Make sizeof() be of type size_t

This matters when sizeof is directly used in arithmetic, ala "uintptr_t t; t &= -sizeof(long)" (for alignment). When sizeof isn't size_t (as it's specified to be) this masking will truncate the high bits of the uintptr_t object (if uintptr_t is larger than uint).

Michael Matz committed 14 years ago

Commit 718fd591 parent b068e294 files · +37 −4Browse files

Unified · Split

4 files

libtcc.c +6 −0
tcc.h +1 −1
tccgen.c +14 −3
tests/tcctest.c +16 −0

libtcc.c+6−0

@@ -745,6 +745,12 @@ static int tcc_compile(TCCState *s1) · 744 unmodified lines
745	745	char_pointer_type.t = VT_BYTE;
746	746	mk_pointer(&char_pointer_type);
747	747
	748	+#if PTR_SIZE == 4
	749	+ size_type.t = VT_INT;
	750	+#else
	751	+ size_type.t = VT_LLONG;
	752	+#endif
	753	+
748	754	func_old_type.t = VT_FUNC;
749	755	func_old_type.ref = sym_push(SYM_FIELD, &int_type, FUNC_CDECL, FUNC_OLD);
750	756

tcc.h+1−1

@@ -1117,7 +1117,7 @@ ST_DATA Sym *local_stack; · 1116 unmodified lines
1117	1117	ST_DATA Sym *local_label_stack;
1118	1118	ST_DATA Sym *global_label_stack;
1119	1119	ST_DATA Sym *define_stack;
1120		−ST_DATA CType char_pointer_type, func_old_type, int_type;
	1120	+ST_DATA CType char_pointer_type, func_old_type, int_type, size_type;
1121	1121	ST_DATA SValue vstack[VSTACK_SIZE], *vtop;
1122	1122	ST_DATA int rsym, anon_sym, ind, loc;
1123	1123

tccgen.c+14−3

@@ -64,7 +64,7 @@ ST_DATA int func_vc; · 63 unmodified lines
64	64	ST_DATA int last_line_num, last_ind, func_ind; /* debug last line number and pc */
65	65	ST_DATA char *funcname;
66	66
67		−ST_DATA CType char_pointer_type, func_old_type, int_type;
	67	+ST_DATA CType char_pointer_type, func_old_type, int_type, size_type;
68	68
69	69	/* ------------------------------------------------------------------------- */
70	70	static void gen_cast(CType *type);
@@ -325,6 +325,17 @@ ST_FUNC void vpushi(int v) · 254 unmodified lines
325	325	vsetc(&int_type, VT_CONST, &cval);
326	326	}
327	327
	328	+/* push a pointer sized constant */
	329	+static void vpushs(long long v)
	330	+{
	331	+ CValue cval;
	332	+ if (PTR_SIZE == 4)
	333	+ cval.i = (int)v;
	334	+ else
	335	+ cval.ull = v;
	336	+ vsetc(&size_type, VT_CONST, &cval);
	337	+}
	338	+
328	339	/* push long long constant */
329	340	static void vpushll(long long v)
330	341	{
@@ -3575,12 +3586,12 @@ ST_FUNC void unary(void) · 3244 unmodified lines
3575	3586	if (!(type.t & VT_VLA)) {
3576	3587	if (size < 0)
3577	3588	tcc_error("sizeof applied to an incomplete type");
3578		− vpushi(size);
	3589	+ vpushs(size);
3579	3590	} else {
3580	3591	vla_runtime_type_size(&type, &align);
3581	3592	}
3582	3593	} else {
3583		− vpushi(align);
	3594	+ vpushs(align);
3584	3595	}
3585	3596	vtop->type.t \|= VT_UNSIGNED;
3586	3597	break;

tests/tcctest.c+16−0

@@ -2155,6 +2155,8 @@ void c99_vla_test(int size1, int size2) · 2154 unmodified lines
2155	2155	#endif
2156	2156	}
2157	2157
	2158	+typedef __SIZE_TYPE__ uintptr_t;
	2159	+
2158	2160	void sizeof_test(void)
2159	2161	{
2160	2162	int a;
@@ -2175,6 +2177,20 @@ void sizeof_test(void) · 14 unmodified lines
2175	2177	ptr = NULL;
2176	2178	printf("sizeof(ptr) = %d\n", sizeof (ptr));
2177	2179
	2180	+ /* The type of sizeof should be as large as a pointer, actually
	2181	+ it should be size_t. */
	2182	+ printf("sizeof(sizeof(int) = %d\n", sizeof(sizeof(int)));
	2183	+ uintptr_t t = 1;
	2184	+ uintptr_t t2;
	2185	+ /* Effectively <<32, but defined also on 32bit machines. */
	2186	+ t <<= 16;
	2187	+ t <<= 16;
	2188	+ t++;
	2189	+ /* This checks that sizeof really can be used to manipulate
	2190	+ uintptr_t objects, without truncation. */
	2191	+ t2 = t & -sizeof(uintptr_t);
	2192	+ printf ("%lu %lu\n", t, t2);
	2193	+
2178	2194	/* some alignof tests */
2179	2195	printf("__alignof__(int) = %d\n", __alignof__(int));
2180	2196	printf("__alignof__(unsigned int) = %d\n", __alignof__(unsigned int));