Revert "cmd/go/internal/modload: record the replacement for the module containing package main in BuildInfo"

This reverts CL 220645 (commit e092fc352a).

Reason for revert: Seems to have broken windows/amd64 longtest

Change-Id: Iffa8c882524250e5845514bc827fcd8927645a44
Reviewed-on: https://go-review.googlesource.com/c/go/+/220722
Run-TryBot: Andrew Bonventre <andybons@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/go/internal/modload/build.go

@@ -207,7 +207,6 @@ func PackageBuildInfo(path string, deps []string) string {
 	if isStandardImportPath(path) || !Enabled() {
 		return ""
 	}
-
 	target := mustFindModule(path, path)
 	mdeps := make(map[module.Version]bool)
 	for _, dep := range deps {
@@ -224,25 +223,26 @@ func PackageBuildInfo(path string, deps []string) string {
 
 	var buf bytes.Buffer
 	fmt.Fprintf(&buf, "path\t%s\n", path)
-
-	writeEntry := func(token string, m module.Version) {
-		mv := m.Version
+	tv := target.Version
+	if tv == "" {
+		tv = "(devel)"
+	}
+	fmt.Fprintf(&buf, "mod\t%s\t%s\t%s\n", target.Path, tv, modfetch.Sum(target))
+	for _, mod := range mods {
+		mv := mod.Version
 		if mv == "" {
 			mv = "(devel)"
 		}
-		fmt.Fprintf(&buf, "%s\t%s\t%s", token, m.Path, mv)
-		if r := Replacement(m); r.Path == "" {
-			fmt.Fprintf(&buf, "\t%s\n", modfetch.Sum(m))
-		} else {
-			fmt.Fprintf(&buf, "\n=>\t%s\t%s\t%s\n", r.Path, r.Version, modfetch.Sum(r))
+		r := Replacement(mod)
+		h := ""
+		if r.Path == "" {
+			h = "\t" + modfetch.Sum(mod)
+		}
+		fmt.Fprintf(&buf, "dep\t%s\t%s%s\n", mod.Path, mv, h)
+		if r.Path != "" {
+			fmt.Fprintf(&buf, "=>\t%s\t%s\t%s\n", r.Path, r.Version, modfetch.Sum(r))
 		}
 	}
-
-	writeEntry("mod", target)
-	for _, mod := range mods {
-		writeEntry("dep", mod)
-	}
-
 	return buf.String()
 }
 

src/cmd/go/testdata/mod/example.com_printversion_v0.1.0.txt

@@ -21,13 +21,7 @@ func main() {
 	info, _ := debug.ReadBuildInfo()
 	fmt.Fprintf(os.Stdout, "path is %s\n", info.Path)
 	fmt.Fprintf(os.Stdout, "main is %s %s\n", info.Main.Path, info.Main.Version)
-	if r := info.Main.Replace; r != nil {
-		fmt.Fprintf(os.Stdout, "\t(replaced by %s %s)\n", r.Path, r.Version)
-	}
 	for _, m := range info.Deps {
 		fmt.Fprintf(os.Stdout, "using %s %s\n", m.Path, m.Version)
-		if r := m.Replace; r != nil {
-			fmt.Fprintf(os.Stdout, "\t(replaced by %s %s)\n", r.Path, r.Version)
-		}
 	}
 }

src/cmd/go/testdata/mod/example.com_printversion_v1.0.0.txt

@@ -29,13 +29,7 @@ func main() {
 	info, _ := debug.ReadBuildInfo()
 	fmt.Fprintf(os.Stdout, "path is %s\n", info.Path)
 	fmt.Fprintf(os.Stdout, "main is %s %s\n", info.Main.Path, info.Main.Version)
-	if r := info.Main.Replace; r != nil {
-		fmt.Fprintf(os.Stdout, "\t(replaced by %s %s)\n", r.Path, r.Version)
-	}
 	for _, m := range info.Deps {
 		fmt.Fprintf(os.Stdout, "using %s %s\n", m.Path, m.Version)
-		if r := m.Replace; r != nil {
-			fmt.Fprintf(os.Stdout, "\t(replaced by %s %s)\n", r.Path, r.Version)
-		}
 	}
 }

