This PR replaces `ffi.md` with links to the corresponding sections of
the manual, so we don't have to keep two documents up to date.
A corresponding reference manual PR re-synchronizes them:
https://github.com/leanprover/reference-manual/pull/714
This PR prevents symbol clashes between (non-`@[export]`) definitions
from different Lean packages.
Previously, if two modules define a function with the same name and were
transitively imported (even privately) by some downstream module,
linking would fail due to a symbol clash. Similarly, if a user defined a
symbol with the same name as one in the `Lean` library, Lean would use
the core symbol even if one did not import `Lean`.
This is solved by changing Lean's name mangling algorithm to include an
optional package identifier. This identifier is provided by Lake via
`--setup` when building a module. This information is weaved through the
elaborator, interpreter, and compiler via a persistent environment
extension that associates modules with their package identifier.
With a package identifier, standard symbols have the form
`lp_<pkg-id>_<mangled-def>`. Without one, the old scheme is used (i.e.,
`l_<mangled-def>`). Module initializers are also prefixed with package
identifier (if any). For example, the initializer for a module `Foo` in
a package `test` is now `initialize_test_Foo` (instead of
`initialize_Foo`). Lake's default for native library names has also been
adjusted accordingly, so that libraries can still, by default, be used
as plugins. Thus, the default library name of the `lean_lib Foo` in
`package test` will now be `libtest_Foo`.
When using Lake to build the Lean core (i.e., `bootstrap = true`), no
package identifier will be used. Thus, definitions in user packages can
never have symbol clashes with core.
Closes#222.
This PR implements zero cost `BaseIO` by erasing the `IO.RealWorld`
parameter from argument lists and structures. This is a **major breaking
change for FFI**.
Concretely:
- `BaseIO` is defined in terms of `ST IO.RealWorld`
- `EIO` (and thus `IO`) is defined in terms of `EST IO.RealWorld`
- The opaque `Void` type is introduced and the trivial structure
optimization updated to account for it. Furthermore, arguments of type
`Void s` are removed from the argument lists of the C functions.
- `ST` is redefined as `Void s -> ST.Out s a` where `ST.Out` is a pair
of `Void s` and `a`
This together has the following major effects on our generated code:
- Functions that return `BaseIO`/`ST`/`EIO`/`IO`/`EST` now do not take
the dummy world parameter anymore. To account for this FFI code needs to
delete the dummy world parameter from the argument lists.
- Functions that return `BaseIO`/`ST` now return their wrapped value
directly. In particular `BaseIO UInt32` now returns a `uint32_t` instead
of a `lean_object*`. To account for this FFI code might have to change
the return type and does not need to call `lean_io_result_mk_ok` anymore
but can instead just `return` values right away (same with extracting
values from `BaseIO` computations.
- Functions that return `EIO`/`IO`/`EST` now only return the equivalent
of an `Except` node which reduces the allocation size. The
`lean_io_result_mk_ok`/`lean_io_result_mk_error` functions were updated
to account for this already so no change is required.
Besides improving performance by dropping allocation (sizes) we can now
also do fun new things such as:
```lean
@[extern "malloc"]
opaque malloc (size : USize) : BaseIO USize
```
This PR adds a function called `lean_setup_libuv` that initializes
required LIBUV components. It needs to be outside of
`lean_initialize_runtime_module` because it requires `argv` and `argc`
to work correctly.
---------
Co-authored-by: Markus Himmel <markus@lean-fro.org>
Co-authored-by: Eric Wieser <wieser.eric@gmail.com>
The layout algorithm, while somewhat finicky, is (unfortunately)
necessary for C code to interface with lean structures. This adds a
(AFAIK) complete description of the layout algorithm, including a worked
example large enough to make it possible to reconstruct the whole
decision diagram.
---------
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
This PR adds links to some folder references in the docs, making them
easier to navigate.
Please advise if these need to be made to be full URIs rather than
relative paths in order to work correctly with the doc generation
tooling that is in place.
The current link goes to doc/dev#init, where there is nothing
about initialization. This PR fixes the link so that it points
to the initialization section lower down on the ffi page.
