diff --git a/pinpoint/final/on_finish_unit.cpp b/pinpoint/final/on_finish_unit.cpp
index f7b638e..a69d7b7 100644
--- a/pinpoint/final/on_finish_unit.cpp
+++ b/pinpoint/final/on_finish_unit.cpp
@@ -4,18 +4,40 @@
 #include <stage1.h>
 
 #include <safe-input.h>
+#include <safe-md5.h>
 #include <pinpoint_config.h>
+#include <pinpoint_error.h>
+
+unsigned char cu_uid_md5[16];
+char cu_uid_hex[33];
+
+static const unsigned char* calculate_cu_uid_md5() {
+	if (!main_input_filename)
+		return nullptr;
+
+	md5_buffer(main_input_filename, strlen(main_input_filename), cu_uid_md5);
+	return cu_uid_md5;
+}
+
+static const char* calculate_cu_uid_hex() {
+	const unsigned char* digest = calculate_cu_uid_md5();
+	if (!digest)
+		return nullptr;
+
+	for (int i = 0; i < 16; ++i)
+		sprintf(cu_uid_hex + 2*i, "%02x", digest[i]);
+
+	cu_uid_hex[32] = '\0';
+	return cu_uid_hex;
+}
 
 void on_finish_unit(void* plugin_data, void* user_data) {
-	/*
-	TODO
-	The result lbasename(...) is not unique (e.g., "file.c" and "sub/file.c")
-	Calculate UID for compilation unit -> hash(main_input_filename)
-	Add UID symbol to CU -> __spslr_cu_<uid>
-	Then dump accumulated data for finalizer
-	*/
+	const char* cu_uid = calculate_cu_uid_hex();
+	if (!cu_uid)
+		pinpoint_fatal("on_finish_unit failed to calculate compilation unit UID");
 
 	std::cout << "Finishing unit \"" << lbasename(main_input_filename) << "\" ..." << std::endl;
+	std::cout << "    Unit UID is 0x" << cu_uid << std::endl;
 
 	for (const auto& [uid, target] : TargetType::all())
 		std::cout << "    Target " << uid << " -> \"" << target.name() << "\" (" << target.size() << ")" << std::endl;
diff --git a/pinpoint/safegcc/safe-md5.h b/pinpoint/safegcc/safe-md5.h
new file mode 100644
index 0000000..8341cb1
--- /dev/null
+++ b/pinpoint/safegcc/safe-md5.h
@@ -0,0 +1,8 @@
+#include <safe-gcc-plugin.h>
+
+#ifndef SAFEGCC_MD5_H
+#define SAFEGCC_MD5_H
+
+#include <md5.h>
+
+#endif