Fix _Alignas

* don't accept _Alignas as type qualifier (after pointer '*'). * accept type-names within _Alignas * add testcases

Michael Matz committed 7 years ago

Commit 38a6aba1 parent fa0ef915 files · +52 −28Browse files

Unified · Split

5 files

tccgen.c +17 −28
tests/tests2/102_alignas.c +28 −0
tests/tests2/102_alignas.expect +1 −0
tests/tests2/60_errors_and_warnings.c +3 −0
tests/tests2/60_errors_and_warnings.expect +3 −0

@@ -4176,20 +4176,25 @@ static int parse_btype(CType type, AttributeDef ad) · 4175 unmodified lines
4176	4176	goto basic_type;
4177	4177	case TOK_ALIGNAS:
4178	4178	{ int n;
4179		− next();
4180		− /* TODO: _Alignas(type) -> _Alignas(_Alignof(type)) */
4181		− if (tok == '(') {
4182		− next();
4183		− n = expr_const();
4184		− if (n <= 0 \|\| (n & (n - 1)) != 0)
	4179	+ AttributeDef ad1;
	4180	+ next();
	4181	+ skip('(');
	4182	+ memset(&ad1, 0, sizeof(AttributeDef));
	4183	+ if (parse_btype(&type1, &ad1)) {
	4184	+ type_decl(&type1, &ad1, &n, TYPE_ABSTRACT);
	4185	+ if (ad1.a.aligned)
	4186	+ n = 1 << (ad1.a.aligned - 1);
	4187	+ else
	4188	+ type_size(&type1, &n);
	4189	+ } else {
	4190	+ n = expr_const();
	4191	+ if (n <= 0 \|\| (n & (n - 1)) != 0)
4185	4192	tcc_error("alignment must be a positive power of two");
4186		− skip(')');
4187		− } else {
4188		− expect("(");
	4193	+ }
	4194	+ skip(')');
	4195	+ ad->a.aligned = exact_log2p1(n);
4189	4196	}
4190		− ad->a.aligned = exact_log2p1(n);
4191		− }
4192		− continue;
	4197	+ continue;
4193	4198	case TOK_LONG:
4194	4199	if ((t & VT_BTYPE) == VT_DOUBLE) {
4195	4200	t = (t & ~(VT_BTYPE\|VT_LONG)) \| VT_LDOUBLE;
@@ -4594,22 +4599,6 @@ static CType type_decl(CType type, AttributeDef ad, int v, int td) · 398 unmodified lines
4594	4599	case TOK_RESTRICT2:
4595	4600	case TOK_RESTRICT3:
4596	4601	goto redo;
4597		− case TOK_ALIGNAS:
4598		− { int n;
4599		− next();
4600		− /* TODO: _Alignas(type) -> _Alignas(_Alignof(type)) */
4601		− if (tok == '(') {
4602		− next();
4603		− n = expr_const();
4604		− if (n <= 0 \|\| (n & (n - 1)) != 0)
4605		− tcc_error("alignment must be a positive power of two");
4606		− skip(')');
4607		− } else {
4608		− expect("(");
4609		− }
4610		− ad->a.aligned = exact_log2p1(n);
4611		− }
4612		− break;
4613	4602	/* XXX: clarify attribute handling */
4614	4603	case TOK_ATTRIBUTE1:
4615	4604	case TOK_ATTRIBUTE2:

tests/tests2/102_alignas.c+28−0

@@ -0,0 +1,28 @@
	1	+_Alignas(16) int i1;
	2	+int _Alignas(16) i2;
	3	+void _Alignas(16) *p2;
	4	+_Alignas(16) i3;
	5	+int _Alignas(double) i4;
	6	+int _Alignas(int) i5;
	7	+#if 0
	8	+/* The following are currently wrongly accepted by TCC but really shouldn't. */
	9	+int _Alignas(int _Alignas(16)) i6; //wrong, 'int _Alignas(16)' is no type-name
	10	+typedef int _Alignas(16) int16aligned_t; //wrong, _Alignas invalid on typedef
	11	+int16aligned_t i7;
	12	+#endif
	13	+/* i8 should get an alignment of 16, because unlike _Alignas the
	14	+ corresponding attribute _does_ apply to type-name, though not in
	15	+ some clang versions. */
	16	+int _Alignas(int __attribute__((aligned(16)))) i8;
	17	+extern int printf(const char*, ...);
	18	+#ifdef _MSC_VER
	19	+#define alignof(x) (int)__alignof(x)
	20	+#else
	21	+#define alignof(x) (int)__alignof__(x)
	22	+#endif
	23	+int main()
	24	+{
	25	+ printf("%d %d %d %d\n",
	26	+ alignof(i1), alignof(i4), alignof(i5), alignof(i8));
	27	+ return 0;
	28	+}

tests/tests2/102_alignas.expect+1−0

@@ -0,0 +1 @@
	1	+16 8 4

tests/tests2/60_errors_and_warnings.c+3−0

@@ -172,4 +172,7 @@ int X=1; · 171 unmodified lines
172	172	int main(void) {
173	173	int t[][][X];
174	174	}
	175	+#elif defined test_invalid_alignas
	176	+/* _Alignas is no type qualifier */
	177	+void * _Alignas(16) p1;
175	178	#endif

tests/tests2/60_errors_and_warnings.expect+3−0

@@ -80,3 +80,6 @@ · 79 unmodified lines
80	80
81	81	[test_vla_1]
82	82	60_errors_and_warnings.c:173: error: need explicit inner array size in VLAs
	83	+
	84	+[test_invalid_alignas]
	85	+60_errors_and_warnings.c:177: error: identifier expected

Fix _Alignas

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