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.
Separate the name of the igen program from the options used to run it.
This allows us to avoid duplicating ../igen/igen in Makefiles and reuse
the existing setting in the common Makefile. This also allows us to
easily harmonize the use of EXEEXT between igen/local.mk and the common
makefiles when cross-compiling for e.g. Windows.
32-bit MIPS programs run on the 64-bit simulator model in 64-bit
sign-extended space. The mapping from 64-bit sign-extended addresses to
32-bit addresses was removed by commit
26f8bf63bf, breaking the 64-bit simulator
model. Add shadow mappings from 64-bit sign extended address space to
32-bit address spaces, in lieu of the AddressTranslation function.
2021-05-04 Faraz Shahbazker <fshahbazker@wavecomp.com>
sim/mips/ChangeLog:
* interp.c (sim_open): Add shadow mappings from 32-bit
address space to 64-bit sign-extended address space.
64-bit BFD for MIPS applies a standard sign extension on all addresses
assuming 64-bit target. These bits are required for 64-bit and can only
be safely truncated for 32-bit target models. This partially reverts commit
b36d953bce
The sign-extension logic modeled by BFD is an integral part of the
MIPS64 architecture spec. It appears in the virtual address map, where
sign extension allows for 32-bit compatibility segments [1] with 64-bit
addressing. Truncating these addresses prematurely (commit
models (-DWITH_TARGET_WORD_BITSIZE=64).
In the ISA itself, direct addressing (Load-Upper-Immediate) and indirect
addressing (Load-Word) both automatically sign-extend their results. These
instructions regenerate the sign-extended addresses even if we don't start
with one (see pr gdb/19447).
Moreover, some instructions like ADD*/SUB* have unpredictable behaviour when
an operand is not correctly sign extended [3]. This affects PC-relative
addressing in particular, so arithmetic on the link-address generated in the
return address register by a jump-and-link is no longer possible, neither is
the use of the PC-relative addressing instructions provided by MIPSR6.
[1] "MIPS64 Architecture for Programmers Volume III: The MIPS64
Privileged Resource Architecture", Document Number: MD00091,
Revision 6.02, December 10, 2015, Section 4.3 "Virtual Address
Spaces", pp. 29-31
https://s3-eu-west-1.amazonaws.com/downloads-mips/documents/MD00091-2B-MIPS64PRA-AFP-06.03.pdf
[2] "MIPS64 Architecture for Programmers Volume II-A: The MIPS64
Instruction Set Reference Manual", Document Number: MD00087,
Revision 6.06, December 15, 2016, Section 3.2 "Alphabetical
List of Instructions", pp. 321
https://s3-eu-west-1.amazonaws.com/downloads-mips/documents/MD00087-2B-MIPS64BIS-AFP-6.06.pdf
[3] "MIPS64 Architecture for Programmers Volume II-A: The MIPS64
Instruction Set Reference Manual", Document Number: MD00087,
Revision 6.06, December 15, 2016, Section 3.2 "Alphabetical
List of Instructions", pp. 56
https://s3-eu-west-1.amazonaws.com/downloads-mips/documents/MD00087-2B-MIPS64BIS-AFP-6.06.pdf
2021-04-23 Faraz Shahbazker <fshahbazker@wavecomp.com>
sim/mips/ChangeLog:
* interp.c (sim_create_inferior): Only truncate sign extension
bits for 32-bit target models
.
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.
There's no need to restrict these to only specific targets as the user
can select them at runtime if they want them. Always build them so we
can improve build coverage too.
This is needed when building for a target whose ar & ranlib are
incompatible with the current build system. For example, building
for Windows on a Linux system.
Then manually import the automake rule for libigen.a, but tweak the
tool variables to use the FOR_BUILD variants.
While libiberty provides a definition for this for systems that lack
the function (e.g. Windows), it doesn't provide a prototype. So add
our own local copy in the one file that uses the func.
Every port using this sets the 1st arg to yes and the 2nd arg to "".
These are the defaults we probably want anyways in order to unify the
codebase, so move them to the macro and only allow ports to declare
extra hardware models.
When building with clang, we get:
error: unknown warning option '-Wmissing-parameter-type' [-Werror,-Wunknown-warning-option]
This is because clang only warns by default when encountering an unknown
warning option, and the probe for supported warning flags is done
without -Werror. All flags are therefore accepted by configure, but
then it breaks when actually compiling a source file with -Werror.
This is equivalent to this commit in gdb:
3e019bdc20
gdb: Use -Werror when checking for (un)supported warning flags
We then see some other compilation errors when building with clang and
-Werror, they can be dealt with later.
This avoids duplicate tests for functions between common m4, arches,
and any other sources that would trigger func tests.
Also manually delete known duplicate function tests between the m4,
bfin, and v850 ports.
The igen/dgen and opc2c tools leak their heap-allocated memory (on
purpose) at program exit, which makes AddressSanitizer fail the tool
execution. This breaks the build, as it makes the tool return a
non-zero exit code.
