commit 14e416355f83cf0a1b871eedec2c92b86dbe76d6
parent f33cda8d6eb1cac5b9042429e85f1096175c7ca5
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 5 Sep 2023 15:30:18 -0300
Added suport for Fixed Buffers
A fixed buffer keeps a binary chunk "forever", so that the program
does not need to copy some of its parts when loading it.
Diffstat:
12 files changed, 160 insertions(+), 34 deletions(-)
diff --git a/lbaselib.c b/lbaselib.c
@@ -337,9 +337,20 @@ static int load_aux (lua_State *L, int status, int envidx) {
}
+static const char *getmode (lua_State *L, int idx) {
+ const char *mode = luaL_optstring(L, idx, "bt");
+ int i = 0;
+ if (mode[i] == 'b') i++;
+ if (mode[i] == 't') i++;
+ if (mode[i] != '\0')
+ luaL_argerror(L, idx, "invalid mode");
+ return mode;
+}
+
+
static int luaB_loadfile (lua_State *L) {
const char *fname = luaL_optstring(L, 1, NULL);
- const char *mode = luaL_optstring(L, 2, NULL);
+ const char *mode = getmode(L, 2);
int env = (!lua_isnone(L, 3) ? 3 : 0); /* 'env' index or 0 if no 'env' */
int status = luaL_loadfilex(L, fname, mode);
return load_aux(L, status, env);
@@ -388,7 +399,7 @@ static int luaB_load (lua_State *L) {
int status;
size_t l;
const char *s = lua_tolstring(L, 1, &l);
- const char *mode = luaL_optstring(L, 3, "bt");
+ const char *mode = getmode(L, 3);
int env = (!lua_isnone(L, 4) ? 4 : 0); /* 'env' index or 0 if no 'env' */
if (s != NULL) { /* loading a string? */
const char *chunkname = luaL_optstring(L, 2, s);
diff --git a/ldo.c b/ldo.c
@@ -977,7 +977,7 @@ struct SParser { /* data to 'f_parser' */
static void checkmode (lua_State *L, const char *mode, const char *x) {
- if (mode && strchr(mode, x[0]) == NULL) {
+ if (strchr(mode, x[0]) == NULL) {
luaO_pushfstring(L,
"attempt to load a %s chunk (mode is '%s')", x, mode);
luaD_throw(L, LUA_ERRSYNTAX);
@@ -988,13 +988,18 @@ static void checkmode (lua_State *L, const char *mode, const char *x) {
static void f_parser (lua_State *L, void *ud) {
LClosure *cl;
struct SParser *p = cast(struct SParser *, ud);
+ const char *mode = p->mode ? p->mode : "bt";
int c = zgetc(p->z); /* read first character */
if (c == LUA_SIGNATURE[0]) {
- checkmode(L, p->mode, "binary");
- cl = luaU_undump(L, p->z, p->name);
+ int fixed = 0;
+ if (strchr(mode, 'B') != NULL)
+ fixed = 1;
+ else
+ checkmode(L, mode, "binary");
+ cl = luaU_undump(L, p->z, p->name, fixed);
}
else {
- checkmode(L, p->mode, "text");
+ checkmode(L, mode, "text");
cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c);
}
lua_assert(cl->nupvalues == cl->p->sizeupvalues);
diff --git a/lfunc.c b/lfunc.c
@@ -265,10 +265,12 @@ Proto *luaF_newproto (lua_State *L) {
void luaF_freeproto (lua_State *L, Proto *f) {
- luaM_freearray(L, f->code, f->sizecode);
+ if (!(f->flag & PF_FIXED)) {
+ luaM_freearray(L, f->code, f->sizecode);
+ luaM_freearray(L, f->lineinfo, f->sizelineinfo);
+ }
luaM_freearray(L, f->p, f->sizep);
luaM_freearray(L, f->k, f->sizek);
- luaM_freearray(L, f->lineinfo, f->sizelineinfo);
luaM_freearray(L, f->abslineinfo, f->sizeabslineinfo);
luaM_freearray(L, f->locvars, f->sizelocvars);
luaM_freearray(L, f->upvalues, f->sizeupvalues);
diff --git a/lobject.h b/lobject.h
@@ -556,6 +556,7 @@ typedef struct AbsLineInfo {
** Flags in Prototypes
*/
#define PF_ISVARARG 1
+#define PF_FIXED 2 /* prototype has parts in fixed memory */
/*
diff --git a/lstring.c b/lstring.c
@@ -207,8 +207,8 @@ static TString *internshrstr (lua_State *L, const char *str, size_t l) {
list = &tb->hash[lmod(h, tb->size)]; /* rehash with new size */
}
ts = createstrobj(L, l, LUA_VSHRSTR, h);
- memcpy(getshrstr(ts), str, l * sizeof(char));
ts->shrlen = cast_byte(l);
+ memcpy(getshrstr(ts), str, l * sizeof(char));
ts->u.hnext = *list;
*list = ts;
tb->nuse++;
diff --git a/ltests.c b/ltests.c
