This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
The ## marker tells automake to not include the comment in its
generated output, so use that in most places where the comment
only makes sense in the inputs.
Use the new target-newlib-syscall module. This is needed to merge all
the architectures into a single build, and sh has a custom syscall
table for its newlib/libgloss port.
We use the program argv to both find the program to run (argv[0]) and
to hold the arguments to the program. Most of the time this is fine,
but if we want to let programs specify argv[0] independently (which is
possible in standard *NIX programs), this double duty doesn't work.
So let's split the path to the program to run out into a separate
field by itself. This simplifies the various sim_open funcs too.
By itself, this code is more of a logical cleanup than something that
is super useful. But it will open up customization of argv[0] in a
follow up commit. Split the changes to make it easier to review.
In <=gcc-7 versions, -fstrict-overflow is enabled by default, and that
triggers warnings in this code that relies on integer overflows to test
for carries. Change the logic to test against the limit directly.
On LLP64 targets where sizeof(long) != sizeof(void*), this code fails:
sim/sh/interp.c:704:24: error: cast from pointer to integer of different size -Werror=pointer-to-int-cast]
704 | do { memstalls += ((((long) PC & 3) != 0) ? (n) : ((n) - 1)); } while (0)
| ^
Since this code simply needs to check alignment, cast it using uintptr_t
which is the right type for this.
Casting 0 to a pointer via (long *) doesn't work on LLP64 targets:
error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
It's also unnecessary here. We can simply pass NULL like every other
bit of code does.
The code assumes that all _WIN32 targets are the same and can
define isnan to _isnan. For mingw targets, they provide an isnan
define already, so no need for the fallback here.
With most of the warnings fixed in interp.c, we can enable -Werror
here too now. There are some -Wmaybe-uninitialized warnings still
lurking that look legitimate, but we don't flag those are fatal,
and I don't have the expertise to dive into each opcode to figure
out the right way to clean them up.
This block of code relies on i to control which bits to test and how
many times to run through the loop, but it never actually initialized
it. There is another chunk of code that handles the pdmsb instruction
that sets i to 16, so use that here too assuming it's correct. The
programming manual suggests this is the right value too, but I am by
no means a SuperH DSP expert. The tests are still passing though ...
These macro expansions are deliberate in not using the computed value
so that they trigger side-effects (possible invalid memory accesses)
but while otherwise being noops. Add a (void) cast so the compiler
knows these are intentional.
Now that we require C11, we can leverage anonymous unions & structs
to fix a long standing issue with the SH register layout. The use
of sregs.i for sh-dsp has generated a lot of compiler warnings about
the access being out of bounds -- it only has 7 elements declared,
but code goes beyond that to reach into the fregs that follow. But
now that we have anonymous unions, we can reduce the nested names
and have sregs cover all of these registers.
Only one file in here still generates warnings, so reduce the -Werror
disable to that alone now that we require GNU make and can set variables
on a per-object basis.
Now that ChangeLog entries are no longer used for sim patches,
this commit renames all relevant sim ChangeLog to ChangeLog-2021,
similar to what we would do in the context of the "Start of New
Year" procedure.
The purpose of this change is to avoid people merging ChangeLog
entries by mistake when applying existing commits that they are
currently working on.
Also throw in a .gitignore entry to keep people from adding new
ChangeLog files anywhere in the sim tree.
These ports only use the pieces that have been unified, so we can
merge them into the common configure script and get rid of their
unique one entirely.
We still compile & link separate run programs, and have dedicated
subdir Makefiles, but the configure script portion is merged.
The sim-hardware configure option allows builders to select a set of
device models to enable. But this seems like unnecessary overkill:
the existence of individual device models doesn't affect performance
at all as they are only enabled at runtime if the config uses them,
and individually these are all <5KB a piece. Stripping off a total
of ~50KB from a ~1MB binary doesn't seem useful, and it's extremely
unlikely anyone will ever bother.
So let's simplify the configure/make logic by turning sim-hardware
into a boolean option like many of the other sim options. Any ports
that have unique device models will declare them in their Makefile
instead of at configure time. This will allow us to (eventually)
unify the setting into the common dir.
Move these options up to the common dir so we only test & export
them once across all ports. This takes a page from the cgen maint
logic to make $(MAINT) work for non-automake Makefiles which will
allow us to merge it together.
Move these options up to the common dir so we only test & export
them once across all ports. It also enables -Werror usage on the
common files we've been pulling out of arch subdirs.
For the ports that still don't build with -Werror, rather than disable
the flag at configure time, do it at make time. This will allow us to
unify these tests in the common sim configure script.
The m4 macro has 2 args: the "wire" settings (which represents the
hardwired port behavior), and the default settings (which are used
if nothing else is specified). If none are specified, the arch is
expected to support both, and the value will be probed based on the
user runtime options or the input program.
