Don't issue warning 204 if the assignment operator is overloaded

Author: Daniel-Cortez

source/compiler/sc.h

@@ -925,6 +925,7 @@ SC_VDECL short fnumber;       /* number of files in the file table (debugging) *
 SC_VDECL short fcurrent;      /* current file being processed (debugging) */
 SC_VDECL short sc_intest;     /* true if inside a test */
 SC_VDECL int pc_sideeffect;   /* true if an expression causes a side-effect */
+SC_VDECL int pc_ovlassignment;/* true if an expression contains an overloaded assignment */
 SC_VDECL int stmtindent;      /* current indent of the statement */
 SC_VDECL int indent_nowarn;   /* skip warning "217 loose indentation" */
 SC_VDECL int sc_tabsize;      /* number of spaces that a TAB represents */

source/compiler/sc1.c

@@ -891,6 +891,7 @@ static void resetglobals(void)
   fcurrent=0;           /* current file being processed (debugging) */
   sc_intest=FALSE;      /* true if inside a test */
   pc_sideeffect=0;      /* true if an expression causes a side-effect */
+  pc_ovlassignment=FALSE;/* true if an expression contains an overloaded assignment */
   stmtindent=0;         /* current indent of the statement */
   indent_nowarn=FALSE;  /* do not skip warning "217 loose indentation" */
   sc_allowtags=TRUE;    /* allow/detect tagnames */
@@ -2380,7 +2381,7 @@ static int declloc(int fstatic)
         lval.ident=iVARIABLE;
         lval.constval=0;
         lval.tag=tag;
-        check_userop(NULL,ctag,lval.tag,2,NULL,&ctag);
+        suppress_w240 |= check_userop(NULL,ctag,lval.tag,2,NULL,&ctag);
         store(&lval);
         markexpr(sEXPR,NULL,0); /* full expression ends after the store */
         assert(staging);        /* end staging phase (optimize expression) */
@@ -2426,6 +2427,8 @@ static int declloc(int fstatic)
     } /* if */
     if (explicit_init)
       markinitialized(sym,!suppress_w240);
+    if (pc_ovlassignment)
+      sym->usage |= uREAD;
   } while (matchtoken(',')); /* enddo */   /* more? */
   needtoken(tTERM);    /* if not comma, must be semicolumn */
   return ident;
@@ -5535,6 +5538,7 @@ static int doexpr(int comma,int chkeffect,int allowarray,int mark_endexpr,
     if (index!=stgidx)
       markexpr(sEXPR,NULL,0);
     pc_sideeffect=FALSE;
+    pc_ovlassignment=FALSE;
     ident=expression(val,tag,symptr,chkfuncresult);
     if (!allowarray && (ident==iARRAY || ident==iREFARRAY))
       error(33,"-unknown-");    /* array must be indexed */

source/compiler/sc3.c

@@ -190,6 +190,8 @@ static void (*unopers[])(void) = { lneg, neg, user_inc, user_dec };
     if (sym==NULL /*|| (sym->usage & uDEFINE)==0*/)
       return FALSE;
   } /* if */
+  if (oper==NULL)
+    pc_ovlassignment=TRUE;
 
   /* check existance and the proper declaration of this function */
   if ((sym->usage & uMISSING)!=0 || (sym->usage & uPROTOTYPED)==0) {
@@ -823,7 +825,6 @@ static int hier14(value *lval1)
   int bwcount,leftarray;
   cell arrayidx1[sDIMEN_MAX],arrayidx2[sDIMEN_MAX];  /* last used array indices */
   cell *org_arrayidx;
-  int assignment=FALSE;
 
   bwcount=bitwise_opercount;
   bitwise_opercount=0;
@@ -879,7 +880,6 @@ static int hier14(value *lval1)
       break;
     case '=':           /* simple assignment */
       oper=NULL;
-      assignment=TRUE;
       if (sc_intest)
         error(211);     /* possibly unintended assignment */
       break;
@@ -1065,12 +1065,14 @@ static int hier14(value *lval1)
   pc_sideeffect=TRUE;
   bitwise_opercount=bwcount;
   lval1->ident=iEXPRESSION;
-  if (assignment) {
+  if (oper==NULL) {
     symbol *sym=lval3.sym;
     assert(sym!=NULL);
     if ((sym->usage & uASSIGNED)!=0 && (sym->vclass==sLOCAL || sym->vclass==sSTATIC))
       error(240,sym->name); /* previously assigned value is unused */
     markinitialized(sym,TRUE);
+    if (pc_ovlassignment)
+      markusage(sym,uREAD);
   } /* if */
   return FALSE;         /* expression result is never an lvalue */
 }

source/compiler/scvars.c

@@ -80,6 +80,7 @@ SC_VDEFINE short fnumber=0;                 /* the file number in the file table
 SC_VDEFINE short fcurrent=0;                /* current file being processed (debugging) */
 SC_VDEFINE short sc_intest=FALSE;           /* true if inside a test */
 SC_VDEFINE int pc_sideeffect=0;             /* true if an expression causes a side-effect */
+SC_VDEFINE int pc_ovlassignment=FALSE;      /* true if an expression contains an overloaded assignment */
 SC_VDEFINE int stmtindent=0;                /* current indent of the statement */
 SC_VDEFINE int indent_nowarn=FALSE;         /* skip warning "217 loose indentation" */
 SC_VDEFINE int sc_tabsize=8;                /* number of spaces that a TAB represents */

source/compiler/tests/warning_240.pwn

@@ -50,6 +50,18 @@ test_arg(arg)
 	arg = 1; // warning 240, warning 204
 }
 
+stock Tag:operator =(oper)
+	return Tag:oper;
+
+test_ovl_assignment()
+{
+	// Overloaded assignments are essentially function calls which may have
+	// desirable side effects, so they shouldn't trigger warning 204.
+	new Tag:a = 1;
+	new Tag:b;
+	b = 2;
+}
+
 main()
 {
 	test_local();
@@ -58,4 +70,5 @@ main()
 	test_global_static();
 	new x = 0;
 	test_arg(x);
+	test_ovl_assignment();
 }