1 files changed, 72 insertions, 15 deletions

diff --git a/lundump.c b/lundump.c
index e8d92a85..45708f96 100644
--- a/lundump.c
+++ b/lundump.c
@@ -21,6 +21,7 @@
 #include "lmem.h"
 #include "lobject.h"
 #include "lstring.h"
+#include "ltable.h"
 #include "lundump.h"
 #include "lzio.h"
 
@@ -34,6 +35,10 @@ typedef struct {
   lua_State *L;
   ZIO *Z;
   const char *name;
+  Table *h;  /* list for string reuse */
+  lu_mem offset;  /* current position relative to beginning of dump */
+  lua_Integer nstr;  /* number of strings in the list */
+  lu_byte fixed;  /* dump is fixed in memory */
 } LoadState;
 
 
@@ -52,6 +57,27 @@ static l_noret error (LoadState *S, const char *why) {
 static void loadBlock (LoadState *S, void *b, size_t size) {
   if (luaZ_read(S->Z, b, size) != 0)
     error(S, "truncated chunk");
+  S->offset += size;
+}
+
+
+static void loadAlign (LoadState *S, int align) {
+  int padding = align - (S->offset % align);
+  if (padding < align) {  /* apd == align means no padding */
+    lua_Integer paddingContent;
+    loadBlock(S, &paddingContent, padding);
+    lua_assert(S->offset % align == 0);
+  }
+}
+
+
+#define getaddr(S,n,t)  cast(t *, getaddr_(S,n,sizeof(t)))
+
+static const void *getaddr_ (LoadState *S, int n, int sz) {
+  const void *block = luaZ_getaddr(S->Z, n * sz);
+  if (block == NULL)
+    error(S, "truncated fixed buffer");
+  return block;
 }
 
 
@@ -62,6 +88,7 @@ static lu_byte loadByte (LoadState *S) {
   int b = zgetc(S->Z);
   if (b == EOZ)
     error(S, "truncated chunk");
+  S->offset++;
   return cast_byte(b);
 }
 
@@ -110,10 +137,16 @@ static lua_Integer loadInteger (LoadState *S) {
 static TString *loadStringN (LoadState *S, Proto *p) {
   lua_State *L = S->L;
   TString *ts;
+  TValue sv;
   size_t size = loadSize(S);
   if (size == 0)  /* no string? */
     return NULL;
-  else if (--size <= LUAI_MAXSHORTLEN) {  /* short string? */
+  else if (size == 1) {  /* previously saved string? */
+    int idx = loadInt(S);  /* get its index */
+    const TValue *stv = luaH_getint(S->h, idx);
+    return tsvalue(stv);
+  }
+  else if (size -= 2, size <= LUAI_MAXSHORTLEN) {  /* short string? */
     char buff[LUAI_MAXSHORTLEN];
     loadVector(S, buff, size);  /* load string into buffer */
     ts = luaS_newlstr(L, buff, size);  /* create string */
@@ -126,6 +159,10 @@ static TString *loadStringN (LoadState *S, Proto *p) {
     L->top.p--;  /* pop string */
   }
   luaC_objbarrier(L, p, ts);
+  S->nstr++;  /* add string to list of saved strings */
+  setsvalue(L, &sv, ts);
+  luaH_setint(L, S->h, S->nstr, &sv);
+  luaC_objbarrierback(L, obj2gco(S->h), ts);
   return ts;
 }
 
@@ -143,13 +180,20 @@ static TString *loadString (LoadState *S, Proto *p) {
 
 static void loadCode (LoadState *S, Proto *f) {
   int n = loadInt(S);
-  f->code = luaM_newvectorchecked(S->L, n, Instruction);
-  f->sizecode = n;
-  loadVector(S, f->code, n);
+  loadAlign(S, sizeof(f->code[0]));
+  if (S->fixed) {
+    f->code = getaddr(S, n, Instruction);
+    f->sizecode = n;
+  }
+  else {
+    f->code = luaM_newvectorchecked(S->L, n, Instruction);
+    f->sizecode = n;
+    loadVector(S, f->code, n);
+  }
 }
 
