[patch] C6X unwinding/exception handling

Mon Oct 10 12:23:00 GMT 2011

> Index: libjava/exception.cc
> ===================================================================
> --- libjava/exception.cc	(revision 179739)
> +++ libjava/exception.cc	(working copy)
> @@ -135,6 +135,7 @@
> {
> _Unwind_Ptr Start;
> _Unwind_Ptr LPStart;
> + _Unwind_Ptr ttype_base;
> const unsigned char *TType;
> const unsigned char *action_table;
> unsigned char ttype_encoding;
> @@ -184,7 +185,7 @@
> _Unwind_Ptr ptr;
>> ptr = (_Unwind_Ptr) (info->TType - (i * 4));
> - ptr = _Unwind_decode_target2(ptr);
> + ptr = _Unwind_decode_typeinfo_ptr (info->ttype_base, (_Unwind_Word)
> ptr);
>> return reinterpret_cast<void **>(ptr);
> }
> @@ -325,6 +326,7 @@
>> // Parse the LSDA header.
> p = parse_lsda_header (context, language_specific_data, &info);
> + info.ttype_base = base_of_encoded_value (info.ttype_encoding, context);
> #ifdef HAVE_GETIPINFO
> ip = _Unwind_GetIPInfo (context, &ip_before_insn);
> #else

No. The purpose of my patch was to remove the arm specific code.
The only difference I can see in this bit of code is that libstdc++ uses 
base_of_encoded_value/read_encoded_value_with_base whereas libjava uses 
context/read_encoded_value.
I expect you want something like the patch below (completely untested).
Paul
Index: exception.cc
===================================================================

--- exception.cc	(revision 178906)
+++ exception.cc	(working copy)
@@ -161,6 +161,11 @@ parse_lsda_header (_Unwind_Context *cont
 info->ttype_encoding = *p++;
 if (info->ttype_encoding != DW_EH_PE_omit)
 {
+#if _GLIBCXX_OVERRIDE_TTYPE_ENCODING
+ /* Older ARM EABI toolchains set this value incorrectly, so use a
+ hardcoded OS-specific format. */
+ info->ttype_encoding = _GLIBCXX_OVERRIDE_TTYPE_ENCODING;
+#endif
 p = read_uleb128 (p, &tmp);
 info->TType = p + tmp;
 }
@@ -176,21 +181,6 @@ parse_lsda_header (_Unwind_Context *cont
 return p;
 }
 
-#ifdef __ARM_EABI_UNWINDER__
-
-static void **
-get_ttype_entry(_Unwind_Context *, lsda_header_info* info, _uleb128_t i)
-{
- _Unwind_Ptr ptr;
-
- ptr = (_Unwind_Ptr) (info->TType - (i * 4));
- ptr = _Unwind_decode_target2(ptr);
- 
- return reinterpret_cast<void **>(ptr);
-}
-
-#else
-
 static void **
 get_ttype_entry (_Unwind_Context *context, lsda_header_info *info, long i)
 {
@@ -202,8 +192,6 @@ get_ttype_entry (_Unwind_Context *contex
 return reinterpret_cast<void **>(ptr);
 }
 
-#endif
-
 // Using a different personality function name causes link failures
 // when trying to mix code using different exception handling models.
 #ifdef SJLJ_EXCEPTIONS
