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Add compiler warning/error for duplicate variable declaration in Lua 5.3.5
--- lparser.c
+++ lparser.c
@@ -11,6 +11,7 @@
#include <string.h>
+#include <stdio.h>
#include "lua.h"
@@ -62,6 +63,12 @@
static void statement (LexState *ls);
static void expr (LexState *ls, expdesc *v);
+static void parser_warning (LexState *ls, const char *msg) {
+ msg = luaO_pushfstring(ls->L, "warning %s", msg);
+ msg = luaG_addinfo(ls->L, msg, ls->source, ls->linenumber);
+ fprintf(stderr, "%s\n", msg);
+ fflush(stderr);
+}
/* semantic error */
static l_noret semerror (LexState *ls, const char *msg) {
@@ -172,9 +179,39 @@
}
+static void var_check_unique_or_shadow (LexState *ls, FuncState *fs, TString *name, int shadowOnly) {
+ Dyndata *dyd = ls->dyd;
+
+ /* allow '_' and '(for...' duplicates */
+ const char *str_name = getstr(name);
+ if(!(str_name[0] == '(' || (tsslen(name) == 1 && str_name[0] == '_'))) {
+ int vidx, nactvar_n, first_block_local;
+ vidx = fs->firstlocal;
+ nactvar_n = dyd->actvar.n;
+ first_block_local = fs->bl ? fs->bl->nactvar+fs->firstlocal : 0;
+ for (; vidx < nactvar_n; ++vidx) {
+ LocVar *lv = &fs->f->locvars[dyd->actvar.arr[vidx].idx];
+ if (lv && name == lv->varname) {
+ if(vidx <= first_block_local) {
+ int saved_top = lua_gettop(ls->L);
+ parser_warning(ls, luaO_pushfstring(ls->L,
+ "Name [%s] already declared will be shadowed", str_name));
+ lua_settop(ls->L, saved_top);
+ }
+ else if(!shadowOnly) {
+ luaX_syntaxerror(ls, luaO_pushfstring(ls->L,
+ "Name [%s] already declared", str_name));
+ }
+ }
+ }
+ }
+ //if(fs->prev) var_check_unique_or_shadow(ls, fs->prev, name, 1);
+}
+
static void new_localvar (LexState *ls, TString *name) {
FuncState *fs = ls->fs;
Dyndata *dyd = ls->dyd;
+ var_check_unique_or_shadow(ls, fs, name, 0);
int reg = registerlocalvar(ls, name);
checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal,
MAXVARS, "local variables");
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