1 files changed, 105 insertions, 0 deletions
diff --git a/src/cmd/dist/buildruntime.go b/src/cmd/dist/buildruntime.go
new file mode 100644
index 0000000..fdc1d25
--- /dev/null
+++ b/src/cmd/dist/buildruntime.go
@@ -0,0 +1,105 @@
+// Copyright 2012 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 main
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"strings"
+)
+
+/*
+ * Helpers for building runtime.
+ */
+
+// mkzversion writes zversion.go:
+//
+//	package sys
+//
+//	const StackGuardMultiplier = <multiplier value>
+//
+func mkzversion(dir, file string) {
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, "// Code generated by go tool dist; DO NOT EDIT.\n")
+	fmt.Fprintln(&buf)
+	fmt.Fprintf(&buf, "package sys\n")
+	fmt.Fprintln(&buf)
+	fmt.Fprintf(&buf, "const StackGuardMultiplierDefault = %d\n", stackGuardMultiplierDefault())
+
+	writefile(buf.String(), file, writeSkipSame)
+}
+
+// mkbuildcfg writes internal/buildcfg/zbootstrap.go:
+//
+//	package buildcfg
+//
+//	const defaultGOROOT = <goroot>
+//	const defaultGO386 = <go386>
+//	...
+//	const defaultGOOS = runtime.GOOS
+//	const defaultGOARCH = runtime.GOARCH
+//
+// The use of runtime.GOOS and runtime.GOARCH makes sure that
+// a cross-compiled compiler expects to compile for its own target
+// system. That is, if on a Mac you do:
+//
+//	GOOS=linux GOARCH=ppc64 go build cmd/compile
+//
+// the resulting compiler will default to generating linux/ppc64 object files.
+// This is more useful than having it default to generating objects for the
+// original target (in this example, a Mac).
+func mkbuildcfg(file string) {
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, "// Code generated by go tool dist; DO NOT EDIT.\n")
+	fmt.Fprintln(&buf)
+	fmt.Fprintf(&buf, "package buildcfg\n")
+	fmt.Fprintln(&buf)
+	fmt.Fprintf(&buf, "import \"runtime\"\n")
+	fmt.Fprintln(&buf)
+	fmt.Fprintf(&buf, "const defaultGO386 = `%s`\n", go386)
+	fmt.Fprintf(&buf, "const defaultGOAMD64 = `%s`\n", goamd64)
+	fmt.Fprintf(&buf, "const defaultGOARM = `%s`\n", goarm)
+	fmt.Fprintf(&buf, "const defaultGOMIPS = `%s`\n", gomips)
+	fmt.Fprintf(&buf, "const defaultGOMIPS64 = `%s`\n", gomips64)
+	fmt.Fprintf(&buf, "const defaultGOPPC64 = `%s`\n", goppc64)
+	fmt.Fprintf(&buf, "const defaultGOEXPERIMENT = `%s`\n", goexperiment)
+	fmt.Fprintf(&buf, "const defaultGO_EXTLINK_ENABLED = `%s`\n", goextlinkenabled)
+	fmt.Fprintf(&buf, "const defaultGO_LDSO = `%s`\n", defaultldso)
+	fmt.Fprintf(&buf, "const version = `%s`\n", findgoversion())
+	fmt.Fprintf(&buf, "const defaultGOOS = runtime.GOOS\n")
+	fmt.Fprintf(&buf, "const defaultGOARCH = runtime.GOARCH\n")
+
+	writefile(buf.String(), file, writeSkipSame)
+}
+
+// mkobjabi writes cmd/internal/objabi/zbootstrap.go:
+//
+//	package objabi
+//
+//	const stackGuardMultiplierDefault = <multiplier value>
+//
+func mkobjabi(file string) {
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, "// Code generated by go tool dist; DO NOT EDIT.\n")
+	fmt.Fprintln(&buf)
+	fmt.Fprintf(&buf, "package objabi\n")
+	fmt.Fprintln(&buf)
+	fmt.Fprintf(&buf, "const stackGuardMultiplierDefault = %d\n", stackGuardMultiplierDefault())
+
+	writefile(buf.String(), file, writeSkipSame)
+}
+
+// stackGuardMultiplierDefault returns a multiplier to apply to the default
+// stack guard size. Larger multipliers are used for non-optimized
+// builds that have larger stack frames.
+func stackGuardMultiplierDefault() int {
+	for _, s := range strings.Split(os.Getenv("GO_GCFLAGS"), " ") {
+		if s == "-N" {
+			return 2
+		}
+	}
+	return 1
+}