Update wrapped_clang to make -add_ast_path options absolute
This should allow us to debug Swift binaries without using dSYMs.
See
https://forums.swift.org/t/improving-swift-lldb-support-for-path-remappings/22694
PiperOrigin-RevId: 244896679
diff --git a/tools/osx/crosstool/wrapped_clang.cc b/tools/osx/crosstool/wrapped_clang.cc
index a087881..2115b8d 100644
--- a/tools/osx/crosstool/wrapped_clang.cc
+++ b/tools/osx/crosstool/wrapped_clang.cc
@@ -57,6 +57,8 @@
namespace {
+constexpr char kAddASTPathPrefix[] = "-Wl,-add_ast_path,";
+
// Returns the base name of the given filepath. For example, given
// /foo/bar/baz.txt, returns 'baz.txt'.
const char *Basename(const char *filepath) {
@@ -151,6 +153,21 @@
return env_value;
}
+// Returns true if `str` starts with the specified `prefix`.
+bool StartsWith(const std::string &str, const std::string &prefix) {
+ return str.compare(0, prefix.size(), prefix) == 0;
+}
+
+// If *`str` begins `prefix`, strip it out and return true.
+// Otherwise leave *`str` unchanged and return false.
+bool StripPrefixStringIfPresent(std::string *str, const std::string &prefix) {
+ if (StartsWith(*str, prefix)) {
+ *str = str->substr(prefix.size());
+ return true;
+ }
+ return false;
+}
+
} // namespace
int main(int argc, char *argv[]) {
@@ -203,9 +220,31 @@
}
FindAndReplace("__BAZEL_XCODE_DEVELOPER_DIR__", developer_dir, &arg);
FindAndReplace("__BAZEL_XCODE_SDKROOT__", sdk_root, &arg);
+
+ // Make the `add_ast_path` options used to embed Swift module references
+ // absolute to enable Swift debugging without dSYMs: see
+ // https://forums.swift.org/t/improving-swift-lldb-support-for-path-remappings/22694
+ if (StripPrefixStringIfPresent(&arg, kAddASTPathPrefix)) {
+ // Only modify relative paths.
+ if (!StartsWith(arg, "/")) {
+ arg = std::string(kAddASTPathPrefix) +
+ std::string(cwd.get()) + "/" + arg;
+ } else {
+ arg = std::string(kAddASTPathPrefix) + arg;
+ }
+ }
+
processed_args.push_back(arg);
}
+ // Special mode that only prints the command. Used for testing.
+ if (getenv("__WRAPPED_CLANG_LOG_ONLY")) {
+ for (const std::string &arg : processed_args)
+ std::cout << arg << ' ';
+ std::cout << "\n";
+ return 0;
+ }
+
// Check to see if we should postprocess with dsymutil.
bool postprocess = false;
if ((!linked_binary.empty()) || (!dsym_path.empty())) {
