From 7c0e93cb89e6aa74881411213abf83faae7c58ee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Storsj=C3=B6?= <martin@martin.st>
Date: Sat, 7 May 2022 00:26:45 +0300
Subject: [PATCH] [libunwind] Fix SEH unwinding on ARM

Check `__SEH__` when checking if ARM EHABI should be implied,
similarly to 4a3722a2c3dff1fe885cc38bf43d3c095c9851e7 / D126866.

Fix a warning by using the right format specifier (PRIxPTR instead
of PRIx64), and add a double->float cast in a codepath that hasn't
been built so far.

This is enough to make SEH unwinding of itanium ABI exceptions on
ARM mostly work - one specific issue is fixed in a separate follow-up
patch.

Differential Revision: https://reviews.llvm.org/D126867
---
 libunwind/include/__libunwind_config.h | 2 +-
 libunwind/include/libunwind.h          | 2 +-
 libunwind/src/Unwind-seh.cpp           | 4 ++--
 libunwind/src/UnwindCursor.hpp         | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/libunwind/include/__libunwind_config.h b/libunwind/include/__libunwind_config.h
index e626567d4e59..5e9de90f649f 100644
--- a/libunwind/include/__libunwind_config.h
+++ b/libunwind/include/__libunwind_config.h
@@ -12,7 +12,7 @@
 #define _LIBUNWIND_VERSION 15000
 
 #if defined(__arm__) && !defined(__USING_SJLJ_EXCEPTIONS__) && \
-    !defined(__ARM_DWARF_EH__)
+    !defined(__ARM_DWARF_EH__) && !defined(__SEH__)
 #define _LIBUNWIND_ARM_EHABI
 #endif
 
diff --git a/libunwind/include/libunwind.h b/libunwind/include/libunwind.h
index 3d8fd2146ebb..f878b46f0348 100644
--- a/libunwind/include/libunwind.h
+++ b/libunwind/include/libunwind.h
@@ -81,7 +81,7 @@ typedef struct unw_addr_space *unw_addr_space_t;
 
 typedef int unw_regnum_t;
 typedef uintptr_t unw_word_t;
-#if defined(__arm__) && !defined(__ARM_DWARF_EH__)
+#if defined(__arm__) && !defined(__ARM_DWARF_EH__) && !defined(__SEH__)
 typedef uint64_t unw_fpreg_t;
 #else
 typedef double unw_fpreg_t;
diff --git a/libunwind/src/Unwind-seh.cpp b/libunwind/src/Unwind-seh.cpp
index f00bc4721ba4..64aaf0a383b8 100644
--- a/libunwind/src/Unwind-seh.cpp
+++ b/libunwind/src/Unwind-seh.cpp
@@ -255,8 +255,8 @@ unwind_phase2_forced(unw_context_t *uc,
           (frameInfo.start_ip + offset > frameInfo.end_ip))
         functionName = ".anonymous.";
       _LIBUNWIND_TRACE_UNWINDING(
-          "unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIx64
-          ", func=%s, lsda=0x%" PRIx64 ", personality=0x%" PRIx64,
+          "unwind_phase2_forced(ex_ojb=%p): start_ip=0x%" PRIxPTR
+          ", func=%s, lsda=0x%" PRIxPTR ", personality=0x%" PRIxPTR,
           (void *)exception_object, frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
diff --git a/libunwind/src/UnwindCursor.hpp b/libunwind/src/UnwindCursor.hpp
index 6e8fc45ebfa8..dc334edbe385 100644
--- a/libunwind/src/UnwindCursor.hpp
+++ b/libunwind/src/UnwindCursor.hpp
@@ -863,7 +863,7 @@ void UnwindCursor<A, R>::setFloatReg(int regNum, unw_fpreg_t value) {
       uint32_t w;
       float f;
     } d;
-    d.f = value;
+    d.f = (float)value;
     _msContext.S[regNum - UNW_ARM_S0] = d.w;
   }
   if (regNum >= UNW_ARM_D0 && regNum <= UNW_ARM_D31) {