[PATCH] Fix gdb.dwarf2/dw2-dir-file-name.exp test for MIPS architectures

[Kwok Cheung Yeung <kwok_yeung at mentor dot com>]

This patch fixes the failures that occur with the 
gdb.dwarf2/dw2-dir-file-name.exp test on 64-bit MIPS and compressed MIPS 
ISAs (i.e. MIPS16 and microMIPS).

The failures on 64-bit occur because the generated DWARF address 
information is always 32-bit, which causes the upper 32-bits of 
addresses to be truncated and causes breakpoints to be set on the wrong 
address if any of the upper 32-bits are non-zero. I suspect that other 
64-bit architectures get away with it because they place all their 
instructions at a VMA lower than 2^32 by default. This patch causes 
64-bit addresses to be generated if a 64-bit target is detected.

The failures on MIPS16 and microMIPS occur because the breakpoint 
address needs to have the LSB set to 1 (used to indicate that the code 
is compressed). However, the function name is interpreted as a data 
label, causing GDB to set breakpoints at even addresses. This is fixed 
by explicitly adding a '.insn' directive (see 
https://sourceware.org/binutils/docs/as/MIPS-insn.html) after the label 
on MIPS only.

Kwok

2014-08-14  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gdb/testsuite/
	* gdb.dwarf2/dw2-dir-file-name.exp (addr_len): New.
	(out_cu): Use addr_len for the size of addresses.
	(out_line): Likewise.  Size DW_LNE_set_address instruction
	according to addr_len.
	* gdb.dwarf2/dw2-dir-file-name.c (START_INSNS): New.
	(FUNC): Add START_INSNS to definition.

Attachment: gdb_dw2-dir-file-name.patch
Description: Text document