[vcpkg] fix extern C around ctermid (#11343)

Additionally, move the system_header invocations to their own header file,
<vcpkg/base/system_header.h>

3 files changed, 41 insertions, 17 deletions

diff --git a/toolsrc/include/pch.h b/toolsrc/include/pch.h
index 03e3f59f7..e23230f6e 100644
--- a/toolsrc/include/pch.h
+++ b/toolsrc/include/pch.h
@@ -1,22 +1,12 @@
 #pragma once
 
 #include <vcpkg/base/pragmas.h>
+#include <vcpkg/base/system_headers.h>
 
 #if defined(_WIN32)
-#define NOMINMAX
-#define WIN32_LEAN_AND_MEAN
-
-#pragma warning(suppress : 4768)
-#include <windows.h>
-
-#pragma warning(suppress : 4768)
-#include <Shlobj.h>
-
 #include <process.h>
 #include <shellapi.h>
 #include <winhttp.h>
-#else
-#include <unistd.h>
 #endif
 
 #include <algorithm>
@@ -29,13 +19,15 @@
 #include <cstdarg>
 #include <cstddef>
 #include <cstdint>
-#define _SILENCE_EXPERIMENTAL_FILESYSTEM_DEPRECATION_WARNING
 #include <cstring>
+
 #if VCPKG_USE_STD_FILESYSTEM
 #include <filesystem>
 #else
+#define _SILENCE_EXPERIMENTAL_FILESYSTEM_DEPRECATION_WARNING
 #include <experimental/filesystem>
 #endif
+
 #include <fstream>
 #include <functional>
 #include <iomanip>
@@ -55,11 +47,6 @@
 #include <sys/time.h>
 #endif
 
-#include <sys/types.h>
-// glibc defines major and minor in sys/types.h, and should not
-#undef major
-#undef minor
-
 #include <system_error>
 #include <thread>
 #include <time.h>
diff --git a/toolsrc/include/vcpkg-test/util.h b/toolsrc/include/vcpkg-test/util.h
index b6ea4b01d..9321f3fd2 100644
--- a/toolsrc/include/vcpkg-test/util.h
+++ b/toolsrc/include/vcpkg-test/util.h
@@ -1,3 +1,5 @@
+#include <vcpkg/base/system_headers.h>
+
 #include <catch2/catch.hpp>
 #include <vcpkg/base/pragmas.h>
 
diff --git a/toolsrc/include/vcpkg/base/system_headers.h b/toolsrc/include/vcpkg/base/system_headers.h
new file mode 100644
index 000000000..9af5bfd92
--- /dev/null
+++ b/toolsrc/include/vcpkg/base/system_headers.h
@@ -0,0 +1,35 @@
+#pragma once
+
+#if defined(_WIN32)
+
+#define NOMINMAX
+#define WIN32_LEAN_AND_MEAN
+
+#pragma warning(suppress : 4768)
+#include <windows.h>
+
+#pragma warning(suppress : 4768)
+#include <Shlobj.h>
+
+#else // ^^^^ Windows / Unix vvvv
+
+// 2020-05-19: workaround for a c standard library bug
+// ctermid is not behind an `extern "C"` barrier, so it's linked incorrectly.
+// This has been reported; remove it after 2023-05-19
+#if __APPLE__
+extern "C" {
+#endif
+
+#include <unistd.h>
+
+#if __APPLE__
+}
+#endif
+
+#endif
+
+#include <sys/types.h>
+// glibc defines major and minor in sys/types.h, and should not
+#undef major
+#undef minor
+