feat: Codegen plugins, powered by WASM

Makefile

@@ -1,4 +1,4 @@
-.PHONY: build build-endtoend test test-ci test-examples test-endtoend regen start psql mysqlsh
+.PHONY: build build-endtoend test test-ci test-examples test-endtoend regen start psql mysqlsh wasm
 
 build:
 	go build ./...

go.mod

@@ -4,6 +4,7 @@ go 1.17
 
 require (
 	github.com/antlr/antlr4/runtime/Go/antlr v0.0.0-20220209173558-ad29539cd2e9
+	github.com/bytecodealliance/wasmtime-go v0.35.0
 	github.com/davecgh/go-spew v1.1.1
 	github.com/go-sql-driver/mysql v1.6.0
 	github.com/google/go-cmp v0.5.7

go.sum

@@ -5,6 +5,10 @@ github.com/antlr/antlr4/runtime/Go/antlr v0.0.0-20220209173558-ad29539cd2e9 h1:z
 github.com/antlr/antlr4/runtime/Go/antlr v0.0.0-20220209173558-ad29539cd2e9/go.mod h1:F7bn7fEU90QkQ3tnmaTx3LTKLEDqnwWODIYppRQ5hnY=
 github.com/benbjohnson/clock v1.1.0 h1:Q92kusRqC1XV2MjkWETPvjJVqKetz1OzxZB7mHJLju8=
 github.com/benbjohnson/clock v1.1.0/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
+github.com/bytecodealliance/wasmtime-go v0.34.0 h1:PaWS0DUusaXaU3aNoSYjag6WmuxjyPYBHgkrC4EXips=
+github.com/bytecodealliance/wasmtime-go v0.34.0/go.mod h1:q320gUxqyI8yB+ZqRuaJOEnGkAnHh6WtJjMaT2CW4wI=
+github.com/bytecodealliance/wasmtime-go v0.35.0 h1:VZjaZ0XOY0qp9TQfh0CQj9zl/AbdeXePVTALy8V1sKs=
+github.com/bytecodealliance/wasmtime-go v0.35.0/go.mod h1:q320gUxqyI8yB+ZqRuaJOEnGkAnHh6WtJjMaT2CW4wI=
 github.com/cockroachdb/apd v1.1.0 h1:3LFP3629v+1aKXU5Q37mxmRxX/pIu1nijXydLShEq5I=
 github.com/cockroachdb/apd v1.1.0/go.mod h1:8Sl8LxpKi29FqWXR16WEFZRNSz3SoPzUzeMeY4+DwBQ=
 github.com/coreos/go-systemd v0.0.0-20190321100706-95778dfbb74e/go.mod h1:F5haX7vjVVG0kc13fIWeqUViNPyEJxv/OmvnBo0Yme4=

internal/cmd/generate.go

@@ -14,6 +14,7 @@ import (
 	"github.com/kyleconroy/sqlc/internal/codegen/golang"
 	"github.com/kyleconroy/sqlc/internal/codegen/kotlin"
 	"github.com/kyleconroy/sqlc/internal/codegen/python"
+	"github.com/kyleconroy/sqlc/internal/codegen/wasm"
 	"github.com/kyleconroy/sqlc/internal/compiler"
 	"github.com/kyleconroy/sqlc/internal/config"
 	"github.com/kyleconroy/sqlc/internal/debug"
@@ -138,6 +139,12 @@ func Generate(ctx context.Context, e Env, dir, filename string, stderr io.Writer
 				Gen: config.SQLGen{Python: sql.Gen.Python},
 			})
 		}
+		if sql.Gen.WASM != nil {
+			pairs = append(pairs, outPair{
+				SQL: sql,
+				Gen: config.SQLGen{WASM: sql.Gen.WASM},
+			})
+		}
 	}
 
 	for _, sql := range pairs {
@@ -196,6 +203,9 @@ func Generate(ctx context.Context, e Env, dir, filename string, stderr io.Writer
 		var genfunc func(req *plugin.CodeGenRequest) (*plugin.CodeGenResponse, error)
 		var out string
 		switch {
+		case sql.Gen.WASM != nil:
+			out = combo.WASM.Out
+			genfunc = wasm.Generate
 		case sql.Gen.Go != nil:
 			out = combo.Go.Out
 			genfunc = golang.Generate

internal/cmd/shim.go

@@ -59,6 +59,7 @@ func pluginSettings(cs config.CombinedSettings) *plugin.Settings {
 		Python:    pluginPythonCode(cs.Python),
 		Kotlin:    pluginKotlinCode(cs.Kotlin),
 		Go:        pluginGoCode(cs.Go),
+		Wasm:      pluginWASM(cs.WASM),
 	}
 }
 
@@ -96,6 +97,13 @@ func pluginGoCode(s config.SQLGo) *plugin.GoCode {
 	}
 }
 
+func pluginWASM(s config.SQLWASM) *plugin.WASM {
+	return &plugin.WASM{
+		Out:  s.Out,
+		Path: s.Path,
+	}
+}
+
 func pluginGoType(o config.Override) *plugin.ParsedGoType {
 	// Note that there is a slight mismatch between this and the
 	// proto api. The GoType on the override is the unparsed type,

internal/codegen/wasm/nowasm.go

@@ -0,0 +1,13 @@
+//go:build !wasmtime
+
+package wasm
+
+import (
+	"fmt"
+
+	"github.com/kyleconroy/sqlc/internal/plugin"
+)
+
+func Generate(req *plugin.CodeGenRequest) (*plugin.CodeGenResponse, error) {
+	return nil, fmt.Errorf("sqlc built without wasmtime support")
+}

