all: drop support for Go 1.18

Go 1.18 has been unsupported for quite a while now (the oldest supported
version is Go 1.21). But more importantly, the golang.org/x/tools module
now requires Go 1.19 or later. So we'll drop this older version.

.circleci/config.yml

@@ -98,9 +98,9 @@ commands:
             - /go/pkg/mod
 
 jobs:
-  test-llvm15-go118:
+  test-llvm15-go119:
     docker:
-      - image: golang:1.18-bullseye
+      - image: golang:1.19-bullseye
     steps:
       - test-linux:
           llvm: "15"
@@ -118,6 +118,6 @@ workflows:
     jobs:
       # This tests our lowest supported versions of Go and LLVM, to make sure at
       # least the smoke tests still pass.
-      - test-llvm15-go118
+      - test-llvm15-go119
       # This tests LLVM 18 support when linking against system libraries.
       - test-llvm18-go122

BUILDING.md

@@ -18,7 +18,7 @@ tarball. If you want to help with development of TinyGo itself, you should follo
 LLVM, Clang and LLD are quite light on dependencies, requiring only standard
 build tools to be built. Go is of course necessary to build TinyGo itself.
 
-  * Go (1.18+)
+  * Go (1.19+)
   * GNU Make
   * Standard build tools (gcc/clang)
   * git

builder/config.go

@@ -27,10 +27,10 @@ func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
 	if err != nil {
 		return nil, err
 	}
-	if major != 1 || minor < 18 || minor > 22 {
+	if major != 1 || minor < 19 || minor > 22 {
 		// Note: when this gets updated, also update the Go compatibility matrix:
 		// https://github.com/tinygo-org/tinygo-site/blob/dev/content/docs/reference/go-compat-matrix.md
-		return nil, fmt.Errorf("requires go version 1.18 through 1.22, got go%d.%d", major, minor)
+		return nil, fmt.Errorf("requires go version 1.19 through 1.22, got go%d.%d", major, minor)
 	}
 
 	return &compileopts.Config{

compiler/interface.go

@@ -514,8 +514,7 @@ var basicTypeNames = [...]string{
 func getTypeCodeName(t types.Type) (string, bool) {
 	switch t := t.(type) {
 	case *types.Named:
-		// Note: check for `t.Obj().Pkg() != nil` for Go 1.18 only.
-		if t.Obj().Pkg() != nil && t.Obj().Parent() != t.Obj().Pkg().Scope() {
+		if t.Obj().Parent() != t.Obj().Pkg().Scope() {
 			return "named:" + t.String() + "$local", true
 		}
 		return "named:" + t.String(), false

go.mod

@@ -1,6 +1,6 @@
 module github.com/tinygo-org/tinygo
 
-go 1.18
+go 1.19
 
 require (
 	github.com/aykevl/go-wasm v0.0.2-0.20240312204833-50275154210c