Improve install_name fixing

Makefile

@@ -111,13 +111,13 @@ build/$(APP_NAME).app/Contents/%: Contents/%
 	mkdir -p $(@D)
 	cp -a $< $@
 
-build/$(APP_NAME).app/Contents/Resources/$(APP_NAME).dmg: build/$(APP_NAME)-build.sparsebundle build/$(APP_NAME).app/Contents/Resources/icon.icns fix_install_names.sh
+build/$(APP_NAME).app/Contents/Resources/$(APP_NAME).dmg: build/$(APP_NAME)-build.sparsebundle build/$(APP_NAME).app/Contents/Resources/icon.icns relativize_install_names.py
 	[ ! -d $(VOLUME) ] || hdiutil detach $(VOLUME)
 	hdiutil attach \
 		build/$(APP_NAME)-build.sparsebundle \
 		-shadow
 	cd $(VOLUME) \
-		&& "$(CURDIR)/fix_install_names.sh"
+		&& "$(CURDIR)/relativize_install_names.py"
 	cp build/$(APP_NAME).app/Contents/Resources/icon.icns $(VOLUME)/.VolumeIcon.icns
 	SetFile -c icnC $(VOLUME)/.VolumeIcon.icns
 	SetFile -a C $(VOLUME)

relativize_install_names.py

@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+
+import os
+import subprocess
+import itertools
+
+from pathlib import Path
+
+OPENFOAM_VERSION = int(subprocess.run(["bin/foamEtcFile", "-show-api"], stdout=subprocess.PIPE, check=True).stdout)
+
+libs = {}
+
+# Find names of OpenFOAM libraries
+if OPENFOAM_VERSION < 2312: # References are already relative in OpenFOAM >= 2312
+                            # See https://develop.openfoam.com/Development/openfoam/-/issues/2948
+    MPI_LIB_PATH = list(Path("platforms").glob("*/lib/*mpi*"))[0]
+    DUMMY_LIB_PTH = list(Path("platforms").glob("*/lib/dummy"))[0]
+
+    for openfoam_lib in Path("platforms").glob("*/lib/**/*.dylib"):
+        # Replace references to dummy MPI libraries with the actual MPI libraries
+        if openfoam_lib.parent == DUMMY_LIB_PTH:
+            libs[openfoam_lib] = MPI_LIB_PATH / openfoam_lib.name
+        else:
+            libs[openfoam_lib] = openfoam_lib
+
+# Find names of dependency libraries
+DEPS_PATH = Path("usr")
+DEPS_PATH_RESOLVED = DEPS_PATH.resolve() # In case "usr" is a symlink
+for dep_path in (DEPS_PATH_RESOLVED / "opt").iterdir():
+    dep_libs = itertools.chain(dep_path.rglob("*.so"), dep_path.rglob("*.dylib"))
+    for dep_lib in dep_libs:
+        libs[dep_lib] = DEPS_PATH / dep_lib.relative_to(DEPS_PATH_RESOLVED)
+
+
+def relativize_install_names(file):
+    otool_stdout = subprocess.run(["otool", "-L", file], stdout=subprocess.PIPE, check=True).stdout.decode()
+    for old_path,new_path in libs.items():
+        if str(old_path.absolute()) in otool_stdout:
+            new_relative_path = os.path.relpath(new_path, start=file.parent)
+            subprocess.run(["install_name_tool",
+                            "-change",
+                                old_path.absolute(),
+                                f"@loader_path/{new_relative_path}",
+                            file])
+
+
+for lib in Path("platforms").glob("*/lib/**/*.dylib"):
+    relativize_install_names(lib)
+
+for bin in Path("platforms").glob("*/bin/*"):
+    relativize_install_names(bin)