From c7a9a8e8f12a1a708b86710ac6fb3170f03eb5f4 Mon Sep 17 00:00:00 2001
From: Nekotekina <nekotekina@gmail.com>
Date: Sun, 19 Mar 2017 15:50:56 +0300
Subject: [PATCH] utils::memory update

---
 Utilities/VirtualMemory.cpp | 64 +++++++++++++++++++++----------------
 Utilities/VirtualMemory.h   | 37 ++++++++++-----------
 2 files changed, 55 insertions(+), 46 deletions(-)

diff --git a/Utilities/VirtualMemory.cpp b/Utilities/VirtualMemory.cpp
index ff6558a0eb..c52539ef7f 100644
--- a/Utilities/VirtualMemory.cpp
+++ b/Utilities/VirtualMemory.cpp
@@ -13,21 +13,49 @@
 
 namespace utils
 {
-	void* memory_reserve(std::size_t size)
+	// Convert memory protection (internal)
+	static auto operator +(protection prot)
 	{
 #ifdef _WIN32
-		return verify("reserve_memory" HERE, ::VirtualAlloc(NULL, size, MEM_RESERVE, PAGE_NOACCESS));
+		DWORD _prot = PAGE_NOACCESS;
+		switch (prot)
+		{
+		case protection::rw: _prot = PAGE_READWRITE; break;
+		case protection::ro: _prot = PAGE_READONLY; break;
+		case protection::no: break;
+		case protection::wx: _prot = PAGE_EXECUTE_READWRITE; break;
+		case protection::rx: _prot = PAGE_EXECUTE_READ; break;
+		}
 #else
-		return verify("reserve_memory" HERE, ::mmap(nullptr, size, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0));
+		int _prot = PROT_NONE;
+		switch (prot)
+		{
+		case protection::rw: _prot = PROT_READ | PROT_WRITE; break;
+		case protection::ro: _prot = PROT_READ; break;
+		case protection::no: break;
+		case protection::wx: _prot = PROT_READ | PROT_WRITE | PROT_EXEC; break;
+		case protection::rx: _prot = PROT_READ | PROT_EXEC; break;
+		}
+#endif
+
+		return _prot;
+	}
+
+	void* memory_reserve(std::size_t size, void* use_addr)
+	{
+#ifdef _WIN32
+		return verify("reserve_memory" HERE, ::VirtualAlloc(use_addr, size, MEM_RESERVE, PAGE_NOACCESS));
+#else
+		return verify("reserve_memory" HERE, ::mmap(use_addr, size, PROT_NONE, MAP_ANON | MAP_PRIVATE | (use_addr ? MAP_FIXED : 0), -1, 0));
 #endif
 	}
 
-	void memory_commit(void* pointer, std::size_t size)
+	void memory_commit(void* pointer, std::size_t size, protection prot)
 	{
 #ifdef _WIN32
-		verify(HERE), ::VirtualAlloc(pointer, size, MEM_COMMIT, PAGE_READWRITE);
+		verify(HERE), ::VirtualAlloc(pointer, size, MEM_COMMIT, +prot);
 #else
-		verify(HERE), ::mprotect((void*)((u64)pointer & -4096), ::align(size, 4096), PROT_READ | PROT_WRITE) != -1;
+		verify(HERE), ::mprotect((void*)((u64)pointer & -4096), ::align(size, 4096), +prot) != -1;
 #endif
 	}
 
@@ -43,30 +71,10 @@ namespace utils
 	void memory_protect(void* pointer, std::size_t size, protection prot)
 	{
 #ifdef _WIN32
-		DWORD _prot = PAGE_NOACCESS;
-		switch (prot)
-		{
-		case protection::rw: _prot = PAGE_READWRITE; break;
-		case protection::ro: _prot = PAGE_READONLY; break;
-		case protection::no: break;
-		case protection::wx: _prot = PAGE_EXECUTE_READWRITE; break;
-		case protection::rx: _prot = PAGE_EXECUTE_READ; break;
-		}
-
 		DWORD old;
-		verify(HERE), ::VirtualProtect(pointer, size, _prot, &old);
+		verify(HERE), ::VirtualProtect(pointer, size, +prot, &old);
 #else
-		int _prot = PROT_NONE;
-		switch (prot)
-		{
-		case protection::rw: _prot = PROT_READ | PROT_WRITE; break;
-		case protection::ro: _prot = PROT_READ; break;
-		case protection::no: break;
-		case protection::wx: _prot = PROT_READ | PROT_WRITE | PROT_EXEC; break;
-		case protection::rx: _prot = PROT_READ | PROT_EXEC; break;
-		}
-
-		verify(HERE), ::mprotect((void*)((u64)pointer & -4096), ::align(size, 4096), _prot) != -1;
+		verify(HERE), ::mprotect((void*)((u64)pointer & -4096), ::align(size, 4096), +prot) != -1;
 #endif
 	}
 }
diff --git a/Utilities/VirtualMemory.h b/Utilities/VirtualMemory.h
index e8381f8c8e..74f441a598 100644
--- a/Utilities/VirtualMemory.h
+++ b/Utilities/VirtualMemory.h
@@ -2,24 +2,6 @@
 
 namespace utils
 {
-	/**
-	* Reserve `size` bytes of virtual memory and returns it.
-	* The memory should be commited before usage.
-	*/
-	void* memory_reserve(std::size_t size);
-
-	/**
-	* Commit `size` bytes of virtual memory starting at pointer.
-	* That is, bake reserved memory with physical memory.
-	* pointer should belong to a range of reserved memory.
-	*/
-	void memory_commit(void* pointer, std::size_t size);
-
-	/**
-	* Decommit all memory committed via commit_page_memory.
-	*/
-	void memory_decommit(void* pointer, std::size_t size);
-
 	// Memory protection type
 	enum class protection
 	{
@@ -30,5 +12,24 @@ namespace utils
 		rx, // Read + execute
 	};
 
+	/**
+	* Reserve `size` bytes of virtual memory and returns it.
+	* The memory should be commited before usage.
+	*/
+	void* memory_reserve(std::size_t size, void* use_addr = nullptr);
+
+	/**
+	* Commit `size` bytes of virtual memory starting at pointer.
+	* That is, bake reserved memory with physical memory.
+	* pointer should belong to a range of reserved memory.
+	*/
+	void memory_commit(void* pointer, std::size_t size, protection prot = protection::rw);
+
+	/**
+	* Decommit all memory committed via commit_page_memory.
+	*/
+	void memory_decommit(void* pointer, std::size_t size);
+
+	// Set memory protection
 	void memory_protect(void* pointer, std::size_t size, protection prot);
 }