fix(go): Compilation errors on GOOS=windows

.github/workflows/library_go_tests.yml

@@ -34,7 +34,12 @@ jobs:
             # the sys.path workaround for generated Dafny doesn't work on Windows.
             # Note: only tests use the sys.path workaround, not source code.
             # Windows source code is tested downstream (ex. ESDK-Python CI).
-            # windows-latest,
+            # TODO: clarify the comment above given:
+            #   Go tests should be performed on a 
+            #   windows machine because packages in StandardLibrary (Time_) uses 
+            #   the syscall package, which does not contain the same functions/types 
+            #   across operating systems. 
+            windows-latest,
             ubuntu-22.04,
             macos-13,
           ]

StandardLibrary/runtimes/go/ImplementationFromDafny-go/Time_/externs.go

@@ -1,7 +1,6 @@
 package _Time
 
 import (
-	"syscall"
 	"time"
 
 	"github.com/aws/aws-cryptographic-material-providers-library/releases/go/smithy-dafny-standard-library/Wrappers"
@@ -35,13 +34,4 @@ func CurrentRelativeTimeMilli() int64 {
 
 func (CompanionStruct_Default___) GetProcessCpuTimeMillis() int64 {
 	return GetProcessCpuTimeMillis()
-}
-
-func GetProcessCpuTimeMillis() int64 {
-	var usage syscall.Rusage
-	err := syscall.Getrusage(syscall.RUSAGE_SELF, &usage)
-	if err != nil {
-		return 0
-	}
-	return (usage.Utime.Nano() + usage.Stime.Nano()) / 1000000
-}
+}

StandardLibrary/runtimes/go/ImplementationFromDafny-go/Time_/externs_unix.go

@@ -0,0 +1,19 @@
+//go:build !windows
+// +build !windows
+
+package _Time
+
+import (
+	"syscall"
+)
+
+
+
+func GetProcessCpuTimeMillis() int64 {
+	var usage syscall.Rusage
+	err := syscall.Getrusage(syscall.RUSAGE_SELF, &usage)
+	if err != nil {
+		return 0
+	}
+	return (usage.Utime.Nano() + usage.Stime.Nano()) / 1000000
+}

StandardLibrary/runtimes/go/ImplementationFromDafny-go/Time_/externs_windows.go

@@ -0,0 +1,23 @@
+//go:build windows
+// +build windows
+
+package _Time
+
+import (
+	"golang.org/x/sys/windows"
+)
+
+
+func GetProcessCpuTimeMillis() int64 {
+	windows.GetCurrentProcessId()
+	var proc_handle windows.Handle
+	var err error
+	if proc_handle, err = windows.OpenProcess(windows.PROCESS_QUERY_INFORMATION|windows.PROCESS_VM_READ, false, uint32(windows.GetCurrentProcessId())); err != nil {
+		return 0
+	}
+	var creation_time, exit_time, kernel_time, user_time *windows.Filetime
+	if err = windows.GetProcessTimes(proc_handle, creation_time, exit_time, kernel_time, user_time); err != nil {
+		return 0
+	}
+	return (int64(kernel_time.Nanoseconds()) + int64(user_time.Nanoseconds())) / 1000000
+}

StandardLibrary/runtimes/go/ImplementationFromDafny-go/go.mod

@@ -1,7 +1,9 @@
 module github.com/aws/aws-cryptographic-material-providers-library/releases/go/smithy-dafny-standard-library
 
-go 1.23.0
+go 1.24.0
 
 require github.com/dafny-lang/DafnyRuntimeGo/v4 v4.9.2
 
 require github.com/google/uuid v1.6.0
+
+require golang.org/x/sys v0.36.0 // indirect

StandardLibrary/runtimes/go/ImplementationFromDafny-go/go.sum

@@ -2,3 +2,5 @@ github.com/dafny-lang/DafnyRuntimeGo/v4 v4.9.2 h1:g/xAj4F7Zt9wXJ6QjfbfocVi/ZYlAF
 github.com/dafny-lang/DafnyRuntimeGo/v4 v4.9.2/go.mod h1:l2Tm4N2DKuq3ljONC2vOATeM9PUpXbIc8SgXdwwqEto=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+golang.org/x/sys v0.36.0 h1:KVRy2GtZBrk1cBYA7MKu5bEZFxQk4NIDV6RLVcC8o0k=
+golang.org/x/sys v0.36.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=