svn commit: r279307 - head/contrib/libcxxrt

[Dimitry Andric]

Author: dim
Date: Thu Feb 26 07:20:05 2015
New Revision: 279307
URL: https://svnweb.freebsd.org/changeset/base/279307

Log:
  Make libcxxrt's parsing of DWARF exception handling tables work on
  architectures with strict alignment, by using memcpy() instead of
  directly reading fields.
  
  Reported by:	Daisuke Aoyama <aoyama at peach.ne.jp>
  Reviewed by:	imp, bapt
  Tested by:	bapt
  MFC after:	3 days
  Differential Revision: https://reviews.freebsd.org/D1967

Modified:
  head/contrib/libcxxrt/dwarf_eh.h

Modified: head/contrib/libcxxrt/dwarf_eh.h
==============================================================================
--- head/contrib/libcxxrt/dwarf_eh.h	Thu Feb 26 02:22:47 2015	(r279306)
+++ head/contrib/libcxxrt/dwarf_eh.h	Thu Feb 26 07:20:05 2015	(r279307)
@@ -218,15 +218,17 @@ static int64_t read_sleb128(dw_eh_ptr_t 
 static uint64_t read_value(char encoding, dw_eh_ptr_t *data)
 {
 	enum dwarf_data_encoding type = get_encoding(encoding);
-	uint64_t v;
 	switch (type)
 	{
 		// Read fixed-length types
 #define READ(dwarf, type) \
 		case dwarf:\
-			v = static_cast<uint64_t>(*reinterpret_cast<type*>(*data));\
-			*data += sizeof(type);\
-			break;
+		{\
+			type t;\
+			memcpy(&t, *data, sizeof t);\
+			*data += sizeof t;\
+			return static_cast<uint64_t>(t);\
+		}
 		READ(DW_EH_PE_udata2, uint16_t)
 		READ(DW_EH_PE_udata4, uint32_t)
 		READ(DW_EH_PE_udata8, uint64_t)
@@ -237,15 +239,11 @@ static uint64_t read_value(char encoding
 #undef READ
 		// Read variable-length types
 		case DW_EH_PE_sleb128:
-			v = read_sleb128(data);
-			break;
+			return read_sleb128(data);
 		case DW_EH_PE_uleb128:
-			v = read_uleb128(data);
-			break;
+			return read_uleb128(data);
 		default: abort();
 	}
-
-	return v;
 }
 
 /**