./build-userland: resolve relative paths

common.py

@@ -95,6 +95,11 @@ consts['github_repo_id'] = 'cirosantilli/linux-kernel-module-cheat'
 consts['asm_ext'] = '.S'
 consts['c_ext'] = '.c'
 consts['cxx_ext'] = '.cpp'
+consts['userland_in_exts'] = [
+    consts['asm_ext'],
+    consts['c_ext'],
+    consts['cxx_ext'],
+]
 consts['header_ext'] = '.h'
 consts['kernel_module_ext'] = '.ko'
 consts['obj_ext'] = '.o'
@@ -1102,6 +1107,50 @@ lunch aosp_{}-eng
         argcopy.__dict__ = dict(list(defaults.items()) + list(argcopy.__dict__.items()) + list(extra_args.items()))
         return argcopy
 
+    def resolve_source(self, in_path, magic_in_dir, in_exts):
+        '''
+        Convert a path-like string to a source file to the full source path,
+        e.g. all follogin work and to do the same:
+
+        - hello
+        - hello.
+        - hello.c
+        - userland/hello
+        - userland/hello.
+        - userland/hello.c
+        - /full/path/to/userland/hello
+        - /full/path/to/userland/hello.
+        - /full/path/to/userland/hello.c
+
+        Also works on directories:
+
+        - arch
+        - userland/arch
+        - /full/path/to/userland/arch
+        '''
+        if os.path.isabs(in_path):
+            return in_path
+        else:
+            paths = [
+                os.path.join(magic_in_dir, in_path),
+                os.path.join(
+                    magic_in_dir,
+                    os.path.relpath(in_path, magic_in_dir),
+                )
+            ]
+            for path in paths:
+                name, ext = os.path.splitext(path)
+                if len(ext) > 1:
+                    try_exts = [ext]
+                else:
+                    try_exts = in_exts + ['']
+                for in_ext in try_exts:
+                    path = name + in_ext
+                    if os.path.exists(path):
+                        return path
+            if not self.env['dry_run']:
+                raise Exception('Source file not found for input: ' + in_path)
+
     def resolve_executable(self, in_path, magic_in_dir, magic_out_dir, out_ext):
         if os.path.isabs(in_path):
             return in_path
@@ -1113,14 +1162,18 @@ lunch aosp_{}-eng
                     os.path.relpath(in_path, magic_in_dir),
                 )
             ]
-            paths[:] = [os.path.splitext(path)[0] + out_ext for path in paths]
             for path in paths:
+                path = os.path.splitext(path)[0] + out_ext
                 if os.path.exists(path):
                     return path
             if not self.env['dry_run']:
                 raise Exception('Executable file not found. Tried:\n' + '\n'.join(paths))
 
-    def resolve_userland(self, path):
+    def resolve_userland_executable(self, path):
+        '''
+        Convert an userland source path-like string to an
+        absolute userland build output path.
+        '''
         return self.resolve_executable(
             path,
             self.env['userland_source_dir'],
@@ -1128,6 +1181,13 @@ lunch aosp_{}-eng
             self.env['userland_build_ext'],
         )
 
+    def resolve_userland_source(self, path):
+        return self.resolve_source(
+            path,
+            self.env['userland_source_dir'],
+            self.env['userland_in_exts']
+        )
+
     def setup(self):
         '''
         Similar to timed_main, but gets run only once for all --arch and --emulator,