memory arena, allocator struct, os alloc and abort, strings, broken build script

.gitignore

@@ -0,0 +1,4 @@
+*.exe
+*.ilk
+*.obj
+*.pdb

bastd.c

@@ -1,6 +1,160 @@
 #ifndef BASTD_C
 #define BASTD_C
 
+////////////////////////////////
+// NOTE(allen): Context Cracking
+
+// NOTE(allen): Untangle Compiler, OS & Architecture
+#if defined(__clang__)
+# define COMPILER_CLANG 1
+
+# if defined(_WIN32)
+#  define OS_WINDOWS 1
+# elif defined(__gnu_linux__)
+#  define OS_LINUX 1
+# elif defined(__APPLE__) && defined(__MACH__)
+#  define OS_MAC 1
+# else
+#  error missing OS detection
+# endif
+
+# if defined(__amd64__)
+#  define ARCH_X64 1
+// TODO(allen): verify this works on clang
+# elif defined(__i386__)
+#  define ARCH_X86 1
+// TODO(allen): verify this works on clang
+# elif defined(__arm__)
+#  define ARCH_ARM 1
+// TODO(allen): verify this works on clang
+# elif defined(__aarch64__)
+#  define ARCH_ARM64 1
+# else
+#  error missing ARCH detection
+# endif
+
+#elif defined(_MSC_VER)
+# define COMPILER_CL 1
+
+# if defined(_WIN32)
+#  define OS_WINDOWS 1
+# else
+#  error missing OS detection
+# endif
+
+# if defined(_M_AMD64)
+#  define ARCH_X64 1
+# elif defined(_M_I86)
+#  define ARCH_X86 1
+# elif defined(_M_ARM)
+#  define ARCH_ARM 1
+// TODO(allen): ARM64?
+# else
+#  error missing ARCH detection
+# endif
+
+#elif defined(__GNUC__)
+# define COMPILER_GCC 1
+
+# if defined(_WIN32)
+#  define OS_WINDOWS 1
+# elif defined(__gnu_linux__)
+#  define OS_LINUX 1
+# elif defined(__APPLE__) && defined(__MACH__)
+#  define OS_MAC 1
+# else
+#  error missing OS detection
+# endif
+
+# if defined(__amd64__)
+#  define ARCH_X64 1
+# elif defined(__i386__)
+#  define ARCH_X86 1
+# elif defined(__arm__)
+#  define ARCH_ARM 1
+# elif defined(__aarch64__)
+#  define ARCH_ARM64 1
+# else
+#  error missing ARCH detection
+# endif
+
+#else
+# error no context cracking for this compiler
+#endif
+
+#if !defined(COMPILER_CL)
+# define COMPILER_CL 0
+#endif
+#if !defined(COMPILER_CLANG)
+# define COMPILER_CLANG 0
+#endif
+#if !defined(COMPILER_GCC)
+# define COMPILER_GCC 0
+#endif
+#if !defined(OS_WINDOWS)
+# define OS_WINDOWS 0
+#endif
+#if !defined(OS_LINUX)
+# define OS_LINUX 0
+#endif
+#if !defined(OS_MAC)
+# define OS_MAC 0
+#endif
+#if !defined(ARCH_X64)
+# define ARCH_X64 0
+#endif
+#if !defined(ARCH_X86)
+# define ARCH_X86 0
+#endif
+#if !defined(ARCH_ARM)
+# define ARCH_ARM 0
+#endif
+#if !defined(ARCH_ARM64)
+# define ARCH_ARM64 0
+#endif
+
+
+// NOTE(allen): Language
+#if defined(__cplusplus)
+# define LANG_CXX 1
+#else
+# define LANG_C 1
+#endif
+
+#if !defined(LANG_CXX)
+# define LANG_CXX 0
+#endif
+#if !defined(LANG_C)
+# define LANG_C 0
+#endif
+
+
+// NOTE(allen): Profiler
+#if !defined(PROFILER_SPALL)
+# define PROFILER_SPALL 0
+#endif
+
+
+// NOTE(allen): Determine Intrinsics Mode
+#if OS_WINDOWS
+# if COMPILER_CL || COMPILER_CLANG
+#  define INTRINSICS_MICROSOFT 1
+# endif
+#endif
+
+#if !defined(INTRINSICS_MICROSOFT)
+# define INTRINSICS_MICROSOFT 0
+#endif
+
+
+// NOTE(allen): Setup Pointer Size Macro
+#if ARCH_X64 || ARCH_ARM64
+# define ARCH_ADDRSIZE 64
+#else
+# define ARCH_ADDRSIZE 32
+#endif
+
+// Types
 #include <stdint.h>
 
