golang.org/x/tools/gopls@v0.15.3/internal/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  	"golang.org/x/tools/gopls/internal/protocol"
    14  	"golang.org/x/tools/internal/tool"
    15  )
    16  
    17  // callHierarchy implements the callHierarchy verb for gopls.
    18  type callHierarchy struct {
    19  	app *Application
    20  }
    21  
    22  func (c *callHierarchy) Name() string      { return "call_hierarchy" }
    23  func (c *callHierarchy) Parent() string    { return c.app.Name() }
    24  func (c *callHierarchy) Usage() string     { return "<position>" }
    25  func (c *callHierarchy) ShortHelp() string { return "display selected identifier's call hierarchy" }
    26  func (c *callHierarchy) DetailedHelp(f *flag.FlagSet) {
    27  	fmt.Fprint(f.Output(), `
    28  Example:
    29  
    30  	$ # 1-indexed location (:line:column or :#offset) of the target identifier
    31  	$ gopls call_hierarchy helper/helper.go:8:6
    32  	$ gopls call_hierarchy helper/helper.go:#53
    33  `)
    34  	printFlagDefaults(f)
    35  }
    36  
    37  func (c *callHierarchy) Run(ctx context.Context, args ...string) error {
    38  	if len(args) != 1 {
    39  		return tool.CommandLineErrorf("call_hierarchy expects 1 argument (position)")
    40  	}
    41  
    42  	conn, err := c.app.connect(ctx, nil)
    43  	if err != nil {
    44  		return err
    45  	}
    46  	defer conn.terminate(ctx)
    47  
    48  	from := parseSpan(args[0])
    49  	file, err := conn.openFile(ctx, from.URI())
    50  	if err != nil {
    51  		return err
    52  	}
    53  
    54  	loc, err := file.spanLocation(from)
    55  	if err != nil {
    56  		return err
    57  	}
    58  
    59  	p := protocol.CallHierarchyPrepareParams{
    60  		TextDocumentPositionParams: protocol.LocationTextDocumentPositionParams(loc),
    61  	}
    62  
    63  	callItems, err := conn.PrepareCallHierarchy(ctx, &p)
    64  	if err != nil {
    65  		return err
    66  	}
    67  	if len(callItems) == 0 {
    68  		return fmt.Errorf("function declaration identifier not found at %v", args[0])
    69  	}
    70  
    71  	for _, item := range callItems {
    72  		incomingCalls, err := conn.IncomingCalls(ctx, &protocol.CallHierarchyIncomingCallsParams{Item: item})
    73  		if err != nil {
    74  			return err
    75  		}
    76  		for i, call := range incomingCalls {
    77  			// From the spec: CallHierarchyIncomingCall.FromRanges is relative to
    78  			// the caller denoted by CallHierarchyIncomingCall.from.
    79  			printString, err := callItemPrintString(ctx, conn, call.From, call.From.URI, call.FromRanges)
    80  			if err != nil {
    81  				return err
    82  			}
    83  			fmt.Printf("caller[%d]: %s\n", i, printString)
    84  		}
    85  
    86  		printString, err := callItemPrintString(ctx, conn, item, "", nil)
    87  		if err != nil {
    88  			return err
    89  		}
    90  		fmt.Printf("identifier: %s\n", printString)
    91  
    92  		outgoingCalls, err := conn.OutgoingCalls(ctx, &protocol.CallHierarchyOutgoingCallsParams{Item: item})
    93  		if err != nil {
    94  			return err
    95  		}
    96  		for i, call := range outgoingCalls {
    97  			// From the spec: CallHierarchyOutgoingCall.FromRanges is the range
    98  			// relative to the caller, e.g the item passed to
    99  			printString, err := callItemPrintString(ctx, conn, call.To, item.URI, call.FromRanges)
   100  			if err != nil {
   101  				return err
   102  			}
   103  			fmt.Printf("callee[%d]: %s\n", i, printString)
   104  		}
   105  	}
   106  
   107  	return nil
   108  }
   109  
   110  // callItemPrintString returns a protocol.CallHierarchyItem object represented as a string.
   111  // item and call ranges (protocol.Range) are converted to user friendly spans (1-indexed).
   112  func callItemPrintString(ctx context.Context, conn *connection, item protocol.CallHierarchyItem, callsURI protocol.DocumentURI, calls []protocol.Range) (string, error) {
   113  	itemFile, err := conn.openFile(ctx, item.URI)
   114  	if err != nil {
   115  		return "", err
   116  	}
   117  	itemSpan, err := itemFile.rangeSpan(item.Range)
   118  	if err != nil {
   119  		return "", err
   120  	}
   121  
   122  	var callRanges []string
   123  	if callsURI != "" {
   124  		callsFile, err := conn.openFile(ctx, callsURI)
   125  		if err != nil {
   126  			return "", err
   127  		}
   128  		for _, rng := range calls {
   129  			call, err := callsFile.rangeSpan(rng)
   130  			if err != nil {
   131  				return "", err
   132  			}
   133  			callRange := fmt.Sprintf("%d:%d-%d", call.Start().Line(), call.Start().Column(), call.End().Column())
   134  			callRanges = append(callRanges, callRange)
   135  		}
   136  	}
   137  
   138  	printString := fmt.Sprintf("function %s in %v", item.Name, itemSpan)
   139  	if len(calls) > 0 {
   140  		printString = fmt.Sprintf("ranges %s in %s from/to %s", strings.Join(callRanges, ", "), callsURI.Path(), printString)
   141  	}
   142  	return printString, nil
   143  }