From abf9ca40b1f649d65ea827a4d9c9f7a876a3b976 Mon Sep 17 00:00:00 2001
From: Allen Webster <yoyo4thdimention@gmail.com>
Date: Wed, 25 Aug 2021 09:17:00 -0700
Subject: [PATCH] memset/memmove overrides

---
 source/md.c | 46 +++++++++++++++++++++++++---------------------
 source/md.h | 22 +++++++++++++++-------
 2 files changed, 40 insertions(+), 28 deletions(-)

diff --git a/source/md.c b/source/md.c
index 4a65442..8d393f7 100644
--- a/source/md.c
+++ b/source/md.c
@@ -1,5 +1,26 @@
 // LICENSE AT END OF FILE (MIT).
 
+//~/////////////////////////////////////////////////////////////////////////////
+/////////////////////////// CRT Implementation /////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+
+#if MD_DEFAULT_MEMSET
+
+#include <stdlib.h>
+#include <string.h>
+
+#if !defined(MD_IMPL_Memset)
+# define MD_IMPL_Memset MD_CRT_Memset
+#endif
+#if !defined(MD_IMPL_Memmove)
+# define MD_IMPL_Memmove MD_CRT_Memmove
+#endif
+
+#define MD_CRT_Memset memset
+#define MD_CRT_Memmove memmove
+
+#endif
+
 //~/////////////////////////////////////////////////////////////////////////////
 /////////////////////////// Win32 Implementation ///////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////
@@ -458,22 +479,6 @@ static MD_Node _md_nil_node =
     &_md_nil_node,         // ref_target
 };
 
-//~ Memory Operations
-
-MD_FUNCTION_IMPL void*
-MD_MemoryZero(void *memory, MD_u64 size)
-{
-    memset(memory, 0, size);
-    return(memory);
-}
-
-MD_FUNCTION_IMPL void*
-MD_MemoryCopy(void *dest, void *src, MD_u64 size)
-{
-    memcpy(dest, src, size);
-    return(dest);
-}
-
 //~ Arena Functions
 
 MD_FUNCTION_IMPL MD_Arena*
@@ -803,7 +808,7 @@ MD_S8ListConcat(MD_String8List *list, MD_String8List *to_push)
             list->last = to_push->last;
         }
     }
-    MD_MemoryZero(to_push, sizeof(*to_push));
+    MD_MemoryZeroStruct(to_push);
 }
 
 MD_FUNCTION_IMPL MD_String8List
@@ -1978,7 +1983,7 @@ MD_MessageListConcat(MD_MessageList *list, MD_MessageList *to_push)
     {
         *list = *to_push;
     }
-    MD_MemoryZero(to_push, sizeof(*to_push));
+    MD_MemoryZeroStruct(to_push);
 }
 
 MD_FUNCTION_IMPL MD_ParseResult
@@ -2331,7 +2336,7 @@ MD_ParseOneNode(MD_Arena *arena, MD_String8 string, MD_u64 offset)
                 }
                 else if(next_token.kind == MD_TokenKind_Newline)
                 {
-                    MD_MemoryZero(&comment_token, sizeof(comment_token));
+                    MD_MemoryZeroStruct(&comment_token);
                 }
             }
             else if((token.kind & MD_TokenGroup_Whitespace) != 0)
@@ -3391,8 +3396,7 @@ MD_MakeCmdLineFromOptions(MD_Arena *arena, MD_String8List options)
             
             //- rjf: insert the fully parsed option
             {
-                MD_CmdLineOption *opt = MD_PushArray(arena, MD_CmdLineOption, 1);
-                MD_MemoryZero(opt, sizeof(*opt));
+                MD_CmdLineOption *opt = MD_PushArrayZero(arena, MD_CmdLineOption, 1);
                 opt->name = option_name;
                 opt->values = option_values;
                 if(cmdln.last_option == 0)
diff --git a/source/md.h b/source/md.h
index dd5deed..8c91b4b 100644
--- a/source/md.h
+++ b/source/md.h
@@ -5,9 +5,16 @@
 #ifndef MD_H
 #define MD_H
 
+// TODO(rjf): implicitly-delimited sets are not having their separator flags
+// appropriately set
+
 /* NOTE(allen): Notes on overrides/macro options:
 **
 ** Overridable :
+**  "memset" ** REQUIRED (default crt-based implementation available)
+**   #define MD_IMPL_Memset             (void*, int, MD_u64) -> void*
+**   #define MD_IMPL_Memmove            (void*, void*, MD_u64) -> void*
+**
 **  "file iteration" ** OPTIONAL
 **   #define MD_IMPL_FileIterBegin      (MD_FileIter*, MD_String8) -> MD_b32
 **   #define MD_IMPL_FileIterNext       (MD_Arena*, MD_FileIter*) -> MD_FileInfo
@@ -37,6 +44,7 @@
 **
 ** Default Implementation Controls
 **  These controls default to '1' i.e. 'enabled'
+**   #define MD_DEFAULT_MEMSET    -> construct "memset" from CRT
 **   #define MD_DEFAULT_FILE_ITER -> construct "file iteration" from OS headers
 **   #define MD_DEFAULT_MEMORY    -> construct "low level memory" from OS headers
 **   #define MD_DEFAULT_ARENA     -> construct "arena" from "low level memory"
@@ -44,10 +52,10 @@
 **
 */
 
-// TODO(rjf): implicitly-delimited sets are not having their separator flags
-// appropriately set
-
 //~ Set default values for controls
+#if !defined(MD_DEFAULT_MEMSET)
+# define MD_DEFAULT_MEMSET 1
+#endif
 #if !defined(MD_DEFAULT_FILE_ITER)
 # define MD_DEFAULT_FILE_ITER 1
 #endif
@@ -293,10 +301,8 @@
 #define MD_GLOBAL static
 
 #include <stdint.h>
-#include <stdlib.h>
 #include <stdio.h>
 #include <stdarg.h>
-#include <string.h>
 #define STB_SPRINTF_DECORATE(name) md_stbsp_##name
 #include "md_stb_sprintf.h"
 
@@ -774,8 +780,10 @@ struct MD_FileIter
 
 //~ Memory Operations
 
-MD_FUNCTION void* MD_MemoryZero(void *memory, MD_u64 size);
-MD_FUNCTION void* MD_MemoryCopy(void *dst, void *src, MD_u64 size);
+#define MD_MemorySet(p,v,z)    (MD_IMPL_Memset(p,v,z))
+#define MD_MemoryZero(p,z)     (MD_IMPL_Memset(p,0,z))
+#define MD_MemoryZeroStruct(p) (MD_IMPL_Memset(p,0,sizeof(*(p))))
+#define MD_MemoryCopy(d,s,z)   (MD_IMPL_Memmove(d,s,z))
 
 //~ Arena Functions