 typedef int8_t I8;
@@ -15,17 +169,34 @@ typedef uint64_t U64;
 typedef float F32;
 typedef double F64;
 
+typedef uintptr_t UPtr;
+typedef ptrdiff_t ISize;
+typedef size_t USize;
+
 typedef U32 B32;
 #define TRUE 1
 #define FALSE 0
 
+// Macros
 #define FUNCTION static
 #define GLOBAL_VAR static
 #define LOCAL_PERSIST static
 
 #define STMNT(s) do{ s }while(0)
 
-// TODO: Add Linux Version
+#define ASSERT(x, msg) STMNT(if (!x) OS_DEBUGBREAK();)
-#define ASSERT(x, msg) STMNT(if (!x) __debugbreak();)
+
+#define CONCAT_(a,b) a##b
+#define CONCAT(a,b) CONCAT_(a,b)
+
+#define NIL 0
+
+#define COUNT_OF(a) (ISize)(sizeof(a) / sizeof(*(a)))
+#define LENGTH_OF(s) (COUNT_OF(s) - 1)
+
+// Includes
+#include "bastd/string.c"
+#include "bastd/os_windows.c"
+#include "bastd/mem.c"
 
 #endif //BASTD_C

bastd/mem.c

@@ -0,0 +1,116 @@
+#ifndef BASTD_MEM_C
+#define BASTD_MEM_C
+
+FUNCTION void *
+M_memorySet(void *buffer, U8 value, ISize length)
+{
+	U8* p = buffer;
+	while (length-- > 0) {
+		*p++ = value;
+	}
+	return buffer;
+}
+
+FUNCTION void *
+M_memoryCopy(void *dst, void *src, size_t n) 
+{ 
+	U8 *s = (U8 *)src; 
+	U8 *d = (U8 *)dst; 
+
+	for (I32 i = 0; i < n; i++) {
+		d[i] = s[i]; 
+	}
+
+	return dst;
+}
+
+/* Alloc function taken from Lua.
+  If ptr == NIL, old_size irrelevant
+  If ptr != NIL, old_size = size of block of memory at ptr
+  If new_size > 0, function like realloc and either resize or create
+  If new_size <= 0, function like free and clear the memory
+*/
+typedef void *(*M_AllocFunc)(void *ctx, void *ptr, ISize old_size, ISize new_size);
+
+typedef struct M_Allocator M_Allocator; 
+struct M_Allocator {
+	M_AllocFunc alloc;
+	void* ctx;
+};
+
+#define M_MAKE(T, n, a) ((T *)((a).alloc((a).ctx, NIL, 0, sizeof(T) * n)))
+#define M_RESIZE(p, o, n, a) ((a).alloc((a).ctx, p, sizeof(*(p)) * o, sizeof(*(p)) * n))
+#define M_RELEASE(p, s, a) ((a).alloc((a).ctx, p, sizeof(*(p)) * s, 0))
+
+/* Linear Allocator (Arena)
+   Allocates variably-sized regions from a fixed-size block of memory.
+   A set of regions is freed by setting the allocator's offset to an earlier
+   value.
+*/
+typedef struct M_Arena M_Arena;
+struct M_Arena {
+	U8* beg;
+	U8* end;
+};
+
+#define DEFAULT_ALIGNMENT (2 * sizeof(void *))
+
+FUNCTION void *
+M_Arena_alloc(void *ctx, void *ptr, ISize old_size, ISize new_size)
+{
+	M_Arena *a = (M_Arena *)ctx;
+
+	if (new_size <= 0) {
+		/*  Arena can only free the most recent block. This allows to follow stack pattern.
+			What we do is move the end pointer forward by the size of the block
+			Then, because there is now more available space, the data will be 
+			ignored following the next allocation.
+		*/
+		ISize padding = -old_size & (DEFAULT_ALIGNMENT - 1);
+		a->end += old_size + padding;
+		return NIL;
+	} else {
+		// Allocate a block
+		ASSERT(new_size > old_size, "Can't reallocate to a smaller block");
+
+		ISize padding = -(UPtr)a->beg & (DEFAULT_ALIGNMENT - 1);
+		ISize available = a->end - a->beg - padding;
+
+		if (available < 0 || new_size > available) {
+			OS_Abort(S8("Out of Memory!"));
+		}
+
+		void *p = NIL;
+
+		if (a->beg == (U8 *)ptr + old_size) {
+			// This was the last allocated block, can extend allocation for realloc
+			p = ptr;
+			a->beg += padding + new_size;
+		} else {
+			// New allocation;
+			p = a->beg + padding;
+			a->beg += padding + new_size;
+			p = M_memorySet(p, 0, new_size);
+			
+			if (ptr != NIL) {
+				// Arbitrary block, copy data from old pointer
+				p = M_memoryCopy(p, ptr, old_size);
+			}
+		}
+
+		return p;
+	}
+}
+
+FUNCTION M_Arena
+M_Arena_create(void* buffer, ISize capacity)
+{
+	M_Arena arena = {0};
+	arena.beg = (U8 *)buffer;
+	arena.end = arena.beg ? arena.beg + capacity : 0;
+	return arena;
+}
+
+#define M_ARENA_ALLOCATOR(a) (M_Allocator){M_Arena_alloc, (void *)&(a)}
+
+#endif//BASTD_MEM_C

