go/types: make tracing configurable (matching types2)

This CL replaces the internal trace flag with Config.trace.
While unexported, it can still be set for testing via reflection.
The typical use is for manual tests, where -v (verbose) turns on
tracing output. Typical use:

        go test -run Manual -v

This change makes go/types match types2 behavior.

Change-Id: I22842f4bba8fd632efe5929c950f4b1cab0a8569
Reviewed-on: https://go-review.googlesource.com/c/go/+/461081
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Robert Griesemer <gri@google.com>
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>

diff --git a/src/go/types/api.go b/src/go/types/api.go
index eda41b366aa6abb4e79db0517a67060fc462ae73..d9d561c25dc73e0a5591a8b61a57c609a0f6ef56 100644 (file)
--- a/src/go/types/api.go
+++ b/src/go/types/api.go
@@ -143,6 +143,9 @@ type Config struct {
        // It is an error to set both FakeImportC and go115UsesCgo.
        go115UsesCgo bool
 
+       // If trace is set, a debug trace is printed to stdout.
+       trace bool
+
        // If Error != nil, it is called with each error found
        // during type checking; err has dynamic type Error.
        // Secondary errors (for instance, to enumerate all types

diff --git a/src/go/types/call.go b/src/go/types/call.go
index db603b5260467cb5289230302e727a4e1f80255d..f0d612d018f9d075d025bfb989ad30d090ae2ee0 100644 (file)
--- a/src/go/types/call.go
+++ b/src/go/types/call.go
@@ -65,7 +65,7 @@ func (check *Checker) instantiateSignature(pos token.Pos, typ *Signature, targs
        assert(check != nil)
        assert(len(targs) == typ.TypeParams().Len())
 
-       if trace {
+       if check.conf.trace {
                check.trace(pos, "-- instantiating signature %s with %s", typ, targs)
                check.indent++
                defer func() {

diff --git a/src/go/types/check.go b/src/go/types/check.go
index 50d8afe4e373a75d5cf4a6f7a7c355c1cba70f20..76be49804248f675020bb9d45db7e30dc86acd5f 100644 (file)
--- a/src/go/types/check.go
+++ b/src/go/types/check.go
@@ -16,10 +16,7 @@ import (
 )
 
 // debugging/development support
-const (
-       debug = false // leave on during development
-       trace = false // turn on for detailed type resolution traces
-)
+const debug = false // leave on during development
 
 // exprInfo stores information about an untyped expression.
 type exprInfo struct {
@@ -313,7 +310,7 @@ func (check *Checker) checkFiles(files []*ast.File) (err error) {
        defer check.handleBailout(&err)
 
        print := func(msg string) {
-               if trace {
+               if check.conf.trace {
                        fmt.Println()
                        fmt.Println(msg)
                }
@@ -377,7 +374,7 @@ func (check *Checker) processDelayed(top int) {
        // this is a sufficiently bounded process.
        for i := top; i < len(check.delayed); i++ {
                a := &check.delayed[i]
-               if trace {
+               if check.conf.trace {
                        if a.desc != nil {
                                check.trace(a.desc.pos.Pos(), "-- "+a.desc.format, a.desc.args...)
                        } else {
@@ -385,7 +382,7 @@ func (check *Checker) processDelayed(top int) {
                        }
                }
                a.f() // may append to check.delayed
-               if trace {
+               if check.conf.trace {
                        fmt.Println()
                }
        }

diff --git a/src/go/types/check_test.go b/src/go/types/check_test.go
index 638355049ec455825eb2530c46c191ed857ff5ad..1107f9592aa2e1f58e952cf9ac80c04404ffb77f 100644 (file)
--- a/src/go/types/check_test.go
+++ b/src/go/types/check_test.go
@@ -145,7 +145,7 @@ func testFiles(t *testing.T, sizes Sizes, filenames []string, srcs [][]byte, man
        flags := flag.NewFlagSet("", flag.PanicOnError)
        flags.StringVar(&conf.GoVersion, "lang", "", "")
        flags.BoolVar(&conf.FakeImportC, "fakeImportC", false, "")
-       flags.BoolVar(addrOldComparableSemantics(&conf), "oldComparableSemantics", false, "")
+       flags.BoolVar(boolFieldAddr(&conf, "oldComparableSemantics"), "oldComparableSemantics", false, "")
        if err := parseFlags(filenames[0], srcs[0], flags); err != nil {
                t.Fatal(err)
        }
@@ -166,6 +166,7 @@ func testFiles(t *testing.T, sizes Sizes, filenames []string, srcs [][]byte, man
        }
 
