shithub: mc

Info  •  Files  •  Log  •  Branches

Write *through* out parameters when dereferencing.

--- a/6/simp.c

+++ b/6/simp.c

@@ -131,18 +131,27 @@

     return n;

 }

-static Node *store(Node *a, Node *b)

+static Node *set(Node *a, Node *b)

 {

     Node *n;

     assert(a != NULL && b != NULL);

-    if (exprop(a) == Ovar)

-        n = mkexpr(a->line, Oset, a, b, NULL);

-    else

-        n = mkexpr(a->line, Ostor, a, b, NULL);

+    assert(exprop(a) == Ovar);

+    n = mkexpr(a->line, Oset, a, b, NULL);

     return n;

 }

+Node *store(Node *a, Node *b)

+{

+    Node *n;

+

+    assert(a != NULL && b != NULL);

+    assert(tybase(exprtype(a))->type == Typtr);

+    n = mkexpr(a->line, Ostor, a, b, NULL);

+    return n;

+}

+

+

 static Node *disp(int line, uint v)

 {

     Node *n;

@@ -680,7 +689,7 @@

     next = genlbl();

     end = genlbl();

     a = rval(s, n->expr.args[0], NULL);

-    append(s, store(r, a));

+    append(s, set(r, a));

     if (exprop(n) == Oland)

         cjmp(s, r, next, end);

     else if (exprop(n) == Olor)

@@ -687,36 +696,11 @@

         cjmp(s, a, end, next);

     append(s, next);

     b = rval(s, n->expr.args[1], NULL);

-    append(s, store(r, b));

+    append(s, set(r, b));

     append(s, end);

     return r;

 }

-static Node *simpslice(Simp *s, Node *n, Node *dst)

-{

-    Node *t;

-    Node *start, *end;

-    Node *base, *sz, *len;

-    Node *stbase, *stlen;

-

-    if (dst)

-        t = dst;

-    else

-        t = temp(s, n);

-    /* *(&slice) = (void*)base + off*sz */

-    base = slicebase(s, n->expr.args[0], n->expr.args[1]);

-    start = ptrsized(s, rval(s, n->expr.args[1], NULL));

-    end = ptrsized(s, rval(s, n->expr.args[2], NULL));

-    len = sub(end, start);

-    stbase = store(addr(t, tyintptr), base);

-    /* *(&slice + ptrsz) = len */

-    sz = addk(addr(t, tyintptr), Ptrsz);

-    stlen = store(sz, len);

-    append(s, stbase);

-    append(s, stlen);

-    return t;

-}

-

 static Node *simpcast(Simp *s, Node *val, Type *to)

 {

     Node *r;

@@ -771,6 +755,38 @@

     return r;

 }

+static Node *simpslice(Simp *s, Node *n, Node *dst)

+{

+    Node *t;

+    Node *start, *end;

+    Node *base, *sz, *len;

+    Node *stbase, *stlen;

+

+    if (dst)

+        t = dst;

+    else

+        t = temp(s, n);

+    /* *(&slice) = (void*)base + off*sz */

+    base = slicebase(s, n->expr.args[0], n->expr.args[1]);

+    start = ptrsized(s, rval(s, n->expr.args[1], NULL));

+    end = ptrsized(s, rval(s, n->expr.args[2], NULL));

+    len = sub(end, start);

+    /* we can be storing through a pointer, in the case

+     * of '*foo = bar'. */

+    if (tybase(exprtype(t))->type == Typtr) {

+        stbase = store(simpcast(s, t, mktyptr(t->line, tyintptr)), base);

+        sz = addk(simpcast(s, t, mktyptr(t->line, tyintptr)), Ptrsz);

+    } else {

+        stbase = store(addr(t, tyintptr), base);

+        sz = addk(addr(t, tyintptr), Ptrsz);

+    }

+    /* *(&slice + ptrsz) = len */

+    stlen = store(sz, len);

+    append(s, stbase);

+    append(s, stlen);

+    return t;

+}

+

 static Node *visit(Simp *s, Node *n)

 {

     size_t i;

@@ -786,7 +802,7 @@

             append(s, n);

         } else {

             r = temp(s, n);

-            append(s, store(r, n));

+            append(s, set(r, n));

         }

     }

     return r;

@@ -808,7 +824,7 @@

             plv = addr(lv, exprtype(lv));

             stor = mkexpr(lhs->line, Oblit, plv, prv, sz, NULL);

         } else {

-            stor = store(lv, load(prv));

+            stor = set(lv, load(prv));

         }

         append(s, stor);

         off += size(lv);

@@ -995,7 +1011,7 @@

             v = rval(s, args[1], NULL);

             v = mkexpr(n->line, fusedmap[exprop(n)], u, v, NULL);

             v->expr.type = u->expr.type;

-            r = store(u, v);

+            r = set(u, v);

             break;

         /* ++expr(x)

@@ -1019,12 +1035,12 @@

          */

         case Opostinc:

             r = rval(s, args[0], NULL);

-            t = store(lval(s, args[0]), addk(r, 1));

+            t = set(lval(s, args[0]), addk(r, 1));

             lappend(&s->incqueue, &s->nqueue, t);

             break;

         case Opostdec:

             r = rval(s, args[0], NULL);

-            t = store(lval(s, args[0]), subk(r, 1));

+            t = set(lval(s, args[0]), subk(r, 1));

             lappend(&s->incqueue, &s->nqueue, t);

             break;

         case Olit:

@@ -1052,7 +1068,7 @@

                 append(s, v);

             } else if (n->expr.nargs && n->expr.args[0]) {

                 t = s->ret;

-                t = store(t, rval(s, args[0], NULL));

+                t = set(t, rval(s, args[0], NULL));

                 append(s, t);

             }

             jmp(s, s->endlbl);