9ff7d7ca44
Add copyright headers in a few files where they were missing. Trim trailing blank comment line where present, for consistency with other engine code. Use the standard libtxt copyright header in one file where it differed (extra (C) and comma compared to other files in libtxt). This also amends tools/const_finder/test/const_finder_test.dart to look for a const an additional four lines down to account for the copyright header added to the test fixture.
Frontend Server
Frontend server is simple wrapper around Dart Frontend. It is a Dart application that compiles Dart source into Dart Kernel binary (.dill-file). Documentation on Dart Kernel (semantic, binary format, etc) can be found here: https://github.com/dart-lang/sdk/wiki/Kernel-Documentation.
Frontend server runs in two modes:
- immediate mode, where Dart source file name is provided as command line argument;
- interactive mode, where communication is happening over stdin/stdout.
Interactive mode instructions
Compile/Recompile
compile <input.dart>
Compiles <input.dart> Dart source file with Dart Frontend. Replies with result response.
recompile <boundary-key>
<path/to/updated/file1.dart>
<path/to/updated/file2.dart>
...
<boundary-key>
Incrementally recompiles Dart program previously compiled in current session, taking into account
changes in the listed files. Replies with result response.
Relative paths should be relative to current working directory for the shell that launched Frontend Server.
Accept/Reject
accept
Accepts results of incremental compilation, so that on next recompilation request Dart Frontend will not include these recompiled files.
reject
Rejects results of incremental compilation, so that on next recompilation request Dart Frontend will include compilation results from previously rejected recompilation in addition to what it will recompile based on newly changed files. Small technical detail is that Dart Frontend will not recompile files from previously rejected recompilation attempts (unless they were changed since then), it will just include appropriate kernel binaries it kept around from those previously rejected compilation requests.
One use of accept and reject instructions is in the context of Dart VM hot-reload. Dart VM can
reject user-provided incremental change to what is currently running. It could happen for variety
of Dart VM internal reasons. For example, if incremental update changes some class to enum,
such update can not be hot-reloaded by VM at this point, will be rejected.
Quit
quit
Stops the server.
Response from the server
result <boundary-key>
<compiler output>
<boundary-key> [<output.dill>]
Response from the Dart Frontend compiler is bracketed by <boundary-key> tags. If the compiler
was able to produce a Dart Kernel file, the name of this file <output.dill> is provided too.
If the compiler encountered unrecoverable errors, there will be no output file name provided.