Subject: [PATCH v1] test-drop-caches: simplify delay loading of NtSetSystemInformation

From: Ben Peart <[email-masked]>
Date: Mon, 30 Apr 2018 14:26:11 +0000

Take advantage of the recent addition of support for lazy loading functions
on Windows to simplfy the loading of NtSetSystemInformation.

Signed-off-by: Ben Peart <[email-masked]>
---

Notes:
    Base Ref: master
    Web-Diff: https://github.com/benpeart/git/commit/6e6ce4a788
    Checkout: git fetch https://github.com/benpeart/git test-drop-caches-v1 && git checkout 6e6ce4a788

 t/helper/test-drop-caches.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/t/helper/test-drop-caches.c b/t/helper/test-drop-caches.c
index 838760898b..dd41da1a2c 100644
--- a/t/helper/test-drop-caches.c
+++ b/t/helper/test-drop-caches.c
@@ -1,5 +1,6 @@
 #include "test-tool.h"
 #include "git-compat-util.h"
+#include "lazyload.h"
 
 #if defined(GIT_WINDOWS_NATIVE)
 
@@ -82,8 +83,6 @@ static int cmd_dropcaches(void)
 {
 	HANDLE hProcess = GetCurrentProcess();
 	HANDLE hToken;
-	HMODULE ntdll;
-	DWORD(WINAPI *NtSetSystemInformation)(INT, PVOID, ULONG);
 	SYSTEM_MEMORY_LIST_COMMAND command;
 	int status;
 
@@ -95,14 +94,9 @@ 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?");
+	DECLARE_PROC_ADDR(ntdll.dll, DWORD, NtSetSystemInformation, INT, PVOID, ULONG);
+	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;
 }

base-commit: 1f1cddd558b54bb0ce19c8ace353fd07b758510d
-- 
2.17.0.windows.1