From 217a461f56cecee1756bef29f9ad2dcd389a255b Mon Sep 17 00:00:00 2001 From: Robert Griesemer Date: Tue, 26 Jan 2021 12:08:18 -0800 Subject: [PATCH] [dev.typeparams] cmd/compile/internal/types2: report unused packages in source order 1) Rather than map-iterate through all file scopes and collect unused packages, collect all imports in the Checker.imports list so that errors are reported in source order. 2) From cmd/compile, borrow the idea of a "dotImportRefs" map to map dot-imported objects to the package they were dot-imported through (we call the map "dotImportMap"). 3) From cmd/compile, borrow the "pkgnotused" function (called Checker.errorUnusedPkg in this code) and clean up unused package error reporting. 4) Adjust unused package error message to match compiler message exactly. 5) Enable one more excluded test case in test/run.go. Change-Id: I4e4e55512a6043a7fd54f576c7441e3dd4077d6f Reviewed-on: https://go-review.googlesource.com/c/go/+/287072 Trust: Robert Griesemer Run-TryBot: Robert Griesemer TryBot-Result: Go Bot Reviewed-by: Robert Findley --- src/cmd/compile/internal/types2/check.go | 36 ++++---- src/cmd/compile/internal/types2/resolver.go | 87 +++++++++---------- .../testdata/importdecl0/importdecl0b.src | 2 +- .../testdata/importdecl1/importdecl1b.src | 2 +- src/cmd/compile/internal/types2/typexpr.go | 8 +- test/run.go | 1 - 6 files changed, 62 insertions(+), 74 deletions(-) diff --git a/src/cmd/compile/internal/types2/check.go b/src/cmd/compile/internal/types2/check.go index 6ba8506916..e2c6c4f606 100644 --- a/src/cmd/compile/internal/types2/check.go +++ b/src/cmd/compile/internal/types2/check.go @@ -74,6 +74,12 @@ type importKey struct { path, dir string } +// A dotImportKey describes a dot-imported object in the given scope. +type dotImportKey struct { + scope *Scope + obj Object +} + // A Checker maintains the state of the type checker. // It must be created with NewChecker. type Checker struct { @@ -92,8 +98,9 @@ type Checker struct { // information collected during type-checking of a set of package files // (initialized by Files, valid only for the duration of check.Files; // maps and lists are allocated on demand) - files []*syntax.File // package files - unusedDotImports map[*Scope]map[*Package]syntax.Pos // positions of unused dot-imported packages for each file scope + files []*syntax.File // list of package files + imports []*PkgName // list of imported packages + dotImportMap map[dotImportKey]*PkgName // maps dot-imported objects to the package they were dot-imported through firstErr error // first error encountered methods map[*TypeName][]*Func // maps package scope type names to associated non-blank (non-interface) methods @@ -110,22 +117,6 @@ type Checker struct { indent int // indentation for tracing } -// addUnusedImport adds the position of a dot-imported package -// pkg to the map of dot imports for the given file scope. -func (check *Checker) addUnusedDotImport(scope *Scope, pkg *Package, pos syntax.Pos) { - mm := check.unusedDotImports - if mm == nil { - mm = make(map[*Scope]map[*Package]syntax.Pos) - check.unusedDotImports = mm - } - m := mm[scope] - if m == nil { - m = make(map[*Package]syntax.Pos) - mm[scope] = m - } - m[pkg] = pos -} - // addDeclDep adds the dependency edge (check.decl -> to) if check.decl exists func (check *Checker) addDeclDep(to Object) { from := check.decl @@ -209,7 +200,8 @@ func NewChecker(conf *Config, pkg *Package, info *Info) *Checker { func (check *Checker) initFiles(files []*syntax.File) { // start with a clean slate (check.Files may be called multiple times) check.files = nil - check.unusedDotImports = nil + check.imports = nil + check.dotImportMap = nil check.firstErr = nil check.methods = nil @@ -291,6 +283,9 @@ func (check *Checker) checkFiles(files []*syntax.File) (err error) { print("== unusedImports ==") check.unusedImports() } + // no longer needed - release memory + check.imports = nil + check.dotImportMap = nil print("== recordUntyped ==") check.recordUntyped() @@ -301,6 +296,9 @@ func (check *Checker) checkFiles(files []*syntax.File) (err error) { } check.pkg.complete = true + + // TODO(gri) There's more memory we should release at this point. + return } diff --git a/src/cmd/compile/internal/types2/resolver.go b/src/cmd/compile/internal/types2/resolver.go index 7ea9bde5fa..2a84015cfc 100644 --- a/src/cmd/compile/internal/types2/resolver.go +++ b/src/cmd/compile/internal/types2/resolver.go @@ -273,21 +273,26 @@ func (check *Checker) collectObjects() { } } - obj := NewPkgName(s.Pos(), pkg, name, imp) + pkgName := NewPkgName(s.Pos(), pkg, name, imp) if s.LocalPkgName != nil { // in a dot-import, the dot represents the package - check.recordDef(s.LocalPkgName, obj) + check.recordDef(s.LocalPkgName, pkgName) } else { - check.recordImplicit(s, obj) + check.recordImplicit(s, pkgName) } if path == "C" { // match cmd/compile (not prescribed by spec) - obj.used = true + pkgName.used = true } // add import to file scope + check.imports = append(check.imports, pkgName) if name == "." { + // dot-import + if check.dotImportMap == nil { + check.dotImportMap = make(map[dotImportKey]*PkgName) + } // merge imported scope with file scope for _, obj := range imp.scope.elems { // A package scope may contain non-exported objects, @@ -301,16 +306,15 @@ func (check *Checker) collectObjects() { if alt := fileScope.Insert(obj); alt != nil { check.errorf(s.LocalPkgName, "%s redeclared in this block", obj.Name()) check.reportAltDecl(alt) + } else { + check.dotImportMap[dotImportKey{fileScope, obj}] = pkgName } } } - // add position to set of dot-import positions for this file - // (this is only needed for "imported but not used" errors) - check.addUnusedDotImport(fileScope, imp, s.Pos()) } else { // declare imported package object in file scope // (no need to provide s.LocalPkgName since we called check.recordDef earlier) - check.declare(fileScope, nil, obj, nopos) + check.declare(fileScope, nil, pkgName, nopos) } case *syntax.ConstDecl: @@ -673,51 +677,38 @@ func (check *Checker) unusedImports() { // any of its exported identifiers. To import a package solely for its side-effects // (initialization), use the blank identifier as explicit package name." - // check use of regular imported packages - for _, scope := range check.pkg.scope.children /* file scopes */ { - for _, obj := range scope.elems { - if obj, ok := obj.(*PkgName); ok { - // Unused "blank imports" are automatically ignored - // since _ identifiers are not entered into scopes. - if !obj.used { - path := obj.imported.path - base := pkgName(path) - if obj.name == base { - if check.conf.CompilerErrorMessages { - check.softErrorf(obj.pos, "%q imported and not used", path) - } else { - check.softErrorf(obj.pos, "%q imported but not used", path) - } - } else { - if check.conf.CompilerErrorMessages { - check.softErrorf(obj.pos, "%q imported and not used as %s", path, obj.name) - } else { - check.softErrorf(obj.pos, "%q imported but not used as %s", path, obj.name) - } - } - } - } - } - } - - // check use of dot-imported packages - for _, unusedDotImports := range check.unusedDotImports { - for pkg, pos := range unusedDotImports { - if check.conf.CompilerErrorMessages { - check.softErrorf(pos, "%q imported and not used", pkg.path) - } else { - check.softErrorf(pos, "%q imported but not used", pkg.path) - } + for _, obj := range check.imports { + if !obj.used && obj.name != "_" { + check.errorUnusedPkg(obj) } } } -// pkgName returns the package name (last element) of an import path. -func pkgName(path string) string { - if i := strings.LastIndex(path, "/"); i >= 0 { - path = path[i+1:] +func (check *Checker) errorUnusedPkg(obj *PkgName) { + // If the