[libcxx-commits] [PATCH] D126867: [libunwind] Fix SEH unwinding on ARM

[Martin Storsjö via Phabricator via libcxx-commits]

mstorsjo created this revision.
mstorsjo added reviewers: MaskRay, efriedma, zzheng.
Herald added subscribers: StephenFan, kristof.beyls.
Herald added projects: libunwind, All.
Herald added a reviewer: libunwind.
mstorsjo requested review of this revision.
Herald added a project: LLVM.
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Check `__SEH__` when checking if ARM EHABI should be impliied.

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.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D126867

Files:
  libunwind/include/__libunwind_config.h
  libunwind/include/libunwind.h
  libunwind/src/Unwind-seh.cpp
  libunwind/src/UnwindCursor.hpp


Index: libunwind/src/UnwindCursor.hpp
===================================================================
--- libunwind/src/UnwindCursor.hpp
+++ libunwind/src/UnwindCursor.hpp
@@ -863,7 +863,7 @@
       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) {
Index: libunwind/src/Unwind-seh.cpp
===================================================================
--- libunwind/src/Unwind-seh.cpp
+++ libunwind/src/Unwind-seh.cpp
@@ -255,8 +255,8 @@
           (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);
     }
Index: libunwind/include/libunwind.h
===================================================================
--- libunwind/include/libunwind.h
+++ libunwind/include/libunwind.h
@@ -81,7 +81,7 @@
 
 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;
Index: libunwind/include/__libunwind_config.h
===================================================================
--- libunwind/include/__libunwind_config.h
+++ 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
 


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