Isolate the Win32 platform runtime's entry point

Core/Intrinsics.hpp

@@ -1,5 +1,3 @@
-#include <intrin.h>
-
 // TODO Eliminate this
 #include <memory.h>
 
@@ -8,6 +6,9 @@ GLOBAL char CPU_BRAND_STRING[0x40] = { "N/A (__cpuid intrinsic not yet supported
 
 #ifdef RAGLITE_COMPILER_MSVC
 
+#include <intrin.h>
+
+// TODO: Should look into whether (and how much) dllimport improves performance?
 #define EXPORT extern "C" __declspec(dllexport)
 
 INTERNAL void IntrinsicsReadCPUID() {
@@ -25,14 +26,25 @@ INTERNAL void IntrinsicsReadCPUID() {
 		__cpuid((int*)CPU_INFO_MASK, 0x80000004);
 		memcpy(CPU_BRAND_STRING + 32, CPU_INFO_MASK, sizeof(CPU_INFO_MASK));
 	}
+}
 
 #define DebugTrap() __debugbreak();
 
 #else
-// TODO Support for the other toolchains
-#endif
+
+#include <cpuid.h>
+
+// TODO: Only relevant if the build script (that doesn't currently exist) uses -fvisibility=hidden
+#define EXPORT extern "C" __attribute__((visibility("default")))
+
+INTERNAL void IntrinsicsReadCPUID() {
+	// NYI: Probably need to rewrite this anyway, so for now just leave it as a placeholder
 }
 
+#define DebugTrap() __builtin_trap();
+
+#endif
+
 // TODO: typeof(x) could simplify this - look into toolchain support/extensions?
 #define Swap(first, second, type) \
 	do {                          \

Core/Platforms/Linux.cpp

@@ -0,0 +1,51 @@
+// ABOUT: This is a placeholder program that has nothing in common with the Win32 platform runtime (delete when porting)
+
+#include <cpuid.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <err.h>
+#include <string.h>
+
+void DebugPrintASCII(unsigned int value) {
+	for(int i = 0; i < 4; i++) {
+		char byte = (value >> (i * 8)) & 0xFF;
+		printf("%c", byte);
+	}
+}
+
+// See https://en.wikipedia.org/wiki/CPUID and https://github.com/gcc-mirror/gcc/blob/master/gcc/config/i386/cpuid.h
+INTERNAL void DebugDumpCPUID() {
+	unsigned int eax, ebx, ecx, edx;
+	// EAX=0: Highest Function Parameter and Manufacturer ID
+	uint EAX_input = 0;
+	unsigned int ret = __get_cpuid(EAX_input, &eax, &ebx, &ecx, &edx);
+	if(ret != 1) {
+		errx(EXIT_FAILURE, "Failed to call CPUID with EAX=%d", EAX_input);
+	}
+
+	printf("CPU Manufacturer ID: ");
+	DebugPrintASCII(ebx);
+	DebugPrintASCII(edx);
+	DebugPrintASCII(ecx);
+	printf("\n");
+}
+
+INTERNAL void PlatformRuntimeMain() {
+	printf("There is no platform runtime for Linux yet. Instead, behold this placeholder program :3\n");
+
+	DebugDumpCPUID();
+	// TODO: Maybe dump some of the other CPU details also? Not really useful right now...
+
+	unsigned eax = 0;
+	unsigned ebx = 0;
+	unsigned ecx = 0;
+	unsigned edx = 0;
+
+	int r = __get_cpuid_count(7, 0, &eax, &ebx, &ecx, &edx);
+	if(!r) {
+		fprintf(stderr, "cpuid leaf 7 unsupported ...\n");
+		return;
+	}
+	printf("cpuid.07h.0: eax=0x%x ebx=0x%x ecx=0x%x edx=0x%x\n",
+		eax, ebx, ecx, edx);
+}

Core/Platforms/MacOS.cpp

@@ -0,0 +1,6 @@
+// ABOUT: This is a placeholder program that has nothing in common with the Win32 platform runtime (delete when porting)
+
+#include <stdio.h>
+INTERNAL void PlatformRuntimeMain() {
+	printf("This is a placeholder program; there's no OSX platform runtime yet...\n");
+}

Core/Platforms/Win32.cpp

@@ -280,8 +280,8 @@ LRESULT CALLBACK MainWindowProcessIncomingMessage(HWND window, UINT message, WPA
 	return result;
 }
 