@@ -1513,8 +1513,11 @@ static int runC (lua_State *L, lua_State *L1, const char *pc) {
luaL_loadfile(L1, luaL_checkstring(L1, getnum));
}
else if EQ("loadstring") {
- const char *s = luaL_checkstring(L1, getnum);
- luaL_loadstring(L1, s);
+ size_t slen;
+ const char *s = luaL_checklstring(L1, getnum, &slen);
+ const char *name = getstring;
+ const char *mode = getstring;
+ luaL_loadbufferx(L1, s, slen, name, mode);
}
else if EQ("newmetatable") {
lua_pushboolean(L1, luaL_newmetatable(L1, getstring));
diff --git a/lundump.c b/lundump.c
@@ -38,6 +38,7 @@ typedef struct {
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;
@@ -70,6 +71,16 @@ static void loadAlign (LoadState *S, int align) {
}
+#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;
+}
+
+
#define loadVar(S,x) loadVector(S,&x,1)
@@ -169,10 +180,16 @@ 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;
loadAlign(S, sizeof(f->code[0]));
- loadVector(S, f->code, n);
+ 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);
+ }
}
@@ -254,9 +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;
@@ -287,7 +310,9 @@ static void loadFunction (LoadState *S, Proto *f) {
f->linedefined = loadInt(S);
f->lastlinedefined = loadInt(S);
f->numparams = loadByte(S);
- f->flag = loadByte(S) & PF_ISVARARG; /* keep only the meaningful flags */
+ 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);
@@ -335,7 +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 == '=')
@@ -346,6 +371,7 @@ 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));
diff --git a/lundump.h b/lundump.h
@@ -26,7 +26,8 @@
#define LUAC_FORMAT 0 /* this is the official format */
/* load one chunk; from lundump.c */
-LUAI_FUNC LClosure* luaU_undump (lua_State* L, ZIO* Z, const char* name);
+LUAI_FUNC LClosure* luaU_undump (lua_State* L, ZIO* Z, const char* name,
+ int fixed);
/* dump one chunk; from ldump.c */
LUAI_FUNC int luaU_dump (lua_State* L, const Proto* f, lua_Writer w,
diff --git a/lzio.c b/lzio.c
@@ -45,17 +45,25 @@ void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
/* --------------------------------------------------------------- read --- */
+
+static int checkbuffer (ZIO *z) {
+ if (z->n == 0) { /* no bytes in buffer? */
+ if (luaZ_fill(z) == EOZ) /* try to read more */
+ return 0; /* no more input */
+ else {
+ z->n++; /* luaZ_fill consumed first byte; put it back */
+ z->p--;
+ }
+ }
+ return 1; /* now buffer has something */
+}
+
+
size_t luaZ_read (ZIO *z, void *b, size_t n) {
while (n) {
size_t m;
- if (z->n == 0) { /* no bytes in buffer? */
- if (luaZ_fill(z) == EOZ) /* try to read more */
- return n; /* no more input; return number of missing bytes */
- else {
- z->n++; /* luaZ_fill consumed first byte; put it back */
- z->p--;
- }
- }
+ if (!checkbuffer(z))
+ return n; /* no more input; return number of missing bytes */
m = (n <= z->n) ? n : z->n; /* min. between n and z->n */
memcpy(b, z->p, m);
z->n -= m;
@@ -66,3 +74,15 @@ size_t luaZ_read (ZIO *z, void *b, size_t n) {
return 0;
}
+
+const void *luaZ_getaddr (ZIO* z, size_t n) {
+ const void *res;
+ if (!checkbuffer(z))
+ return NULL; /* no more input */
+ if (z->n < n) /* not enough bytes? */
+ return NULL; /* block not whole; cannot give an address */
+ res = z->p; /* get block address */
+ z->n -= n; /* consume these bytes */
+ z->p += n;
+ return res;
+}
diff --git a/lzio.h b/lzio.h
@@ -48,6 +48,7 @@ LUAI_FUNC void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader,
void *data);
LUAI_FUNC size_t luaZ_read (ZIO* z, void *b, size_t n); /* read next n bytes */
+LUAI_FUNC const void *luaZ_getaddr (ZIO* z, size_t n);
/* --------- Private Part ------------------ */
diff --git a/manual/manual.of b/manual/manual.of
@@ -2730,7 +2730,8 @@ For such errors, Lua does not call the @x{message handler}.
