all: drop support for Go 1.16 and Go 1.17

.circleci/config.yml

@@ -112,9 +112,9 @@ commands:
             - /go/pkg/mod
 
 jobs:
-  test-llvm14-go116:
+  test-llvm14-go118:
     docker:
-      - image: golang:1.16-buster
+      - image: golang:1.18-buster
     steps:
       - test-linux:
           llvm: "14"
@@ -131,7 +131,7 @@ workflows:
     jobs:
       # This tests our lowest supported versions of Go and LLVM, to make sure at
       # least the smoke tests still pass.
-      - test-llvm14-go116
+      - test-llvm14-go118
       # This tests a beta version of Go. It should be removed once regular
       # release builds are built using this version.
       - test-llvm14-go119

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 (1.16+)
+  * Go (1.18+)
   * Standard build tools (gcc/clang)
   * git
   * CMake

builder/config.go

@@ -33,8 +33,8 @@ func NewConfig(options *compileopts.Options) (*compileopts.Config, error) {
 	if err != nil {
 		return nil, fmt.Errorf("could not read version from GOROOT (%v): %v", goroot, err)
 	}
-	if major != 1 || minor < 16 || minor > 19 {
-		return nil, fmt.Errorf("requires go version 1.16 through 1.19, got go%d.%d", major, minor)
+	if major != 1 || minor < 18 || minor > 19 {
+		return nil, fmt.Errorf("requires go version 1.18 through 1.19, got go%d.%d", major, minor)
 	}
 
 	clangHeaderPath := getClangHeaderPath(goenv.Get("TINYGOROOT"))

cgo/cgo_test.go

@@ -5,7 +5,6 @@ import (
 	"flag"
 	"fmt"
 	"go/ast"
-	"go/build"
 	"go/format"
 	"go/parser"
 	"go/token"
@@ -40,20 +39,6 @@ func TestCGo(t *testing.T) {
 	} {
 		name := name // avoid a race condition
 		t.Run(name, func(t *testing.T) {
-			// Skip tests that require specific Go version.
-			if name == "errors" {
-				ok := false
-				for _, version := range build.Default.ReleaseTags {
-					if version == "go1.16" {
-						ok = true
-						break
-					}
-				}
-				if !ok {
-					t.Skip("Results for errors test are only valid for Go 1.16+")
-				}
-			}
-
 			// Read the AST in memory.
 			path := filepath.Join("testdata", name+".go")
 			fset := token.NewFileSet()

compiler/compiler.go

@@ -22,10 +22,6 @@ import (
 	"tinygo.org/x/go-llvm"
 )
 
-var typeParamUnderlyingType = func(t types.Type) types.Type {
-	return t
-}
-
 func init() {
 	llvm.InitializeAllTargets()
 	llvm.InitializeAllTargetMCs()
@@ -345,7 +341,6 @@ func (c *compilerContext) getLLVMType(goType types.Type) llvm.Type {
 // makeLLVMType creates a LLVM type for a Go type. Don't call this, use
 // getLLVMType instead.
 func (c *compilerContext) makeLLVMType(goType types.Type) llvm.Type {
-	goType = typeParamUnderlyingType(goType)
 	switch typ := goType.(type) {
 	case *types.Array:
 		elemType := c.getLLVMType(typ.Elem())
@@ -420,6 +415,8 @@ func (c *compilerContext) makeLLVMType(goType types.Type) llvm.Type {
 			members[i] = c.getLLVMType(typ.Field(i).Type())
 		}
 		return c.ctx.StructType(members, false)
+	case *types.TypeParam:
+		return c.getLLVMType(typ.Underlying())
 	case *types.Tuple:
 		members := make([]llvm.Type, typ.Len())
 		for i := 0; i < typ.Len(); i++ {
@@ -455,7 +452,6 @@ func (c *compilerContext) getDIType(typ types.Type) llvm.Metadata {
 // createDIType creates a new DWARF type. Don't call this function directly,
 // call getDIType instead.
 func (c *compilerContext) createDIType(typ types.Type) llvm.Metadata {
-	typ = typeParamUnderlyingType(typ)
 	llvmType := c.getLLVMType(typ)
 	sizeInBytes := c.targetData.TypeAllocSize(llvmType)
 	switch typ := typ.(type) {
@@ -619,6 +615,8 @@ func (c *compilerContext) createDIType(typ types.Type) llvm.Metadata {
 		})
 		temporaryMDNode.ReplaceAllUsesWith(md)
 		return md
+	case *types.TypeParam:
+		return c.getDIType(typ.Underlying())
 	default:
 		panic("unknown type while generating DWARF debug type: " + typ.String())
 	}

compiler/compiler_test.go

@@ -9,7 +9,6 @@ import (
 	"testing"
 
 	"github.com/tinygo-org/tinygo/compileopts"
-	"github.com/tinygo-org/tinygo/goenv"
 	"github.com/tinygo-org/tinygo/loader"
 	"tinygo.org/x/go-llvm"
 )
@@ -34,12 +33,6 @@ func TestCompiler(t *testing.T) {
 		t.Fatal("could not parse LLVM version:", llvm.Version)
 	}
 
-	// Determine Go minor version (e.g. 16 in go1.16.3).
-	_, goMinor, err := goenv.GetGorootVersion(goenv.Get("GOROOT"))
-	if err != nil {
-		t.Fatal("could not read Go version:", err)
-	}
-
 	// Determine which tests to run, depending on the Go and LLVM versions.
 	tests := []testCase{
 		{"basic.go", "", ""},
@@ -62,12 +55,6 @@ func TestCompiler(t *testing.T) {
 		tests = append(tests, testCase{"intrinsics.go", "cortex-m-qemu", ""})
 		tests = append(tests, testCase{"intrinsics.go", "wasm", ""})
 	}
-	if goMinor >= 17 {
-		tests = append(tests, testCase{"go1.17.go", "", ""})
-	}
-	if goMinor >= 18 {
-		tests = append(tests, testCase{"generics.go", "", ""})
-	}
 
 	for _, tc := range tests {
 		name := tc.file