embedded bytecode, was Re: extension for lua bytecode files

[Tony Finch <dot@...>]

On Sat, 16 Jun 2007, Thomas Lauer wrote:
>
> This works very well. I have a 'shell' along the lines of lua.c which
> loads three or four byte-code libraries either from internal byte arrays
> or from external .lbc files.

I have been using a helper program to make this kind of array, but I would
have thought that it's a common enough requirement to build in to luac:

--- luac.c.orig	Fri Jun  2 17:37:11 2006
+++ luac.c	Sat Jun 16 18:26:12 2007
@@ -30,6 +30,7 @@
 static int dumping=1;			/* dump bytecodes? */
 static int stripping=0;			/* strip debug information? */
 static char Output[]={ OUTPUT };	/* default output file name */
+static const char* Ccode;		/* C wrapper name */
 static const char* output=Output;	/* actual output file name */
 static const char* progname=PROGNAME;	/* actual program name */

@@ -55,6 +56,7 @@
  "usage: %s [options] [filenames].\n"
  "Available options are:\n"
  "  -        process stdin\n"
+ "  -c name  output C wrapper\n"
  "  -l       list\n"
  "  -o name  output to file " LUA_QL("name") " (default is \"%s\")\n"
  "  -p       parse only\n"
@@ -84,6 +86,11 @@
   }
   else if (IS("-"))			/* end of options; use stdin */
    break;
+  else if (IS("-c"))			/* output C wrapper */
+  {
+   Ccode=argv[++i];
+   if (Ccode==NULL || *Ccode==0) usage(LUA_QL("-c") " needs argument");
+  }
   else if (IS("-l"))			/* list */
    ++listing;
   else if (IS("-o"))			/* output file */
@@ -144,6 +151,33 @@
  }
 }

+static void Cprologue(FILE *D)
+{
+ fprintf(D,"/* auto-generated by luac */\n"
+           "void luaload_%s(lua_State *L) {\n"
+           " static const char bytecode[] = {\n  ", Ccode);
+}
+
+static void Cepilogue(FILE *D)
+{
+ fprintf(D,"};\n if(luaL_loadbuffer(L,bytecode,sizeof(bytecode),"
+           "\"%s\"))\n  lua_error(L);\n}\n", Ccode);
+}
+
+static int Cwriter(lua_State* L, const void* p, size_t size, void* u)
+{
+ UNUSED(L);
+ while (size > 0) {
+  if (fprintf((FILE*)u, "%d,", *(unsigned char *)p) < 0)
+   return 1;
+  p++; size--;
+  if (size % 20 == 0)
+   if (fprintf((FILE*)u, "\n  ") < 0)
+    return 1;
+ }
+ return 0;
+}
+
 static int writer(lua_State* L, const void* p, size_t size, void* u)
 {
  UNUSED(L);
@@ -174,9 +208,11 @@
  {
   FILE* D= (output==NULL) ? stdout : fopen(output,"wb");
   if (D==NULL) cannot("open");
+  if (Ccode != NULL) Cprologue(D);
   lua_lock(L);
-  luaU_dump(L,f,writer,D,stripping);
+  luaU_dump(L,f, (Ccode != NULL) ? Cwriter : writer, D,stripping);
   lua_unlock(L);
+  if (Ccode != NULL) Cepilogue(D);
   if (ferror(D)) cannot("write");
   if (fclose(D)) cannot("close");
  }


Tony.
-- 
f.a.n.finch  <dot@dotat.at>  http://dotat.at/
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