-int WINAPI WinMain(HINSTANCE instance, HINSTANCE, LPSTR,
-	int) {
+INTERNAL void PlatformRuntimeMain() {
+	HINSTANCE instance = GetModuleHandle(NULL);
 	hardware_tick_t applicationStartTime = PerformanceMetricsNow();
 
 	IntrinsicsReadCPUID();
@@ -326,7 +326,7 @@ int WINAPI WinMain(HINSTANCE instance, HINSTANCE, LPSTR,
 		GetSystemMetrics(SM_CYSMICON), LR_DEFAULTCOLOR);
 
 	ATOM classGUID = RegisterClassEx(&windowClass);
-	ASSUME(classGUID != NULL, "Failed to register window class (...really?)");
+	ASSUME(classGUID, "Failed to register window class (...really?)");
 
 	// TODO: On modern Windows systems, MAX_PATH is insufficient and Unicode paths should ideally be supported (later?)
 	TCHAR executableFileSystemPath[MAX_PATH];
@@ -385,6 +385,4 @@ int WINAPI WinMain(HINSTANCE instance, HINSTANCE, LPSTR,
 	}
 
 	timeEndPeriod(requestedSchedulerGranularityInMilliseconds);
-
-	return 0;
 }

Core/RagLite2.cpp

@@ -11,4 +11,18 @@ GLOBAL memory_arena_t TRANSIENT_MEMORY = {};
 
 #ifdef RAGLITE_PLATFORM_WINDOWS
 #include "Platforms/Win32.cpp"
-#endif
+#elifdef RAGLITE_PLATFORM_MACOS
+#include "Platforms/MacOS.cpp"
+#elifdef RAGLITE_PLATFORM_LINUX
+#include "Platforms/Linux.cpp"
+#endif
+
+#ifdef RAGLITE_PLATFORM_WINDOWS
+int APIENTRY WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
+#else
+int main()
+#endif
+{
+	PlatformRuntimeMain();
+	return 0;
+}

Core/RagLite2.hpp

@@ -18,13 +18,13 @@
 #error "Unsupported Platform: OS-specific code paths have yet to be ported"
 #endif
 
-#define RAGLITE_COMPILER_GCC 0
-#define RAGLITE_COMPILER_LLVM 0
-#define RAGLITE_COMPILER_MSVC 0
-
-#ifdef _MSC_VER
-#undef RAGLITE_COMPILER_MSVC
-#define RAGLITE_COMPILER_MSVC 1
+// NOTE: Should probably use feature detection macros, but for now assume the latest (tested) version will work
+#if defined(__clang__)
+#define RAGLITE_COMPILER_CLANG
+#elif defined(_MSC_VER)
+#define RAGLITE_COMPILER_MSVC
+#elif defined(__GNUC__)
+#define RAGLITE_COMPILER_GCC 1
 #else
 #define RAGLITE_UNSUPPORTED_COMPILER
 #endif
@@ -44,10 +44,10 @@
 #define EXPAND_AS_STRING(x) #x
 #define TOSTRING(x) EXPAND_AS_STRING(x)
 
-constexpr size_t BITS_PER_BYTE = 8ULL;
+constexpr int BITS_PER_BYTE = 8;
 #define Bits(bits) ((bits) / BITS_PER_BYTE)
 
-constexpr size_t PLATFORM_POINTER_SIZE = sizeof(void*);
+constexpr int PLATFORM_POINTER_SIZE = sizeof(void*);
 static_assert(PLATFORM_POINTER_SIZE == Bits(64), "Only 64-bit platforms are currently supported");
 
 #if defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__

msys2build.sh

@@ -0,0 +1,6 @@
+# NOTE: This is not a full port of the MSVC build script, but rather a placeholder for local testing.
+# NOTE: Eventually, a proper (more portable) solution will be required. But not today... so this is all there is
+
+mkdir -p BuildArtifacts
+RUNTIME_LIBS="-l gdi32 -l shlwapi -l user32 -l xinput -l winmm -l imagehlp -l ws2_32"
+gcc Core/RagLite2.cpp -o BuildArtifacts/RagLiteMSYS2.exe $RUNTIME_LIBS

unixbuild.sh

@@ -0,0 +1,6 @@
+# NOTE: This is not a full port of the MSVC build script, but rather a placeholder for local testing.
+# NOTE: Eventually, a proper (more portable) solution will be required. But not today... so this is all there is
+
+mkdir -p BuildArtifacts
+RUNTIME_LIBS=""
+gcc Core/RagLite2.cpp -o BuildArtifacts/RagLite2 $RUNTIME_LIBS -lm -fvisibility=hidden