update

Author: adambenhassen

src/runtime/proc.go

@@ -728,21 +728,13 @@ const (
 	_GoidCacheBatch = 16
 )
 
-// cpuinit sets up CPU feature flags and calls internal/cpu.Initialize. 
-func cpuinit() {
+// cpuinit sets up CPU feature flags and calls internal/cpu.Initialize. env should be the complete
+// value of the GODEBUG environment variable.
+func cpuinit(env string) {
 	switch GOOS {
 	case "aix", "darwin", "ios", "dragonfly", "freebsd", "netbsd", "openbsd", "illumos", "solaris", "linux":
 		cpu.DebugOptions = true
 	}
-
-	// find GODEBUG in envs
-	var env string // env should be the complete value of the GODEBUG environment variable.
-	for _, value := range envs {
-		if stringslite.HasPrefix(value, "GODEBUG=") {
-			env = value
-			break
-		}
-	}
 	cpu.Initialize(env)
 
 	// Support cpu feature variables are used in code generated by the compiler
@@ -761,6 +753,49 @@ func cpuinit() {
 	}
 }
 
+// getGodebugEarly extracts the environment variable GODEBUG from the environment on
+// Unix-like operating systems and returns it. This function exists to extract GODEBUG
+// early before much of the runtime is initialized.
+func getGodebugEarly() string {
+	const prefix = "GODEBUG="
+	var env string
+	switch GOOS {
+	case "aix", "darwin", "ios", "dragonfly", "freebsd", "netbsd", "openbsd", "illumos", "solaris", "linux":
+		// Similar to goenv_unix but extracts the environment value for
+		// GODEBUG directly.
+		// TODO(moehrmann): remove when general goenvs() can be called before cpuinit()
+
+		// If the binary is an archive or a library, the operating system is Linux,
+		// and the system uses Musl, then read the environment variables from the
+		// /proc/self/environ file. Iterate over each null-terminated string read
+		// from the file. If any string has the specified prefix, return that string.
+		if libmusl {
+			for _, value := range readNullTerminatedStringsFromFile(procEnviron) {
+				if stringslite.HasPrefix(value, prefix) {
+					return value
+				}
+			}
+			return env
+		}
+
+		n := int32(0)
+		for argv_index(argv, argc+1+n) != nil {
+			n++
+		}
+
+		for i := int32(0); i < n; i++ {
+			p := argv_index(argv, argc+1+i)
+			s := unsafe.String(p, findnull(p))
+
+			if stringslite.HasPrefix(s, prefix) {
+				env = gostring(p)[len(prefix):]
+				break
+			}
+		}
+	}
+	return env
+}
+
 // The bootstrap sequence is:
 //
 //	call osinit
@@ -806,10 +841,10 @@ func schedinit() {
 	moduledataverify()
 	stackinit()
 	mallocinit()
-	goenvs()
-	cpuinit()  // must run before alginit
-	randinit() // must run before alginit, mcommoninit
-	alginit()  // maps, hash, rand must not be used before this call
+	godebug := getGodebugEarly()
+	cpuinit(godebug) // must run before alginit
+	randinit()       // must run before alginit, mcommoninit
+	alginit()        // maps, hash, rand must not be used before this call
 	mcommoninit(gp.m, -1)
 	modulesinit()   // provides activeModules
 	typelinksinit() // uses maps, activeModules
@@ -820,6 +855,7 @@ func schedinit() {
 	initSigmask = gp.m.sigmask
 
 	goargs()
+	goenvs()
 	secure()
 	checkfds()
 	parsedebugvars()