Add savi-lang-plumber binary, capable of printing cache files as YAML.

This tool will be used to inspect and test the intermediate data
structures in between compiler micro-passes, as seen in the
compact binary files emitted to the savi-cache directory.

Author: jemc

Makefile

@@ -129,11 +129,14 @@ gen.capnp.check: gen.capnp
 # Update deps for the Self-hosted Savi compiler subprograms.
 self-hosted.deps: PHONY SAVI
 	echo && $(SAVI) deps update --cd self-hosted --for savi-lang-broker
+	echo && $(SAVI) deps update --cd self-hosted --for savi-lang-plumber
 	echo && $(SAVI) deps update --cd self-hosted --for savi-lang-parse
 
 # Create the self-hosted Savi compiler subprograms.
 self-hosted/bin/savi-lang-broker: $(SAVI) $(shell find self-hosted/src/savi-lang-broker self-hosted/src/SaviWorker self-hosted/src/SaviProto -name '*.savi')
 	echo && $(SAVI) build --cd self-hosted savi-lang-broker --print-perf --backtrace
+self-hosted/bin/savi-lang-plumber: $(SAVI) $(shell find self-hosted/src/savi-lang-plumber self-hosted/src/SaviWorker self-hosted/src/SaviProto -name '*.savi')
+	echo && $(SAVI) build --cd self-hosted savi-lang-plumber --print-perf --backtrace
 self-hosted/bin/savi-lang-parse: $(SAVI) $(shell find self-hosted/src/savi-lang-parse self-hosted/src/SaviWorker self-hosted/src/SaviProto -name '*.savi')
 	echo && $(SAVI) build --cd self-hosted savi-lang-parse --print-perf --backtrace
 

self-hosted/manifest.savi

@@ -26,6 +26,9 @@
     :from "github:savi-lang/Logger"
     :depends on Time
 
+  :dependency ByteStream v0
+    :from "github:savi-lang/ByteStream"
+
   :dependency IO v0
     :from "github:savi-lang/IO"
     :depends on ByteStream
@@ -47,9 +50,6 @@
   :transitive dependency Time v0
     :from "github:savi-lang/Time"
 
-  :transitive dependency ByteStream v0
-    :from "github:savi-lang/ByteStream"
-
   :transitive dependency OSError v0
     :from "github:savi-lang/OSError"
 
@@ -68,6 +68,11 @@
   :sources "src/savi-lang-broker/*.savi"
   :copies SaviWorker
 
+:manifest bin "savi-lang-plumber"
+  :sources "src/savi-lang-plumber/*.savi"
+  :sources "src/SaviProto/SaviProto.AST.capnp.savi"
+  :copies SaviWorker
+
 :manifest bin "savi-lang-parse"
   :sources "src/savi-lang-parse/*.savi"
   :sources "src/SaviProto/SaviProto.AST.capnp.savi"

self-hosted/src/savi-lang-parse/Main.TestMode.savi

@@ -9,11 +9,24 @@
 
   :fun ref io_react(action IO.Action)
     case action == (
-    | IO.Action.Closed |
-      @handle_code(@io.read_stream.extract_all.as_string)
+    | IO.Action.Read |
+      try (
+        if @_reader.read!(@io.read_stream) @_handle_segments
+      |
+        @env.err.print("Maximum total capnpc segments size exceeded")
+      )
     )
     @
 
+  :fun ref _handle_segments
+    try (
+      message = CapnProto.Message(CapnProto.Meta.CodeGeneratorRequest)
+        .from_segments!(@_reader.take_segments)
+      @_generate(message.root)
+    |
+      @env.err.print("Failed to parse the root of the capnpc data")
+    )
+
   :fun handle_code(code String)
     nanos = Time.Measure.nanoseconds -> (
       printer = PEG.Parser(_Token, String).new(_Grammar.new, _TreePrinter.new)

self-hosted/src/savi-lang-plumber/Main.savi

@@ -0,0 +1,80 @@
+:class _CLI
+  :var to_yaml: ""
+
+  :is CLI.Option.Data
+  :fun non define_cli_options(defs CLI.Option.Defs) None
+    defs.string("to-yaml")
+
+  :fun ref trace_data_mutable(trace TraceData.Mutator) None
+    trace.object(identity_digest_of @) -> (key |
+      case key == (
+      | "to-yaml" | trace.replace_string(@to_yaml) -> (v | @to_yaml = v)
+      )
+    )
+
+:actor Main
+  :let env Env
+  :new (@env)
+    cli = try (
+      CLI.Parser(_CLI).parse!(_CLI.new, @env.args)
+    | error |
+      @env.err.print(error.message)
+      @env.exit_code = 1
+      return
+    )
+    log = _Log.new(@env.err, Logger.Level.Debug)
+
+    case (
+    | cli.options.to_yaml != "" |
+      path = File.Path.ReadOnly.new(@env.root, cli.options.to_yaml)
+      ToYAML.new(log, path, @env.out)
+    )
+
+:actor ToYAML
+  :let log _Log
+  :let path File.Path.Readable
+  :let out Env.OutStream
+  :new (@log, @path, @out)
+    File.Loader.new.load_from_file(@path, @)
+
+  :is File.Loader.ResultActor
+  :be result_of_load_from_file(
+    path File.Path.Readable
+    result File.Result
+    content Bytes'iso
+  )
+    if (result != File.Result.Success) (
+      @log.error -> ("Failed to load file \(path.string): \(result)")
+      return
+    )
+
+    stream = ByteStream.Pair.new
+    stream.write << --content
+    try stream.write.flush!
+
+    reader = CapnProto.Segments.Reader.new
+    try (
+      res = reader.read!(stream.read)
+      if !res (
+        @log.error -> ("Incomplete data at \(path.string)")
+        return
+      )
+    |
+      @log.error -> ("Failed to read the data at \(path.string)")
+      return
+    )
+
+    try (
+      case @path.ext_name == (
+      | "savi-parse" |
+        message = CapnProto.Message(SaviProto.AST.Document)
+          .from_segments!(reader.take_segments)
+        @out.print(Inspect.TraceData.Printer.Deterministic.print(message.root))
+      |
+        @log.error -> ("Unsupported file extension \(path.ext_name)")
+        return
+      )
+    |
+      @log.error -> ("Error reading segments from \(path.string)")
+    )
+