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Andreas Arnez 7942e96e43 Big-endian targets: Don't ignore offset into DW_OP_stack_value
Recently I fixed a bug that caused a DW_OP_implicit_pointer with non-zero
offset into a DW_OP_implicit_value to be handled incorrectly on big-endian
targets.  GDB ignored the offset and copied the wrong bytes:

  https://sourceware.org/ml/gdb-patches/2017-01/msg00251.html

But there is still a similar issue when a DW_OP_implicit_pointer points
into a DW_OP_stack_value instead; and again, the offset is ignored.  There
is an important difference, though: While implicit values are treated like
blocks of data and anchored at the lowest-addressed byte, stack values
traditionally contain integer numbers and are anchored at the *least
significant* byte.  Also, stack values do not come in varying sizes, but
are cut down appropriately when used.  Thus, on big-endian targets the
scenario looks like this (higher addresses shown right):

  |<- - - - - Stack value - - - - - - ->|
                  |                     |
                  |<- original object ->|
                  |
                  | offset ->|####|
			      ^^^^
                              de-referenced
			      implicit pointer

(Note how the original object's size influences the position of the
de-referenced implicit pointer within the stack value.  This is not the
case for little-endian targets, where the original object starts at offset
zero within the stack value.)

This patch implements the logic indicated in the above diagram and adds an
appropriate test case.  A new function dwarf2_fetch_die_type_sect_off is
added; it is used for retrieving the original object's type, so its size
can be determined.  That type is passed to dwarf2_evaluate_loc_desc_full
via a new parameter.

gdb/ChangeLog:

	* dwarf2loc.c (indirect_synthetic_pointer): Get data type of
	pointed-to DIE and pass it to dwarf2_evaluate_loc_desc_full.
	(dwarf2_evaluate_loc_desc_full): New parameter subobj_type; rename
	byte_offset to subobj_byte_offset.  Fix the handling of
	DWARF_VALUE_STACK on big-endian targets when coming via an
	implicit pointer.
	(dwarf2_evaluate_loc_desc): Adjust call to
	dwarf2_evaluate_loc_desc_full.
	* dwarf2loc.h (dwarf2_fetch_die_type_sect_off): New declaration.
	* dwarf2read.c (dwarf2_fetch_die_type_sect_off): New function.

gdb/testsuite/ChangeLog:

	* lib/dwarf.exp: Add support for DW_OP_implicit_pointer.
	* gdb.dwarf2/nonvar-access.exp: Add test for stack value location
	and implicit pointer into such a location.
2017-03-16 19:50:24 +01:00
bfd Automatic date update in version.in 2017-03-16 00:00:45 +00:00
binutils Add support for a GNU BUILD note type to record the enum size. 2017-03-16 16:44:55 +00:00
config
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gas gas/arc: Limit special handling of t/nt flag to ARCv2 2017-03-16 10:07:22 +00:00
gdb Big-endian targets: Don't ignore offset into DW_OP_stack_value 2017-03-16 19:50:24 +01:00
gold Mips: Fix TLS LDM GOT entry. 2017-03-15 16:51:35 -07:00
gprof
include Add support for a GNU BUILD note type to record the enum size. 2017-03-16 16:44:55 +00:00
intl
ld ld-checks: tweak overflow checks. 2017-03-15 10:23:19 +01:00
libdecnumber
libiberty Merge libiberty: Initialize d_printing in all cplus_demangle_fill_* functions. 2017-03-13 20:51:42 +01:00
opcodes RISC-V: Fix assembler for c.li, c.andi and c.addiw 2017-03-15 07:47:52 -07:00
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		   README for GNU development tools

This directory contains various GNU compilers, assemblers, linkers, 
debuggers, etc., plus their support routines, definitions, and documentation.

If you are receiving this as part of a GDB release, see the file gdb/README.
If with a binutils release, see binutils/README;  if with a libg++ release,
see libg++/README, etc.  That'll give you info about this
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It is now possible to automatically configure and build a variety of
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	./configure 
	make

To install them (by default in /usr/local/bin, /usr/local/lib, etc),
then do:
	make install

(If the configure script can't determine your type of computer, give it
the name as an argument, for instance ``./configure sun4''.  You can
use the script ``config.sub'' to test whether a name is recognized; if
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	CC=gcc ./configure
	make

A similar example using csh:

	setenv CC gcc
	./configure
	make

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