bastd/os.c

@@ -0,0 +1,17 @@
+#ifndef BASTD_OS_C
+#define BASTD_OS_C
+
+FUNCTION void OS_Abort(S8 msg);
+FUNCTION void *OS_Alloc(ISize cap);
+
+#if defined(OS_WINDOWS)
+
+#include "os_windows.c"
+
+#elif defined(OS_LINUX)
+
+#include "os_linux.c"
+
+#endif//OS_WINDOWS
+
+#endif//BASTD_OS_C

bastd/os_windows.c

@@ -0,0 +1,23 @@
+#ifndef BASTD_OS_WINDOWS_C
+#define BASTD_OS_WINDOWS_C
+
+#include <windows.h>
+
+#define OS_DEBUGBREAK() __debugbreak();
+
+FUNCTION void
+OS_Abort(S8 msg)
+{
+    HANDLE stderr = GetStdHandle(-12);
+    U32 dummy;
+    WriteFile(stderr, msg.raw, msg.length, &dummy, 0);
+    ExitProcess(101);
+}
+
+FUNCTION void *
+OS_Alloc(ISize cap)
+{
+	return VirtualAlloc(NIL, cap, MEM_COMMIT | MEM_RESERVE, PAGE_READWRITE);
+}
+
+#endif//BASTD_OS_WINDOWS_C

bastd/string.c

@@ -0,0 +1,12 @@
+#ifndef BASTD_STRING_C
+#define BASTD_STRING_C
+
+typedef struct S8 S8;
+struct S8 {
+	ISize length;
+	U8 *raw;
+};
+
+#define S8(s) (S8){(U8 *)s, LENGTH_OF(s)}
+
+#endif//BASTD_STRING_C

build.bat

@@ -0,0 +1,8 @@
+@echo off
+
+if not exist build\ mkdir build
+pushd build
+
+cl /Zi ..\main.c
+
+popd

