Text file src/cmd/go/testdata/script/list_modindex_dupactionid.txt

     1  # This is a regression test for #652435. It checks that we don't generate
     2  # multiple action entry ids for the same index file. That was happening
     3  # previously because we sometimes generated the action id with unclean
     4  # paths (and the rest of the time with clean paths) for the same package.
     5  # This test will use a go program ('check') to check the cache that there are
     6  # no two action entry files that point to the same object id.
     7  
     8  [short] skip 'builds and runs a go program'
     9  sleep 2s # Sleep so that the unpacked files are > 2 seconds old. The index won't be used if the modified times on the files are newer.
    10  go build -o check$GOEXE check.go
    11  cd mod
    12  env GOCACHE=$WORK/newcache # Run list command in a clean cache.
    13  go list all
    14  exec ../check$GOEXE
    15  
    16  -- mod/go.mod --
    17  module example.com/foo
    18  -- mod/foo.go --
    19  package foo
    20  -- check.go --
    21  package main
    22  
    23  import (
    24  	"errors"
    25  	"log"
    26  	"os"
    27  	"path/filepath"
    28  	"strings"
    29  )
    30  
    31  func main() {
    32  	cachedir := os.Getenv("GOCACHE")
    33  	if cachedir == "" {
    34  		log.Fatal("GOCACHE env var is empty; expected it to be set")
    35  	}
    36  
    37  	// Read the top level cache directory. The cache directory contains directories with
    38  	// each of the possible two hex digit prefixes (00-FF) of a cache entry's id.
    39  	// Those directories in turn contain files with the hex id followed by either
    40  	// "-a" for the action entries or "-d" for the object entries. We want to check
    41  	// if two action entries point to the same object entry so we'll iterate through
    42  	// all the "-a" files and see if any two of them refer to the same object id
    43  	// (corresponding to a "-d" file).
    44  	dirs, err := os.ReadDir(cachedir)
    45  	if err != nil {
    46  		log.Fatal(err)
    47  	}
    48  
    49  	seen := map[string]string{} // object id -> action id
    50  
    51  	for _, entry := range dirs {
    52  		if entry.IsDir() && len(entry.Name()) == 2 {
    53  			prefixdir := filepath.Join(cachedir, entry.Name())
    54  			entries, err := os.ReadDir(prefixdir)
    55  			if err != nil {
    56  				log.Fatal(err)
    57  			}
    58  
    59  			for _, entry := range entries {
    60  				if !strings.HasSuffix(entry.Name(), "-a") {
    61  					// not an action id entry
    62  					continue
    63  				}
    64  				actionEntryFile := filepath.Join(prefixdir, entry.Name())
    65  				objid, err := objectid(actionEntryFile)
    66  				if err != nil {
    67  					log.Fatal(err)
    68  				}
    69  				if other, ok := seen[objid]; ok {
    70  					log.Printf("found two action entry files (%s, %s) pointing to the same object id: %s", other, entry.Name(), objid)
    71  					os.Exit(1)
    72  				}
    73  				seen[objid] = entry.Name()
    74  			}
    75  		}
    76  	}
    77  }
    78  
    79  // objectid returns the object id that the given actionEntryFile points to.
    80  func objectid(actionEntryFile string) (string, error) {
    81  	// See cmd/go/internal/cache.(*DiskCache).get for the code that reads
    82  	// from the action entry files. The following is based on that function.
    83  	const (
    84  		HashSize  = 32
    85  		hexSize   = HashSize * 2
    86  		entrySize = 2 + 1 + hexSize + 1 + hexSize + 1 + 20 + 1 + 20 + 1
    87  	)
    88  
    89  	entry, err := os.ReadFile(actionEntryFile)
    90  	if err != nil {
    91  		return "", err
    92  	}
    93  	if len(entry) < entrySize {
    94  		return "", errors.New("entry file incomplete")
    95  	}
    96  	if entry[0] != 'v' || entry[1] != '1' || entry[2] != ' ' || entry[3+hexSize] != ' ' || entry[3+hexSize+1+hexSize] != ' ' || entry[3+hexSize+1+hexSize+1+20] != ' ' || entry[entrySize-1] != '\n' {
    97  		return "", errors.New("invalid header")
    98  	}
    99  	return string(entry[3+hexSize+1 : 3+hexSize+1+hexSize]), nil
   100  }
   101  

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