_rule)
   unset(_component_register_module_header_files)
 
   add_custom_command(OUTPUT "gparams_register_modules.cpp"
-    COMMAND "${PYTHON_EXECUTABLE}"
+    COMMAND "${Python3_EXECUTABLE}"
     "${PROJECT_SOURCE_DIR}/scripts/mk_gparams_register_modules_cpp.py"
     "${CMAKE_CURRENT_BINARY_DIR}"
     ${_register_module_header_files}

doc/CMakeLists.txt

@@ -58,7 +58,7 @@ endif()
 
 add_custom_target(api_docs ${ALWAYS_BUILD_DOCS_ARG}
   COMMAND
-  "${PYTHON_EXECUTABLE}" "${MK_API_DOC_SCRIPT}"
+  "${Python3_EXECUTABLE}" "${MK_API_DOC_SCRIPT}"
   --build "${PROJECT_BINARY_DIR}"
   --doxygen-executable "${DOXYGEN_EXECUTABLE}"
   --output-dir "${DOC_DEST_DIR}"

src/CMakeLists.txt

@@ -217,7 +217,7 @@ if (MSVC)
   set(dll_module_exports_file "${CMAKE_CURRENT_BINARY_DIR}/api_dll.def")
   add_custom_command(OUTPUT "${dll_module_exports_file}"
     COMMAND
-      "${PYTHON_EXECUTABLE}"
+      "${Python3_EXECUTABLE}"
       "${PROJECT_SOURCE_DIR}/scripts/mk_def_file.py"
       "${dll_module_exports_file}"
       "libz3"

src/api/CMakeLists.txt

@@ -18,7 +18,7 @@ foreach (gen_file ${generated_files})
 endforeach()
 
 add_custom_command(OUTPUT ${generated_files}
-  COMMAND "${PYTHON_EXECUTABLE}"
+  COMMAND "${Python3_EXECUTABLE}"
   "${PROJECT_SOURCE_DIR}/scripts/update_api.py"
   ${Z3_FULL_PATH_API_HEADER_FILES_TO_SCAN}
   "--api_output_dir"

src/api/dotnet/CMakeLists.txt

@@ -9,7 +9,7 @@ set(VER_TWEAK "${Z3_VERSION_TWEAK}")
 # Generate Native.cs
 set(Z3_DOTNET_NATIVE_FILE "${CMAKE_CURRENT_BINARY_DIR}/Native.cs")
 add_custom_command(OUTPUT "${Z3_DOTNET_NATIVE_FILE}"
-  COMMAND "${PYTHON_EXECUTABLE}"
+  COMMAND "${Python3_EXECUTABLE}"
     "${PROJECT_SOURCE_DIR}/scripts/update_api.py"
     ${Z3_FULL_PATH_API_HEADER_FILES_TO_SCAN}
     "--dotnet-output-dir"
@@ -25,7 +25,7 @@ add_custom_command(OUTPUT "${Z3_DOTNET_NATIVE_FILE}"
 # Generate Enumerations.cs
 set(Z3_DOTNET_CONST_FILE "${CMAKE_CURRENT_BINARY_DIR}/Enumerations.cs")
 add_custom_command(OUTPUT "${Z3_DOTNET_CONST_FILE}"
-  COMMAND "${PYTHON_EXECUTABLE}"
+  COMMAND "${Python3_EXECUTABLE}"
     "${PROJECT_SOURCE_DIR}/scripts/mk_consts_files.py"
     ${Z3_FULL_PATH_API_HEADER_FILES_TO_SCAN}
     "--dotnet-output-dir"

src/api/java/CMakeLists.txt

@@ -16,7 +16,7 @@ set(Z3_JAVA_PACKAGE_NAME "com.microsoft.z3")
 set(Z3_JAVA_NATIVE_JAVA "${CMAKE_CURRENT_BINARY_DIR}/Native.java")
 set(Z3_JAVA_NATIVE_CPP "${CMAKE_CURRENT_BINARY_DIR}/Native.cpp")
 add_custom_command(OUTPUT "${Z3_JAVA_NATIVE_JAVA}" "${Z3_JAVA_NATIVE_CPP}"
-  COMMAND "${PYTHON_EXECUTABLE}"
+  COMMAND "${Python3_EXECUTABLE}"
     "${PROJECT_SOURCE_DIR}/scripts/update_api.py"
     ${Z3_FULL_PATH_API_HEADER_FILES_TO_SCAN}
     "--java-input-dir"
@@ -74,7 +74,7 @@ foreach (enum_file ${Z3_JAVA_ENUMERATION_PACKAGE_FILES})
   )
 endforeach()
 add_custom_command(OUTPUT ${Z3_JAVA_ENUMERATION_PACKAGE_FILES_FULL_PATH}
-  COMMAND "${PYTHON_EXECUTABLE}"
+  COMMAND "${Python3_EXECUTABLE}"
     "${PROJECT_SOURCE_DIR}/scripts/mk_consts_files.py"
     ${Z3_FULL_PATH_API_HEADER_FILES_TO_SCAN}
     "--java-output-dir"

src/api/python/CMakeLists.txt

@@ -33,7 +33,7 @@ endforeach()
 
 # Generate z3core.py
 add_custom_command(OUTPUT "${z3py_bindings_build_dest}/z3/z3core.py"
-  COMMAND "${PYTHON_EXECUTABLE}"
+  COMMAND "${Python3_EXECUTABLE}"
     "${PROJECT_SOURCE_DIR}/scripts/update_api.py"
     ${Z3_FULL_PATH_API_HEADER_FILES_TO_SCAN}
     "--z3py-output-dir"
@@ -49,7 +49,7 @@ list(APPEND build_z3_python_bindings_target_depends "${z3py_bindings_build_dest}
 
 # Generate z3consts.py
 add_custom_command(OUTPUT "${z3py_bindings_build_dest}/z3/z3consts.py"
-  COMMAND "${PYTHON_EXECUTABLE}"
+  COMMAND "${Python3_EXECUTABLE}"
     "${PROJECT_SOURCE_DIR}/scripts/mk_consts_files.py"
     ${Z3_FULL_PATH_API_HEADER_FILES_TO_SCAN}
     "--z3py-output-dir"
@@ -96,7 +96,7 @@ if (Z3_INSTALL_PYTHON_BINDINGS)
   if (NOT DEFINED CMAKE_INSTALL_PYTHON_PKG_DIR)
     message(STATUS "CMAKE_INSTALL_PYTHON_PKG_DIR not set. Trying to guess")
     execute_process(
-      COMMAND "${PYTHON_EXECUTABLE}" "-c"
+      COMMAND "${Python3_EXECUTABLE}" "-c"
         "import sysconfig; print(sysconfig.get_path('purelib'))"
       RESULT_VARIABLE exit_code
       OUTPUT_VARIABLE CMAKE_INSTALL_PYTHON_PKG_DIR

src/ast/pattern/CMakeLists.txt

@@ -7,7 +7,7 @@ if (EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/database.h")
 endif()
 
 add_custom_command(OUTPUT "database.h"
-  COMMAND "${PYTHON_EXECUTABLE}"
+  COMMAND "${Python3_EXECUTABLE}"
           "${PROJECT_SOURCE_DIR}/scripts/mk_pat_db.py"
           "${CMAKE_CURRENT_SOURCE_DIR}/database.smt2"
           "${CMAKE_CURRENT_BINARY_DIR}/database.h"