For reasons unknown, if you give MSVC:
// Foo.h
struct Foo
{
...
};
extern const Foo gFoo;
// Foo.cpp, which necessarily includes Foo.h.
extern constexpr Foo gFoo = {
};
MSVC will create a static initializer for gFoo and place it in the
read/write data section, rather than the read-only data section.
Removing the `extern const` declaration seems to be enough to make this
problem go away. We need to adjust the declaration of other variables
to compensate for the non-visibility of gFoo in the header file.
Going through XPConnect for JS-to-JS access in the blocklist service adds no
benefit, but does add a lot of overhead and maintenance burden.
MozReview-Commit-ID: Lf1mDK0b0B0
--HG--
extra : rebase_source : 410ed3fcf999d7c7775ef4926c89f67d9e342da8
Otherwise, one can do thinkos like:
MakeScopeExit(...);
and the scope exiting function will execute much earlier than the
intended:
auto guard = MakeScopeExit(...);
This patch goes through the XPConnect conversion methods, and adds cases for
T_DOMOBJECT which call the Wrap, Unwrap, and Cleanup methods from the
nsXPTDOMObjectInfo objects created in the last part.
For consistency with normal interface pointers, and because it wasn't too
complex, I also added support for including T_DOMOBJECTs in XPCOM arrays.
Unlike the other lists in xptinfo, this list contains relocations. Each
DOMObject has 3 functions generated for it, `Wrap`, `Unwrap` and `Cleanup`,
which perform the necessary actions. These are stored as function pointers.
Wrap gets the DOMObject wrapper using the DOM binding code, Unwrap gets the
underlying C++ object, and addrefs it (as XPCOM methods return native types
via getter_AddRefs), and Cleanup releases a reference to the underlying
C++ object, for when the unwrapped object is used as a temporary during a call.
To generate the code, we need to have the declaration of the native C++ type
in scope, so we also emit #include-s for the headerFiles.
They are parsed into a WebIDL object, and lowered into C++, Rust, and XPT.
For C++ code, we generate a correctly namespaced forward declaration. In Rust,
the types are exposed as `*const c_void`, as we don't have WebIDL type
information there.
The XPT code generator needs to know the header filename in order to perform
correct codegen, so we also get that information.
Due to the decision to keep the old API on nsXPTInterfaceInfo in part 4, this is
a fairly straightforward patch.
1. I had to change a couple of consumers of `IsRetval()` due to the movement of
that flag.
2. I changed all code which held a nsIInterfaceInfo to hold an `const
nsXPTInterfaceInfo*` instead.
3. I changed code which used the nsIInterfaceInfoManager to instead call the
static methods on nsXPTInterfaceInfo.
This patch contains the meat of the changes here. The following summarize the changes:
1. xptinfo.h is rewritten to expose the new interface for reading the XPT data,
The nsXPTInterfaceInfo object exposes methods with the same signatures as
the methods on nsIInterfaceInfo, to make converting code which used
nsIInterfaceInfo as easy as possible, even when those methods don't have
signatures which make a ton of sense anymore. There are also a few methods
which are unnecessary (they return `true` or similar), which should be
removed over time.
Members of the data structures are made private in order to prevent reading
them directly. Code should instead call the getter methods. This should make
it easier to change their memory representation in the future. Constructing
these structs is made possible by making the structs `friend class` with the
XPTConstruct class, which is implemented by the code generator, and is able
to access the private fields.
In addition, rather than using integers with flag constants, I opted for
using C++ bitfields to store individual flags, as I found it made it easier
to both write the code generator, and reason about the layouts of the types.
I was able to shave a byte off of each nsXPTParamInfo (4 bytes -> 3 bytes)
by shoving the flags into spare bits in the nsXPTType. Unfortunately there
was not enough room for the retval flag. Fortunately, we already depend in
our code on the retval parameter being the last parameter, so I worked
around this by removing the retval flag and instead having a `hasretval`
flag on the method itself.
2. An xptinfo.cpp file is added for out-of-line definitions of more complex
methods, and the internal implementation details of the perfect hash.
Notable is the handling of xptshim interfaces. As the type is uniform, a
flag is checked when trying to read constant information, and a different
table with pointers into webidl data structures is checked when the type is
determined to be a shim.
