* dwarf2-frame.c (struct dwarf2_cie): Add ptr_size member.

	Throughout, call read_encoded_value with ptr_size rather than addr_size.
	(decode_frame_entry_1): Remove redundant setting of
	addr_size.  Call gdbarch_dwarf2_addr_size rather than gdbarch_ptr_bit
	to determine addr_size in Dwarf versions < 4.  Set ptr_size dependent
	on examined frame section.  Add comment to explain why.
	* gdbarch.sh (dwarf2_addr_size): Define as variable.  Add lengthy
	comment to explain usage.
	* gdbarch.c: Regenerate.
	* gdbarch.h: Regenerate.

	* xstormy16-tdep.c (xstormy16_gdbarch_init): Set dwarf2_addr_size to 4.

1 files changed, 19 insertions, 2 deletions

diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h
index d2b0e5afec8..f6c7ce81aef 100644
--- a/gdb/gdbarch.h
+++ b/gdb/gdbarch.h
@@ -154,8 +154,8 @@ extern void set_gdbarch_long_double_format (struct gdbarch *gdbarch, const struc
    / addr_bit will be set from it.
   
    If gdbarch_ptr_bit and gdbarch_addr_bit are different, you'll probably
-   also need to set gdbarch_pointer_to_address and gdbarch_address_to_pointer
-   as well.
+   also need to set gdbarch_dwarf2_addr_size, gdbarch_pointer_to_address and
+   gdbarch_address_to_pointer as well.
   
    ptr_bit is the size of a pointer on the target */
 
@@ -167,6 +167,23 @@ extern void set_gdbarch_ptr_bit (struct gdbarch *gdbarch, int ptr_bit);
 extern int gdbarch_addr_bit (struct gdbarch *gdbarch);
 extern void set_gdbarch_addr_bit (struct gdbarch *gdbarch, int addr_bit);
 
+/* dwarf2_addr_size is the target address size as used in the Dwarf debug
+   info.  For .debug_frame FDEs, this is supposed to be the target address
+   size from the associated CU header, and which is equivalent to the
+   DWARF2_ADDR_SIZE as defined by the target specific GCC back-end.
+   Unfortunately there is no good way to determine this value.  Therefore
+   dwarf2_addr_size simply defaults to the target pointer size.
+  
+   dwarf2_addr_size is not used for .eh_frame FDEs, which are generally
+   defined using the target's pointer size so far.
+  
+   Note that dwarf2_addr_size only needs to be redefined by a target if the
+   GCC back-end defines a DWARF2_ADDR_SIZE other than the target pointer size,
+   and if Dwarf versions < 4 need to be supported. */
+
+extern int gdbarch_dwarf2_addr_size (struct gdbarch *gdbarch);
+extern void set_gdbarch_dwarf2_addr_size (struct gdbarch *gdbarch, int dwarf2_addr_size);
+
 /* One if `char' acts like `signed char', zero if `unsigned char'. */
 
 extern int gdbarch_char_signed (struct gdbarch *gdbarch);