internal/lsp: use builtin package for signature help
This change uses the builtin package to derive the signature help for
builtin functions.
Updates golang/go#31696
Change-Id: I458b3a89bdf143e7018e8be7cb6a5e8c068a47c2
Reviewed-on: https://go-review.googlesource.com/c/tools/+/176922
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
diff --git a/internal/lsp/cmd/cmd_test.go b/internal/lsp/cmd/cmd_test.go
index 5474238..316b46e 100644
--- a/internal/lsp/cmd/cmd_test.go
+++ b/internal/lsp/cmd/cmd_test.go
@@ -55,7 +55,7 @@
//TODO: add command line symbol tests when it works
}
-func (r *runner) Signature(t *testing.T, data tests.Signatures) {
+func (r *runner) SignatureHelp(t *testing.T, data tests.Signatures) {
//TODO: add command line signature tests when it works
}
diff --git a/internal/lsp/lsp_test.go b/internal/lsp/lsp_test.go
index 05bae65..7c4943b 100644
--- a/internal/lsp/lsp_test.go
+++ b/internal/lsp/lsp_test.go
@@ -471,7 +471,7 @@
return msg.String()
}
-func (r *runner) Signature(t *testing.T, data tests.Signatures) {
+func (r *runner) SignatureHelp(t *testing.T, data tests.Signatures) {
for spn, expectedSignatures := range data {
m := r.mapper(spn.URI())
loc, err := m.Location(spn)
diff --git a/internal/lsp/source/completion_format.go b/internal/lsp/source/completion_format.go
index 6894254..da3774e 100644
--- a/internal/lsp/source/completion_format.go
+++ b/internal/lsp/source/completion_format.go
@@ -6,6 +6,7 @@
import (
"bytes"
+ "context"
"fmt"
"go/ast"
"go/printer"
@@ -111,20 +112,12 @@
item.Kind = ConstantCompletionItem
case *types.Builtin:
item.Kind = FunctionCompletionItem
- builtinPkg := c.view.BuiltinPackage()
- if builtinPkg == nil || builtinPkg.Scope == nil {
+ decl := lookupBuiltin(c.view, obj.Name())
+ if decl == nil {
break
}
- fn := builtinPkg.Scope.Lookup(obj.Name())
- if fn == nil {
- break
- }
- decl, ok := fn.Decl.(*ast.FuncDecl)
- if !ok {
- break
- }
- params, _ := c.formatFieldList(decl.Type.Params)
- results, writeResultParens := c.formatFieldList(decl.Type.Results)
+ params, _ := formatFieldList(c.ctx, c.view, decl.Type.Params)
+ results, writeResultParens := formatFieldList(c.ctx, c.view, decl.Type.Results)
item.Label, item.Detail = formatFunction(obj.Name(), params, results, writeResultParens)
item.plainSnippet, item.placeholderSnippet = c.functionCallSnippets(obj.Name(), params)
case *types.TypeName:
@@ -139,13 +132,29 @@
return item
}
+func lookupBuiltin(v View, name string) *ast.FuncDecl {
+ builtinPkg := v.BuiltinPackage()
+ if builtinPkg == nil || builtinPkg.Scope == nil {
+ return nil
+ }
+ fn := builtinPkg.Scope.Lookup(name)
+ if fn == nil {
+ return nil
+ }
+ decl, ok := fn.Decl.(*ast.FuncDecl)
+ if !ok {
+ return nil
+ }
+ return decl
+}
+
var replacer = strings.NewReplacer(
`ComplexType`, `complex128`,
`FloatType`, `float64`,
`IntegerType`, `int`,
)
-func (c *completer) formatFieldList(list *ast.FieldList) ([]string, bool) {
+func formatFieldList(ctx context.Context, v View, list *ast.FieldList) ([]string, bool) {
if list == nil {
return nil, false
}
@@ -158,8 +167,8 @@
p := list.List[i]
cfg := printer.Config{Mode: printer.UseSpaces | printer.TabIndent, Tabwidth: 4}
b := &bytes.Buffer{}
- if err := cfg.Fprint(b, c.view.FileSet(), p.Type); err != nil {
- c.view.Logger().Errorf(c.ctx, "unable to print type %v", p.Type)
+ if err := cfg.Fprint(b, v.FileSet(), p.Type); err != nil {
+ v.Logger().Errorf(ctx, "unable to print type %v", p.Type)
continue
}
typ := replacer.Replace(b.String())
diff --git a/internal/lsp/source/signature_help.go b/internal/lsp/source/signature_help.go
index 1d9f81f..ea5a644 100644
--- a/internal/lsp/source/signature_help.go
+++ b/internal/lsp/source/signature_help.go
@@ -10,7 +10,6 @@
"go/ast"
"go/token"
"go/types"
- "strings"
"golang.org/x/tools/go/ast/astutil"
)
@@ -48,6 +47,22 @@
return nil, fmt.Errorf("cannot find an enclosing function")
}
+ // Get the object representing the function, if available.
