From ddef7081786ed746de47f6c50c5a8da6f5d68905 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Magiera?= <magik6k@gmail.com>
Date: Mon, 11 Oct 2021 22:25:41 +0200
Subject: [PATCH] Basic inline codegen

---
 build/params_shared_vals.go |  8 ++++
 gen/inline-gen/main.go      | 95 +++++++++++++++++++++++++++++++++++++
 gen/inlinegen-data.json     |  7 +++
 3 files changed, 110 insertions(+)
 create mode 100644 gen/inline-gen/main.go
 create mode 100644 gen/inlinegen-data.json

diff --git a/build/params_shared_vals.go b/build/params_shared_vals.go
index 22d1c30e3..f15cbc35c 100644
--- a/build/params_shared_vals.go
+++ b/build/params_shared_vals.go
@@ -28,8 +28,16 @@ const UnixfsLinksPerLevel = 1024
 const AllowableClockDriftSecs = uint64(1)
 
 // TODO: This is still terrible...What's the impact of updating this before mainnet actually upgrades
+/* inline-gen template
+
+const NewestNetworkVersion = network.Version{{.latestNetworkVersion}}
+
+inline-gen start */
+
 const NewestNetworkVersion = network.Version14
 
+//inline-gen end
+
 // Epochs
 const ForkLengthThreshold = Finality
 
diff --git a/gen/inline-gen/main.go b/gen/inline-gen/main.go
new file mode 100644
index 000000000..4e669099f
--- /dev/null
+++ b/gen/inline-gen/main.go
@@ -0,0 +1,95 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/fs"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"text/template"
+)
+
+const (
+	stateGlobal = iota
+	stateTemplate
+	stateGen
+)
+
+func main() {
+	db, err := ioutil.ReadFile(os.Args[2])
+	if err != nil {
+		panic(err)
+	}
+	var data map[string]interface{}
+	if err := json.Unmarshal(db, &data); err != nil {
+		panic(err)
+	}
+
+	err = filepath.WalkDir(os.Args[1], func(path string, d fs.DirEntry, err error) error {
+		if d.IsDir() {
+			return nil
+		}
+		if filepath.Ext(path) != ".go" {
+			return nil
+		}
+		fb, err := ioutil.ReadFile(path)
+		if err != nil {
+			return err
+		}
+
+		lines := strings.Split(string(fb), "\n")
+
+		outLines := make([]string, 0, len(lines))
+		var templateLines []string
+
+		state := stateGlobal
+
+		for i, line := range lines {
+			ln := i+1
+			switch state {
+			case stateGlobal:
+				outLines = append(outLines, line)
+				if line == `/* inline-gen template` {
+					state = stateTemplate
+					fmt.Printf("template section start %s:%d\n", path, ln)
+				}
+			case stateTemplate:
+				outLines = append(outLines, line) // output all template lines
+
+				if line == `inline-gen start */` {
+					state = stateGen
+					fmt.Printf("generated section start %s:%d\n", path, ln)
+					continue
+				}
+				templateLines = append(templateLines, line)
+			case stateGen:
+				if line != `//inline-gen end` {
+					continue
+				}
+				state = stateGlobal
+				fmt.Printf("inline gen:\n")
+				fmt.Println(strings.Join(templateLines, "\n"))
+
+				tpl, err := template.New("").Parse(strings.Join(templateLines, "\n"))
+				if err != nil {
+					fmt.Printf("%s:%d: parsing template: %s\n", path, ln, err)
+					os.Exit(1)
+				}
+				var b bytes.Buffer
+				err = tpl.Execute(&b, data)
+
+				outLines = append(outLines, strings.Split(b.String(), "\n")...)
+				fmt.Println("inline gen-ed:\n", b.String())
+
+				outLines = append(outLines, line)
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		panic(err)
+	}
+}
diff --git a/gen/inlinegen-data.json b/gen/inlinegen-data.json
new file mode 100644
index 000000000..1c8a4ecd8
--- /dev/null
+++ b/gen/inlinegen-data.json
@@ -0,0 +1,7 @@
+{
+  "actorVersions": [0, 2, 3, 4, 5, 6],
+  "latestActorsVersion":  6,
+
+  "networkVersions": [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14],
+  "latestNetworkVersion":  14
+}
\ No newline at end of file