offsets-tool: new location and OSXCross support

Also fixed:
- 'os_utils.find_executable' was not working.
- Wrong macOS OSXCross tool prefix (was using target arch instead of host arch).

ios.py

@@ -302,6 +302,7 @@ class iOSCrossTable:
 
 
 def setup_ios_cross_template(env: dict, opts: iOSOpts, target: str, host_arch: str):
+
     target_triple = iOSCrossTable.target_triples[target]
     device_target = iOSCrossTable.device_targets[target]
     offsets_dumper_abi = iOSCrossTable.offsets_dumper_abis[target]
@@ -334,7 +335,7 @@ def setup_ios_cross_template(env: dict, opts: iOSOpts, target: str, host_arch: s
         env['_ios-%s_PATH' % target] = osxcross_bin
 
         wrapper_path = create_osxcross_wrapper(opts, 'ios', target, opts.osx_toolchain_path)
-        name_fmt = path_join(osxcross_bin, target + '-apple-' + opts.osx_triple_abi + '-%s')
+        name_fmt = path_join(osxcross_bin, host_arch + '-apple-' + opts.osx_triple_abi + '-%s')
         name_fmt = "%s %s" % (wrapper_path, name_fmt)
     else:
         tools_path = path_join(opts.osx_toolchain_path, 'usr', 'bin')
@@ -348,13 +349,34 @@ def setup_ios_cross_template(env: dict, opts: iOSOpts, target: str, host_arch: s
     env['_ios-%s_RANLIB' % target] = name_fmt % 'ranlib'
     env['_ios-%s_STRIP' % target] = name_fmt % 'strip'
 
-    libclang = path_join(opts.ios_toolchain_path, 'usr', 'lib', 'libclang.dylib') if sys.platform == 'darwin' else os.environ['LIBCLANG_PATH']
+    libclang = os.environ.get('LIBCLANG_PATH', '')
+    if libclang and not os.path.isfile(libclang):
+        raise RuntimeError('Specified libclang file not found: \'%s\'' % libclang)
 
-    env['_ios-%s_OFFSETS_DUMPER_ARGS' % target] = [
+    if not libclang:
+        libclang = try_find_libclang(toolchain_path=opts.ios_toolchain_path)
+
+    if not libclang:
+        raise RuntimeError('Cannot find libclang shared library; specify a path manually with the \'LIBCLANG_PATH\' environment variable.')
+
+    offsets_dumper_args = [
         '--libclang=%s' % libclang,
         '--sysroot=%s' % ios_sysroot_path
     ]
 
+    if sys.platform != 'darwin':
+        # Needed in order to locate the iOS toolchain's clang to use with offsets-tool
+        setup_ios_device_template(env, opts, device_target)
+        ios_clang = env['_ios-%s_CC' % device_target]
+
+        # Extra CFLAGS needed in order to make offsets-tool work with OSXCross.
+        offsets_dumper_args += ['--extra-cflag=' + cflag for cflag in [
+            '-target', 'aarch64-apple-darwin',
+            '-resource-dir', get_clang_resource_dir(ios_clang)
+        ]]
+
+    env['_ios-%s_OFFSETS_DUMPER_ARGS' % target] = offsets_dumper_args
+
     AC_VARS = ['ac_cv_func_shm_open_working_with_mmap=no']
 
     CFLAGS = ['-isysroot', osx_sysroot_path, '-mmacosx-version-min=10.9', '-Qunused-arguments']

os_utils.py

@@ -72,8 +72,8 @@ ENV_PATH_SEP = ';' if os.name == 'nt' else ':'
 
 def find_executable(name) -> str:
     is_windows = os.name == 'nt'
-    windows_exts = ENV_PATH_SEP.split(os.environ['PATHEXT']) if is_windows else None
-    path_dirs = ENV_PATH_SEP.split(os.environ['PATH'])
+    windows_exts = os.environ['PATHEXT'].split(ENV_PATH_SEP) if is_windows else None
+    path_dirs = os.environ['PATH'].split(ENV_PATH_SEP)
 
     search_dirs = path_dirs + [os.getcwd()] # cwd is last in the list
 
@@ -160,6 +160,44 @@ def chmod_plus_x(file):
     os.chmod(file, st.st_mode | ((stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH) & ~umask))
 
