commit ec748fcb0a6913a814f106218e9fde3a73ffc014
parent c196348717dfda116726145220e5d1311547980e
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 16 Oct 2002 17:41:13 -0300
correct handling of opened files in presence of memory allocation
errors
Diffstat:
| M | lauxlib.c | | | 40 | ++++++++++++++++++++++------------------ |
| M | liolib.c | | | 56 | +++++++++++++++++++++++++++++++------------------------- |
2 files changed, 53 insertions(+), 43 deletions(-)
diff --git a/lauxlib.c b/lauxlib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lauxlib.c,v 1.86 2002/09/16 19:49:45 roberto Exp roberto $
+** $Id: lauxlib.c,v 1.87 2002/10/04 14:31:40 roberto Exp roberto $
** Auxiliary functions for building Lua libraries
** See Copyright Notice in lua.h
*/
@@ -345,38 +345,42 @@ static const char *getF (lua_State *L, void *ud, size_t *size) {
}
-static int errfile (lua_State *L, const char *filename) {
- if (filename == NULL) filename = "stdin";
+static int errfile (lua_State *L, int fnameindex) {
+ const char *filename = lua_tostring(L, fnameindex) + 1;
lua_pushfstring(L, "cannot read %s: %s", filename, strerror(errno));
+ lua_remove(L, fnameindex);
return LUA_ERRFILE;
}
LUALIB_API int luaL_loadfile (lua_State *L, const char *filename) {
LoadF lf;
- int status;
+ int status, readstatus;
int c;
- int old_top = lua_gettop(L);
- lf.f = (filename == NULL) ? stdin : fopen(filename, "r");
- if (lf.f == NULL) return errfile(L, filename); /* unable to open file */
+ int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */
+ if (filename == NULL) {
+ lua_pushliteral(L, "=stdin");
+ lf.f = stdin;
+ }
+ else {
+ lua_pushfstring(L, "@%s", filename);
+ lf.f = fopen(filename, "r");
+ }
+ if (lf.f == NULL) return errfile(L, fnameindex); /* unable to open file */
c = ungetc(getc(lf.f), lf.f);
if (!(isspace(c) || isprint(c)) && lf.f != stdin) { /* binary file? */
fclose(lf.f);
lf.f = fopen(filename, "rb"); /* reopen in binary mode */
- if (lf.f == NULL) return errfile(L, filename); /* unable to reopen file */
+ if (lf.f == NULL) return errfile(L, fnameindex); /* unable to reopen file */
}
- if (filename == NULL)
- lua_pushliteral(L, "=stdin");
- else
- lua_pushfstring(L, "@%s", filename);
status = lua_load(L, getF, &lf, lua_tostring(L, -1));
- lua_remove(L, old_top+1); /* remove filename from stack */
- if (ferror(lf.f)) {
- lua_settop(L, old_top); /* ignore results from `lua_load' */
- return errfile(L, filename);
+ readstatus = ferror(lf.f);
+ if (lf.f != stdin) fclose(lf.f); /* close file (even in case of errors) */
+ if (readstatus) {
+ lua_settop(L, fnameindex); /* ignore results from `lua_load' */
+ return errfile(L, fnameindex);
}
- if (lf.f != stdin)
- fclose(lf.f);
+ lua_remove(L, fnameindex);
return status;
}
diff --git a/liolib.c b/liolib.c
@@ -1,5 +1,5 @@
/*
-** $Id: liolib.c,v 2.19 2002/09/19 20:12:47 roberto Exp roberto $
+** $Id: liolib.c,v 2.20 2002/10/11 20:40:32 roberto Exp roberto $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/
@@ -68,18 +68,25 @@ static FILE *tofile (lua_State *L, int findex) {
}
-static void newfile (lua_State *L, FILE *f) {
- lua_boxpointer(L, f);
+/*
+** When creating file handles, always creates a `closed' file handle
+** before opening the actual file; so, if there is a memory error, the
+** file is not left opened.
+*/
+static FILE **newfile (lua_State *L) {
+ FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *));
+ *pf = NULL; /* file handle is currently `closed' */
lua_pushliteral(L, FILEHANDLE);
lua_rawget(L, LUA_REGISTRYINDEX);
lua_setmetatable(L, -2);
+ return pf;
}
static void registerfile (lua_State *L, FILE *f, const char *name,
const char *impname) {
lua_pushstring(L, name);
- newfile(L, f);
+ *newfile(L) = f;
if (impname) {
lua_pushstring(L, impname);
lua_pushvalue(L, -2);
@@ -89,16 +96,6 @@ static void registerfile (lua_State *L, FILE *f, const char *name,
}
-static int setnewfile (lua_State *L, FILE *f) {
- if (f == NULL)
- return pushresult(L, 0);
- else {
- newfile(L, f);
- return 1;
- }
-}
-
-
static int aux_close (lua_State *L) {
FILE *f = tofile(L, 1);
if (f == stdin || f == stdout || f == stderr)
@@ -126,8 +123,11 @@ static int io_gc (lua_State *L) {
static int io_open (lua_State *L) {
- FILE *f = fopen(luaL_check_string(L, 1), luaL_opt_string(L, 2, "r"));
- return setnewfile(L, f);
+ const char *filename = luaL_check_string(L, 1);
+ const char *mode = luaL_opt_string(L, 2, "r");
+ FILE **pf = newfile(L);
+ *pf = fopen(filename, mode);
+ return (*pf == NULL) ? pushresult(L, 0) : 1;
}
@@ -136,14 +136,19 @@ static int io_popen (lua_State *L) {
luaL_error(L, "`popen' not supported");
return 0;
#else
- FILE *f = popen(luaL_check_string(L, 1), luaL_opt_string(L, 2, "r"));
- return setnewfile(L, f);
+ const char *filename = luaL_check_string(L, 1);
+ const char *mode = luaL_opt_string(L, 2, "r");
+ FILE **pf = newfile(L);
+ *pf = popen(filename, mode);
+ return (*pf == NULL) ? pushresult(L, 0) : 1;
#endif
}
static int io_tmpfile (lua_State *L) {
- return setnewfile(L, tmpfile());
+ FILE **pf = newfile(L);
+ *pf = tmpfile();
+ return (*pf == NULL) ? pushresult(L, 0) : 1;
}
@@ -168,9 +173,9 @@ static int g_iofile (lua_State *L, const char *name, const char *mode) {
const char *filename = lua_tostring(L, 1);
lua_pushstring(L, name);
if (filename) {
- FILE *f = fopen(filename, mode);
- luaL_arg_check(L, f, 1, strerror(errno));
- newfile(L, f);
+ FILE **pf = newfile(L);
+ *pf = fopen(filename, mode);
+ luaL_arg_check(L, *pf, 1, strerror(errno));
}
else {
tofile(L, 1); /* check that it's a valid file handle */
@@ -218,9 +223,10 @@ static int io_lines (lua_State *L) {
return f_lines(L);
}
else {
- FILE *f = fopen(luaL_check_string(L, 1), "r");
- luaL_arg_check(L, f, 1, strerror(errno));
- newfile(L, f);
+ const char *filename = luaL_check_string(L, 1);
+ FILE **pf = newfile(L);
+ *pf = fopen(filename, "r");
+ luaL_arg_check(L, *pf, 1, strerror(errno));
aux_lines(L, lua_gettop(L), 1);
return 1;
}