Fix that by disabling leak detection through the setting of that
environment variable.
I also changed the opc2c rules for m32c to go through a temporary file.
What happened is that the failing opc2c would produce an incomplete file
(probably because ASan exits the process before stdout is flushed).
This meant that further make attempts didn't try to re-create the file,
as it already existed. A "clean" was therefore necessary. This can
also happen in regular builds if the user interrupts the build (^C) in
the middle of the opc2c execution and tries to resume it. Going to a
temporary file avoids this issue.
sim/m32c/ChangeLog:
* Makefile.in: Set ASAN_OPTIONS when running opc2c.
sim/mips/ChangeLog:
* Makefile.in: Set ASAN_OPTIONS when running igen.
sim/mn10300/ChangeLog:
* Makefile.in: Set ASAN_OPTIONS when running igen.
sim/ppc/ChangeLog:
* Makefile.in: Set ASAN_OPTIONS when running igen.
sim/v850/ChangeLog:
* Makefile.in: Set ASAN_OPTIONS when running igen.
Change-Id: I00f21d4dc1aff0ef73471925d41ce7c23e83e082
sim/mips/ChangeLog
* interp.c (sim_monitor): Add switch entries for unlink (13),
lseek (14), and stat (15).
Derived from patch authored by Steve Ellcey <sellcey@mips.com>
This simplifies the build a bit (especially for deps in port subdirs),
and avoids recursive make. This in turn speeds up the build, and sets
us up for multi-target.
Rather than require $AR be set and then default to `ar`, use the
standard AC_CHECK_TOOL helper to find a good prefixed tool. In
practice this shouldn't change much as we seem to have macros in
the tree that were already setting it up, but we shouldn't rely
on that implicitly.
All the scripts were using this implicitly already, so there's no real
change for them, but we want to call it explicitly as the CPP tool is
used to generate nltvals.def.
We don't need a variable to add a dependency to the "all" target, and
having one doesn't really add value. Switch to the target directly for
the few ports that actually use this.
This file is quite large and is getting unmanageable. Split it apart
to follow aclocal best practices by putting one-macro-per-file. There
shouldn't be any real functional changes here as can be seen in the
configure script regens.
Rather than hand maintain m4 includes in various autotool files,
use AC_CONFIG_MACRO_DIRS to declare the relevant search paths.
This simplifies the code, makes it more robust, and cleans out
unused logic from configure.
Few arches implement STATE_WATCHPOINTS()->pc while all of them implement
sim_pc_get. Lets switch the sim-watch core for monitoring pc events to
the sim_pc_get API so this module works for all ports, and then we can
delete this old back channel of snooping in the port's cpu state -- the
code needs the pointer to the pc storage so that it can read out bytes
and compare them to the watchrange.
This also fixes the logic on multi-cpu sims by removing the limitation
of only being able to watch CPU0's state.
The AC_CONFIG_HEADER macro is long deprecated, so switch to the
newer form. This also gets rid of the position limitation, and
drops support for an argument to SIM_AC_COMMON which we haven't
used anywhere.
These settings might have made sense in darker compiler times, but I
think they're largely obsolete now. Looking through the values that
get used in HDEFINES, it's quite limited, and configure itself should
handle them. If we still need something, we can leverage standard
autoconf macros instead, after we get a clear user report.
TDEFINES was never set anywhere and was always empty, so prune that.
Existing ports already have sizeof_pc set to the same size as sim_cia,
so simply make that part of the core code. We already assume this in
places by way of sim_pc_{get,set}, and this is how it's documented in
the sim-base.h API.
There is code to allow sims to pick different register word sizes from
address sizes, but most ports use the defaults for both (32-bits), and
the few that support multiple register sizes never change the address
size (so address defaults to register). I can't think of any machine
where the register hardware size would be larger than the address word
size either. We have ABIs that behave that way (e.g. x32), but the
hardware is still equivalent register sized.
Since we require C11 now, we can assume many headers exist, and
clean up all of the conditional includes. It's not like any of
this code actually accounted for the headers not existing, just
whether we could include them.
The strings.h cleanup is a little nuanced: it isn't in C11, but
every use of it in the codebase will include strings.h only if
string.h doesn't exist. Since we now assume the C11 string.h
exists, we'll never include strings.h, so we can delete it.
We've had this off for a long time because the sim code was way too
full of warnings for it to be feasible. However, I've cleaned things
up significantly from when this was first merged, and we can start to
turn this around.
Change the macro to enable -Werror by default, and allow ports to opt
out. New ports will get it automatically (and we can push back on
them if they try to turn it off).
Also turn it off for the few ports that still hit warnings for me.
All the rest will get the new default, and we'll wait for feedback
if/when new issues come up.
With GDB requiring a C++11 compiler now, this hopefully shouldn't
be a big deal. It's been 10 years since C11 came out, so should
be plenty of time to upgrade.
This will allow us to start cleaning up random header logic and
many of our non-standard custom types.