package was imported with a name other than the final + // import path element, show it explicitly in the error message. + // Note that this handles both renamed imports and imports of + // packages containing unconventional package declarations. + // Note that this uses / always, even on Windows, because Go import + // paths always use forward slashes. + path := obj.imported.path + elem := path + if i := strings.LastIndex(elem, "/"); i >= 0 { + elem = elem[i+1:] + } + if obj.name == "" || obj.name == "." || obj.name == elem { + if check.conf.CompilerErrorMessages { + check.softErrorf(obj, "imported and not used: %q", path) + } else { + check.softErrorf(obj, "%q imported but not used", path) + } + } else { + if check.conf.CompilerErrorMessages { + check.softErrorf(obj, "imported and not used: %q as %s", path, obj.name) + } else { + check.softErrorf(obj, "%q imported but not used as %s", path, obj.name) + } } - return path } // dir makes a good-faith attempt to return the directory diff --git a/src/cmd/compile/internal/types2/testdata/importdecl0/importdecl0b.src b/src/cmd/compile/internal/types2/testdata/importdecl0/importdecl0b.src index 48ecb5e46f..19b55aff76 100644 --- a/src/cmd/compile/internal/types2/testdata/importdecl0/importdecl0b.src +++ b/src/cmd/compile/internal/types2/testdata/importdecl0/importdecl0b.src @@ -8,7 +8,7 @@ import "math" import m "math" import . "testing" // declares T in file scope -import . /* ERROR "imported but not used" */ "unsafe" +import . /* ERROR .unsafe. imported but not used */ "unsafe" import . "fmt" // declares Println in file scope import ( diff --git a/src/cmd/compile/internal/types2/testdata/importdecl1/importdecl1b.src b/src/cmd/compile/internal/types2/testdata/importdecl1/importdecl1b.src index ee70bbd8e7..43a7bcd753 100644 --- a/src/cmd/compile/internal/types2/testdata/importdecl1/importdecl1b.src +++ b/src/cmd/compile/internal/types2/testdata/importdecl1/importdecl1b.src @@ -4,7 +4,7 @@ package importdecl1 -import . /* ERROR "imported but not used" */ "unsafe" +import . /* ERROR .unsafe. imported but not used */ "unsafe" type B interface { A diff --git a/src/cmd/compile/internal/types2/typexpr.go b/src/cmd/compile/internal/types2/typexpr.go index 9ab84b594b..b758c0f358 100644 --- a/src/cmd/compile/internal/types2/typexpr.go +++ b/src/cmd/compile/internal/types2/typexpr.go @@ -56,12 +56,12 @@ func (check *Checker) ident(x *operand, e *syntax.Name, def *Named, wantType boo } assert(typ != nil) - // The object may be dot-imported: If so, remove its package from - // the map of unused dot imports for the respective file scope. + // The object may have been dot-imported. + // If so, mark the respective package as used. // (This code is only needed for dot-imports. Without them, // we only have to mark variables, see *Var case below). - if pkg := obj.Pkg(); pkg != check.pkg && pkg != nil { - delete(check.unusedDotImports[scope], pkg) + if pkgName := check.dotImportMap[dotImportKey{scope, obj}]; pkgName != nil { + pkgName.used = true } switch obj := obj.(type) { diff --git a/test/run.go b/test/run.go index a1c68494c3..8b487aa76f 100644 --- a/test/run.go +++ b/test/run.go @@ -1956,7 +1956,6 @@ var excluded = map[string]bool{ "fixedbugs/issue18331.go": true, // missing error about misuse of //go:noescape (irgen needs code from noder) "fixedbugs/issue18393.go": true, // types2 not run after syntax errors "fixedbugs/issue19012.go": true, // multiple errors on same line - "fixedbugs/issue20298.go": true, // types2 non-deterministically reports unused imports "fixedbugs/issue20233.go": true, // types2 reports two instead of one error (pref: compiler) "fixedbugs/issue20245.go": true, // types2 reports two instead of one error (pref: compiler) "fixedbugs/issue20250.go": true, // correct diagnostics, but different lines (probably irgen's fault) -- 2.50.0