        // typecheck and collect typechecker errors
+       *boolFieldAddr(&conf, "trace") = manual && testing.Verbose()
        if imp == nil {
                imp = importer.Default()
        }
@@ -299,10 +300,11 @@ func readCode(err Error) int {
        return int(v.FieldByName("go116code").Int())
 }
 
-// addrOldComparableSemantics(conf) returns &conf.oldComparableSemantics (unexported field).
-func addrOldComparableSemantics(conf *Config) *bool {
+// boolFieldAddr(conf, name) returns the address of the boolean field conf.<name>.
+// For accessing unexported fields.
+func boolFieldAddr(conf *Config, name string) *bool {
        v := reflect.Indirect(reflect.ValueOf(conf))
-       return (*bool)(v.FieldByName("oldComparableSemantics").Addr().UnsafePointer())
+       return (*bool)(v.FieldByName(name).Addr().UnsafePointer())
 }
 
 // TestManual is for manual testing of a package - either provided

diff --git a/src/go/types/decl.go b/src/go/types/decl.go
index adc485c400994f953fc68c6b9b56ca6821215282..018ff7f38e3aa420d3f07d73c319bd91277c48b1 100644 (file)
--- a/src/go/types/decl.go
+++ b/src/go/types/decl.go
@@ -54,7 +54,7 @@ func pathString(path []Object) string {
 // objDecl type-checks the declaration of obj in its respective (file) environment.
 // For the meaning of def, see Checker.definedType, in typexpr.go.
 func (check *Checker) objDecl(obj Object, def *Named) {
-       if trace && obj.Type() == nil {
+       if check.conf.trace && obj.Type() == nil {
                if check.indent == 0 {
                        fmt.Println() // empty line between top-level objects for readability
                }
@@ -264,7 +264,7 @@ loop:
                }
        }
 
-       if trace {
+       if check.conf.trace {
                check.trace(obj.Pos(), "## cycle detected: objPath = %s->%s (len = %d)", pathString(cycle), obj.Name(), len(cycle))
                if tparCycle {
                        check.trace(obj.Pos(), "## cycle contains: generic type in a type parameter list")
@@ -707,7 +707,7 @@ func (check *Checker) declareTypeParams(tparams []*TypeParam, names []*ast.Ident
                tparams = append(tparams, tpar)
        }
 
-       if trace && len(names) > 0 {
+       if check.conf.trace && len(names) > 0 {
                check.trace(names[0].Pos(), "type params = %v", tparams[len(tparams)-len(names):])
        }
 

diff --git a/src/go/types/errors.go b/src/go/types/errors.go
index b52019ddf5166aaf163ab67ed1288029a44ed88e..4c4cd038149156e39084a2fa02607aec9506b4a3 100644 (file)
--- a/src/go/types/errors.go
+++ b/src/go/types/errors.go
@@ -266,7 +266,7 @@ func (check *Checker) report(errp *error_) {
                check.firstErr = err
        }
 
