Instead of building one Clang `ASTContext` per compilation, the
`--share-cpp-ast` flag causes us to build a single `ASTContext` and
share it across all contexts. One new abstraction is added: `CppDomain`
represents the Carbon-side view of a Clang AST that might be shared
across multiple `SemIR::File`s. This object owns the Clang instance and
the AST.
For now, we have no isolation between the C++ state exposed to different
Carbon compilations, and we have no multiplexing of generated LLVM IR
from C++ into different Carbon compilations, so the mode is not usable
yet. The plan is to keep it behind a flag until it's ready.
Assisted-by: Gemini via Antigravity
Refactors the link driver to automatically compile and cache the carbon
prelude for use in linking.
Implements a `carbon_library` rule for compiling the Core library
dependencies in the examples.
Support multi-file compilation, and in particular imports of files from
the prelude, in `carbon language_server`.
In order to properly interface with `CompileDriver`, also switch over to
building a proper VFS from the documents we're given.
Assisted-by: Gemini via Antigravity
This is the first draft of the implementation of
[p6333](https://docs.carbon-lang.dev/proposals/p6333.html).
The `build` subcommand shared logic with the `compile` and `link`
subcommands,
so I've moved some of the functionality in `compile` and `link` to
shared
`CompileDriver` and `LinkDriver` classes, respectively. This also
required exposing the
`CompileOptions` and `LinkOptions` subcommand structs for re-use.
There's still some work to do on the proposal, most notably the package
include automatic path resolution and import, and the refactors to
`carbon compile`.
Richard Smith
Lucile Rose Nihlen
Lucile Rose Nihlen