internal/codegen/wasm/wasm.go

@@ -0,0 +1,118 @@
+//go:build wasmtime
+
+package wasm
+
+import (
+	"context"
+	_ "embed"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"runtime/trace"
+
+	wasmtime "github.com/bytecodealliance/wasmtime-go"
+
+	"github.com/kyleconroy/sqlc/internal/plugin"
+)
+
+func Generate(req *plugin.CodeGenRequest) (*plugin.CodeGenResponse, error) {
+	ctx := context.Background() // XXX
+
+	engine := wasmtime.NewEngine()
+	// module, err = wasmtime.NewModuleDeserialize(engine, pythonModule)
+	// if err != nil {
+	// 	panic(err)
+	// }
+
+	// out, err := module.Serialize()
+	// if err != nil {
+	// 	panic(err)
+	// }
+
+	// err = os.WriteFile("sqlc-codegen-python.module", out, 0644)
+	// if err != nil {
+	// 	panic(err)
+	// }
+
+	linker := wasmtime.NewLinker(engine)
+	if err := linker.DefineWasi(); err != nil {
+		return nil, err
+	}
+
+	stdinBlob, err := req.MarshalVT()
+	if err != nil {
+		return nil, err
+	}
+
+	dir, err := ioutil.TempDir("", "out")
+	if err != nil {
+		return nil, fmt.Errorf("temp dir: %w", err)
+	}
+
+	defer os.RemoveAll(dir)
+	stdinPath := filepath.Join(dir, "stdin")
+	stderrPath := filepath.Join(dir, "stderr")
+	stdoutPath := filepath.Join(dir, "stdout")
+
+	if err := os.WriteFile(stdinPath, stdinBlob, 0755); err != nil {
+		return nil, fmt.Errorf("write file: %w", err)
+	}
+
+	// Configure WASI imports to write stdout into a file.
+	wasiConfig := wasmtime.NewWasiConfig()
+	wasiConfig.SetStdinFile(stdinPath)
+	wasiConfig.SetStdoutFile(stdoutPath)
+	wasiConfig.SetStderrFile(stderrPath)
+
+	store := wasmtime.NewStore(engine)
+	store.SetWasi(wasiConfig)
+
+	// Set the version to the same as in the WAT.
+	// wasi, err := wasmtime.NewWasiInstance(store, wasiConfig, "wasi_snapshot_preview1")
+	// if err != nil {
+	// 	return fmt.Errorf("new wasi instances: %w", err)
+	// }
+
+	// Create our module
+	//
+	// Compiling modules requires WebAssembly binary input, but the wasmtime
+	// package also supports converting the WebAssembly text format to the
+	// binary format.
+	wasm, err := os.ReadFile(req.Settings.Wasm.Path)
+	if err != nil {
+		return nil, fmt.Errorf("read file: %w", err)
+	}
+
+	moduRegion := trace.StartRegion(ctx, "wasmtime.NewModule")
+	module, err := wasmtime.NewModule(store.Engine, wasm)
+	moduRegion.End()
+	if err != nil {
+		return nil, fmt.Errorf("define wasi: %w", err)
+	}
+
+	linkRegion := trace.StartRegion(ctx, "linker.Instantiate")
+	instance, err := linker.Instantiate(store, module)
+	linkRegion.End()
+	if err != nil {
+		return nil, fmt.Errorf("define wasi: %w", err)
+	}
+
+	// Run the function
+
+	callRegion := trace.StartRegion(ctx, "call _start")
+	nom := instance.GetExport(store, "_start").Func()
+	_, err = nom.Call(store)
+	callRegion.End()
+	if err != nil {
+		return nil, fmt.Errorf("call: %w", err)
+	}
+
+	// Print WASM stdout
+	stdoutBlob, err := os.ReadFile(stdoutPath)
+	if err != nil {
+		return nil, fmt.Errorf("read file: %w", err)
+	}
+	var resp plugin.CodeGenResponse
+	return &resp, resp.UnmarshalVT(stdoutBlob)
+}

internal/config/config.go

@@ -114,6 +114,7 @@ type SQLGen struct {
 	Go     *SQLGo     `json:"go,omitempty" yaml:"go"`
 	Kotlin *SQLKotlin `json:"kotlin,omitempty" yaml:"kotlin"`
 	Python *SQLPython `json:"python,omitempty" yaml:"python"`
+	WASM   *SQLWASM   `json:"wasm,omitempty" yaml:"wasm"`
 }
 
 type SQLGo struct {
@@ -155,6 +156,11 @@ type SQLPython struct {
 	EmitPydanticModels  bool       `json:"emit_pydantic_models,omitempty" yaml:"emit_pydantic_models"`
 }
 
+type SQLWASM struct {
+	Out  string `json:"out" yaml:"out"`
+	Path string `json:"path" yaml:"path"`
+}
+
 type Override struct {
 	// name of the golang type to use, e.g. `github.com/segmentio/ksuid.KSUID`
 	GoType GoType `json:"go_type" yaml:"go_type"`
@@ -352,6 +358,7 @@ type CombinedSettings struct {
 	Go        SQLGo
 	Kotlin    SQLKotlin
 	Python    SQLPython
+	WASM      SQLWASM
 	Rename    map[string]string
 	Overrides []Override
 }
@@ -379,5 +386,8 @@ func Combine(conf Config, pkg SQL) CombinedSettings {
 		cs.Python = *pkg.Gen.Python
 		cs.Overrides = append(cs.Overrides, pkg.Gen.Python.Overrides...)
 	}
+	if pkg.Gen.WASM != nil {
+		cs.WASM = *pkg.Gen.WASM
+	}
 	return cs
 }