This patch introduces support for specifing views in .loc directives, so that the compiler can use the assembler to generate line number information and have the assembler determine view numbers to multiple views at the same program counter.

binutils* dwarf.c (struct State_Machine_Registers): Add view field.
	(reset_state_machine): Reset view.
	(process_extended_line_op): Reset view when appropriate.
	(display_debug_lines_raw): Increment or reset view when appropriate.
	Print nonzero views.  Support print view resets, disabled by default.
	(display_debug_lines_decoded): Likewise.  Disambiguate op_code tests,
	enabling printing of end_sequence.
	* testsuite/binutils-all/dw2-1.W: Add nonzero views.
	* testsuite/binutils-all/dw2-3.W: Likewise.
	* testsuite/binutils-all/dw2-3gabi.W: Likewise.
	* testsuite/binutils-all/dw5.W: Add end sequence lines.
	* testsuite/binutils-all/i386/compressed-1a.d: Add nonzero views.
	* testsuite/binutils-all/libdw2-compressedgabi.out: Likewise.
	* testsuite/binutils-all/objdump.W: Likewise.
	* testsuite/binutils-all/objdump.WL: Add end sequence lines.
	* testsuite/binutils-all/x86-64/compressed-1a.d: Add nonzero views.

gas	* doc/as.texinfo (.loc): Document view support.
	* dwarf2dbg.c (unused): Check offset of next in struct line_entry.
	(current): Initialize view.
	(force_reset_view, view_assert_failed): New variables.
	(reverse_line_entry_list): New function.
	(set_or_check_view): Likewise.
	(dwarf2_gen_line_info_1): Call it.
	(dwarf2_where): Set view to NULL.
	(dwarf2_emit_insn): Return early when called before first file.
	(dwarf2_directive_loc): Add view support.  Emit insn
	immediately when view option is given.
	(process_entries): Avoid set_address to reset view when a known
	address change already implies the view reset.
	(dwarf2dbg_final_check): New function.
	* dwarf2dbg.h (struct dwarf2_line_info): Add view.
	(dwarf2dbg_final_check): Declare.
	* read.c (s_leb128): Parse expression as deferred.
	* testsuite/gas/all/gas.exp: Run sleb128-9.
	* testsuite/gas/all/sleb128-9.d: New.
	* testsuite/gas/all/sleb128-9.l: New.
	* testsuite/gas/all/sleb128-9.s: New.
	* testsuite/gas/elf/dwarf2-1.d: Add nonzero views.
	* testsuite/gas/elf/dwarf2-2.d: Likewise.
	* testsuite/gas/elf/dwarf2-5.d: New.
	* testsuite/gas/elf/dwarf2-5.s: New.
	* testsuite/gas/elf/dwarf2-6.d: New.
	* testsuite/gas/elf/dwarf2-6.s: New.
	* testsuite/gas/elf/dwarf2-7.d: New.
	* testsuite/gas/elf/dwarf2-7.s: New.
	* testsuite/gas/elf/dwarf2-8.d: New.
	* testsuite/gas/elf/dwarf2-8.l: New.
	* testsuite/gas/elf/dwarf2-8.s: New.
	* testsuite/gas/elf/dwarf2-9.d: New.
	* testsuite/gas/elf/dwarf2-9.l: New.
	* testsuite/gas/elf/dwarf2-9.s: New.
	* testsuite/gas/elf/dwarf2-10.d: New.
	* testsuite/gas/elf/dwarf2-10.l: New.
	* testsuite/gas/elf/dwarf2-10.s: New.
	* testsuite/gas/elf/dwarf2-11.d: New.
	* testsuite/gas/elf/dwarf2-11.s: New.
	* testsuite/gas/elf/dwarf2-12.d: New.
	* testsuite/gas/elf/dwarf2-12.s: New.
	* testsuite/gas/elf/dwarf2-13.d: New.
	* testsuite/gas/elf/dwarf2-13.s: New.
	* testsuite/gas/elf/dwarf2-14.d: New.
	* testsuite/gas/elf/dwarf2-14.s: New.
	* testsuite/gas/elf/dwarf2-15.d: New.
	* testsuite/gas/elf/dwarf2-15.s: New.
	* testsuite/gas/elf/dwarf2-16.d: New.
	* testsuite/gas/elf/dwarf2-16.s: New.
	* testsuite/gas/elf/dwarf2-17.d: New.
	* testsuite/gas/elf/dwarf2-17.s: New.
	* testsuite/gas/elf/dwarf2-18.d: New.
	* testsuite/gas/elf/dwarf2-18.s: New.
	* testsuite/gas/elf/elf.exp: Run dwarf2-5..18 tests.
	* testsuite/gas/i386/dw2-compress-1.d: Add nonzero views.
	* testsuite/gas/i386/dw2-compressed-1.d: Likewise.
	* testsuite/gas/i386/ilp32/lns/lns-duplicate.d: Likewise.
	* testsuite/gas/lns/lns-big-delta.d: Likewise.
	* testsuite/gas/lns/lns-duplicate.d: Likewise.
	* testsuite/gas/mips/loc-swap-2.d: Likewise.
	* testsuite/gas/mips/loc-swap-3.d: Likewise.
	* testsuite/gas/mips/loc-swap.d: Likewise.
	* testsuite/gas/mips/micromips@loc-swap-2.d: Likewise.
	* testsuite/gas/mips/micromips@loc-swap.d: Likewise.
	* testsuite/gas/mips/mips16@loc-swap-2.d: Likewise.
	* testsuite/gas/mips/mips16@loc-swap.d: Likewise.
	* testsuite/gas/mips/mips16e@loc-swap.d: Likewise.
	* write.c (write_object_file): Check pending view asserts.
	(cvt_frag_to_fill): Complain about undefined leb128 operand.

1 files changed, 13 insertions, 0 deletions

diff --git a/gas/doc/as.texinfo b/gas/doc/as.texinfo
index b82204d..8aa83ef 100644
--- a/gas/doc/as.texinfo
+++ b/gas/doc/as.texinfo
@@ -5833,6 +5833,19 @@ state machine to @var{value}, which must be an unsigned integer.
 This directive will set the @code{discriminator} register in the @code{.debug_line}
 state machine to @var{value}, which must be an unsigned integer.
 
+@item view @var{value}
+This option causes a row to be added to @code{.debug_line} in reference to the
+current address (which might not be the same as that of the following assembly
+instruction), and to associate @var{value} with the @code{view} register in the
+@code{.debug_line} state machine.  If @var{value} is a label, both the
+@code{view} register and the label are set to the number of prior @code{.loc}
+directives at the same program location.  If @var{value} is the literal
+@code{0}, the @code{view} register is set to zero, and the assembler asserts
+that there aren't any prior @code{.loc} directives at the same program
+location.  If @var{value} is the literal @code{-0}, the assembler arrange for
+the @code{view} register to be reset in this row, even if there are prior
+@code{.loc} directives at the same program location.
+
 @end table
 
 @node Loc_mark_labels