Use common build directory for ports and system libs. NFC (#23932)

Split out from #23924

Author: sbc100

tools/ports/__init__.py

@@ -233,7 +233,7 @@ def erase():
 
   @staticmethod
   def get_build_dir():
-    return cache.get_path('ports-builds')
+    return system_libs.get_build_dir()
 
   name_cache: Set[str] = set()
 

tools/ports/sdl2_gfx.py

@@ -3,8 +3,6 @@
 # University of Illinois/NCSA Open Source License.  Both these licenses can be
 # found in the LICENSE file.
 
-import os
-
 TAG = '2b147ffef10ec541d3eace326eafe11a54e635f8'
 HASH = 'f39f1f50a039a1667fe92b87d28548d32adcf0eb8526008656de5315039aa21f29d230707caa47f80f6b3a412a577698cd4bbfb9458bb92ac47e6ba993b8efe6'
 
@@ -16,8 +14,6 @@ def needed(settings):
 
 
 def get(ports, settings, shared):
-  sdl_build = os.path.join(ports.get_build_dir(), 'sdl2')
-  assert os.path.exists(sdl_build), 'You must use SDL2 to use SDL2_gfx'
   ports.fetch_project('sdl2_gfx', f'https://github.com/svn2github/sdl2_gfx/archive/{TAG}.zip', sha512hash=HASH)
 
   def create(final):

tools/ports/sdl2_image.py

@@ -3,7 +3,6 @@
 # University of Illinois/NCSA Open Source License.  Both these licenses can be
 # found in the LICENSE file.
 
-import os
 from typing import Dict, Set
 
 TAG = 'release-2.6.0'
@@ -52,8 +51,6 @@ def get_lib_name(settings):
 
 
 def get(ports, settings, shared):
-  sdl_build = os.path.join(ports.get_build_dir(), 'sdl2')
-  assert os.path.exists(sdl_build), 'You must use SDL2 to use SDL2_image'
   ports.fetch_project('sdl2_image', f'https://github.com/libsdl-org/SDL_image/archive/refs/tags/{TAG}.zip', sha512hash=HASH)
   libname = get_lib_name(settings)
 

tools/ports/sdl2_mixer.py

@@ -36,8 +36,6 @@ def get_lib_name(settings):
 
 
 def get(ports, settings, shared):
-  sdl_build = os.path.join(ports.get_build_dir(), 'sdl2')
-  assert os.path.exists(sdl_build), 'You must use SDL2 to use SDL2_mixer'
   ports.fetch_project('sdl2_mixer', f'https://github.com/libsdl-org/SDL_mixer/archive/{TAG}.zip', sha512hash=HASH)
   libname = get_lib_name(settings)
 

tools/ports/sdl2_net.py

@@ -3,8 +3,6 @@
 # University of Illinois/NCSA Open Source License.  Both these licenses can be
 # found in the LICENSE file.
 
-import os
-
 TAG = 'version_2'
 HASH = '317b22ad9b6b2f7b40fac7b7c426da2fa2da1803bbe58d480631f1e5b190d730763f2768c77c72affa806c69a1e703f401b15a1be3ec611cd259950d5ebc3711'
 
@@ -16,8 +14,6 @@ def needed(settings):
 
 
 def get(ports, settings, shared):
-  sdl_build = os.path.join(ports.get_build_dir(), 'sdl2')
-  assert os.path.exists(sdl_build), 'You must use SDL2 to use SDL2_net'
   ports.fetch_project('sdl2_net', f'https://github.com/emscripten-ports/SDL2_net/archive/{TAG}.zip', sha512hash=HASH)
 
   def create(final):

tools/system_libs.py

@@ -79,6 +79,10 @@ def get_base_cflags(build_dir, force_object_files=False, preprocess=True):
   return flags
 
 
+def get_build_dir():
+  return cache.get_path('build')
+
+
 def clean_env():
   # building system libraries and ports should be hermetic in that it is not
   # affected by things like EMCC_CFLAGS which the user may have set.
@@ -150,7 +154,7 @@ def create_lib(libname, inputs):
 
 
 def get_top_level_ninja_file():
-  return os.path.join(cache.get_path('build'), 'build.ninja')
+  return os.path.join(get_build_dir(), 'build.ninja')
 
 
 def run_ninja(build_dir):
@@ -552,7 +556,7 @@ def customize_build_cmd(self, cmd, _filename):
   def do_build(self, out_filename, generate_only=False):
     """Builds the library and returns the path to the file."""
     assert out_filename == self.get_path(absolute=True)
-    build_dir = os.path.join(cache.get_path('build'), self.get_base_name())
+    build_dir = os.path.join(get_build_dir(), self.get_base_name())
     if USE_NINJA:
       self.generate_ninja(build_dir, out_filename)
       if not generate_only: