diff options
Diffstat (limited to 'vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go')
-rw-r--r-- | vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go b/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go new file mode 100644 index 00000000..fdc7da05 --- /dev/null +++ b/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go @@ -0,0 +1,160 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package packagesdriver fetches type sizes for go/packages and go/analysis. +package packagesdriver + +import ( + "bytes" + "context" + "encoding/json" + "fmt" + "go/types" + "log" + "os" + "os/exec" + "strings" + "time" +) + +var debug = false + +// GetSizes returns the sizes used by the underlying driver with the given parameters. +func GetSizes(ctx context.Context, buildFlags, env []string, dir string, usesExportData bool) (types.Sizes, error) { + // TODO(matloob): Clean this up. This code is mostly a copy of packages.findExternalDriver. + const toolPrefix = "GOPACKAGESDRIVER=" + tool := "" + for _, env := range env { + if val := strings.TrimPrefix(env, toolPrefix); val != env { + tool = val + } + } + + if tool == "" { + var err error + tool, err = exec.LookPath("gopackagesdriver") + if err != nil { + // We did not find the driver, so use "go list". + tool = "off" + } + } + + if tool == "off" { + return GetSizesGolist(ctx, buildFlags, env, dir, usesExportData) + } + + req, err := json.Marshal(struct { + Command string `json:"command"` + Env []string `json:"env"` + BuildFlags []string `json:"build_flags"` + }{ + Command: "sizes", + Env: env, + BuildFlags: buildFlags, + }) + if err != nil { + return nil, fmt.Errorf("failed to encode message to driver tool: %v", err) + } + + buf := new(bytes.Buffer) + cmd := exec.CommandContext(ctx, tool) + cmd.Dir = dir + cmd.Env = env + cmd.Stdin = bytes.NewReader(req) + cmd.Stdout = buf + cmd.Stderr = new(bytes.Buffer) + if err := cmd.Run(); err != nil { + return nil, fmt.Errorf("%v: %v: %s", tool, err, cmd.Stderr) + } + var response struct { + // Sizes, if not nil, is the types.Sizes to use when type checking. + Sizes *types.StdSizes + } + if err := json.Unmarshal(buf.Bytes(), &response); err != nil { + return nil, err + } + return response.Sizes, nil +} + +func GetSizesGolist(ctx context.Context, buildFlags, env []string, dir string, usesExportData bool) (types.Sizes, error) { + args := []string{"list", "-f", "{{context.GOARCH}} {{context.Compiler}}"} + args = append(args, buildFlags...) + args = append(args, "--", "unsafe") + stdout, err := InvokeGo(ctx, env, dir, usesExportData, args...) + if err != nil { + return nil, err + } + fields := strings.Fields(stdout.String()) + if len(fields) < 2 { + return nil, fmt.Errorf("could not determine GOARCH and Go compiler") + } + goarch := fields[0] + compiler := fields[1] + return types.SizesFor(compiler, goarch), nil +} + +// InvokeGo returns the stdout of a go command invocation. +func InvokeGo(ctx context.Context, env []string, dir string, usesExportData bool, args ...string) (*bytes.Buffer, error) { + if debug { + defer func(start time.Time) { log.Printf("%s for %v", time.Since(start), cmdDebugStr(env, args...)) }(time.Now()) + } + stdout := new(bytes.Buffer) + stderr := new(bytes.Buffer) + cmd := exec.CommandContext(ctx, "go", args...) + // On darwin the cwd gets resolved to the real path, which breaks anything that + // expects the working directory to keep the original path, including the + // go command when dealing with modules. + // The Go stdlib has a special feature where if the cwd and the PWD are the + // same node then it trusts the PWD, so by setting it in the env for the child + // process we fix up all the paths returned by the go command. + cmd.Env = append(append([]string{}, env...), "PWD="+dir) + cmd.Dir = dir + cmd.Stdout = stdout + cmd.Stderr = stderr + if err := cmd.Run(); err != nil { + exitErr, ok := err.(*exec.ExitError) + if !ok { + // Catastrophic error: + // - executable not found + // - context cancellation + return nil, fmt.Errorf("couldn't exec 'go %v': %s %T", args, err, err) + } + + // Export mode entails a build. + // If that build fails, errors appear on stderr + // (despite the -e flag) and the Export field is blank. + // Do not fail in that case. + if !usesExportData { + return nil, fmt.Errorf("go %v: %s: %s", args, exitErr, stderr) + } + } + + // As of writing, go list -export prints some non-fatal compilation + // errors to stderr, even with -e set. We would prefer that it put + // them in the Package.Error JSON (see https://golang.org/issue/26319). + // In the meantime, there's nowhere good to put them, but they can + // be useful for debugging. Print them if $GOPACKAGESPRINTGOLISTERRORS + // is set. + if len(stderr.Bytes()) != 0 && os.Getenv("GOPACKAGESPRINTGOLISTERRORS") != "" { + fmt.Fprintf(os.Stderr, "%s stderr: <<%s>>\n", cmdDebugStr(env, args...), stderr) + } + + // debugging + if false { + fmt.Fprintf(os.Stderr, "%s stdout: <<%s>>\n", cmdDebugStr(env, args...), stdout) + } + + return stdout, nil +} + +func cmdDebugStr(envlist []string, args ...string) string { + env := make(map[string]string) + for _, kv := range envlist { + split := strings.Split(kv, "=") + k, v := split[0], split[1] + env[k] = v + } + + return fmt.Sprintf("GOROOT=%v GOPATH=%v GO111MODULE=%v PWD=%v go %v", env["GOROOT"], env["GOPATH"], env["GO111MODULE"], env["PWD"], args) +} |