5bb9839887
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. |
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| .. | ||
| lib | ||
| .gitignore | ||
| clean.sh | ||
| main.c | ||
| Makefile | ||
| README.md | ||
| test.sh | ||
Reverse FFI
This a simple example of how a Lake library (lib/) can be used from a foreign language and build system (main.c and Makefile).