memory: add default allocator

Signed-off-by: Ronald Caesar <github43132@proton.me>

CMakeLists.txt

@@ -37,6 +37,7 @@ add_library(Ballistic STATIC
     src/decoder_table_gen.c
     src/bal_engine.c
     src/bal_translator.c
+    src/bal_memory.c
 )
 
 target_include_directories(Ballistic PUBLIC include)

include/bal_memory.h

@@ -10,6 +10,7 @@
 #ifndef BALLISTIC_MEMORY_H
 #define BALLISTIC_MEMORY_H
 
+#include "bal_attributes.h"
 #include <stdint.h>
 #include <stddef.h>
 
@@ -57,6 +58,15 @@ typedef struct
 
 } bal_allocator_t;
 
+/*!
+ * @brief Populates an allocator struct with the default implementation.
+ *
+ * @param[out] allocator The strict to populate. Must not be NULL.
+ *
+ * @warn Only supports Windows and POSIX systems.
+ */
+BAL_COLD void get_default_allocator(bal_allocator_t *out_allocator);
+
 #endif /* BALLISTIC_MEMORY_H */
 
 /*** end of file ***/

src/bal_memory.c

@@ -0,0 +1,65 @@
+#include "bal_memory.h"
+#include "bal_platform.h"
+#include <stdlib.h>
+#include <stddef.h>
+
+void *default_allocate(void *, size_t, size_t);
+void  default_free(void *, void *, size_t);
+
+void
+get_default_allocator (bal_allocator_t *out_allocator)
+{
+    out_allocator->allocator = NULL;
+    out_allocator->allocate  = default_allocate;
+    out_allocator->free      = default_free;
+}
+
+#if BAL_PLATFORM_POSIX
+
+void *
+default_allocate (void *allocator, size_t alignment, size_t size)
+{
+    if (0 == size)
+    {
+        return NULL;
+    }
+
+    void *memory = aligned_alloc(alignment, size);
+
+    return memory;
+}
+
+void
+default_free (void *allocator, void *pointer, size_t size)
+{
+    free(pointer);
+}
+
+#endif /* BAL_PLATFORM_POSIX */
+
+#if BAL_PLATFORM_WINDOWS
+
+#include <malloc.h>
+
+void *
+default_allocate (void *allocator, size_t alignment, size_t size)
+{
+    if (0 == size)
+    {
+        return NULL;
+    }
+
+    void *memory = _aligned_malloc(alignment, size);
+
+    return memory;
+}
+
+void
+default_free (void *allocator, void *pointer, size_t size)
+{
+    _aligned_free(pointer);
+} 
+
+#endif /* BAL_PLATFORM_WINDOWS */
+
+/*** end of file ***/