AK: Print VERIFY() error messages in release builds

Until now, VERIFY() failures would just cause a __builtin_trap() in
release builds, which made them a bit too harsh. This commit adds an
out-of-line helper function that prints the error before trapping.

2 files changed, 26 insertions, 3 deletions

diff --git a/AK/Assertions.cpp b/AK/Assertions.cpp
new file mode 100644
index 0000000000..d8ac028345
--- /dev/null
+++ b/AK/Assertions.cpp
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Assertions.h>
+#include <AK/Format.h>
+
+#if !defined(KERNEL) && defined(NDEBUG)
+extern "C" {
+
+void ak_verification_failed(char const* message)
+{
+    dbgln("VERIFICATION FAILED: {}", message);
+    __builtin_trap();
+}
+}
+
+#endif
diff --git a/AK/Assertions.h b/AK/Assertions.h
index 648d9b9d49..ab628c14a6 100644
--- a/AK/Assertions.h
+++ b/AK/Assertions.h
@@ -13,9 +13,12 @@
 #    ifndef NDEBUG
 #        define VERIFY assert
 #    else
-#        define VERIFY(expr)              \
-            (__builtin_expect(!(expr), 0) \
-                    ? __builtin_trap()    \
+#        define __stringify_helper(x) #        x
+#        define __stringify(x) __stringify_helper(x)
+extern "C" __attribute__((noreturn)) void ak_verification_failed(char const*);
+#        define VERIFY(expr)                                                                \
+            (__builtin_expect(!(expr), 0)                                                   \
+                    ? ak_verification_failed(#expr "\n" __FILE__ ":" __stringify(__LINE__)) \
                     : (void)0)
 #    endif
 #    define VERIFY_NOT_REACHED() VERIFY(false) /* NOLINT(cert-dcl03-c,misc-static-assert) No, this can't be static_assert, it's a runtime check */