[test] Generalize runtime library searching

Allow detecting the compiler runtime libraries for
non-Darwin platforms, allowing us to test that
programs relying on these libraries link successfully.

Author: hamishknight

test/Profiler/coverage_inlined_counters_exec.swift

@@ -21,6 +21,9 @@
 // REQUIRES: profile_runtime
 // REQUIRES: executable_test
 
+// FIXME: Currently fails on non-Darwin (https://github.com/swiftlang/swift/issues/75240)
+// REQUIRES: OS=macosx
+
 //--- a.swift
 @_transparent
 public func foo() {}

test/lit.cfg

@@ -375,6 +375,12 @@ if test_resource_dir:
    config.resource_dir_opt = ("-resource-dir %s" % test_resource_dir)
 else:
     test_resource_dir = make_path(config.swift_lib_dir, 'swift')
+
+lit_config.note('Using resource dir: ' + test_resource_dir)
+
+test_clang_resource_dir = lit.util.executeCommand([config.clang, '-print-resource-dir'])[0].rstrip()
+lit_config.note('Using Clang resource dir: ' + test_clang_resource_dir)
+
 config.swift_system_overlay_opt = ""
 config.clang_system_overlay_opt = ""
 config.windows_vfs_overlay_opt = ""
@@ -396,9 +402,9 @@ config.substitutions.append( ('%windows_vfs_overlay_opt', config.windows_vfs_ove
 stdlib_resource_dir_opt = config.resource_dir_opt
 sourcekitd_framework_dir = config.swift_lib_dir
 config.substitutions.append( ('%test-resource-dir', test_resource_dir) )
-lit_config.note('Using resource dir: ' + test_resource_dir)
 
 # Parse the variant triple.
+# FIXME: We ought to parse 'run_environment' separately from 'run_os'.
 (run_cpu, run_vendor, run_os, run_vers) = re.match('([^-]+)-([^-]+)-([^0-9]+)(.*)', config.variant_triple).groups()
 if run_os == 'ios' and run_vers.endswith('-macabi'):
     run_vers = run_vers[0:-len('-macabi')]
@@ -2235,8 +2241,7 @@ if config.target_sdk_name in simulator_sdks:
 else:
     config.substitutions.append(('%target-is-simulator', 'false'))
 
-config.compiler_rt_libs = []
-config.compiler_rt_platform = {
+config.compiler_rt_darwin_platform = {
     'iphoneos': 'ios',
     'appletvos': 'tvos',
     'watchos': 'watchos',
@@ -2246,50 +2251,82 @@ config.compiler_rt_platform = {
     'appletvsimulator': 'tvossim',
     'xrsimulator': 'xrossim',
     'macosx': 'osx'
-}.get(config.target_sdk_name, run_cpu)
+}.get(config.target_sdk_name, run_os)
+
+def find_compiler_rt_libs():
+    base = make_path(test_clang_resource_dir, 'lib')
+    libs = {}
 
-def source_compiler_rt_libs(path):
+    # First check to see if this is 'clang/lib/darwin', it has its own custom filename pattern.
+    path = make_path(base, 'darwin')
     if os.path.exists(path):
-        config.compiler_rt_libs.extend([lib for lib in
-                                        os.listdir(path)
-                                        if lib.startswith('libclang_rt.')
-                                        and config.compiler_rt_platform in lib])
+        for lib in os.listdir(path):
+            # Include any libraries with the platform name.
+            match = re.match(r'libclang_rt\.(?:(\w+)_)?' + config.compiler_rt_darwin_platform, lib)
+            if not match:
+                continue
+            component = match[1]
+            # An empty component corresponds to the 'builtins' library.
+            if not component:
+                component = 'builtins'
+            libs[component] = lib
+
+        return (path, libs)
+
+    # Next check for the old scheme 'clang/lib/<os-name>', ignoring
+    # any target environment which is currently part of 'run_os'.
+    path = make_path(base, run_os.split('-')[0])
+    if os.path.exists(path):
+        # We should then have the architecture in the name.
+        for lib in os.listdir(path):
+            match = re.match(r'(?:lib)?clang_rt\.(\w+)-' + run_cpu, lib)
+            if match:
+                libs[match[1]] = lib
+
+        return (path, libs)
 
-compiler_rt_dir = make_path(test_resource_dir, 'clang', 'lib',
-                            platform.system().lower())
-source_compiler_rt_libs(compiler_rt_dir)
+    # Finally, check the new scheme 'clang/lib/<target>'
+    path = make_path(base, config.variant_triple)
+    if os.path.exists(path):
+        # We can include all the libraries here that match the base pattern.
+        for lib in os.listdir(path):
+            match = re.match(r'(?:lib)?clang_rt\.(\w+)\.', lib)
+            if match:
+                libs[match[1]] = lib
+
+        return (path, libs)
+
+    lit_config.warning("Couldn't find clang_rt directory")
+    return (None, {})
+
+(compiler_rt_path, compiler_rt_libs) = find_compiler_rt_libs()
+if compiler_rt_path:
+    lit_config.note("Using clang_rt directory: " + compiler_rt_path)
+    if compiler_rt_libs:
+        lit_config.note("Found clang_rt libs: {}".format(compiler_rt_libs))
+    else:
+        lit_config.warning("Couldn't find any clang_rt libs for %s" % config.variant_triple)
 
 def check_runtime_libs(features_to_check):
-    for lib in config.compiler_rt_libs:
-        for (libname, feature) in features_to_check.items():
-            if lib.startswith("libclang_rt." + libname + "_"):
-                config.available_features.add(feature)
+    for (libname, feature) in features_to_check.items():
+        if libname in compiler_rt_libs:
+            config.available_features.add(feature)
 
 runtime_libs = {
     'profile': 'profile_runtime',
     'asan': 'asan_runtime',
     'ubsan': 'ubsan_runtime',
     'scudo': 'scudo_runtime',
     'safestack': 'safestack_runtime',
-    'fuzzer': 'fuzzer_runtime'
+    'fuzzer': 'fuzzer_runtime',
+    'builtins': 'c_runtime'
 }
 
 if run_ptrsize == '64' and 'libdispatch' in config.available_features:
     runtime_libs['tsan'] = 'tsan_runtime'
 
 check_runtime_libs(runtime_libs)
 
-# From https://stackoverflow.com/a/2393022
-def strip_right(text, suffix):
-    if not text.endswith(suffix):
-        return text
-    return text[:len(text)-len(suffix)]
-
-base_runtime_lib_name = (
-    'libclang_rt.' + strip_right(config.compiler_rt_platform, 'sim') + '.a')
-if os.path.exists(make_path(compiler_rt_dir, base_runtime_lib_name)):
-    config.available_features.add('c_runtime')
-
 config.substitutions.append(('%target-objc-interop', run_objc_interop))
 
 # For testing the remote-run utility itself, see if we can find an sftp-server