Fix handling of unevaluated subexpression of const

we were emitting error messages for something like 'static int i = 2 || 1/0', even though the exception would be in the unevaluated part. This doesn't destroy const-ness, so we must accept it. This requires splitting the nocode_wanted values a bit more, so that nocode_wanted due to const_wanted can be differentiated from nocode_wanted due to non-evaluation.

Michael Matz committed 6 years ago

Commit 4a70b2b1 parent 38776184 files · +32 −18Browse files

Unified · Split

4 files

tccgen.c +5 −4
tests/tcctest.c +6 −0
tests/tests2/60_errors_and_warnings.c +4 −0
tests/tests2/60_errors_and_warnings.expect +17 −14

tccgen.c+5−4

@@ -53,6 +53,7 @@ static SValue _vstack[1 + VSTACK_SIZE]; · 52 unmodified lines
53	53
54	54	ST_DATA int const_wanted; /* true if constant wanted */
55	55	ST_DATA int nocode_wanted; /* no code generation wanted */
	56	+#define unevalmask 0xffff /* unevaluated subexpression */
56	57	#define NODATA_WANTED (nocode_wanted > 0) /* no static data output wanted either */
57	58	#define STATIC_DATA_WANTED (nocode_wanted & 0xC0000000) /* only static data output */
58	59
@@ -2273,7 +2274,7 @@ static void gen_opic(int op) · 2214 unmodified lines
2273	2274	case TOK_UMOD:
2274	2275	/* if division by zero, generate explicit division */
2275	2276	if (l2 == 0) {
2276		− if (const_wanted)
	2277	+ if (const_wanted && !(nocode_wanted & unevalmask))
2277	2278	tcc_error("division by zero in constant");
2278	2279	goto general_case;
2279	2280	}
@@ -5104,7 +5105,7 @@ ST_FUNC void unary(void) · 2824 unmodified lines
5104	5105	}
5105	5106	} else if (tok == '{') {
5106	5107	int saved_nocode_wanted = nocode_wanted;
5107		− if (const_wanted)
	5108	+ if (const_wanted && !(nocode_wanted & unevalmask))
5108	5109	tcc_error("expected constant");
5109	5110	/* save all registers */
5110	5111	save_regs(0);
@@ -6152,9 +6153,9 @@ ST_FUNC void gexpr(void) · 1041 unmodified lines
6152	6153	static void expr_const1(void)
6153	6154	{
6154	6155	const_wanted++;
6155		− nocode_wanted++;
	6156	+ nocode_wanted += unevalmask + 1;
6156	6157	expr_cond();
6157		− nocode_wanted--;
	6158	+ nocode_wanted -= unevalmask + 1;
6158	6159	const_wanted--;
6159	6160	}
6160	6161

tests/tcctest.c+6−0

@@ -950,6 +950,8 @@ void expr2_test() · 949 unmodified lines
950	950	printf("res= %d %d\n", a, b);
951	951	}
952	952
	953	+int const_len_ar[sizeof(1/0)]; /* div-by-zero, but in unevaluated context */
	954	+
953	955	void constant_expr_test()
954	956	{
955	957	int a;
@@ -958,6 +960,7 @@ void constant_expr_test() · 2 unmodified lines
958	960	printf("%d\n", a * 16);
959	961	printf("%d\n", a * 1);
960	962	printf("%d\n", a + 0);
	963	+ printf("%d\n", sizeof(const_len_ar));
961	964	}
962	965
963	966	int tab4[10];
@@ -1845,6 +1848,8 @@ arrtype2 sinit22 = {5,6,7}; · 881 unmodified lines
1845	1848	int sinit23[2] = { "astring" ? sizeof("astring") : -1,
1846	1849	&sinit23 ? 42 : -1 };
1847	1850
	1851	+int sinit24 = 2 \|\| 1 / 0; /* exception in constant but unevaluated context */
	1852	+
1848	1853	extern int external_inited = 42;
1849	1854
1850	1855	void init_test(void)
@@ -1959,6 +1964,7 @@ void init_test(void) · 108 unmodified lines
1959	1964	printf("arrtype6: %d\n", sizeof(arrtype2));
1960	1965
1961	1966	printf("sinit23= %d %d\n", sinit23[0], sinit23[1]);
	1967	+ printf("sinit24=%d\n", sinit24);
1962	1968	printf("linit18= %d %d\n", linit18[0], linit18[1]);
1963	1969	}
1964	1970

