29 files changed, 219 insertions(+), 1 deletions(-)

M .golangci.toml
M go.mod
M go.sum
A pkg/typecheck/testdata/scopes/empty.snow
A pkg/typecheck/testdata/scopes/empty.snow.err
A pkg/typecheck/testdata/scopes/empty.snow.want
A pkg/typecheck/testdata/scopes/fn.snow
A pkg/typecheck/testdata/scopes/fn.snow.err
A pkg/typecheck/testdata/scopes/fn.snow.want
A pkg/typecheck/testdata/scopes/fn_nested_block.snow
A pkg/typecheck/testdata/scopes/fn_nested_block.snow.err
A pkg/typecheck/testdata/scopes/fn_nested_block.snow.want
A pkg/typecheck/testdata/scopes/fn_params.snow
A pkg/typecheck/testdata/scopes/fn_params.snow.err
A pkg/typecheck/testdata/scopes/fn_params.snow.want
A pkg/typecheck/testdata/scopes/fn_params_locals.snow
A pkg/typecheck/testdata/scopes/fn_params_locals.snow.err
A pkg/typecheck/testdata/scopes/fn_params_locals.snow.want
A pkg/typecheck/testdata/scopes/fns.snow
A pkg/typecheck/testdata/scopes/fns.snow.err
A pkg/typecheck/testdata/scopes/fns.snow.want
A pkg/typecheck/testdata/scopes/let.snow
A pkg/typecheck/testdata/scopes/let.snow.err
A pkg/typecheck/testdata/scopes/let.snow.want
A pkg/typecheck/testdata/scopes/var.snow
A pkg/typecheck/testdata/scopes/var.snow.err
A pkg/typecheck/testdata/scopes/var.snow.want
M pkg/typecheck/typecheck.go
M pkg/typecheck/typecheck_test.go

@@ 51,5 51,8 @@
 
     # pkg/codegen
     "`testUpdateCodegenTests` is a global variable",
+
+    # pkg/typecheck
+    "`testUpdateScopesTests` is a global variable",
   ]
 

@@ 8,6 8,7 @@ require (
 	github.com/gorilla/schema v1.1.0
 	github.com/hashicorp/go-multierror v1.0.0 // indirect
 	github.com/kelseyhightower/envconfig v1.4.0
+	github.com/kr/pretty v0.1.0
 	github.com/kylelemons/godebug v1.1.0
 	github.com/mna/httpparms v0.0.0-20160806173130-30c778d9c13f
 	github.com/pquerna/ffjson v0.0.0-20190930134022-aa0246cd15f7 // indirect

@@ 33,8 33,10 @@ github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7V
 github.com/kelseyhightower/envconfig v1.4.0 h1:Im6hONhd3pLkfDFsbRgu68RDNkGF1r3dvMUtDTo2cv8=
 github.com/kelseyhightower/envconfig v1.4.0/go.mod h1:cccZRl6mQpaq41TPp5QxidR+Sa3axMbJDNb//FQX6Gg=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kylelemons/godebug v1.1.0 h1:RPNrshWIDI6G2gRW9EHilWtl7Z6Sb1BR0xunSBf0SNc=
 github.com/kylelemons/godebug v1.1.0/go.mod h1:9/0rRGxNHcop5bhtWyNeEfOS8JIWk580+fNqagV/RAw=

@@ 0,0 1,4 @@
+<nil> {
+.  *ast.File {
+.  }
+}

@@ 0,0 1,2 @@
+fn test() {
+}

@@ 0,0 1,7 @@
+<nil> {
+.  *ast.File {
+.  .  test
+.  .  *ast.FnDef {
+.  .  }
+.  }
+}

@@ 0,0 1,11 @@
+fn test(x: int, y: int) -> int {
+  let s1: int 
+  {
+    let s2: int 
+    {
+      let inside: int
+      var s1: int
+    }
+    let s2b: int
+  }
+}

@@ 0,0 1,18 @@
+<nil> {
+.  *ast.File {
+.  .  test
+.  .  *ast.FnDef {
+.  .  .  s1
+.  .  .  x
+.  .  .  y
+.  .  .  *ast.Block {
+.  .  .  .  s2
+.  .  .  .  s2b
+.  .  .  .  *ast.Block {
+.  .  .  .  .  inside
+.  .  .  .  .  s1
+.  .  .  .  }
+.  .  .  }
+.  .  }
+.  }
+}

@@ 0,0 1,3 @@
+fn test(x: int, y: int) -> int {
+  return x + y
+}

@@ 0,0 1,9 @@
+<nil> {
+.  *ast.File {
+.  .  test
+.  .  *ast.FnDef {
+.  .  .  x
+.  .  .  y
+.  .  }
+.  }
+}

@@ 0,0 1,4 @@
+fn test(x: int, y: int) -> int {
+  var z = x + y
+  return z
+}

@@ 0,0 1,10 @@
+<nil> {
+.  *ast.File {
+.  .  test
+.  .  *ast.FnDef {
+.  .  .  x
+.  .  .  y
+.  .  .  z
+.  .  }
+.  }
+}

@@ 0,0 1,12 @@
+fn add(x: int, y: int) -> int {
+  let z = x + y
+  return z
+}
+
+fn main() {
+  let result: int = add(1, 3)
+  println(result)
+}
+
+@extern{import: "fmt", symbol: "Println"}
+fn println(x: int)