Ideally we could remove this once we remove the remaining consumers of the
existing shim interfaces.
3. A python code generator which takes in the json XPT files generated in the
previous part, and emits a xptdata.cpp file with the data structures. I did
my best to heavily comment the code.
This code uses the friend class trick to construct the private fields of the
structs, and avoid a dependency on the ordering of fields in xptinfo.h.
The sInterfaces array's order is determined by a generated perfect hash
which is also written into the binary. This should allow for fast lookups by
IID or name of interfaces in memory. The hash function used for the perfect
hash is a simple FNV hash, as they're pretty fast.
For perfect hashing of names, another table is created which contains
indexes into the sInterfaces table. Lookup by name is less common, and this
form of lookup should still be very fast.
4. The necessary Makefiles are updated to use the new code generator, and
generate the file correctly.
This patch adds a python script based on the old typelib.py script which takes
in a parsed XPIDL file, and generates a json-based XPT file to use as a build
intermediate. I did my best to keep the generated format simple.
In the previous patch, one of the files which was deleted is ShimInterfaceInfo.
This is an implementor of nsIInterfaceInfo which exists for legacy reasons, in
order to allow Components.interfaces.nsIDOM* to have the correct constants and
IIDs associated with them.
As that file was deleted, this information now has to be stored in the typelib.
To do this, the information is moved to the xptshim and xptshimfile attributes
on the relevant xpcom interfaces.
xptshim(...) means that this xpcom interface is a shim for the WebIDL interface
with the specified name.
xptshimfile(...) is for use when the webidl interface is declared in another
interface's .webidl file, (in our case, MessageManager.webidl). It contains the
name of the parent binding, such that we can #include the correct file in our
generated code.
This patch does not add the code which uses these changes, only the parsing
logic.
Unfortunately, I wasn't able to figure out a way to make firefox build & run in
the intermediate stages of these commits. Because of this, I am going to just
delete most of the code which I am deleting in the first patch, as I figure that
those are somewhat uninteresting changes, and then make the other changes in the
following patches.
In total, the following things are deleted:
1. All of xpcom/typelib, except for `xpt/tools` - this directory is being
subsumed entirely into xpcom/reflect/xptinfo.
2. Most of the code in xpcom/reflect/xptinfo, it is being rewritten to avoid
allocating and contain all of the necessary data structures.
3. idl-parser's typelib.py XPT generator, as it will be replaced.
4. Most includes of files which have been deleted.
NOTE: xpcom/typelib/xpt/tools/xpt.py was not removed, as it is used by bundling
code & bundling tests, which we don't want to remove yet.
...on Windows, at least. Apparently if you have environment variables
set that contain multibyte characters, and ask for them with getenv, you
get garbage. Or perhaps you get something sensible, but then passing it
to fopen produces garbage. Either way, the most reasonable way to
handle this is to use the Windows wide-character APIs all over.
We need to detect the flatpak environment on multiple places.
Making the ShouldUseFlatpakPortal() exported to the nsIGIOService
allows us to reuse it.
MozReview-Commit-ID: 41NJyR3fqZQ
--HG--
extra : rebase_source : 4ebb9ba2ff98d3c6d924223485e028929eb801ed
c_char isn't i8 on some platforms such as Android/arm, so we should use c_char
instead.
MozReview-Commit-ID: 486BCGvYAE0
--HG--
extra : rebase_source : 0ee9d510de5cd8ab20daa1709c7425ca95dc8793
Kris Maglione
Nathan Froyd
Gabriele Svelto
Aaron Klotz
Jorg K
Nika Layzell
Dorel Luca
Peter Van der Beken
Matt Woodrow
Csoregi Natalia
Nicholas Nethercote
Jan Horak
Makoto Kato
Margareta Eliza Balazs
Gijs Kruitbosch
Jeff Walden
Noemi Erli
Jan de Mooij
Andreea Pavel
Tom Bannister
Sebastian Hengst
Eric Rahm
Sylvestre Ledru
Karl Tomlinson
Honza Bambas
Andrea Marchesini
Tristan Bourvon
Jim Blandy
arthur.iakab