1 files changed, 94 insertions, 0 deletions
diff --git a/src/fluent-bit/plugins/in_exec/in_exec_win32_compat.h b/src/fluent-bit/plugins/in_exec/in_exec_win32_compat.h
new file mode 100644
index 000000000..9f0dfe695
--- /dev/null
+++ b/src/fluent-bit/plugins/in_exec/in_exec_win32_compat.h
@@ -0,0 +1,94 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/*  Fluent Bit
+ *  ==========
+ *  Copyright (C) 2015-2022 The Fluent Bit Authors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+#ifndef FLB_IN_EXEC_WIN32_COMPAT_H
+#define FLB_IN_EXEC_WIN32_COMPAT_H
+
+#include <stdio.h>
+#include <fluent-bit/flb_info.h>
+
+/*
+ * Work around lack of sys/wait.h and POSIX exit status macros from waitpid()
+ * in win32's _popen() and _pclose() implementation, since fluent-bit uses
+ * these in the in_exec plugin.
+ *
+ * On POSIX-like OSes this'll just use the standard macros with a name alias.
+ *
+ * On windows, where the concept of a signal exit does not exist, it defines
+ * dummy macros to indicate that the process exited normally and extract the
+ * exit code.
+ *
+ * These macros are for use with flb_pclose() only. Do not use them with
+ * other APIs that may differ in return value semantics.
+ */
+#ifdef FLB_HAVE_SYS_WAIT_H
+#include <sys/wait.h>
+#define FLB_WIFEXITED(status) WIFEXITED((status))
+#define FLB_WEXITSTATUS(status) WEXITSTATUS((status))
+#define FLB_WIFSIGNALED(status) WIFSIGNALED((status))
+#define FLB_WTERMSIG(status) WTERMSIG((status))
+#else
+#define FLB_WIFEXITED(status) (1)
+#define FLB_WEXITSTATUS(status) ((status) & 0x00ff)
+#define FLB_WIFSIGNALED(status) (0)
+#define FLB_WTERMSIG(status) (-1)
+#endif
+
+/*
+ * Because Windows has to do everything differently, call _popen() and
+ * _pclose() instead of the POSIX popen() and pclose() functions.
+ *
+ * flb_pclose() has different return value semantics on Windows vs non-windows
+ * targets because it propagates the pclose() or _pclose() return value
+ * directly. You MUST use the FLB_WIFEXITED(), FLB_WEXITSTATUS(),
+ * FLB_WIFSIGNALED() and FLB_WTERMSIG() macros to consume the return value,
+ * rather than the underlying POSIX macros or manual bit-shifts.
+ */
+#if !defined(FLB_SYSTEM_WINDOWS)
+static inline FILE* flb_popen(const char *command, const char *type) {
+    return popen(command, type);
+}
+static inline int flb_pclose(FILE *stream) {
+    return pclose(stream);
+}
+#define FLB_PCLOSE pclose
+#else
+static inline FILE* flb_popen(const char *command, const char *type) {
+    return _popen(command, type);
+}
+/*
+ * flb_pclose() has the same return value on Windows as win32 _pclose(), rather
+ * than posix pclose(). The process exit code is not bit-shifted to the high
+ * byte.
+ *
+ * The MSVC docs for _pclose() at
+ * https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/pclose?view=msvc-170
+ * are misleading; they say that "The format of the return value is the same as
+ * for _cwait, except the low-order and high-order bytes are swapped." But
+ * _cwait isn't documented as having any meaningful return on success, the
+ * process exit code is meant to be in  its "termstat" out parameter per
+ * https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/cwait?view=msvc-170
+ * The return code of _pclose() actually appears to be the process exit code
+ * without the bit-shift that waitpid() applies.
+ */
+static inline int flb_pclose(FILE *stream) {
+    return _pclose(stream);
+}
+#endif
+
+#endif /* FLB_IN_EXEC_WIN32_COMPAT_H */