Warn if mtouch loads an assembly from a different location than requested
(which might be because there are multiple assemblies with the same name).
Also rework the MT0023 check a bit by explicitly loading the root assembly
first, and then detecting if any loaded assemblies matches the root assembly.
This results in code that's a bit more obvious, and it also works correctly
with extensions (previously the entire MT0023 check was skipped for
extensions).
Detect when assemblies have native dependencies between them (which can happen
when there are multiple binding projects, and the native libraries in those
binding projects have dependencies between them), and add the proper link
arguments (this is only required when building to dynamic libraries or
frameworks, since otherwise everything is linked to one big binary and there
are no dependency problems).
https://bugzilla.xamarin.com/show_bug.cgi?id=43689
The previous build system kept a forward-pointing single linked list of tasks
to execute: task X had a list of subsequent tasks to execute. If task X was
up-to-date, it was not created (and the next tasks were directly added to the
list of tasks to execute).
In this world it became complicated to merge output from tasks (for instance
if the output of task X and task Y should be a consumed by a single task
producing a single output, since the corresponding task would end up in both
X's and Y's list of subsequent tasks).
Example: creating a single framework from the aot-compiled output of multiple
assemblies.
So I've reversed the logic: now we keep track of the final output, and then
each task has a list of dependencies that must be built.
This makes it trivial to create merging tasks (for the previous example, there
could for instance be a CreateFrameworkTask, where its dependencies would be
all the corresponding AotTasks).
We also always create every task, and then each task decides when its executed
whether it should do anything or not. This makes it unnecessary to 'forward-
delete' files when creating tasks (say you have three tasks, A, B, C; B
depends on A, and C depends on B; if A's output isn't up-to-date, it has to
delete its own output if it exists, otherwise B would not detect that it would
have to re-execute, because at task *creation* time, B's input hadn't
changed).
Additionally make it based on async/await, since much of the work happens in
externel processes (and we don't need to spin up additional threads just to
run external processes). This makes us have less code run on background
threads, which makes any issues with thread-safety less likely.
Compute the dependency map for assemblies earlier, and store the results.
In a later commit we'll need to know if a dependency map was successfully
computed when determining if a task is up-to-date or not.
Rework the code that copies assemblies and their related files to the app
bundle to take into account that we might be building to frameworks now.
Also strip the assemblies when they're copied (if they must be stripped),
which removes the need for custom logic to copy files related to stripped
assemblies.
Additionally change how we handle duplicated assemblies by checking for
duplication before copying them to the app bundle. This allows us to copy
assemblies to the root directory (not the .monotouch-[32|64] subdirectory) if
the 32-bit and 64-bit versions are identical, which also means we won't need
symlinks anymore.
Create a custom AssemblyCollection class that contains a dictionary with
assembly identity (name) -> Assembly mapping.
This also means that we can detect if we end up loading multiple assemblies
with the same identity, and show an error in that case (even if that case
should never happen since we cache assemblies based on the identity, it's nice
to have code that ensures it).
Event sequence:
* mtouch is executed with the linker disabled.
* The linker pipeline copies all input assemblies (since the linker is
disabled the assemblies don't change) into the PreBuild directory. This will
keep the original timestamps of the input assemblies.
* mtouch is executed again, when none of the input assemblies changed.
* The linker pipeline will re-execute, because it will see that at least one
of the input assemblies (at least the .exe) is newer than at least one of
the assemblies in the PreBuild directory (usually a framework assembly,
because those have the original timestamp from their install location).
Fix:
Touch all the assemblies in the PreBuild directory after the linker pipeline
executes the first time. This way the second time mtouch is executed, it will
find that all assemblies in the PreBuild directory have timestamps later than
all the input assemblies, so it will load the cached linked assemblies,
instead of re-executing the linker pipeline.
Switch to a new API introduced in Cecil added new API to get all the
attributes in an assembly, without having to traverse (and load) every type
and member.
This makes mtouch significantly faster when computing the list of referenced
assemblies, which is noticable when mtouch later determines nothing else needs
to be done (because nothing changed).
A few tests show that mtouch is now approximately twice as fast:
* A customer test project goes from 2s to 1s.
* A simple test app goes from 1.3s to 0.6.
https://bugzilla.xamarin.com/show_bug.cgi?id=49087
The native linker treats object files (.o) and static libraries (.a files,
which are archives of .o files) differently.
The native linker will always include object files into the executable:
$ echo "void xxx () {}" > foo.m
$ clang -c foo.m -o foo.o -arch x86_64
$ ld foo.o -dylib -o foo.dylib -macosx_version_min 10.12 -arch x86_64
$ nm foo.dylib
0000000000000fe0 T _xxx
However, if the object file is inside a static library:
$ echo "void xxx () {}" > foo.m
$ clang -c foo.m -o foo.o -arch x86_64
$ ar cru foo.a foo.o
$ ld foo.a -dylib -o foo.dylib -macosx_version_min 10.12 -arch x86_64
$ nm foo.dylib
<no output>
This means that our testing library (libtest.a) which is a fat library of
_object files_, do not show the problems reported in bug #51548.
