test-drop-caches: simplify delay loading of NtSetSystemInformation

Take advantage of the recent addition of support for lazy loading functions[1]
on Windows to simplify the loading of NtSetSystemInformation.

[1] db2f7c48cb (Win32: simplify loading of DLL functions, 2017-09-25)

Signed-off-by: Ben Peart <benpeart@microsoft.com>
Reviewed-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/t/helper/test-drop-caches.c b/t/helper/test-drop-caches.c
index 838760898b6f4ccfc0d7a3c4bd2c8653020a93ec..d6bcfddf13352b92d6be4d9d5b8e7d7f05cc06ee 100644 (file)
--- a/t/helper/test-drop-caches.c
+++ b/t/helper/test-drop-caches.c
@@ -2,6 +2,7 @@
 #include "git-compat-util.h"
 
 #if defined(GIT_WINDOWS_NATIVE)
+#include "lazyload.h"
 
 static int cmd_sync(void)
 {
@@ -82,8 +83,7 @@ static int cmd_dropcaches(void)
 {
        HANDLE hProcess = GetCurrentProcess();
        HANDLE hToken;
-       HMODULE ntdll;
-       DWORD(WINAPI *NtSetSystemInformation)(INT, PVOID, ULONG);
+       DECLARE_PROC_ADDR(ntdll.dll, DWORD, NtSetSystemInformation, INT, PVOID, ULONG);
        SYSTEM_MEMORY_LIST_COMMAND command;
        int status;
 
@@ -95,14 +95,8 @@ static int cmd_dropcaches(void)
 
        CloseHandle(hToken);
 
-       ntdll = LoadLibrary("ntdll.dll");
-       if (!ntdll)
-               return error("Can't load ntdll.dll, wrong Windows version?");
-
-       NtSetSystemInformation =
-               (DWORD(WINAPI *)(INT, PVOID, ULONG))GetProcAddress(ntdll, "NtSetSystemInformation");
-       if (!NtSetSystemInformation)
-               return error("Can't get function addresses, wrong Windows version?");
+       if (!INIT_PROC_ADDR(NtSetSystemInformation))
+               return error("Could not find NtSetSystemInformation() function");
 
        command = MemoryPurgeStandbyList;
        status = NtSetSystemInformation(
@@ -115,8 +109,6 @@ static int cmd_dropcaches(void)
        else if (status != STATUS_SUCCESS)
                error("Unable to execute the memory list command %d", status);
 
-       FreeLibrary(ntdll);
-
        return status;
 }