From 8970c40ce9a9a4e5f582b48f69b77bd90d8e678e Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Thu, 4 Apr 2024 23:29:08 +0200
Subject: Add DLL API

---
 deimos/core/os.h         | 16 ++++++++++++++--
 deimos/core/os_win32.cpp | 16 ++++++++++++++++
 deimos/core/std.h        |  8 ++++++++
 3 files changed, 38 insertions(+), 2 deletions(-)

(limited to 'deimos')

diff --git a/deimos/core/os.h b/deimos/core/os.h
index 88b1c55..3cff6ba 100644
--- a/deimos/core/os.h
+++ b/deimos/core/os.h
@@ -17,20 +17,32 @@ class OsConsoleApi
 {
 public:
     OsConsoleApi() = default;
-
     deimos_NO_COPY_MOVE(OsConsoleApi);
-
     virtual ~OsConsoleApi() = default;
 
     virtual void Write(OsConsoleType, Span<const std::byte> data) = 0;
 };
 
+struct OsDll;
+
+class OsDllApi
+{
+public:
+    OsDllApi() = default;
+    deimos_NO_COPY_MOVE(OsDllApi);
+    virtual ~OsDllApi() = default;
+
+    virtual OsDll* Open(gsl::czstring) = 0;
+    virtual void* GetSymbol(OsDll*, gsl::czstring) = 0;
+};
+
 class OsApi
 {
 public:
     static constexpr IdName kApiName{"deimos::OsApi"};
 
     OsConsoleApi* console{};
+    OsDllApi* dll{};
 };
 
 class OsConsoleWriter : public IWriter
diff --git a/deimos/core/os_win32.cpp b/deimos/core/os_win32.cpp
index ca608d8..1c6b664 100644
--- a/deimos/core/os_win32.cpp
+++ b/deimos/core/os_win32.cpp
@@ -35,14 +35,30 @@ public:
     }
 };
 
+class Win32OsDllApiImpl : public OsDllApi
+{
+public:
+    OsDll* Open(gsl::czstring name) override
+    {
+        return std::bit_cast<OsDll*>(::LoadLibraryA(name));
+    }
+
+    void* GetSymbol(OsDll* dll, gsl::czstring name) override
+    {
+        return std::bit_cast<void*>(::GetProcAddress(std::bit_cast<HMODULE>(dll), name));
+    }
+};
+
 class Win32OsApiImpl : public OsApi
 {
     Win32OsConsoleApiImpl m_console_api;
+    Win32OsDllApiImpl m_dll_api;
 
 public:
     Win32OsApiImpl()
     {
         console = &m_console_api;
+        dll = &m_dll_api;
     }
 };
 
diff --git a/deimos/core/std.h b/deimos/core/std.h
index 89d7da5..42bedbe 100644
--- a/deimos/core/std.h
+++ b/deimos/core/std.h
@@ -22,6 +22,7 @@ template<typename T> concept signed_integral = integral<T> && __is_signed(T);
 template<typename T> concept unsigned_integral = integral<T> && __is_unsigned(T);
 
 template<typename T> constexpr bool is_trivially_destructible_v = __is_trivially_destructible(T);
+template<typename T> constexpr bool is_trivially_copyable_v = __is_trivially_copyable(T);
 
 template<typename U, typename V> constexpr bool _is_same_helper = false;
 template<typename T> constexpr bool _is_same_helper<T, T> = true;
@@ -78,6 +79,13 @@ constexpr T exchange(T& obj, U&& new_value)
 enum __attribute__((__may_alias__)) byte : uint8_t {};
 static_assert(sizeof(byte) == 1, "");
 
+template<typename To, typename From>
+requires (sizeof(To) == sizeof(From)) && is_trivially_copyable_v<To> && is_trivially_copyable_v<From>
+constexpr To bit_cast(const From& from) noexcept
+{
+    return __builtin_bit_cast(To, from);
+}
+
 template<typename T>
 class initializer_list
 {
-- 
cgit