 
+def get_clang_resource_dir(clang_command):
+    import shlex
+    from subprocess import check_output
+    return check_output(shlex.split(clang_command) + ['-print-resource-dir']).strip().decode('utf-8')
+
+
+def try_find_libclang(toolchain_path: str = '', llvm_config=''):
+    import sys
+    from subprocess import check_output
+
+    hint_paths = []
+
+    if toolchain_path:
+        libclang = os.path.join(toolchain_path, 'usr', 'lib', 'libclang.dylib')
+        if os.path.isfile(libclang):
+            print('Found libclang at: \'%s\'' % libclang)
+            return libclang
+
+    if not llvm_config:
+        llvm_config = find_executable('llvm-config')
+        if not llvm_config:
+            print('WARNING: llvm-config not found')
+            return ''
+    elif not os.path.isfile(llvm_config):
+        raise RuntimeError('Specified llvm-config file not found: \'%s\'' % llvm_config)
+
+    llvm_libdir = check_output([llvm_config, '--libdir']).strip().decode('utf-8')
+    if llvm_libdir:
+        libsuffix = '.dylib' if sys.platform == 'darwin' else '.so'
+        hints = ['libclang', 'clang']
+        libclang = next((p for p in [os.path.join(llvm_libdir, h + libsuffix) for h in hints] if os.path.isfile(p)), '')
+        if libclang:
+            print('Found libclang at: \'%s\'' % libclang)
+        return libclang
+
+    return ''
+
+
 def create_osxcross_wrapper(opts: RuntimeOpts, product: str, target: str, toolchain_path : str):
     # OSXCROSS toolchain executables use rpath to locate the toolchain's shared libraries.
     # However, when moving the toolchain without care, the rpaths can be broken.

patch_mono.py

@@ -32,6 +32,11 @@ def main(raw_args):
         'mono_ios_asl_log_deprecated.diff'
     ]
 
+    if os.path.isfile(os.path.join(mono_source_root, 'mono/tools/offsets-tool/offsets-tool.py')):
+        patches += ['offsets-tool-extra-cflags_new.diff']
+    else:
+        patches += ['offsets-tool-extra-cflags_old.diff']
+
     from subprocess import Popen
     from sys import exit
     for patch in patches:

runtime.py

@@ -101,21 +101,28 @@ def setup_runtime_cross_template(env: dict, opts: RuntimeOpts, product: str, tar
 
     env['_cross-runtime_%s-%s_CONFIGURE_FLAGS' % (product, target)] = CONFIGURE_FLAGS
 
-    # Setup offsets-tool-py
-    run_command('make', ['-C', '%s/tools/offsets-tool-py' % opts.mono_source_root, 'setup'], name='make offsets-tool-py')
+    new_offsets_tool_path = '%s/mono/tools/offsets-tool/offsets-tool.py' % opts.mono_source_root
+    old_offsets_tool_path = '%s/tools/offsets-tool-py/offsets-tool.py' % opts.mono_source_root
 
-    # Run offsets-tool in its virtual env
+    old_offsets_tool = not os.path.isfile(new_offsets_tool_path)
 
-    virtualenv_vars = source('%s/tools/offsets-tool-py/offtool/bin/activate' % opts.mono_source_root)
+    offsets_tool_env = None
 
-    offsets_tool_env = os.environ.copy()
-    offsets_tool_env.update(virtualenv_vars)
+    if old_offsets_tool:
+        # Setup old offsets-tool-py if present (new location doesn't require setup)
+        run_command('make', ['-C', '%s/tools/offsets-tool-py' % opts.mono_source_root, 'setup'], name='make offsets-tool-py')
+
+        # Run offsets-tool in its virtual env
+        virtualenv_vars = source('%s/tools/offsets-tool-py/offtool/bin/activate' % opts.mono_source_root)
+
+        offsets_tool_env = os.environ.copy()
+        offsets_tool_env.update(virtualenv_vars)
 
     build_dir = '%s/%s-%s-%s' % (opts.configure_dir, product, target, opts.configuration)
     mkdir_p(build_dir)
 
     run_command('python3', [
-            '%s/tools/offsets-tool-py/offsets-tool.py' % opts.mono_source_root,
+            old_offsets_tool_path if old_offsets_tool else new_offsets_tool_path,
             '--targetdir=%s/%s-%s-%s' % (opts.configure_dir, product, device_target, opts.configuration),
             '--abi=%s' % offsets_dumper_abi,
             '--monodir=%s' % opts.mono_source_root,