+ // There is no object in certain cases such as calling a function returned by
+ // a function (e.g. "foo()()").
+ var obj types.Object
+ switch t := callExpr.Fun.(type) {
+ case *ast.Ident:
+ obj = pkg.GetTypesInfo().ObjectOf(t)
+ case *ast.SelectorExpr:
+ obj = pkg.GetTypesInfo().ObjectOf(t.Sel)
+ }
+
+ // Handle builtin functions separately.
+ if obj, ok := obj.(*types.Builtin); ok {
+ return builtinSignature(ctx, f.View(), callExpr, obj.Name(), pos)
+ }
+
// Get the type information for the function being called.
sigType := pkg.GetTypesInfo().TypeOf(callExpr.Fun)
if sigType == nil {
@@ -60,21 +75,60 @@
}
qf := qualifier(fAST, pkg.GetTypes(), pkg.GetTypesInfo())
- var paramInfo []ParameterInformation
- for i := 0; i < sig.Params().Len(); i++ {
- param := sig.Params().At(i)
- label := types.TypeString(param.Type(), qf)
- if sig.Variadic() && i == sig.Params().Len()-1 {
- label = strings.Replace(label, "[]", "...", 1)
- }
- if param.Name() != "" {
- label = fmt.Sprintf("%s %s", param.Name(), label)
- }
- paramInfo = append(paramInfo, ParameterInformation{
- Label: label,
- })
- }
+ params := formatParams(sig.Params(), sig.Variadic(), qf)
+ results, writeResultParens := formatResults(sig.Results(), qf)
+ activeParam := activeParameter(callExpr, sig.Params().Len(), sig.Variadic(), pos)
+ var name string
+ if obj != nil {
+ name = obj.Name()
+ } else {
+ name = "func"
+ }
+ return signatureInformation(name, params, results, writeResultParens, activeParam), nil
+}
+
+func builtinSignature(ctx context.Context, v View, callExpr *ast.CallExpr, name string, pos token.Pos) (*SignatureInformation, error) {
+ decl := lookupBuiltin(v, name)
+ if decl == nil {
+ return nil, fmt.Errorf("no function declaration for builtin: %s", name)
+ }
+ params, _ := formatFieldList(ctx, v, decl.Type.Params)
+ results, writeResultParens := formatFieldList(ctx, v, decl.Type.Results)
+
+ var (
+ numParams int
+ variadic bool
+ )
+ if decl.Type.Params.List != nil {
+ numParams = len(decl.Type.Params.List)
+ lastParam := decl.Type.Params.List[numParams-1]
+ if _, ok := lastParam.Type.(*ast.Ellipsis); ok {
+ variadic = true
+ }
+ }
+ activeParam := activeParameter(callExpr, numParams, variadic, pos)
+ return signatureInformation(name, params, results, writeResultParens, activeParam), nil
+}
+
+func signatureInformation(name string, params, results []string, writeResultParens bool, activeParam int) *SignatureInformation {
+ paramInfo := make([]ParameterInformation, 0, len(params))
+ for _, p := range params {
+ paramInfo = append(paramInfo, ParameterInformation{Label: p})
+ }
+ label, detail := formatFunction(name, params, results, writeResultParens)
+ // Show return values of the function in the label.
+ if detail != "" {
+ label += " " + detail
+ }
+ return &SignatureInformation{
+ Label: label,
+ Parameters: paramInfo,
+ ActiveParameter: activeParam,
+ }
+}
+
+func activeParameter(callExpr *ast.CallExpr, numParams int, variadic bool, pos token.Pos) int {
// Determine the query position relative to the number of parameters in the function.
var activeParam int
var start, end token.Pos
@@ -88,38 +142,10 @@
}
// Don't advance the active parameter for the last parameter of a variadic function.