-       if trace {
+       if check.conf.trace {
                pos := e.Pos
                msg := e.Msg
                check.trace(pos, "ERROR: %s", msg)

diff --git a/src/go/types/expr.go b/src/go/types/expr.go
index aa90145b367e51dc4c69ddba409261b2de1d9696..adf3d21fced6a3b58bc7a4572bc9a0f91c05c72c 100644 (file)
--- a/src/go/types/expr.go
+++ b/src/go/types/expr.go
@@ -1224,7 +1224,7 @@ const (
 // If allowGeneric is set, the operand type may be an uninstantiated
 // parameterized type or function value.
 func (check *Checker) rawExpr(x *operand, e ast.Expr, hint Type, allowGeneric bool) exprKind {
-       if trace {
+       if check.conf.trace {
                check.trace(e.Pos(), "-- expr %s", e)
                check.indent++
                defer func() {

diff --git a/src/go/types/named.go b/src/go/types/named.go
index c08997aa779c4a05b51529fbd815ed1732e87336..04638abbdc483e1cb0dfcfed72654e99bf8c101f 100644 (file)
--- a/src/go/types/named.go
+++ b/src/go/types/named.go
@@ -581,7 +581,7 @@ func (check *Checker) context() *Context {
 // returning the result. Returns Typ[Invalid] if there was an error.
 func (n *Named) expandUnderlying() Type {
        check := n.check
-       if check != nil && trace {
+       if check != nil && check.conf.trace {
                check.trace(n.obj.pos, "-- Named.expandUnderlying %s", n)
                check.indent++
                defer func() {

diff --git a/src/go/types/stmt.go b/src/go/types/stmt.go
index ac6255d42ac06b07cfe0f4ce437767bd7ac37262..1a4c58888a94082569348416e1f145b246a11427 100644 (file)
--- a/src/go/types/stmt.go
+++ b/src/go/types/stmt.go
@@ -19,7 +19,7 @@ func (check *Checker) funcBody(decl *declInfo, name string, sig *Signature, body
                panic("function body not ignored")
        }
 
-       if trace {
+       if check.conf.trace {
                check.trace(body.Pos(), "-- %s: %s", name, sig)
        }
 

diff --git a/src/go/types/subst.go b/src/go/types/subst.go
index 5a49c0447f3b9c33036259338f4d9e3920f59a58..5876b61edfadc9030bb38475cab852713bc47543 100644 (file)
--- a/src/go/types/subst.go
+++ b/src/go/types/subst.go
@@ -204,7 +204,7 @@ func (subst *subster) typ(typ Type) Type {
        case *Named:
                // dump is for debugging
                dump := func(string, ...any) {}
-               if subst.check != nil && trace {
+               if subst.check != nil && subst.check.conf.trace {
                        subst.check.indent++
                        defer func() {
                                subst.check.indent--

diff --git a/src/go/types/typeset.go b/src/go/types/typeset.go
index d68446df66d7f49f44d97e7e9b0099dcdf715fe3..35fb155bfa7d3b8b94eb9c9d42b92e2661be0817 100644 (file)
--- a/src/go/types/typeset.go
+++ b/src/go/types/typeset.go
@@ -170,7 +170,7 @@ func computeInterfaceTypeSet(check *Checker, pos token.Pos, ityp *Interface) *_T
                return &topTypeSet
        }
 
-       if check != nil && trace {
+       if check != nil && check.conf.trace {
                // Types don't generally have position information.
                // If we don't have a valid pos provided, try to use
                // one close enough.

diff --git a/src/go/types/typexpr.go b/src/go/types/typexpr.go
index 03817dded19ace430e04a3db12c659583f500c0f..6a92dcb9b73caa8d665ab534e3ade556de28e01f 100644 (file)
--- a/src/go/types/typexpr.go
+++ b/src/go/types/typexpr.go
@@ -214,7 +214,7 @@ func goTypeName(typ Type) string {
 // typInternal drives type checking of types.
 // Must only be called by definedType or genericType.
 func (check *Checker) typInternal(e0 ast.Expr, def *Named) (T Type) {
-       if trace {
+       if check.conf.trace {
                check.trace(e0.Pos(), "-- type %s", e0)
                check.indent++
                defer func() {
@@ -395,7 +395,7 @@ func (check *Checker) typInternal(e0 ast.Expr, def *Named) (T Type) {
 }
 
 func (check *Checker) instantiatedType(ix *typeparams.IndexExpr, def *Named) (res Type) {
-       if trace {
+       if check.conf.trace {
                check.trace(ix.Pos(), "-- instantiating type %s with %s", ix.X, ix.Indices)
                check.indent++
                defer func() {