 
-static void loadFunction(LoadState *S, Proto *f, TString *psource);
+static void loadFunction(LoadState *S, Proto *f);
 
 
 static void loadConstants (LoadState *S, Proto *f) {
@@ -198,7 +242,7 @@ static void loadProtos (LoadState *S, Proto *f) {
   for (i = 0; i < n; i++) {
     f->p[i] = luaF_newproto(S->L);
     luaC_objbarrier(S->L, f, f->p[i]);
-    loadFunction(S, f->p[i], f->source);
+    loadFunction(S, f->p[i]);
   }
 }
 
@@ -227,9 +271,15 @@ static void loadUpvalues (LoadState *S, Proto *f) {
 static void loadDebug (LoadState *S, Proto *f) {
   int i, n;
   n = loadInt(S);
-  f->lineinfo = luaM_newvectorchecked(S->L, n, ls_byte);
-  f->sizelineinfo = n;
-  loadVector(S, f->lineinfo, n);
+  if (S->fixed) {
+    f->lineinfo = getaddr(S, n, ls_byte);
+    f->sizelineinfo = n;
+  }
+  else {
+    f->lineinfo = luaM_newvectorchecked(S->L, n, ls_byte);
+    f->sizelineinfo = n;
+    loadVector(S, f->lineinfo, n);
+  }
   n = loadInt(S);
   f->abslineinfo = luaM_newvectorchecked(S->L, n, AbsLineInfo);
   f->sizeabslineinfo = n;
@@ -255,14 +305,14 @@ static void loadDebug (LoadState *S, Proto *f) {
 }
 
 
-static void loadFunction (LoadState *S, Proto *f, TString *psource) {
+static void loadFunction (LoadState *S, Proto *f) {
   f->source = loadStringN(S, f);
-  if (f->source == NULL)  /* no source in dump? */
-    f->source = psource;  /* reuse parent's source */
   f->linedefined = loadInt(S);
   f->lastlinedefined = loadInt(S);
   f->numparams = loadByte(S);
-  f->is_vararg = loadByte(S);
+  f->flag = loadByte(S) & PF_ISVARARG;  /* get only the meaningful flags */
+  if (S->fixed)
+    f->flag |= PF_FIXED;  /* signal that code is fixed */
   f->maxstacksize = loadByte(S);
   loadCode(S, f);
   loadConstants(S, f);
@@ -310,7 +360,7 @@ static void checkHeader (LoadState *S) {
 /*
 ** Load precompiled chunk.
 */
-LClosure *luaU_undump(lua_State *L, ZIO *Z, const char *name) {
+LClosure *luaU_undump (lua_State *L, ZIO *Z, const char *name, int fixed) {
   LoadState S;
   LClosure *cl;
   if (*name == '@' || *name == '=')
@@ -321,15 +371,22 @@ LClosure *luaU_undump(lua_State *L, ZIO *Z, const char *name) {
     S.name = name;
   S.L = L;
   S.Z = Z;
+  S.fixed = fixed;
+  S.offset = 1;  /* fist byte was already read */
   checkHeader(&S);
   cl = luaF_newLclosure(L, loadByte(&S));
   setclLvalue2s(L, L->top.p, cl);
   luaD_inctop(L);
+  S.h = luaH_new(L);  /* create list of saved strings */
+  S.nstr = 0;
+  sethvalue2s(L, L->top.p, S.h);  /* anchor it */
+  luaD_inctop(L);
   cl->p = luaF_newproto(L);
   luaC_objbarrier(L, cl, cl->p);
-  loadFunction(&S, cl->p, NULL);
+  loadFunction(&S, cl->p);
   lua_assert(cl->nupvalues == cl->p->sizeupvalues);
   luai_verifycode(L, cl->p);
+  L->top.p--;  /* pop table */
   return cl;
 }