From 5122a99e441b1819a2bf47ce6eb4566e724c5800 Mon Sep 17 00:00:00 2001
From: Daniel_Cortez <gromovstanislav@yandex.ru>
Date: Fri, 28 Jun 2019 20:52:13 +0700
Subject: [PATCH] Fix local variables being able to be self-assigned through
 initialization

---
 source/compiler/sc1.c | 3 +++
 source/compiler/sc3.c | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/source/compiler/sc1.c b/source/compiler/sc1.c
index 2fe3934..52bbc96 100644
--- a/source/compiler/sc1.c
+++ b/source/compiler/sc1.c
@@ -2359,7 +2359,10 @@ static int declloc(int fstatic)
         int ctag = tag;         /* set to "tag" by default */
         int explicit_init=FALSE;/* is the variable explicitly initialized? */
         if (matchtoken('=')) {
+          sym->usage &= ~uDEFINE;   /* temporarily mark the variable as undefined to prevent
+                                     * possible self-assignment through its initialization expression */
           doexpr(FALSE,FALSE,FALSE,FALSE,&ctag,NULL,TRUE);
+          sym->usage |= uDEFINE;
           explicit_init=TRUE;
         } else {
           ldconst(0,sPRI);      /* uninitialized variable, set to zero */
diff --git a/source/compiler/sc3.c b/source/compiler/sc3.c
index cf9454d..993e358 100644
--- a/source/compiler/sc3.c
+++ b/source/compiler/sc3.c
@@ -1833,6 +1833,8 @@ static int primary(value *lval)
         ldconst(0,sPRI);    /* load 0 */
         return FALSE;       /* return 0 for labels (expression error) */
       } /* if */
+      if ((sym->usage & uDEFINE)==0)
+        error_suggest(17,st,NULL,estSYMBOL,esfVARCONST);    /* undefined symbol */
       lval->sym=sym;
       lval->ident=sym->ident;
       lval->tag=sym->tag;