From 60f36b8d0274ce94ae0e2511df625118ce8f9076 Mon Sep 17 00:00:00 2001
From: Thiago Macieira <thiago.macieira@intel.com>
Date: Wed, 14 May 2025 19:26:22 -0700
Subject: [PATCH] QTest::CrashHandler: extract the address of the crashing
 instruction

From the user and machine context provided in the signal handler.

Linux w/ GDB prints:
   0x563bb2ab7346 <_ZN11tst_Crashes5crashEv+28>:	movl   $0x1,(%rax)

FreeBSD w/ LLDB prints:
(lldb) x/i 0x0000319a0ae86996
    0x319a0ae86996: c7 40 04 01 00 00 00  other       movl   $0x1, 0x4(%rax)

macOS w/ LLDB prints (after disabling the check for SIP):
(lldb) x/i 0x00000001054086c8
    0x1054086c8: movl   $0x1, 0x4(%rax)

Done-With: Samuel Gaist
Done-With: Ivan Solovev
Change-Id: Iac02025b1922b6b4d927fffd3efe210ef51fc759
Reviewed-by: Ahmad Samir <a.samirh78@gmail.com>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Samuel Gaist <samuel.gaist@idiap.ch>
---
 src/testlib/qtestcrashhandler_unix.cpp | 41 +++++++++++++++++++++++++-
 1 file changed, 40 insertions(+), 1 deletion(-)

diff --git a/src/testlib/qtestcrashhandler_unix.cpp b/src/testlib/qtestcrashhandler_unix.cpp
index ca10efa8e2f..d66a5423797 100644
--- a/src/testlib/qtestcrashhandler_unix.cpp
+++ b/src/testlib/qtestcrashhandler_unix.cpp
@@ -35,6 +35,13 @@
 # if !defined(Q_OS_INTEGRITY)
 #  include <sys/resource.h>
 # endif
+# if __has_include(<sys/ucontext.h>)
+#  include <sys/ucontext.h>
+# elif __has_include(<ucontext.h>)
+#  include <ucontext.h>
+# else
+using ucontext_t = void;
+# endif
 
 #if defined(Q_OS_MACOS)
 #include <QtCore/private/qcore_mac_p.h>
@@ -361,7 +368,39 @@ void printTestRunTime()
 static quintptr getProgramCounter(void *ucontext)
 {
     quintptr pc = 0;
-    Q_UNUSED(ucontext);
+    if ([[maybe_unused]] auto ctx = static_cast<ucontext_t *>(ucontext)) {
+#if 0 // keep the list below alphabetical
+
+#elif defined(Q_OS_DARWIN) && defined(Q_PROCESSOR_ARM_64)
+        pc = ctx->uc_mcontext->__ss.__pc;
+#elif defined(Q_OS_DARWIN) && defined(Q_PROCESSOR_X86_64)
+        pc = ctx->uc_mcontext->__ss.__rip;
+
+#elif defined(Q_OS_FREEBSD) && defined(Q_PROCESSOR_X86_32)
+        pc = ctx->uc_mcontext.mc_eip;
+#elif defined(Q_OS_FREEBSD) && defined(Q_PROCESSOR_X86_64)
+        pc = ctx->uc_mcontext.mc_rip;
+
+#elif defined(Q_OS_LINUX) && defined(Q_PROCESSOR_ARM_32)
+        // pc = ctx->uc_mcontext.arm_pc;                // untested
+#elif defined(Q_OS_LINUX) && defined(Q_PROCESSOR_ARM_64)
+        pc = ctx->uc_mcontext.pc;
+#elif defined(Q_OS_LINUX) && defined(Q_PROCESSOR_MIPS)
+        // pc = ctx->uc_mcontext.pc;                    // untested
+#elif defined(Q_OS_LINUX) && defined(Q_PROCESSOR_LOONGARCH)
+        // pc = ctx->uc_mcontext.__pc;                  // untested
+#elif defined(Q_OS_LINUX) && defined(Q_PROCESSOR_POWER_32)
+        // pc = ctx->uc_mcontext.uc_regs->gregs[PT_NIP]; // untested
+#elif defined(Q_OS_LINUX) && defined(Q_PROCESSOR_POWER_64)
+        // pc = ctx->uc_mcontext.gregs[PT_NIP];         // untested
+#elif defined(Q_OS_LINUX) && defined(Q_PROCESSOR_RISCV)
+        // pc = ctx->uc_mcontext.__gregs[REG_PC];       // untested
+#elif defined(Q_OS_LINUX) && defined(Q_PROCESSOR_X86_32)
+        pc = ctx->uc_mcontext.gregs[REG_EIP];
+#elif defined(Q_OS_LINUX) && defined(Q_PROCESSOR_X86_64)
+        pc = ctx->uc_mcontext.gregs[REG_RIP];
+#endif
+    }
     return pc;
 }