Only two arches today set the default value (bpf & mips). We can
probably let this go as it only shows up in one scenario: the sim
is invoked, but with no inputs, and no user endian selection. This
means bpf will not behave like the other arches: an error is shown
and forces the user to make a choice. If an input program is used
though, we'll still switch the default to that. This allows us to
remove the WITH_DEFAULT_TARGET_BYTE_ORDER setting.
For the ports that set a "wire" endian, move it to the runtime init
of the respective sim_open calls. This allows us to change the
WITH_TARGET_BYTE_ORDER to purely a user-selected configure setting
if they want to force a specific endianness.
With all the endian logic moved to runtime selection, we can move
the configure call up to the common dir so we only process it once
across all ports.
The ppc arch was picking the wire endian based on the target used,
but since we weren't doing that for other biendian arches, we can
let this go too. We'll rely on the input selecting the endian, or
make the user decide.
All of the settings in here are handled by the common top-level
config.h, so drop the individual arch-config.h files entirely.
This will also help guarantee that we don't add any new arch
specific defines that would affect common code which will help
with the effort of unifying them.
Currently, the sim-config module will abort if alignment settings
haven't been specified by the port's configure.ac. This is a bit
weird when we've allowed SIM_AC_OPTION_ALIGNMENT to seem like it's
optional to use. Thus everyone invokes it.
There are 4 alignment settings, but really only 2 matters: strict
and nonstrict. The "mixed" setting is just the default ("unset"),
and "forced" isn't used directly by anyone (it's available as a
runtime option for some ports).
The m4 macro has 2 args: the "wire" settings (which represents the
hardwired port behavior), and the default settings (which are used
if nothing else is specified). If none are specified, then the
build won't work (see above as if SIM_AC_OPTION_ALIGNMENT wasn't
called). If default settings are provided, then that is used, but
we allow the user to override at runtime. Otherwise, the "wire"
settings are used and user runtime options to change are ignored.
Most ports specify a default, or set the "wire" to nonstrict. A
few set "wire" to strict, but it's not clear that's necessary as
it doesn't make the code behavior, by default, any different. It
might make things a little faster, but we should provide the user
the choice of the compromises to make: force a specific mode at
compile time for faster runtime, or allow the choice at runtime.
More likely it seems like an oversight when these ports were
initially created, and/or copied & pasted from existing ports.
With all that backstory, let's get to what this commit does.
First kill off the idea of a compile-time default alignment and
set it to nonstrict in the common code. For any ports that want
strict alignment by default, that code is moved to sim_open while
initializing the sim. That means WITH_DEFAULT_ALIGNMENT can be
completely removed.
Moving the default alignment to the runtime also allows removal
of setting the "wire" settings at configure time. Which allows
removing of all arguments to SIM_AC_OPTION_ALIGNMENT and moving
that call to common code.
The macro logic can be reworked to not pass WITH_ALIGNMENT as -D
CPPFLAG and instead move it to config.h.
All of these taken together mean we can hoist the macro up to the
top level and share it among all sims so behavior is consistent
among all the ports.
Move these options up to the common dir so we only test & export
them once across all ports. The AC_INIT macro does a lot of the
heavy lifting already which allows further simplification.
Move these options up to the common dir so we only test & export
them once across all ports.
The ppc code needs a little extra care with its trace settings as
it's not exactly the same API as the common code. The other knobs
are the same though.
Move the various platform tests up a level to avoid duplication
across the ports. When building multiple versions, this speeds
things up a bit.
For now we move the obvious stuff up a level, but we don't turn
own the config.h entirely just yet -- we still have some tests
related to libraries that need consideration.
Currently all ports have to declare sim_state themselves in their
sim-main.h and then embed the common sim_state_base & sim_cpu in it.
This dynamic makes it impossible to share common object code among
multiple ports because the core data structure is always different.
Let's invert this relationship: common code declares sim_state, and
if the port actually needs state on a per-instance basis, it can use
the new arch_data field for it. Most ports don't actually use it,
so they don't need to declare anything at all.
This is the first in a series of changes: it adds a define to select
between the old & new layouts, then converts all the ports that don't
need custom state over to the new layout.
The defs.h header will take care of including the various config.h
headers. For now, it's just config.h, but we'll add more when we
integrate gnulib in.
This header should be used instead of config.h, and should be the
first include in every .c file. We won't rely on the old behavior
where we expected files to include the port's sim-main.h which then
includes the common sim-basics.h which then includes config.h. We
have a ton of code that includes things before sim-main.h, and it
sometimes needs to be that way. Creating a dedicated header avoids
the ordering mess and implicit inclusion that shows up otherwise.
The gdb/callback.h & gdb/remote-sim.h headers have nothing to do with
gdb and are really definitions for the libsim API under the sim/ tree.
While gdb uses those headers as a client, it's not specific to it. So
create a new sim/ namespace and move the headers there.
Joel Brobecker
Mike Frysinger