Add compiler warning/error for duplicate variable declaration in Lua 5.2.4
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
--- lparser.c | |
+++ lparser.c | |
@@ -6,6 +6,7 @@ | |
#include <string.h> | |
+#include <stdio.h> | |
#define lparser_c | |
#define LUA_CORE | |
@@ -67,6 +68,15 @@ | |
} | |
+static void parser_warning (LexState *ls, const char *msg) { | |
+ char buff[LUA_IDSIZE]; | |
+ luaO_chunkid(buff, getstr(ls->source), LUA_IDSIZE); | |
+ msg = luaO_pushfstring(ls->L, "%s:%d: warning %s", buff, ls->linenumber, msg); | |
+ fprintf(stderr, "%s\n", msg); | |
+ fflush(stderr); | |
+} | |
+ | |
+ | |
/* semantic error */ | |
static l_noret semerror (LexState *ls, const char *msg) { | |
ls->t.token = 0; /* remove 'near to' from final message */ | |
@@ -178,6 +188,29 @@ | |
static void new_localvar (LexState *ls, TString *name) { | |
FuncState *fs = ls->fs; | |
Dyndata *dyd = ls->dyd; | |
+ /* allow '_' and '(for...' duplicates */ | |
+ const char *str_name = getstr(name); | |
+ if(!(str_name[0] == '(' || (name->tsv.len == 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 { | |
+ luaX_syntaxerror(ls, luaO_pushfstring(ls->L, | |
+ "Name [%s] already declared", str_name)); | |
+ } | |
+ } | |
+ } | |
+ } | |
int reg = registerlocalvar(ls, name); | |
checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal, | |
MAXVARS, "local variables"); |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment