Fix invalid size with GNU designated initializers

the uninitialized cumofs was leading to random sizes for the memset when initializing local structures, potentially leading to segfaults from it. Only a problem with GNU designated initializers, which we didn't test very well. See testcase.

Michael Matz committed 7 years ago

Commit 9e429db1 parent ce1ef5b3 files · +10 −1Browse files

Unified · Split

3 files

tccgen.c +2 −1
tests/tests2/90_struct-init.c +7 −0
tests/tests2/90_struct-init.expect +1 −0

tccgen.c+2−1

             c += index * elem_size;
             nb_elems = index_last - index + 1;
         } else {
-            int cumofs = 0;
+            int cumofs;
             next();
             l = tok;
         struct_field:
             next();
             if ((type->t & VT_BTYPE) != VT_STRUCT)
                 expect("struct/union type");
+            cumofs = 0;
 	    f = find_field(type, l, &cumofs);
             if (!f)
                 expect("field");

tests/tests2/90_struct-init.c+7−0

   struct T lt2 = { { [1 ... 5] = 9, [6 ... 10] = elt, [4 ... 7] = elt+1 }, 1 };
   struct SSU lssu1 = { 5, 3 };
   struct SSU lssu2 = { .y = 5, .x = 3 };
+  /* designated initializers in GNU form */
+#if defined(__GNUC__) || defined(__TINYC__)
+  struct S ls4 = {a: 1, b: 2, c: {3, 4}};
+#else
+  struct S ls4 = {.a = 1, .b = 2, .c = {3, 4}};
+#endif
   print(ls);
   print(ls2);
   print(lt);
   print(lssu1);
   print(lssu2);
   print(flow);
+  print(ls4);
 }
 #endif

tests/tests2/90_struct-init.expect+1−0

@@ -39,6 +39,7 @@ lt2: 0 9 9 9 43 43 43 43 42 42 42 0 0 0 0 0 1 · 38 unmodified lines
39	lssu1: 5 0 0 0 3 0 0 0	39	lssu1: 5 0 0 0 3 0 0 0
40	lssu2: 5 0 0 0 3 0 0 0	40	lssu2: 5 0 0 0 3 0 0 0
41	flow: 9 8 7 6 0 0 0 0 0 0 0 0 0 0 0 0 6 5 4 3 0 0 0 0 0 0 0 0 0 0 0 0	41	flow: 9 8 7 6 0 0 0 0 0 0 0 0 0 0 0 0 6 5 4 3 0 0 0 0 0 0 0 0 0 0 0 0
		42	ls4: 1 2 3 4
42	one	43	one
43	two	44	two
44	three	45	three

Fix invalid size with GNU designated initializers

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