github.com/jhump/golang-x-tools@v0.0.0-20220218190644-4958d6d39439/internal/lsp/cmd/call_hierarchy.go (about)

     1  // Copyright 2020 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package cmd
     6  
     7  import (
     8  	"context"
     9  	"flag"
    10  	"fmt"
    11  	"strings"
    12  
    13  	"github.com/jhump/golang-x-tools/internal/lsp/protocol"
    14  	"github.com/jhump/golang-x-tools/internal/span"
    15  	"github.com/jhump/golang-x-tools/internal/tool"
    16  )
    17  
    18  // callHierarchy implements the callHierarchy verb for gopls.
    19  type callHierarchy struct {
    20  	app *Application
    21  }
    22  
    23  func (c *callHierarchy) Name() string      { return "call_hierarchy" }
    24  func (c *callHierarchy) Parent() string    { return c.app.Name() }
    25  func (c *callHierarchy) Usage() string     { return "<position>" }
    26  func (c *callHierarchy) ShortHelp() string { return "display selected identifier's call hierarchy" }
    27  func (c *callHierarchy) DetailedHelp(f *flag.FlagSet) {
    28  	fmt.Fprint(f.Output(), `
    29  Example:
    30  
    31  	$ # 1-indexed location (:line:column or :#offset) of the target identifier
    32  	$ gopls call_hierarchy helper/helper.go:8:6
    33  	$ gopls call_hierarchy helper/helper.go:#53
    34  `)
    35  	printFlagDefaults(f)
    36  }
    37  
    38  func (c *callHierarchy) Run(ctx context.Context, args ...string) error {
    39  	if len(args) != 1 {
    40  		return tool.CommandLineErrorf("call_hierarchy expects 1 argument (position)")
    41  	}
    42  
    43  	conn, err := c.app.connect(ctx)
    44  	if err != nil {
    45  		return err
    46  	}
    47  	defer conn.terminate(ctx)
    48  
    49  	from := span.Parse(args[0])
    50  	file := conn.AddFile(ctx, from.URI())
    51  	if file.err != nil {
    52  		return file.err
    53  	}
    54  
    55  	loc, err := file.mapper.Location(from)
    56  	if err != nil {
    57  		return err
    58  	}
    59  
    60  	p := protocol.CallHierarchyPrepareParams{
    61  		TextDocumentPositionParams: protocol.TextDocumentPositionParams{
    62  			TextDocument: protocol.TextDocumentIdentifier{URI: loc.URI},
    63  			Position:     loc.Range.Start,
    64  		},
    65  	}
    66  
    67  	callItems, err := conn.PrepareCallHierarchy(ctx, &p)
    68  	if err != nil {
    69  		return err
    70  	}
    71  	if len(callItems) == 0 {
    72  		return fmt.Errorf("function declaration identifier not found at %v", args[0])
    73  	}
    74  
    75  	for _, item := range callItems {
    76  		incomingCalls, err := conn.IncomingCalls(ctx, &protocol.CallHierarchyIncomingCallsParams{Item: item})
    77  		if err != nil {
    78  			return err
    79  		}
    80  		for i, call := range incomingCalls {
    81  			// From the spec: CallHierarchyIncomingCall.FromRanges is relative to
    82  			// the caller denoted by CallHierarchyIncomingCall.from.
    83  			printString, err := callItemPrintString(ctx, conn, call.From, call.From.URI, call.FromRanges)
    84  			if err != nil {
    85  				return err
    86  			}
    87  			fmt.Printf("caller[%d]: %s\n", i, printString)
    88  		}
    89  
    90  		printString, err := callItemPrintString(ctx, conn, item, "", nil)
    91  		if err != nil {
    92  			return err
    93  		}
    94  		fmt.Printf("identifier: %s\n", printString)
    95  
    96  		outgoingCalls, err := conn.OutgoingCalls(ctx, &protocol.CallHierarchyOutgoingCallsParams{Item: item})
    97  		if err != nil {
    98  			return err
    99  		}
   100  		for i, call := range outgoingCalls {
   101  			// From the spec: CallHierarchyOutgoingCall.FromRanges is the range
   102  			// relative to the caller, e.g the item passed to
   103  			printString, err := callItemPrintString(ctx, conn, call.To, item.URI, call.FromRanges)
   104  			if err != nil {
   105  				return err
   106  			}
   107  			fmt.Printf("callee[%d]: %s\n", i, printString)
   108  		}
   109  	}
   110  
   111  	return nil
   112  }
   113  
   114  // callItemPrintString returns a protocol.CallHierarchyItem object represented as a string.
   115  // item and call ranges (protocol.Range) are converted to user friendly spans (1-indexed).
   116  func callItemPrintString(ctx context.Context, conn *connection, item protocol.CallHierarchyItem, callsURI protocol.DocumentURI, calls []protocol.Range) (string, error) {
   117  	itemFile := conn.AddFile(ctx, item.URI.SpanURI())
   118  	if itemFile.err != nil {
   119  		return "", itemFile.err
   120  	}
   121  	itemSpan, err := itemFile.mapper.Span(protocol.Location{URI: item.URI, Range: item.Range})
   122  	if err != nil {
   123  		return "", err
   124  	}
   125  
   126  	callsFile := conn.AddFile(ctx, callsURI.SpanURI())
   127  	if callsURI != "" && callsFile.err != nil {
   128  		return "", callsFile.err
   129  	}
   130  	var callRanges []string
   131  	for _, rng := range calls {
   132  		callSpan, err := callsFile.mapper.Span(protocol.Location{URI: item.URI, Range: rng})
   133  		if err != nil {
   134  			return "", err
   135  		}
   136  
   137  		spn := fmt.Sprint(callSpan)
   138  		callRanges = append(callRanges, fmt.Sprint(spn[strings.Index(spn, ":")+1:]))
   139  	}
   140  
   141  	printString := fmt.Sprintf("function %s in %v", item.Name, itemSpan)
   142  	if len(calls) > 0 {
   143  		printString = fmt.Sprintf("ranges %s in %s from/to %s", strings.Join(callRanges, ", "), callsURI.SpanURI().Filename(), printString)
   144  	}
   145  	return printString, nil
   146  }