src/cmd/go/testdata/script/version_replace.txt

@@ -1,33 +0,0 @@
-[short] skip
-
-go mod download example.com/printversion@v0.1.0 example.com/printversion@v1.0.0
-
-go install example.com/printversion
-
-go run example.com/printversion
-cmp stdout out.txt
-
-go version -m $GOPATH/bin/printversion
-stdout '^.*[/\\]bin[/\\]printversion: .*$'
-stdout '^	path	example.com/printversion$'
-stdout '^	mod	example.com/printversion	v0.1.0$'
-stdout '^	=>	example.com/printversion	v1.0.0	h1:.*$'
-stdout '^	dep	example.com/version	v1.0.0$'
-stdout '^	=>	example.com/version	v1.0.1	h1:.*$'
-
--- go.mod --
-module golang.org/issue/37392
-go 1.14
-require (
-	example.com/printversion v0.1.0
-)
-replace (
-	example.com/printversion => example.com/printversion v1.0.0
-	example.com/version v1.0.0 => example.com/version v1.0.1
-)
--- out.txt --
-path is example.com/printversion
-main is example.com/printversion v0.1.0
-	(replaced by example.com/printversion v1.0.0)
-using example.com/version v1.0.0
-	(replaced by example.com/version v1.0.1)

src/runtime/debug/mod.go

@@ -47,27 +47,9 @@ func readBuildInfo(data string) (*BuildInfo, bool) {
 		repLine  = "=>\t"
 	)
 
-	readEntryFirstLine := func(elem []string) (Module, bool) {
-		if len(elem) != 2 && len(elem) != 3 {
-			return Module{}, false
-		}
-		sum := ""
-		if len(elem) == 3 {
-			sum = elem[2]
-		}
-		return Module{
-			Path:    elem[0],
-			Version: elem[1],
-			Sum:     sum,
-		}, true
-	}
+	info := &BuildInfo{}
 
-	var (
-		info = &BuildInfo{}
-		last *Module
-		line string
-		ok   bool
-	)
+	var line string
 	// Reverse of cmd/go/internal/modload.PackageBuildInfo
 	for len(data) > 0 {
 		i := strings.IndexByte(data, '\n')
@@ -81,33 +63,42 @@ func readBuildInfo(data string) (*BuildInfo, bool) {
 			info.Path = elem
 		case strings.HasPrefix(line, modLine):
 			elem := strings.Split(line[len(modLine):], "\t")
-			last = &info.Main
-			*last, ok = readEntryFirstLine(elem)
-			if !ok {
+			if len(elem) != 3 {
 				return nil, false
 			}
+			info.Main = Module{
+				Path:    elem[0],
+				Version: elem[1],
+				Sum:     elem[2],
+			}
 		case strings.HasPrefix(line, depLine):
 			elem := strings.Split(line[len(depLine):], "\t")
-			last = new(Module)
-			info.Deps = append(info.Deps, last)
-			*last, ok = readEntryFirstLine(elem)
-			if !ok {
+			if len(elem) != 2 && len(elem) != 3 {
 				return nil, false
 			}
+			sum := ""
+			if len(elem) == 3 {
+				sum = elem[2]
+			}
+			info.Deps = append(info.Deps, &Module{
+				Path:    elem[0],
+				Version: elem[1],
+				Sum:     sum,
+			})
 		case strings.HasPrefix(line, repLine):
 			elem := strings.Split(line[len(repLine):], "\t")
 			if len(elem) != 3 {
 				return nil, false
 			}
-			if last == nil {
+			last := len(info.Deps) - 1
+			if last < 0 {
 				return nil, false
 			}
-			last.Replace = &Module{
+			info.Deps[last].Replace = &Module{
 				Path:    elem[0],
 				Version: elem[1],
 				Sum:     elem[2],
 			}
-			last = nil
 		}
 	}
 	return info, true