@item{@defid{LUA_ERRERR}| error while running the @x{message handler}.}
-@item{@defid{LUA_ERRSYNTAX}| syntax error during precompilation.}
+@item{@defid{LUA_ERRSYNTAX}| syntax error during precompilation
+or format error in a binary chunk.}
@item{@defid{LUA_YIELD}| the thread (coroutine) yields.}
@@ -3646,6 +3647,18 @@ and loads it accordingly (see program @idx{luac}).
The string @id{mode} works as in function @Lid{load},
with the addition that
a @id{NULL} value is equivalent to the string @St{bt}.
+Moreover, it may have a @Char{B} instead of a @Char{b},
+meaning a @emphx{fixed buffer} with the binary dump.
+
+A fixed buffer means that the address returned by the reader function
+should contain the chunk until everything created by the chunk has
+been collected.
+(In general, a fixed buffer would keep the chunk
+as its contents until the end of the program,
+for instance with the chunk in ROM.)
+Moreover, for a fixed buffer,
+the reader function should return the entire chunk in the first read.
+(As an example, @Lid{luaL_loadbufferx} does that.)
@id{lua_load} uses the stack internally,
so the reader function must always leave the stack
@@ -5688,6 +5701,8 @@ This function returns the same results as @Lid{lua_load}.
@id{name} is the chunk name,
used for debug information and error messages.
The string @id{mode} works as in the function @Lid{lua_load}.
+In particular, this function supports mode @Char{B} for
+fixed buffers.
}
diff --git a/testes/api.lua b/testes/api.lua
@@ -407,7 +407,7 @@ do
concat 3]]) == "hi alo mundo")
-- "argerror" without frames
- assert(T.checkpanic("loadstring 4") ==
+ assert(T.checkpanic("loadstring 4 name bt") ==
"bad argument #4 (string expected, got no value)")
@@ -420,7 +420,7 @@ do
if not _soft then
local msg = T.checkpanic[[
pushstring "function f() f() end"
- loadstring -1; call 0 0
+ loadstring -1 name t; call 0 0
getglobal f; call 0 0
]]
assert(string.find(msg, "stack overflow"))
@@ -430,7 +430,7 @@ do
assert(T.checkpanic([[
pushstring "return {__close = function () Y = 'ho'; end}"
newtable
- loadstring -2
+ loadstring -2 name t
call 0 1
setmetatable -2
toclose -1
@@ -458,6 +458,8 @@ if not _soft then
print'+'
end
+
+
local lim = _soft and 500 or 12000
local prog = {"checkstack " .. (lim * 2 + 100) .. "msg", "newtable"}
for i = 1,lim do
@@ -481,10 +483,20 @@ for i = 1,lim do assert(t[i] == i*10); t[i] = undef end
assert(next(t) == nil)
prog, g, t = nil
+do -- shrink stack
+ local m1, m2 = 0, collectgarbage"count" * 1024
+ while m1 ~= m2 do -- repeat until stable
+ collectgarbage()
+ m1 = m2
+ m2 = collectgarbage"count" * 1024
+ end
+end
+
+
-- testing errors
a = T.testC([[
- loadstring 2; pcall 0 1 0;
+ loadstring 2 name t; pcall 0 1 0;
pushvalue 3; insert -2; pcall 1 1 0;
pcall 0 0 0;
return 1
@@ -498,7 +510,7 @@ local function check3(p, ...)
assert(#arg == 3)
assert(string.find(arg[3], p))
end
-check3(":1:", T.testC("loadstring 2; return *", "x="))
+check3(":1:", T.testC("loadstring 2 name t; return *", "x="))
check3("%.", T.testC("loadfile 2; return *", "."))
check3("xxxx", T.testC("loadfile 2; return *", "xxxx"))
@@ -509,6 +521,35 @@ local function checkerrnopro (code, msg)
assert(not stt and string.find(err, msg))
end
+
+do
+ print("testing load of binaries in fixed buffers")
+ local source = {}
+ local N = 1000
+ -- create a somewhat "large" source
+ for i = 1, N do source[i] = "X = X + 1; " end
+ source = table.concat(source)
+ -- give chunk an explicit name to avoid using source as name
+ source = load(source, "name1")
+ -- dump without debug information
+ source = string.dump(source, true)
+ -- each "X=X+1" generates 4 opcodes with 4 bytes each
+ assert(#source > N * 4 * 4)
+ collectgarbage(); collectgarbage()
+ local m1 = collectgarbage"count" * 1024
+ -- load dump using fixed buffer
+ local code = T.testC([[
+ loadstring 2 name B;
+ return 1
+ ]], source)
+ collectgarbage()
+ local m2 = collectgarbage"count" * 1024
+ -- load used fewer than 300 bytes
+ assert(m2 > m1 and m2 - m1 < 300)
+ X = 0; code(); assert(X == N); X = nil
+end
+
+
if not _soft then
collectgarbage("stop") -- avoid __gc with full stack
checkerrnopro("pushnum 3; call 0 0", "attempt to call")
