Executable compiler plugins are programs invoked by the host compiler
and communicate with the host with IPC via standard IO (stdin/stdout.)
Each message is serialized in JSON, prefixed with a header which is a
64bit little-endian integer indicating the size of the message.
* Basic/ExecuteWithPipe: External program invocation. Lik
llvm::sys::ExecuteNoWait() but establishing pipes to the child's
stdin/stdout
* Basic/Sandbox: Sandboxed execution helper. Create command line
arguments to be executed in sandbox environment (similar to SwiftPM's
pluging sandbox)
* AST/PluginRepository: ASTContext independent plugin manager
* ASTGen/PluginHost: Communication with the plugin. Messages are
serialized by ASTGen/LLVMJSON
rdar://101508815
Align the grammar of macro declarations with SE-0382, so that macro
definitions are parsed as an expression. External macro definitions
are referenced via a referenced to the macro `#externalMacro`. Define
that macro in the standard library, and recognize uses of it as the
definition of other macros to use externally-defined macros. For
example, this means that the "stringify" macro used in a lot of
examples is now defined as something like this:
@expression macro stringify<T>(_ value: T) -> (T, String) =
#externalMacro(module: "MyMacros", type: "StringifyMacro")
We still parse the old "A.B" syntax for two reasons. First, it's
helpful to anyone who has existing code using the prior syntax, so they
get a warning + Fix-It to rewrite to the new syntax. Second, we use it
to define builtin macros like `externalMacro` itself, which looks like this:
@expression
public macro externalMacro<T>(module: String, type: String) -> T =
Builtin.ExternalMacro
This uses the same virtual `Builtin` module as other library builtins,
and we can expand it to handle other builtin macro implementations
(such as #line) over time.