- if !sig.Variadic() || activeParam < sig.Params().Len()-1 {
+ if !variadic || activeParam < numParams-1 {
activeParam++
}
start = expr.Pos() + 1 // to account for commas
}
-
- // Get the object representing the function, if available.
- // There is no object in certain cases such as calling a function returned by
- // a function (e.g. "foo()()").
- var obj types.Object
- switch t := callExpr.Fun.(type) {
- case *ast.Ident:
- obj = pkg.GetTypesInfo().ObjectOf(t)
- case *ast.SelectorExpr:
- obj = pkg.GetTypesInfo().ObjectOf(t.Sel)
- }
-
- var name string
- if obj != nil {
- name = obj.Name()
- } else {
- name = "func"
- }
-
- results, writeResultParens := formatResults(sig.Results(), qf)
- label, detail := formatFunction(name, formatParams(sig.Params(), sig.Variadic(), qf), results, writeResultParens)
- if sig.Results().Len() > 0 {
- label += " " + detail
- }
- return &SignatureInformation{
- Label: label,
- Parameters: paramInfo,
- ActiveParameter: activeParam,
- }, nil
+ return activeParam
}
diff --git a/internal/lsp/source/source_test.go b/internal/lsp/source/source_test.go
index 7913b9c..7087430 100644
--- a/internal/lsp/source/source_test.go
+++ b/internal/lsp/source/source_test.go
@@ -420,7 +420,7 @@
return msg.String()
}
-func (r *runner) Signature(t *testing.T, data tests.Signatures) {
+func (r *runner) SignatureHelp(t *testing.T, data tests.Signatures) {
ctx := context.Background()
for spn, expectedSignatures := range data {
f, err := r.view.GetFile(ctx, spn.URI())
diff --git a/internal/lsp/testdata/signature/signature.go b/internal/lsp/testdata/signature/signature.go
index 7e826a0..dd50035 100644
--- a/internal/lsp/testdata/signature/signature.go
+++ b/internal/lsp/testdata/signature/signature.go
@@ -53,10 +53,11 @@
var ms myStruct
ms.foo(nil) //@signature("nil", "foo(e *json.Decoder) (*big.Int, error)", 0)
- _ = make([]int, 1, 2) //@signature("2", "make([]int, int, int) []int", 2)
+ _ = make([]int, 1, 2) //@signature("2", "make(t Type, size ...int) Type", 1)
Foo(myFunc(123), 456) //@signature("myFunc", "Foo(a string, b int) (c bool)", 0)
Foo(myFunc(123), 456) //@signature("123", "myFunc(foo int) string", 0)
- panic("oops!") //@signature("oops", "panic(interface{})", 0)
+ panic("oops!") //@signature("oops", "panic(v interface{})", 0)
+ println("hello", "world") //@signature("world", "println(args ...Type)", 0)
}
diff --git a/internal/lsp/tests/tests.go b/internal/lsp/tests/tests.go
index 5ffe3ac..a263160 100644
--- a/internal/lsp/tests/tests.go
+++ b/internal/lsp/tests/tests.go
@@ -35,7 +35,7 @@
ExpectedTypeDefinitionsCount = 2
ExpectedHighlightsCount = 2
ExpectedSymbolsCount = 1
- ExpectedSignaturesCount = 19
+ ExpectedSignaturesCount = 20
ExpectedCompletionSnippetCount = 11
ExpectedLinksCount = 2
)
@@ -89,7 +89,7 @@
Definition(*testing.T, Definitions)
Highlight(*testing.T, Highlights)
Symbol(*testing.T, Symbols)
- Signature(*testing.T, Signatures)
+ SignatureHelp(*testing.T, Signatures)
Link(*testing.T, Links)
}
@@ -291,12 +291,12 @@
tests.Symbol(t, data.Symbols)
})
- t.Run("Signatures", func(t *testing.T) {
+ t.Run("SignatureHelp", func(t *testing.T) {
t.Helper()
if len(data.Signatures) != ExpectedSignaturesCount {
t.Errorf("got %v signatures expected %v", len(data.Signatures), ExpectedSignaturesCount)
}
- tests.Signature(t, data.Signatures)
+ tests.SignatureHelp(t, data.Signatures)
})
t.Run("Links", func(t *testing.T) {