@@ 0,0 1,18 @@
+<nil> {
+.  *ast.File {
+.  .  add
+.  .  main
+.  .  println
+.  .  *ast.FnDef {
+.  .  .  x
+.  .  .  y
+.  .  .  z
+.  .  }
+.  .  *ast.FnDef {
+.  .  .  result
+.  .  }
+.  .  *ast.FnDef {
+.  .  .  x
+.  .  }
+.  }
+}

@@ 0,0 1,1 @@
+let y: string = "abc"

@@ 0,0 1,5 @@
+<nil> {
+.  *ast.File {
+.  .  y
+.  }
+}

@@ 0,0 1,1 @@
+var x: int

@@ 0,0 1,5 @@
+<nil> {
+.  *ast.File {
+.  .  x
+.  }
+}

@@ 8,10 8,31 @@ import (
 	"strings"
 
 	"git.sr.ht/~mna/snow/pkg/ast"
+	"git.sr.ht/~mna/snow/pkg/parser"
 	"git.sr.ht/~mna/snow/pkg/scanner"
 	"git.sr.ht/~mna/snow/pkg/token"
 )
 
+// CheckFiles is a helper function that parses and typechecks code for the
+// provided source files. It returns the typechecked *Unit and an error.
+// The error, if non-nil, is guaranteed to be a scanner.ErrorList.
+func CheckFiles(files ...string) (*Unit, error) {
+	if len(files) == 0 {
+		return nil, nil
+	}
+
+	fset, fs, err := parser.ParseFiles(files...)
+	if err != nil {
+		return nil, err
+	}
+
+	var c checker
+	for _, f := range fs {
+		c.checkFile(fset, f)
+	}
+	return c.unit, c.errors.Err()
+}
+
 type checker struct {
 	fset         *token.FileSet
 	unit         *Unit


@@ 64,6 85,7 @@ func (c *checker) Visit(n ast.Node) ast.Visitor {
 		// no need to close this scope, currentScope is reset to Universe
 		// on each new file to check.
 		c.openScope(n)
+		return c
 
 	case *ast.FnDef:
 		// the function's name is in the current scope, while the arguments are in


@@ 164,7 186,7 @@ func (s *Scope) WriteTo(w io.Writer, n int, recurse bool) {
 	const ind = ".  "
 	indn := strings.Repeat(ind, n)
 
-	fmt.Fprintf(w, "%s%s scope %p {\n", indn, s.Node, s)
+	fmt.Fprintf(w, "%s%T {\n", indn, s.Node)
 
 	syms := make([]string, 0, len(s.Symbols))
 	for sym := range s.Symbols {

@@ 1,1 1,81 @@
 package typecheck
+
+import (
+	"bytes"
+	"flag"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"git.sr.ht/~mna/snow/pkg/scanner"
+	"github.com/kylelemons/godebug/diff"
+)
+
+var testUpdateScopesTests = flag.Bool("test.update-scopes-tests", false, "If set, replace expected typecheck scopes test results with actual results.")
+
+func TestScopes(t *testing.T) {
+	baseDir := filepath.Join("testdata", "scopes")
+	fis, err := ioutil.ReadDir(baseDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, fi := range fis {
+		if !fi.Mode().IsRegular() {
+			continue
+		}
+		if filepath.Ext(fi.Name()) != ".snow" {
+			continue
+		}
+
+		t.Run(fi.Name(), func(t *testing.T) {
+			unit, err := CheckFiles(filepath.Join(baseDir, fi.Name()))
+			if unit == nil && err != nil {
+				t.Fatal(err)
+			}
+
+			var ebuf bytes.Buffer
+			scanner.PrintError(&ebuf, err)
+
+			var buf bytes.Buffer
+			//pretty.Println(unit)
+			unit.Universe.WriteTo(&buf, 0, true)
+
+			wantFile := filepath.Join(baseDir, fi.Name()+".want")
+			errFile := filepath.Join(baseDir, fi.Name()+".err")
+			if *testUpdateScopesTests {
+				if err := ioutil.WriteFile(wantFile, buf.Bytes(), 0666); err != nil {
+					t.Fatal(err)
+				}
+
+				if err := ioutil.WriteFile(errFile, ebuf.Bytes(), 0666); err != nil {
+					t.Fatal(err)
+				}
+				return
+			}
+
+			// validate scopes output
+			want, err := ioutil.ReadFile(wantFile)
+			if err != nil && !os.IsNotExist(err) {
+				t.Fatal(err)
+			}
+			if patch := diff.Diff(buf.String(), string(want)); patch != "" {
+				t.Logf("got:\n%s\n", buf.String())
+				t.Logf("want:\n%s\n", string(want))
+				t.Errorf("diff:\n%s\n", patch)
+			}
+
+			// validate errors output
+			ewant, err := ioutil.ReadFile(errFile)
+			if err != nil && !os.IsNotExist(err) {
+				t.Fatal(err)
+			}
+			if patch := diff.Diff(ebuf.String(), string(ewant)); patch != "" {
+				t.Logf("got error(s):\n%s\n", ebuf.String())
+				t.Logf("want error(s):\n%s\n", string(ewant))
+				t.Errorf("diff error(s):\n%s\n", patch)
+			}
+		})
+	}
+}