So:
a) I've fixed the creation of libtest.a to be a fat library of _static
libraries_. This causes the `FastDev_LinkWithTest` test to fail exactly
like in bug #51548.
b) I've made mtouch pass `-u <native symbol>` to the native linker, for every
native symbol referenced in a managed assembly, when creating a dylib.
Amazingly this seems to work fine even with symbols to Objective-C classes
(`_OBJC_CLASS_$_<class name>`).
c) This also required adding support for collecting the Objective-C names of
all managed types registered with Objective-C to the linker. The
information is already available in the static registrar, but that would
require us to make sure the static registrar is executed before compiling
dylibs, which means those two tasks won't be able to run in parallel (also
there's no guarantee we'll even run the static registrar).
https://bugzilla.xamarin.com/show_bug.cgi?id=51548
So that there can be multiple caches in the same process (which we'll have
once mtouch can compile extensions and the container app in the same process).
* [mtouch] Remove most static state and put it on an instance.
Remove most static state, and put it on an instance (of Application) instead.
Soon we'll build multiple apps (app extensions) in the same process, and we
need to make sure we're not inadvertedly (and incorrectly) sharing state
between apps, so remove as much static state as possible to avoid any
problems.
* [mtouch] Rename GetIsUsingClang -> IsUsingClang.
* [mtouch] Bring back PreBuildDirectory
Some mtouch unit tests failed because of timestamp checks. It's not clear
it's always a win (it's not in my original test case) not to copy (to
target) as it means we have to copy earlier (PreBuild + Build).
More investigation needed, there's probably a better way to achieve both.
In the mean time this should fix the failing tests cases.
* Fix up / simplify logic and avoid duplicate calls to IsUpdate
Right now the logic exists in a few places, both in and outside the
linker. We recently began to use part of the linker pipeline in normal /
all builds so it's easier to share (and unify) the code now.
The real gain is to avoid copying assemblies, in particular large ones,
more than strictly needed while building.
E.g. a build including a very large 1.3GB assembly, with several
native libraries embedded, save a lot of time avoiding the rewrites
mtouch (before)
Total time: 64202 ms
mtouch (after)
Total time: 34840 ms
* Add XM support for RemoveUserResourcesSubStep
* Tests supplied by @chamons
Run the partial static registrar separately for 32-bit and 64-bit, since this
is required with the upcoming changes to embed metadata tokens inside the
generated output, because the metadata tokens are different between the 32-bit
and 64-bit versions of Xamarin.iOS.dll.
Also make sure to properly resolve the 32-bit and 64-bit assemblies correctly
(by setting the ArchDirectory on the assembly resolver), so that we don't pick
up the reference assembly (which does not have the right metadata tokens).
Additionally stop running the partial static registrar for MonoTouch.Dialog-1,
since with the upcoming changes to use metadata tokens in the generated
output, we won't support registering anything more than once. This shouldn't
make much of an impact, because MonoTouch.Dialog-1 is fairly small, and
doesn't take long to register in the dynamic registrar. For device builds (or
when the static registrar is selected) this has no effect, since in that case
we're registering everythinga anyway.
Link the executable with LinkWith attributes' libraries in the simulator when
doing incremental builds, since we don't create dylibs there.
Fixes several mtouch test failures:
1) Test Failure : Xamarin.MTouch.FastDev_NoFastSim_LinkAll(Unified)
2) Test Failure : Xamarin.MTouch.FastDev_NoFastSim_LinkAll(TVOS)
3) Test Failure : Xamarin.MTouch.FastDev_NoFastSim_LinkSDK(Unified)
4) Test Failure : Xamarin.MTouch.FastDev_NoFastSim_LinkSDK(TVOS)
5) Test Failure : Xamarin.MTouch.FastDev_NoFastSim_NoLink(Unified)
6) Test Failure : Xamarin.MTouch.FastDev_NoFastSim_NoLink(TVOS)
7) Test Failure : Xamarin.MTouch.FastDev_Sim(Unified)
8) Test Failure : Xamarin.MTouch.FastDev_Sim(TVOS)
Update mdb files even if the corresponding assembly didn't change, because the
mdb can change even if the assembly didn't (if whitespace was modified in the
source code, causing code lines to move).
https://bugzilla.xamarin.com/show_bug.cgi?id=39535
IIRC this used to be needed with a (rather old) version of Cecil.
The current code does nothing as the Load will only hit the cache
and not other properties are changed (compared to the old commented
code)
Native libraries are already linked into the dylib for the binding assembly,
which means that if we also link it into the main executable, the native code
ends up twice in the app (which is bad for many reasons).
https://bugzilla.xamarin.com/show_bug.cgi?id=42473
Fix NullReferenceException in PInvoke wrapper generation when incremental
builds are enabled and the linker didn't run because cached results were
found.
https://bugzilla.xamarin.com/show_bug.cgi?id=44763
* [tests] Remove Classic SDK tests.
* Remove XI/Classic support.
This also means we can remove support for the legacy registrars.
* [monotouch-test] Remove legacy registrar tests.
* [tests/mtouch] Remove Classic tests (and legacy registrar logic).
* [tests/scripted] Fix tests to reference Xamarin.iOS.dll.
Rolf Bjarne Kvinge
Sebastien Pouliot