internal/configgen: add special handling for toolchain program versions

Main module version information is not stamped in toolchain binaries,
and therefore we do not have a program version for toolchain programs.

Rather than add special handling for toolchain programs in many places,
to handle the missing version, instead enforce the convention that for
toolchain programs, program version == go version.

Specifically:
- Add internal/telemetry.{IsToolchainProgram,ProgramInfo}, to share the
  logic for interrogating program information.
- Update ProgramInfo to reuse the go version as program version for
  toolchain programs.
- Update config generation to reuse the go version list as program
  version list, for toolchain programs.
- Use the go/version package rather than copying it, now that it is
  available. This means that the config generator requires go1.22, which
  should be fine as it is only run by developers or RelUI.
- Update config generation and validation to use go/version package
  rather than semver package for working with toolchain program
  versions.
- Move chartconfig.Validate to configgen.ValidateChartConfig, since
  validation now requires the go/version package and requires go1.22
  (chartconfig is linked by more packages).

For golang/go#67244

Change-Id: I226b18d37e1ad973002b19afa8afdb8cf97b358c
Reviewed-on: https://go-review.googlesource.com/c/telemetry/+/585198
Auto-Submit: Robert Findley <[email protected]>
Reviewed-by: Hyang-Ah Hana Kim <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: findleyr

internal/configgen/gover.go

@@ -4,7 +4,7 @@
 
 //go:generate go run . -w
 
-//go:build go1.21
+//go:build go1.22
 
 // Package configgen generates the upload config file stored in the config.json
 // file of golang.org/x/telemetry/config based on the chartconfig stored in
@@ -16,6 +16,7 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
+	"go/version"
 	"log"
 	"os"
 	"os/exec"
@@ -154,7 +155,7 @@ func generate(gcfgs []chartconfig.ChartConfig, padding padding) (*telemetry.Uplo
 	}
 
 	for i, r := range gcfgs {
-		if err := chartconfig.Validate(r); err != nil {
+		if err := ValidateChartConfig(r); err != nil {
 			// TODO(rfindley): this is a poor way to identify the faulty record. We
 			// should probably store position information in the ChartConfig.
 			return nil, fmt.Errorf("chart config #%d (%q): %v", i, r.Title, err)
@@ -189,27 +190,52 @@ func generate(gcfgs []chartconfig.ChartConfig, padding padding) (*telemetry.Uplo
 
 	for _, p := range programs {
 		minVersion := minVersions[p.Name]
-		versions, err := listProxyVersions(p.Name)
-		if err != nil {
-			return nil, fmt.Errorf("listing versions for %q: %v", p.Name, err)
-		}
-		// Filter proxy versions in place.
-		i := 0
-		for _, v := range versions {
-			if !semver.IsValid(v) {
-				// In order to perform semver comparison below, we must have valid
-				// versions. This should always be the case for the proxy.
-				// Trust, but verify.
-				return nil, fmt.Errorf("invalid semver %q returned from proxy for %q", v, p.Name)
+
+		// Collect eligible program versions. If p is a toolchain tool (cmd/go,
+		// cmd/compile, etc), these come out of the Go versions queried above.
+		// Otherwise, they come from the proxy.
+		//
+		// In both of these cases, the versions should be valid, but we verify
+		// anyway as otherwise the version comparison is meaningless.
+		// (and in fact, there is an invalid go1.9.2rc2 version in the proxy)
+		if telemetry.IsToolchainProgram(p.Name) {
+			// Note: no need to pad versions for toolchain programs, since the
+			// toolchain is released infrequently.
+			// (and in any case, version padding only works for semantic versions)
+			for _, v := range ucfg.GoVersion {
+				if !version.IsValid(v) {
+					// The proxy toolchain versions list go1.9.2rc2, which is invalid.
+					// Skip it. Note: this also filters out "devel", but that is added
+					// back below.
+					continue
+				}
+
+				if minVersion == "" || version.Compare(minVersion, v) <= 0 {
+					p.Versions = append(p.Versions, v)
+				}
+			}
+		} else {
+			versions, err := listProxyVersions(p.Name)
+			if err != nil {
+				return nil, fmt.Errorf("listing versions for %q: %v", p.Name, err)
 			}
-			if minVersion == "" || semver.Compare(minVersion, v) <= 0 {
-				versions[i] = v
-				i++
+			// Filter proxy versions in place.
+			i := 0
+			for _, v := range versions {
+				if !semver.IsValid(v) {
+					return nil, fmt.Errorf("invalid semver %q returned from proxy for %q", v, p.Name)
+				}
+				if minVersion == "" || semver.Compare(minVersion, v) <= 0 {
+					versions[i] = v
+					i++
+				}
 			}
+			p.Versions = padVersions(versions[:i], prereleasesForProgram(p.Name), padding)
 		}
-		p.Versions = padVersions(versions[:i], prereleasesForProgram(p.Name), padding)
-		// TODO(hakim): allow to collect counters from gopls@devel. go.dev/issues/62271
-		if p.Name == "golang.org/x/tools/gopls" {
+		// Allow collecting counters for devel versions of gopls and toolchain
+		// programs.
+		// TODO(golang/go#62271): revert once no longer needed
+		if p.Name == "golang.org/x/tools/gopls" || telemetry.IsToolchainProgram(p.Name) {
 			p.Versions = append(p.Versions, "devel") // added at the end.
 		}
 		ucfg.Programs = append(ucfg.Programs, p)
@@ -360,7 +386,7 @@ type byGoVersion []string
 func (vs byGoVersion) Len() int      { return len(vs) }
 func (vs byGoVersion) Swap(i, j int) { vs[i], vs[j] = vs[j], vs[i] }
 func (vs byGoVersion) Less(i, j int) bool {
-	cmp := Compare(vs[i], vs[j])
+	cmp := version.Compare(vs[i], vs[j])
 	if cmp != 0 {
 		return cmp < 0
 	}
@@ -445,7 +471,7 @@ func padVersions(versions []string, prereleasePatterns []string, padding padding
 	// This assumes that the program in question doesn't patch older releases
 	// (as is the case with gopls). If that assumption ever changes, we may need
 	// to apply padding to older versions as well.
-	versionsToPad := []version{parsedLatest}
+	versionsToPad := []semversion{parsedLatest}
 
