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Add compiler warning/error for duplicate variable declaration in LuaJIT 2.1
--- lj_parse.c
+++ lj_parse.c
@@ -27,6 +27,8 @@
#include "lj_parse.h"
#include "lj_vm.h"
#include "lj_vmevent.h"
+
+#include <stdio.h>
/* -- Parser structures and definitions ----------------------------------- */
@@ -164,6 +166,12 @@
LJ_STATIC_ASSERT((int)BC_MODVV-(int)BC_ADDVV == (int)OPR_MOD-(int)OPR_ADD);
/* -- Error handling ------------------------------------------------------ */
+
+static void parser_warning (LexState *ls, const char *msg) {
+ const char *str = strdata(ls->chunkname);
+ fprintf(stderr, "%s:%d: warning %s\n", (str[0] == '@') ? str+1 : str , ls->linenumber, msg);
+ fflush(stderr);
+}
LJ_NORET LJ_NOINLINE static void err_syntax(LexState *ls, ErrMsg em)
{
@@ -1034,7 +1042,27 @@
{
FuncState *fs = ls->fs;
MSize vtop = ls->vtop;
- checklimit(fs, fs->nactvar+n, LJ_MAX_LOCVAR, "local variables");
+ BCReg i, nactvar_n = fs->nactvar+n;
+
+ if(name && name > ((GCstr*)0xffff)) { /*some names are made from casting ints */
+ /* allow '_' and '(for...' duplicates */
+ const char *str_name = strdata(name);
+ if(!(str_name[0] == '(' || (name->len == 1 && str_name[0] == '_'))) {
+ for (i=0; i < nactvar_n; ++i) {
+ if (name == strref(var_get(ls, fs, i).name)) {
+ if(fs->bl && i < fs->bl->nactvar) {
+ parser_warning(ls, lj_strfmt_pushf(ls->L,
+ "Name [%s] already declared will be shadowed", str_name));
+ }
+ else {
+ lj_lex_error(ls, 0, LJ_ERR_XNAMEDUP, str_name);
+ }
+ }
+ }
+ }
+ }
+
+ checklimit(fs, nactvar_n, LJ_MAX_LOCVAR, "local variables");
if (LJ_UNLIKELY(vtop >= ls->sizevstack)) {
if (ls->sizevstack >= LJ_MAX_VSTACK)
lj_lex_error(ls, 0, LJ_ERR_XLIMC, LJ_MAX_VSTACK);
--- lj_errmsg.h
+++ lj_errmsg.h
@@ -145,6 +145,7 @@
ERRDEF(XLUNDEF, "undefined label " LUA_QS)
ERRDEF(XLDUP, "duplicate label " LUA_QS)
ERRDEF(XGSCOPE, "<goto %s> jumps into the scope of local " LUA_QS)
+ERRDEF(XNAMEDUP, "duplicate name " LUA_QS)
/* Bytecode reader errors. */
ERRDEF(BCFMT, "cannot load incompatible bytecode")
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