examples/memory.c

@@ -0,0 +1,38 @@
+int
+main(void)
+{
+	ISize buffer_size = 100 * sizeof(U8);
+	M_Arena arena = M_Arena_create(OS_Alloc(buffer_size), buffer_size);
+	M_Allocator permanent_allocator = M_ARENA_ALLOCATOR(arena);
+
+	{
+		/* By cloning an arena at the start of the scope, all changes to the
+		   arena are now local to the scope, so all allocations with be freed
+		   at the end automatically.
+		*/
+		M_Arena scratch_arena = arena;
+		M_Allocator scratch_allocator = M_ARENA_ALLOCATOR(scratch_arena);
+
+		U8* array = M_MAKE(U8, 20, scratch_allocator);
+		for (int i = 0; i < 20; i++) {
+			array[i] = i;
+		}
+	} // Auto clears here
+
+	OS_DEBUGBREAK();
+
+	U8* array = M_MAKE(U8, 10, permanent_allocator);
+	for (int i = 10; i-- > 0;) {
+		array[10 - i] = i;
+	}
+	OS_DEBUGBREAK();
+
+	array = M_RESIZE(array, 10, 20, permanent_allocator);
+	for (int i = 20; i-- > 0;) {
+		array[20 - i] = i;
+	}
+	OS_DEBUGBREAK();
+
+	M_RELEASE(array, 20, permanent_allocator);
+	OS_DEBUGBREAK();
+}

main.c

@@ -5,16 +5,16 @@
 Line */
 
 // "GLOBAL_VAR" macro expands to "static"
-GLOBAL_VAR F32 evil_number = 666 // variables names use snake_case
+GLOBAL_VAR F32 evil_number = 666; // variables names use snake_case
 
 typedef struct RenderVertex RenderVertex; // typedefs come before structs
 struct RenderVertex { // struct names use PascalCase
-	F32 x, y, z
+	F32 x, y, z;
-}
+};
 
 // Generic pattern. the output type will be "Slice_RenderVertex"
-#define SLICE_TYPE RenderVertex
+// #define SLICE_TYPE RenderVertex
-#include "slice.h"
+// #include "slice.h"
 
 // all functions prefixed with "FUNCTION" macro, which expands to "static"
 FUNCTION I8 // primitive types follow rust style
@@ -29,32 +29,32 @@ addTwo(I8 a, I8 b) // Function names use camelCase
    defined as "static" , incase you decide to move it to a different
    compilation unit
 */
-CALLBACK Error
+// CALLBACK Error
-start(Slice_S8 args, Buffer stdin, Buffer stdout)
+// start(Slice_S8 args, Buffer stdin, Buffer stdout)
-{
+// {
-	/* all functions that belong to a type or a module are styled
+// 	/* all functions that belong to a type or a module are styled
-	   "m_TypeName_functionName". "m" is a lower-case shortened version of the
+// 	   "m_TypeName_functionName". "m" is a lower-case shortened version of the
-	   module's name (usually 1-3 letters).
+// 	   module's name (usually 1-3 letters).
-	*/
+// 	*/
-	Buffer_appendS8(&stdout, args[0]);
+// 	Buffer_appendS8(&stdout, args[0]);
-	Buffer_flush(&stdout);
+// 	Buffer_flush(&stdout);
 
-	r_Window window = r_Window_create(1280, 720, "Bastd Example");
+// 	r_Window window = r_Window_create(1280, 720, "Bastd Example");
-	I32 frame_number = 0;
+// 	I32 frame_number = 0;
 
-	for (!window.should_close) {
+// 	for (!window.should_close) {
-		frame_number += 1;
+// 		frame_number += 1;
 
-		// if there is no module, function is styled "TypeName_functionName"
+// 		// if there is no module, function is styled "TypeName_functionName"
-		Buffer_appendS8(&stdout, "Current frame: ");
+// 		Buffer_appendS8(&stdout, "Current frame: ");
-		Buffer_appendI32(&stdout, frame_number);
+// 		Buffer_appendI32(&stdout, frame_number);
-		Buffer_appendChar(&stdout, '\n');
+// 		Buffer_appendChar(&stdout, '\n');
-		Buffer_flush(&stdout);
+// 		Buffer_flush(&stdout);
 
-		r_Window_tick(&window);
+// 		r_Window_tick(&window);
-	}
+// 	}
 
-	/* Enum names are styled with PascalCase. Enum values are styled
+// 	/* Enum names are styled with PascalCase. Enum values are styled
-	   "TypeName_value_name"*/
+// 	   "TypeName_value_name"*/
-	return Error_success;
+// 	return Error_success;
-}
+// }