 	var maj, min, patch int
 	for _, toPad := range versionsToPad {
@@ -501,16 +527,16 @@ func padVersions(versions []string, prereleasePatterns []string, padding padding
 }
 
 // version is a parsed semantic version.
-type version struct {
+type semversion struct {
 	major, minor, patch int
 	pre                 string
 }
 
 // parseSemver attempts to parse semver components out of the provided semver
 // v. If v is not valid semver in canonical form, parseSemver returns _, _, _,
 // _, false.
-func parseSemver(v string) (_ version, ok bool) {
-	var parsed version
+func parseSemver(v string) (_ semversion, ok bool) {
+	var parsed semversion
 	v, parsed.pre, _ = strings.Cut(v, "-")
 	if _, err := fmt.Sscanf(v, "v%d.%d.%d", &parsed.major, &parsed.minor, &parsed.patch); err == nil {
 		ok = true

internal/configgen/main.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.21
+//go:build go1.22
 
 package main
 

internal/configgen/main_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.21
+//go:build go1.22
 
 package main
 

internal/configgen/syslist.go

@@ -2,18 +2,23 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package chartconfig
+//go:build go1.22
+
+package main
 
 import (
 	"errors"
 	"fmt"
+	"go/version"
 
 	"golang.org/x/mod/semver"
+	"golang.org/x/telemetry/internal/chartconfig"
+	"golang.org/x/telemetry/internal/telemetry"
 )
 
-// Validate checks that a ChartConfig is complete and coherent, returning an
-// error describing all problems encountered, or nil.
-func Validate(cfg ChartConfig) error {
+// ValidateChartConfig checks that a ChartConfig is complete and coherent,
+// returning an error describing all problems encountered, or nil.
+func ValidateChartConfig(cfg chartconfig.ChartConfig) error {
 	var errs []error
 	reportf := func(format string, args ...any) {
 		errs = append(errs, fmt.Errorf(format, args...))
@@ -39,8 +44,12 @@ func Validate(cfg ChartConfig) error {
 	if cfg.Depth != 0 && cfg.Type != "stack" {
 		reportf("depth can only be set for \"stack\" chart types")
 	}
-	if cfg.Version != "" && !semver.IsValid(cfg.Version) {
-		reportf("%q is not valid semver", cfg.Version)
+	valid := semver.IsValid
+	if telemetry.IsToolchainProgram(cfg.Program) {
+		valid = version.IsValid
+	}
+	if cfg.Version != "" && !valid(cfg.Version) {
+		reportf("%q is not a valid version (must be a go version or semver)", cfg.Version)
 	}
 	return errors.Join(errs...)
 }