My previous fix for issue 23179 was incomplete; it turns out that if
an unnamed parameter is below a specific size threshold, it gets
register-promoted away by the compiler (hence not encountered during
some parts of DWARF inline info processing), but if it is sufficiently
large, it is allocated to the stack as a named variable and treated as
a regular parameter by DWARF generation. Interestingly, something in
the ppc64le build of k8s causes an unnamed parameter to be retained
(where on amd64 it is deleted), meaning that this wasn't caught in my
amd64 testing.
The fix is to insure that "_" params are treated in the same way that
"~r%d" return temps are when matching up post-optimization inlined
routine params with pre-inlining declarations. I've also updated the
test case to include a "_" parameter with a very large size, which
also triggers the bug on amd64.
Fixes#23179.
Change-Id: I961c84cc7a873ad3f8f91db098a5e13896c4856e
Reviewed-on: https://go-review.googlesource.com/84975
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Change the compiler's DWARF inline info generation to be more careful
about producing consistent instances of abstract function DIEs. The
new strategy is to insure that the only params/variables created in an
abstract subprogram DIE are those corresponding to declarations in the
original pre-inlining version of the code. If a concrete subprogram
winds up with other vars as part of the compilation process (return
temps, for example, or scalars generated by splitting a structure into
pieces) these are emitted as regular param/variable DIEs instead of
concrete DIEs.
The linker dwarf test now has a couple of new testpoints that include
checks to make sure that all abstract DIE references are
sane/resolvable; this will help catch similar problems in the future.
Fixes#23046.
Change-Id: I9b0030da8673fbb80b7ad50461fcf8c6ac823a37
Reviewed-on: https://go-review.googlesource.com/83675
Run-TryBot: Than McIntosh <thanm@google.com>
Run-TryBot: Heschi Kreinick <heschi@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The DWARF inline info generation code was using file/line/column (from
src.Pos) as a means of matching up pre- and post-optimization variable
nodes. This turns out to be problematic since it looks as though
distinct formals on the same line can be assigned the same column
number. Work around this issue by adding variable names to the
disambiguation code. Added a testpoint to the linker DWARF test that
checks to make sure each abstract origin offset of distinct within a
given DWARF DW_AT_inlined_routine body.
Fixes#23020.
Change-Id: Ie09bbe01dc60822d84d4085547b138e644036fb3
Reviewed-on: https://go-review.googlesource.com/82396
Reviewed-by: David Chase <drchase@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Compiler and linker changes to support DWARF inlined instances,
see https://go.googlesource.com/proposal/+/HEAD/design/22080-dwarf-inlining.md
for design details.
This functionality is gated via the cmd/compile option -gendwarfinl=N,
where N={0,1,2}, where a value of 0 disables dwarf inline generation,
a value of 1 turns on dwarf generation without tracking of formal/local
vars from inlined routines, and a value of 2 enables inlines with
variable tracking.
Updates #22080
Change-Id: I69309b3b815d9fed04aebddc0b8d33d0dbbfad6e
Reviewed-on: https://go-review.googlesource.com/75550
Run-TryBot: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Chase <drchase@google.com>