tests/tests2/60_errors_and_warnings.c+4−0

@@ -151,6 +151,10 @@ int ga = 0.42 { 2 }; · 150 unmodified lines
151	151	struct S { int a, b; };
152	152	struct T { struct S x; };
153	153	struct T gt = { 42 a: 1, 43 };
	154	+#elif defined test_invalid_4
	155	+enum E {
	156	+ x = 1 / 0
	157	+};
154	158	#elif defined test_conflicting_types
155	159	int i;
156	160	void foo(void) {

tests/tests2/60_errors_and_warnings.expect+17−14

@@ -72,37 +72,40 @@ · 71 unmodified lines
72	72	[test_invalid_3]
73	73	60_errors_and_warnings.c:153: error: ',' expected (got "a")
74	74
	75	+[test_invalid_4]
	76	+60_errors_and_warnings.c:157: error: division by zero in constant
	77	+
75	78	[test_conflicting_types]
76		−60_errors_and_warnings.c:159: error: incompatible types for redefinition of 'i'
	79	+60_errors_and_warnings.c:163: error: incompatible types for redefinition of 'i'
77	80
78	81	[test_nested_types]
79		−60_errors_and_warnings.c:166: error: struct/union/enum already defined
	82	+60_errors_and_warnings.c:170: error: struct/union/enum already defined
80	83
81	84	[test_vla_1]
82		−60_errors_and_warnings.c:173: error: need explicit inner array size in VLAs
	85	+60_errors_and_warnings.c:177: error: need explicit inner array size in VLAs
83	86
84	87	[test_invalid_alignas]
85		−60_errors_and_warnings.c:177: error: identifier expected
	88	+60_errors_and_warnings.c:181: error: identifier expected
86	89
87	90	[test_static_assert]
88		−60_errors_and_warnings.c:183: error: "ONE is not 1"
	91	+60_errors_and_warnings.c:187: error: "ONE is not 1"
89	92
90	93	[test_void_array]
91		−60_errors_and_warnings.c:186: error: declaration of an array of incomplete type elements
	94	+60_errors_and_warnings.c:190: error: declaration of an array of incomplete type elements
92	95
93	96	[test_incomplete_enum_array]
94		−60_errors_and_warnings.c:189: error: declaration of an array of incomplete type elements
	97	+60_errors_and_warnings.c:193: error: declaration of an array of incomplete type elements
95	98
96	99	[test_incomplete_struct_array]
97		−60_errors_and_warnings.c:192: error: declaration of an array of incomplete type elements
	100	+60_errors_and_warnings.c:196: error: declaration of an array of incomplete type elements
98	101
99	102	[test_const_fun_array]
100		−60_errors_and_warnings.c:196: error: declaration of an array of functions
	103	+60_errors_and_warnings.c:200: error: declaration of an array of functions
101	104
102	105	[test_incomplete_array_array]
103	106
104	107	[test_extern_array]
105		−60_errors_and_warnings.c:212: error: incompatible types for redefinition of 'x'
	108	+60_errors_and_warnings.c:216: error: incompatible types for redefinition of 'x'
106	109
107	110	[test_func_1]
108	111	hello: a = 123
@@ -111,17 +114,17 @@ hello: a = 123 · 2 unmodified lines
111	114	hello: a = 123
112	115
113	116	[test_func_3]
114		−60_errors_and_warnings.c:242: warning: static storage ignored for redefinition of 'hello'
	117	+60_errors_and_warnings.c:246: warning: static storage ignored for redefinition of 'hello'
115	118	hello: a = 123
116	119
117	120	[test_func_4]
118	121	hello: a = 123
119	122
120	123	[test_func_5]
121		−60_errors_and_warnings.c:242: error: incompatible types for redefinition of 'hello'
	124	+60_errors_and_warnings.c:246: error: incompatible types for redefinition of 'hello'
122	125
123	126	[test_func_6]
124		−60_errors_and_warnings.c:230: error: function without file scope cannot be static
	127	+60_errors_and_warnings.c:234: error: function without file scope cannot be static
125	128
126	129	[test_var_1]
127	130	main : 1 ; 1
@@ -134,6 +137,6 @@ main : 2 ; 2 · 6 unmodified lines
134	137	bar : 3 ; 3
135	138
136	139	[test_var_3]
137		−60_errors_and_warnings.c:274: error: incompatible types for redefinition of 'xxx'
	140	+60_errors_and_warnings.c:278: error: incompatible types for redefinition of 'xxx'
138	141
139	142	[test_var_4]

Fix handling of unevaluated subexpression of const

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