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

@@ -6783,13 +6783,14 @@ static int decl_designator(CType type, Section sec, unsigned long c, · 6782 unmodified lines
6783	6783	c += index * elem_size;
6784	6784	nb_elems = index_last - index + 1;
6785	6785	} else {
6786		− int cumofs = 0;
	6786	+ int cumofs;
6787	6787	next();
6788	6788	l = tok;
6789	6789	struct_field:
6790	6790	next();
6791	6791	if ((type->t & VT_BTYPE) != VT_STRUCT)
6792	6792	expect("struct/union type");
	6793	+ cumofs = 0;
6793	6794	f = find_field(type, l, &cumofs);
6794	6795	if (!f)
6795	6796	expect("field");

tests/tests2/90_struct-init.c+7−0

@@ -175,6 +175,12 @@ void foo (struct W w, struct pkthdr phdr_) · 174 unmodified lines
175	175	struct T lt2 = { { [1 ... 5] = 9, [6 ... 10] = elt, [4 ... 7] = elt+1 }, 1 };
176	176	struct SSU lssu1 = { 5, 3 };
177	177	struct SSU lssu2 = { .y = 5, .x = 3 };
	178	+ /* designated initializers in GNU form */
	179	+#if defined(__GNUC__) \|\| defined(__TINYC__)
	180	+ struct S ls4 = {a: 1, b: 2, c: {3, 4}};
	181	+#else
	182	+ struct S ls4 = {.a = 1, .b = 2, .c = {3, 4}};
	183	+#endif
178	184	print(ls);
179	185	print(ls2);
180	186	print(lt);
@@ -194,6 +200,7 @@ void foo (struct W w, struct pkthdr phdr_) · 13 unmodified lines
194	200	print(lssu1);
195	201	print(lssu2);
196	202	print(flow);
	203	+ print(ls4);
197	204	}
198	205	#endif
199	206

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	39	lssu1: 5 0 0 0 3 0 0 0
40	40	lssu2: 5 0 0 0 3 0 0 0
41	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	43	one
43	44	two
44	45	three

Fix invalid size with GNU designated initializers

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