build script: merging of installations with missing files and directories

build.py

@@ -1745,6 +1745,9 @@ class Builder(object):
         content = None
 
         for path in paths:
+            if not os.path.exists(path):
+                return False
+
             with open(path, 'rb') as f:
                 if content:
                     if content != f.read():
@@ -1755,48 +1758,74 @@ class Builder(object):
         return True
 
     @staticmethod
-    def _merge_install_paths(src_paths: typing.Sequence[str], dst_path: str):
+    def _merge_file(src: os.DirEntry, src_sub_paths: typing.Sequence[str], dst_path: str):
+        with open(src.path, 'rb') as f:
+            header = f.read(8)
+
+        is_executable = header[:4] == b'\xcf\xfa\xed\xfe'
+        is_library = header == b'!<arch>\n'
+
+        if is_executable or is_library:
+            # Merge executable and library files
+            dst_file = dst_path + os.sep + src.name
+
+            args = ['lipo']
+            args += src_sub_paths
+            args += ['-create', '-output', dst_file]
+            subprocess.check_call(args)
+
+            # TODO: check if ad-hoc code signing is really needed
+            # See https://github.com/Homebrew/brew/commit/e945b1c42ab44feb1c6814f47cc833d76b1a921c
+            if is_executable:
+                args = ('codesign', '--sign', '-', dst_file)
+                subprocess.check_call(args)
+        else:
+            if not Builder._compare_files(src_sub_paths):
+                print(f'WARNING: Source files for {dst_path + os.sep + src.name} don\'t match')
+            shutil.copy(src_sub_paths[0], dst_path)
+
+    @staticmethod
+    def _merge_missing_files(src_paths: typing.Sequence[str], dst_path: str):
+        shifted_src_paths = [path for path in src_paths]
+        last_path_index = len(src_paths) - 1
+
+        for _ in range(last_path_index):
+            shifted_src_paths.append(shifted_src_paths[0])
+            del shifted_src_paths[0]
+
+            if not os.path.exists(shifted_src_paths[0]):
+                continue
+
+            Builder._merge_install_paths(shifted_src_paths, dst_path, missing_files_only=True)
+
+    @staticmethod
+    def _merge_install_paths(src_paths: typing.Sequence[str], dst_path: str, missing_files_only=False):
         if len(src_paths) <= 1:
             return
 
-        if os.path.exists(dst_path):
+        if not missing_files_only:
-            shutil.rmtree(dst_path)
+            if os.path.exists(dst_path):
+                shutil.rmtree(dst_path)
 
-        os.makedirs(dst_path)
+        os.makedirs(dst_path, exist_ok=True)
 
         for src in os.scandir(src_paths[0]):
-            src_sub_path = [path + os.sep + src.name for path in src_paths]
+            src_sub_paths = [path + os.sep + src.name for path in src_paths]
 
             if src.is_dir():
-                Builder._merge_install_paths(src_sub_path, dst_path + os.sep + src.name)
+                Builder._merge_install_paths(src_sub_paths, dst_path + os.sep + src.name, missing_files_only)
             elif src.name.endswith('.la'):
                 # Skip libtool files
                 continue
+            elif missing_files_only:
+                for src_sub_path in src_sub_paths[1:]:
+                    if not os.path.exists(src_sub_path):
+                        shutil.copy(src_sub_paths[0], dst_path)
             else:
-                with open(src.path, 'rb') as f:
+                Builder._merge_file(src, src_sub_paths, dst_path)
-                    header = f.read(8)
 
-                is_executable = header[:4] == b'\xcf\xfa\xed\xfe'
+        if not missing_files_only:
-                is_library = header == b'!<arch>\n'
+            Builder._merge_missing_files(src_paths, dst_path)
-
-                if is_executable or is_library:
-                    # Merge executable and library files
-                    dst_file = dst_path + os.sep + src.name
-
-                    args = ['lipo']
-                    args += src_sub_path
-                    args += ['-create', '-output', dst_file]
-                    subprocess.check_call(args)
-
-                    # TODO: check if ad-hoc code signing is really needed
-                    # See https://github.com/Homebrew/brew/commit/e945b1c42ab44feb1c6814f47cc833d76b1a921c
-                    if is_executable:
-                        args = ('codesign', '--sign', '-', dst_file)
-                        subprocess.check_call(args)
-                else:
-                    if not Builder._compare_files(src_sub_path):
-                        print(f'WARNING: Source files for {dst_path + os.sep + src.name} don\'t match')
-                    shutil.copy(src_sub_path[0], dst_path)
 
     def architecture(self) -> str:
         return self.platform.architecture if self.platform else ''