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From: mural <mural@ctli.io>
To: ~eliasnaur/gio-patches@lists.sr.ht
Cc: mural <mural@ctli.io>
Subject: [gio] app/internal/log: add logger for Windows DebugView
Date: Fri, 10 Jan 2020 22:45:48 +0800
Message-Id: <20200110144548.34087-1-mural@ctli.io>
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Signed-off-by: mural <mural@ctli.io>
---
 app/internal/log/log_windows.go | 41 +++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 app/internal/log/log_windows.go

diff --git a/app/internal/log/log_windows.go b/app/internal/log/log_windo=
ws.go
new file mode 100644
index 0000000..2019bcd
--- /dev/null
+++ b/app/internal/log/log_windows.go
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package log
+
+import (
+	"io"
+	"log"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+type logger struct{}
+
+var (
+	kernel32           =3D syscall.NewLazyDLL("kernel32")
+	outputDebugStringW =3D kernel32.NewProc("OutputDebugStringW")
+	debugView          *logger
+)
+
+func init() {
+	// Windows DebugView already includes timestamps.
+	log.SetFlags(log.Flags() &^ log.LstdFlags)
+
+	var out io.Writer
+	if syscall.Stderr !=3D syscall.InvalidHandle {
+		out =3D os.Stderr
+	} else {
+		out =3D debugView
+	}
+	log.SetOutput(out)
+}
+
+func (l *logger) Write(buf []byte) (int, error) {
+	p, err :=3D syscall.UTF16PtrFromString(string(buf))
+	if err !=3D nil {
+		return 0, err
+	}
+	outputDebugStringW.Call(uintptr(unsafe.Pointer(p)))
+	return len(buf), nil
+}
--=20
2.19.1